Posted by & filed under Data, Mountains & hills, Science, Software engineering, May 2 2024.


Following on from my blog posting from July 2023 ‘Snowpatches and satellites‘, I have been involved in some technical development work using Earth Observation (EO) technologies and satellite imagery.

For many years I have monitored and observed long-lasting snowpatches in the Scottish mountains, and as mentioned in the previous blog posting, I have carried this out as part of a community of observers (or ‘citizen scientists’). This community has grown over the years, using social media platforms like Facebook. Records of observations, fieldwork and data collected are published every year in the Weather Journal. The community was led by Adam Watson for many years, and continues to be inspired by him. Iain Cameron now continues Adam’s work.

During this time I often wondered if I could combine this activity with my professional experience of software engineering and data analysis, to build an application that would in some way support the work of the Scottish snowpatch community.

I recently joined a small ad-hoc group of software engineers and developers from this community who had similar aims. Our focus was on retrieving data about snowpatches remotely via EO techniques and data available on the internet, as opposed to on-site observations. An opportunity has arisen in recent years to use satellite imagery data from the Copernicus programme. This imagery is free to use, but getting access to it involves some hurdles. The simplest way is to use the Copernicus Browser, but an API is available for more sophisticated usage, and this is what our group was interested in.

One of the aims of the group was to use Machine Learning techniques (such as CNNs) to overcome one of the main difficulties in using satellite imagery to observe Scottish snowpatches, namely cloud cover. Cloud cover is probably the single most important factor affecting satellite imagery of the Scottish Highlands and it can be difficult to find an image that shows snowpatches that are distinct or free from cloud cover, particularly during the winter months. There can be only one day a month, or even none, when suitable imagery is available.

Satellite imagery in optical ‘true colour’ (i.e. electromagnetic spectrum wavelengths corresponding roughly to those that a human eye can see) is available from the Copernicus programme Sentinel-2 satellite. Other satellites offer imagery using other types of radiation such as Synthetic Aperture Radar (SAR) from the Sentinel-1 satellite. SAR can penetrate cloud cover and this is one area that offers potential scope for future investigation, but the focus in the group of developers was on true colour or RGB imagery.


The Copernicus Browser is a very useful tool but it does have a fairly cluttered interface with a lot of options and features. I thought there was scope for developing a tool which was more streamlined and targeted towards the Scottish snowpatch community, and which could be used as a front-end or delivery interface for the work carried out by the group.

The work to utilise Machine Learning techniques is ongoing in the group of developers, but my initial focus was on building an application to could best serve the requirements of the Scottish snowpatches community using existing data and technques. With that in mind I developed with the other software engineers in the group the idea of a web-based application and interactive tool with the principal aim of allowing a user to graphically explore and visualise the appearance and location of well-known long-lasting snowpatches in the Scottish Highlands, using web maps, satellite imagery data and existing support for classifying features on the images.

With Murray Cutforth (, I developed a tool that matched these requirements. The tool can be seen at:, and some help information about using the tool can be seen at:

In my experience, one of the most difficult problems to overcome when developing bespoke web-based applications is finding a suitable platform to host the application. This is not straightforward if the application has a requirement that it should have no ongoing financial dependencies (i.e. paying fees for webhosting or cloud computing services), needs to have no barriers to being as publicly available and easy-to-access as possible on the web (i.e. not behind an authentication or registration barrier, and with no subscription, registration or advertising barriers), and needs to have an independent and long-term ‘lifespan’ (i.e. it is not a temporary implementation that is tied to a particular individual developer and their credit card). GitHub Pages can help with this, but quickly reaches a limitation as the service only supports client-side web technologies such as HTML and JavaScript. When an application is built with a server-side technology such as PHP or Python, or interacts with a database, using GitHub pages is no longer appropriate. Jupyter Binder and Google Colab are also possibilities but are limited to only hosting ‘computational notebooks‘, whilst Binder is limited to Python code and Colab requires a credit card to use even the limited free tier service, which may get charged if resource usage goes over a certain limit. A solution to this for the specific case of Python was suggested to me by the group of developers, namely Streamlit. Streamlit requires no payment and allows Python code which is hosted on GitHub to be served up in a ‘clean’ web-based application, hosted in the cloud. This became the platform architecture of the tool that we built.


The tool enables satellite images to be retrieved from a list of recognised long-lasting snowpatch areas in the Scottish Highlands. A satellite image corresponding to the location appears in a square window (a 10km by 10km bounding box), overlaid on a map allowing the wider context of the satellite image within the Scottish Highlands to be visualised. A date period is also selected and the least cloudy image is used from that period. Transparency of the layers is also configurable for visualisation purposes.

The tool uses data from the Sentinel-2 satellite to create a ‘true colour’ image corresponding what a human eye might see. An important thing to note is that this data is not a ‘snapshot’ taken on one particular day, rather it is a combination of data from the whole date range selected, using data from the least cloudy days, to generate the ‘best’ image of the area available. Images are combined via mosaicking, pixel-by-pixel. A narrow date range will enable a particular single date to be identified, but this increases the chance that there will be no data available due to 1) the satellite orbit was not over the area selected; 2) the satellite was over the area at night; 3) there was significant cloud cover during the date range selected.

The tool uses data from the Copernicus Data Space Ecosystem (CDSE). To retrieve this data, an API is available, which requires using a Python package called sentinelHub. The tool uses this API and was built on some sample client code.

The tool uses an OpenStreetmap (OSM) base map layer for the satellite imagery using Folium, a python package which allows the use of the Leaflet JavaScript library through a Python API.

The tool also allows another data layer to be visualised on the map, and that is a land cover or ‘Scene Classification’ map, generated by an algorithm developed by the CDSE. This shows the results as purple polygons outlining the areas the algorithm has classified as ‘snow/ice’. This algorithm is not perfect, and can miss some snowpatches around 100m² (10m by 10m) in size and can sometimes classify areas of cloud cover as ‘snow/ice;. An important consideration is that this algorithm does not use Machine Learning (ML) techniques, so there is potential for improvement using an ML approach.

The tool also requires a user to have a CDSE account and generate special OAuth client authentication details. This is required as the tool uses a quota for accessing the CDSE data, which resets every month.

The GitHub repository for the code is at:


Developing this tool showed what is possible with existing platforms, services, technologies and data. The tool has limitations (which are listed below) but I think it will still be useful for the Scottish snowpatch community, albeit perhaps to a small group of technically-minded observers within the community. I will monitor any feedback I receive from the community and incorporate this into ongoing development discussions with the rest of the group of developers. The tool is very much an initial version, and there is much scope for future development.

Limitations/future development

  • The approach of ‘mosaicking’ data with the least cloud-cover mentioned above means that the resulting images used in the tool do not have a specific single date, rather a data range, which can be a bit confusing and possibly of not much use for serious snowpatch observations (i.e. recording melt dates). The best way to deal with this issue and use the sentinelHub API is to allow a user to choose a percentage cloud cover value, and then show graphically on a calendar interface those dates with images available for the area that have cloud cover less than the chosen value. This is exactly what the Copernicus Browser does, and this is the resource to use if this more detailed approach is required.
  • Development of support in the web interface for smartphones and smaller screens like tablets.
  • The requirement for a personal SentinelHub OAuth client account is a bit of a hurdle, and could perhaps be overcome by creating a group CDSE account with a suitable data quota.
  • Integration of Machine Learning functionality that may be developed by the group of developers in the future.

Posted by & filed under Mountains & hills, Science, July 25 2023.


For many years, the extent of snow cover in the Scottish Highlands has been recorded and documented by groups of ground-based observers from a volunteer community of ‘citizen scientists’. This winter snow cover melts in the spring and summer months, leaving behind remnant snowpatches, some of which have shown themselves to be ‘perennial’, lasting until the subsequent winter snowfalls (Cameron et al. 2023). The numbers of snowpatch ‘survivals’ have been recorded and there is much debate as to what this data might mean in terms of climate variability, both in terms of how this may impact the upland environment in Scotland in the future (Cameron 2021; Rivington et al. 2019), but also the past, in terms of when true glacial ice may have existed in the Scottish mountains (Were there glaciers in the mountains of Scotland as recently as the mid-19th century?) (Harrison et al. 2022).

The existing research (in the domain of both established scientific research institutes and external volunteers) has focused on modelling and ground-based observations (Using GIS techniques to analyse and model the topographical environment and dependencies of long-lasting snowpatch locations in the Scottish mountains) (Spencer et al. 2014; Rivington et al. 2019), but the potential for utilising Earth Observation (EO) data, imagery, analysis techniques and resources for this from satellite platforms has not been fully explored in the context of the Scottish Highlands. EO can be used to analyse and map snow cover in mountain environments and has demonstrated its effectiveness in this regard using synthetic-aperture radar (SAR) and multispectral imaging (Koehler et al. 2022).

The snowpatches in the Scottish Highlands exist in a wider, global context, both physically (The Scottish mountains: on the glacial ‘knife-edge’) and in terms of approaches to environmental management and research. The seventeen Sustainable Development Goals (SDGs) from the United Nations Framework Convention on Climate Change (UNFCCC) are interlinked and have many mutual dependencies (Kavvada et al., 2020), but some of the goals are directly related to the upland mountain environments of the earth’s surface, and in particular, snow and ice features in these environments such as glaciers, icefields, snow cover and snowpatches.

Snow and ice cover on the earth are important environmental features for the SDGs. They have been identified as an Essential Climate Variable (ECV) within the Global Climate Observing System (GCOS) (Dietz et al., 2015; Bayat et al., 2021).

Snow and ice features can also be considered as part of the cryosphere of the earth, and as such the Intergovernmental Panel on Climate Change (IPCC) has explicitly identified this as a crucial component in the task of meeting many of the targets of several different SDGs (Pörtner et al., 2019).

Using EO and satellite-based remote sensing (RS) are essential for this because “Continuous, long-term, and large-scale ground-based data collection on snow cover dynamics…is particularly difficult in fragmented and inaccessible high-altitude mountain areas” (Koehler et al., 2022:2). Snow cover can vary significantly within short time spans and often extends over vast areas. EO techniques have the ability to overcome these difficulties.

Sustainable Development Goals

Table 1 shows the details of the two most relevant SDG targets and indicators related to snow and ice features in the global upland and mountain environment, from SDG 6 (Clean Water and Sanitation) and SDG 15 (Life on Land). There are also strong links to SDG 8 (Decent Work and Economic Growth) and SDG 13 (Climate Action) (Kavvada et al., 2020).

Table 1. Relevant goals, targets and indicators.

 Goal 6 Ensure availability and sustainable management of water and sanitation for all
  Target 6.6 Protect and restore water-related ecosystems
   Indicator 6.6.1 Change in the extent of water-related ecosystems over time
 Goal 15 Protect, restore and promote sustainable use of terrestrial ecosystems
  Target 15.4 Ensure conservation of mountain ecosystems
   Indicator 15.4.1 Coverage by protected areas of important sites for mountain biodiversity


Snow cover on the earth’s surface directly impacts climate due to its high albedo and reflection of sunlight, affecting the regional and global energy balance. It also affects local habitats, ecosystems and biodiversity of plants and animals. Snow cover that has a duration throughout the year, as exists in some mountain environments, has a prominent role in influencing these systems. Snow and ice features in mountains also act as an important freshwater resource for some areas of the world, providing the means for electricity generation, agriculture and drinking water (Koehler et al., 2022).

The economy and trade of mountainous areas, as well as the lifestyles of people living in these areas, are impacted by snow and ice features. Examples of this are the skiing industry and mountain-related tourism in the Scottish Highlands and the European Alps (Harrison et al., 2001; Koehler et al., 2022).


There are several EO techniques that can be used to observe and analyse snow cover globally.

An important source of data for analysing snow cover is the Global SnowPack (GSP). This is a dataset of snow cover across the globe with a temporal resolution of daily observations at a point on the earth’s surface (with a timeseries starting in the year 2000), and a spatial resolution of 500m. The data is obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on the Earth Observing System Terra spacecraft platform (Hall et al., 1995; Dietz et al., 2015). This instrument operates in spectral bands of visible/optical wavelengths of light and is thus affected by cloud cover and darkness (particularly in the polar regions). Another optical wavelength instrument that has been used to analyse snow cover is the Advanced Very High Resolution Radiometer (AVHRR) instrument carried on various EO platforms such as the National Oceanic and Atmospheric Administration (NOAA) family of polar orbiting satellites.

These EO sensors and instruments have relatively low spatial resolution. Better spatial resolution of snow cover data (using similar optical wavelength spectral bands) is available from the NASA/USGS Landsat and Copernicus Programme Sentinel-2 platforms (30m and 10-60m respectively), although with lower temporal resolution (Koehler et al., 2022).

To overcome these limitations of observing global snow cover, another EO technology can be used, synthetic aperture radar (SAR), on platforms like Copernicus Programme Sentinel-1 and Advanced Land Observing Satellite-2 (ALOS-2) PALSAR-2. The active sensing approach of SAR produces data independent from clouds and illumination conditions. SAR also offers many advantages over technologies that utilise optical/multispectral imagery to observe snow cover, including better spatial resolution and the ability to penetrate the surface snowpack as well as cloud cover (using polarisation of the signal). A disadvantage of SAR is the lower temporal resolution (>5 days) and a smaller timeseries of data due to the relative newness of the technology and satellite platforms (Tsai et al., 2019a).

Various data analysis methods are also used to overcome the limitations of cloud cover and darkness with optical wavelength measurements as well. One method is to fill in gaps in the data by using interpolation combined with spectral indices (such as the Normalised Difference Water Index or NDWI) to classify snow and ice features (Dietz et al., 2015; Koehler et al., 2022). Another method is to use Machine Learning (ML) approaches and algorithms, combining optical wavelength data with SAR data, as well as using land cover and Digital Elevation Model (DEM) data (Tsai et al., 2019b; Cresson, 2020).

A further step is the validation of data gathered from EO platforms using ‘ground-truth’ on-site data measurements of snow and ice features such as depth and extent. This step is one requirement in the characterisation of global snow cover as an ECV (Bayat et al., 2021). An example is the Copernicus High Resolution Snow & Ice Monitoring Service which uses Sentinel-2 data and weather station snow depth measurements from various countries (Barrou Dumont et al., 2021).


The importance and relevance of snow and ice features in the mountainous regions of the earth’s surface and their impact on the achievement of the SDGs is clear. Snowpatches in the Scottish Highlands are a small part of this bigger picture. The importance of using EO techniques and data, and their superiority in terms of effectiveness when compared to other forms of observations, with this specific focus, is also clear.

There are still limitations to overcome however, primarily in generating timeseries of datasets of a sufficient length with sufficient temporal and spatial resolution, to allow deep and accurate analysis, classification and forecasting techniques. The current research environment is rich in potential in this respect and offers good scope for future results.

Achieving the SDGs has many difficulties and barriers, which are covered in detail in Kavadda et al. (2020), but in the context of using EO techniques to measure global snow cover significant progress in this area is likely.


Barrou Dumont, Z., Gascoin, S., Hagolle, O., Ablain, M., Jugier, R., Salgues, G., Marti, F., Dupuis, A., Dumont, M. and Morin, S. (2021) Brief communication: evaluation of the snow cover detection in the Copernicus High Resolution Snow & Ice Monitoring Service. The Cryosphere, 15(10): 4975-4980.

Bayat, B., Camacho, F., Nickeson, J., Cosh, M., Bolten, J., Vereecken, H. and Montzka, C. (2021) Toward operational validation systems for global satellite-based terrestrial essential climate variables. International Journal of Applied Earth Observation and Geoinformation, 95.102240.

Cameron, I. (2021) The Vanishing Ice. Vertebrate Publishing.

Cameron, I., Fyffe, B. and Kish, A. (2023) No Scottish snow patches survive until winter 2022/23. Weather, 78(4): 101-103.

Cresson, R. (2020) Deep Learning for Remote Sensing Images with Open Source Software. CRC Press.

Dietz, A.J., Kuenzer, C. and Dech, S. (2015) Global SnowPack: a new set of snow cover parameters for studying status and dynamics of the planetary snow cover extent. Remote sensing letters, 6(11): 844-853.

Hall, D.K., Riggs, G.A. and Salomonson, V.V. (1995) Mapping global snow cover using moderate resolution imaging spectroradiometer (MODIS) data. Glaciological Data: 33-36.

Harrison, S., Rowan, A.V., Dye, A.R., Plummer, M.A. and Anderson, K. (2022) Late Holocene glaciers in western Scotland? Geografiska Annaler: Series A, Physical Geography, 104(2): 57-69.

Harrison, S.J., Winterbottom, S.J. and Johnson, R.C. (2001) A preliminary assessment of the socio-economic and environmental impacts of recent changes in winter snow cover in Scotland. Scottish Geographical Journal, 117(4): 297-312.

Kavvada, A., Metternicht, G., Kerblat, F., Mudau, N., Haldorson, M., Laldaparsad, S., Friedl, L., Held, A. and Chuvieco, E. (2020) Towards delivering on the sustainable development goals using earth observations. Remote Sensing of Environment, 247:111930.

Koehler, J., Bauer, A., Dietz, A.J. and Kuenzer, C. (2022) Towards forecasting future snow cover dynamics in the European Alps – The potential of long optical remote-sensing time series. Remote Sensing, 14(18): 4461.

Pörtner, H.O., Roberts, D.C., Masson-Delmotte, V., Zhai, P., Tignor, M., Poloczanska, E., Mintenbeck, K., Alegría, A., Nicolai, M., Okem, A. and Petzold, J. (2019) IPCC special report on the ocean and cryosphere in a changing climate. IPCC Intergovernmental Panel on Climate Change: Geneva, Switzerland, 1(3):1-755.

Rivington, M., Spencer, M., Gimona, A., Artz, R., Wardell-Johnson, D. and Ball, J. (2019) Snow Cover and Climate Change in the Cairngorms National Park: Summary Assessment. ClimateXChange, Edinburgh.

Spencer, M., Essery, R., Chambers, L. and Hogg, S. (2014) The historical snow survey of Great Britain: digitised data for Scotland. Scottish Geographical Journal, 130(4): 252-265.

Tsai, Y.L.S., Dietz, A., Oppelt, N. and Kuenzer, C. (2019a) Remote sensing of snow cover using spaceborne SAR: A review. Remote Sensing, 11(12):1456.

Tsai, Y.L.S., Dietz, A., Oppelt, N. and Kuenzer, C. (2019b) Wet and dry snow detection using Sentinel-1 SAR data for mountainous areas with a machine learning technique. Remote Sensing, 11(8): 895.

Posted by & filed under Data, Science, January 19 2022.

1. Truth in Data

In a blog posting from April 2020, I discussed the development of a visualisation of data related to the global COVID-19 pandemic. In the comments below the blog posting, I mentioned that there are several issues with the data in terms of accuracy and what the ‘truth’ of the data actually is. I will expand on this here.

Defining precisely what the ‘truth’ is in data and statistics is not easy. Most statistical data in the real world is generated from statistical samples and then a process of inductive inference, based on statistical theory, is used to generalise observations and conclusions to a broader ‘population’. Many errors and biases can be introduced in this process, and many assumptions must be made. A common error is that the sample is not representative of the population (Baggini, 2017; Spiegelhalter, 2019).

Another error is that all conclusions about data collected in the real world ultimately rely on how well the conceptual ‘model’ used for the data collection and analysis approximates the real world, and sometimes too much faith can be based on the model’s claims to objective ‘truth’, leading to sensationalist claims in newspapers (Cairo, 2016).

Epidemiology, and data concerning the global COVID-19 pandemic is no different, and any claims for objective conclusions about the impact of the pandemic on global society based on this data must include details about how the data is collected, analysed and presented, and the assumptions that have been made in this process.

The global pandemic of the last 2 years has seen newspapers, TV and web news reports and social media full of data in perhaps an unprecedented fashion; people have never been more exposed to statistics, graphs and data visualisations concerning the number of COVID-19 cases and deaths. Some of this has demonstrated good examples of data collection and analysis (European Centre for Disease Prevention and Control, 2021), and presentation in the form of data visualisations (BBC, 2021a; The Guardian, 2020a),  but there have been many bad examples of misleading communication concerning the ‘truth’ of the pandemic (The Conversation, 2020).

This flood of data (or ‘infodemic’) has led to much discussion about how well the data reflects reality: how many people around the globe have the virus, and how many people have died because of it? Issues of ‘truth’ in health data have never been more hotly debated and analysed. There are many threats to truth, including a general mistrust in science, experts and politicians, but also a reliance on untrustworthy social media sources and groups promoting ‘disinformation’ and anti-vaccination beliefs (The Lancet, 2020).

A common bias in many countries inherent in collecting data about cases of infection by COVID-19 is that only people with symptoms are tested, so asymptomatic cases are unrecorded, resulting in a systematic bias causing an underestimation of infection rates, which can be quite significant (Spiegelhalter and Masters, 2021). “The apparently simple task of counting COVID-19 deaths is far from easy, with no ‘true’ answer” (Spiegelhalter and Masters, 2021: 108).

In many cases, including in western governments, collection of COVID-19 data has fallen short of statistical ideals. For instance, in the UK at the start of the pandemic, COVID-19 ‘deaths’ were presented in a way which was misleading (there was no time limit for deaths after the date of a recorded infection). This was changed to a 28-day limit in August 2020 (Spiegelhalter and Masters, 2021).

2. Comparing Countries

One problem with the presentation of this data globally has been the difficulties arising from a lack of any standardised way of analysing the data and presenting case and death numbers. Different countries (and even health and statistics agencies within the same country) use different methods and definitions: for example, even within western Europe there are important differences, with some countries counting deaths in care homes and hospitals and others not, and some countries only counting deaths where the virus is mentioned on death certificates, and others only where there has previously been a positive test for the individual. Others use only numbers of excess deaths (‘excess mortality’).

Another issue with comparing death rates between countries is that some countries have quite differing age distributions among their populations, and COVID-19, which causes more deaths in older people, disproportionally affects countries with a relatively elderly population. Comparing countries at a national level is also problematic because death rates (in 2020) in some countries were highly localised within regions and cities (such as Spain and Italy) and some countries were affected throughout the entire national area (such as the UK). Data collected at country-level hides this geographic distribution. There are also different data anonymisation and aggregation practices between countries.

Other countries such as Tanzania, North Korea, China, Iran and Turkmenistan are governed by unstable, secretive or undemocratic governments and the data they have claimed about numbers of cases and deaths in their respective countries are probably wildly inaccurate. Even a country such as the USA did not start properly collecting and reporting data at a federal level until March 2021 (BBC, 2020; The Guardian, 2021; Spiegelhalter and Masters, 2021).

3. Outlook and the Future

In April 2020, Professor David Spiegelhalter wrote an article for the Guardian website that outlined the difficulties inherent in comparing COVID-19 cases and deaths between countries. This was then interpreted by the UK Prime Minister Boris Johnson, in a statement in the UK parliament in May 2020, as meaning that comparing countries was, in the words of the chief medical officer Professor Chris Whitty, a “fruitless exercise”. This highly public example shows that the ‘truth’ of data can be distorted with poor presentation and communication, and Professor Spiegelhalter tried to clarify things in subsequent public writing to emphasise that “we should now use other countries to try and learn why our numbers are high” (The Guardian, 2020b).

Even with all of these difficulties, it is important to study the differences between populations and countries. Some useful science, and ‘truths’ can be evaluated from the data, such as that one particular strategy used by a group of countries to control the virus (such as a national lockdown or social distancing) is associated with a broadly different mortality rate than another strategy used by other countries.

Improvements in data communications to the public, and better effectiveness in terms of affecting outcomes in dealing with the pandemic, can be fostered by international collaboration, diversity of approaches, and better data collection and education (Pearce et al., 2020).


Baggini, J. (2017) A Short History of Truth: Consolations for a Post-Truth World. Quercus.

BBC (2020) Coronavirus: Why are international comparisons difficult? [Online] [accessed 15th November 2021]

BBC (2021a) Covid map: Coronavirus cases, deaths, vaccinations by country [Online] [accessed 15th November 2021]

BBC (2021b) Covid: The UK is Europe’s virus hotspot – does it matter? [Online] [accessed 25th November 2021]

Cairo, A. (2016) The Truthful Art: Data, Charts and Maps for Communication. New Riders.

The Conversation (2020) Next slide please: data visualisation expert on what’s wrong with the UK government’s coronavirus charts [Online] [accessed 25th November 2021]

European Centre for Disease Prevention and Control (ECDPC) (2021) How ECDPC collects and processes COVID-19 data [Online] [accessed 15th November 2021]

The Guardian (2020a) How coronavirus spread across the globe – visualised [Online] [accessed 15th November 2021]

The Guardian (2020b) Author of Guardian article on death tolls asks UK government to stop using it [Online] [accessed 15th November 2021]

The Guardian (2021) Which countries have fared worst in the pandemic? [Online] [accessed 15th November 2021]

The Lancet (2020) The truth is out there, somewhere. Lancet, 396(10247): 291.

Pearce, N., Lawlor, D. A., & Brickley, E. B. (2020) Comparisons between countries are essential for the control of COVID-19. International journal of epidemiology, 49(4): 1059-1062.

Spiegelhalter, D. (2019) The Art of Statistics: Learning from Data. Pelican Books.

Spiegelhalter, D. and Masters, A. (2021) Covid by Numbers: Making Sense of the Pandemic with Data. Pelican Books.

Posted by & filed under IT & the Internet, Science, Software engineering, April 10 2020.



One thing that has become noticeable in the current COVID-19 pandemic is a plethora of web-based visualisations about the impact of the virus. Most of these are line graphs showing exponential or vaguely bell-shaped curves and peaks typical of mathematical models of the spread of diseases.


Many of these visualisations show the spatial, or geographic, distribution of the virus, typically with a static map showing cases and deaths per country, or area of a country. Many of these visualisations also show the temporal distribution, typically with a line or bar chart. There aren’t many visualisations that combine both of these approaches, showing the spatial and temporal simultaneously.

The UK BBC and Guardian news websites have recently posted a couple of articles with good visualisations:

The BBC page has an animated horizontal bar chart that dynamically shows the changing rank over time of countries by number of cases of the virus reported in that country. This combines the spatial and temporal aspects of the spread of the virus, but without a map.

I like the ‘dynamic globe’ Guardian visualisation, which does show the spatial and temporal distribution of the virus in a very clever and technically impressive way, but I feel that it is a bit too visually ‘busy’ and perhaps counter-intuitive in terms of the amount of visual elements that a viewer has to process.

I have developed my own GIS visualisation that expresses what I think I as a consumer of this data would like to see, in terms of perceiving and understanding how the virus has spread across the world.

One of the major challenges in creating a visualisation like this is obtaining the data to drive the visualisation – contemporary events are so current and fast-changing, that any data that is collected in the immediate short-term is necessarily incomplete and subject to all sorts of limitations in terms of authority, accuracy, relevancy and future revisions.

With these caveats in mind, I settled on using data from the European Centre for Disease Prevention and Control (ECDPC), which collects data about reported COVID-19 virus-related cases and deaths from each country in the world, starting from 31/12/19. This data is open, and made available with daily updates for anyone to obtain and utilise, in data analysis-friendly formats such as CSV and JSON. The data is rich enough (using things such as ISO 3166 country codes) and granularised enough (by country and day) that it allows for further development, allowing the combination of the virus data with data from other sources, such as spatial data in the form of country polygons (from Natural Earth, an open service provided by the North American Cartographic Information Society) and country centroids (from WorldMap, an open service provided by the Center for Geographic Analysis at Harvard University). I used mapshaper to convert the country polygons Shapefile to GeoJSON format, and also generalise the polygons to reduce the file size without compromising the visualisation of individual countries too much.

I used the D3 JavaScript library for creating the interface, which is a very powerful and open-source tool for creating web-based visualisations, with good support for maps and spatial data. One of my frustrations with many map-based visualisations on the web is that they use inappropriate map projections such as Mercator, but D3 allowed me to use the Kavrayskiy VII projection, which I believe is a good compromise in terms of representing shapes and distances on the globe of the Earth relatively accurately and intuitively to the viewer, on a flat interface.

I used D3 to create a ‘proportional symbol map’ (this terminology is taken from Andy Kirk’s taxonomy of chart types, in his book ‘Data Visualisation: A Handbook for Data Driven Design‘, 1st edition, page 203) using circles to represent data values, with the area of a circle directly proportional to the data value. The circle centres are located on the centroid point of each country. One of the idiosyncrasies of using centroids as a single point to represent the location of a country is that some countries have centroids in perhaps counter-intuitive locations, such as France (due to the location of French Guiana) and the USA (due to the locations of Alaska and Hawaii). This is explained here. For these two countries, I manually edited the centroid data to make it more intuitive and visually appealing to a viewer (but of course less geographically accurate).

D3 also allowed me to ‘animate’ the map, so that daily data is cycled and new data is shown once per second, with the circles shrinking or expanding corresponding to the changing data values, allowing a viewer to see the temporal progression and geographic spread of the virus over time in a dynamic way. This is done using D3 transitions. I used PHP server scripts to harvest and manipulate the raw data into formats I could use.

I chose a starting date for the visualisation of 01/02/20. The alarming spread of the virus becomes visually apparent at about the mid-March 2020 point. The visualisation is designed to update automatically with new data harvested daily from the ECPDC, so the full progression of the pandemic should become apparent over time. At the time of writing this blog posting (mid-April 2020) the world (and particularly Europe and the USA) is deep in the middle of the pandemic.

The visualisation is hosted on an AWS EC2 instance and can be seen here:

And the code can be seen on GitHub here:

Posted by & filed under IT & the Internet, Mountains & hills, Personal, Science, Software engineering, August 24 2017.

The three-year part-time remote learning UNIGIS UK MSc course I recently finished had two very different components – the first two years consisted of teaching modules of learning materials and assessed assignments (see my earlier blog posting about this here), and the third year involved the planning, development and writing of a dissertation, which is the final ‘research’ stage in getting the MSc degree. A dissertation is different from taught components of a course in that it requires formal academic research undertaken by the student and is a significant piece of original work, based on ideas originating largely from the student, and implemented and developed on the student’s own initiative and using their own skills. It is a real test of whether a student has ‘academic’ skills and is what sets a masters postgraduate degree apart from undergraduate degrees.

I had been thinking about ideas for my dissertation since the start of the course and I knew I wanted to explore the topic of exploring the physical characteristics of landscape in some way using my existing skills and experience as a web developer and software engineer, allied to the types of analysis and methods that are used in the field of Geographic Information Systems or Science (GIS). The primary starting point for an original piece of research is to establish a ‘research question’ that addresses some area in the field that has not been explored before, so my plan for getting ideas for this was to read as many published academic research papers as I could in the field of GIS that covered areas like land use, rural and upland environments and the use of spatial data models such as Digital Elevation Models. What really sparked the idea for what became my dissertation topic was a paper entitled ‘A GIS model for mapping spatial patterns and distribution of wild land in Scotland‘ by Dr Steve Carver(and others) of the Wildland Research Institute at the University of Leeds.

This paper led to a lot of further reading about the use of GIS techniques, spatial concepts and maps to explore the idea of ‘wilderness’ or ‘wild land’ which appealed to my existing interest in mountains, and I decided to concentrate on using the Scottish Highlands as a location for the focus of the research. The idea of ‘wild land’ in Scotland and what this actually means in a practical sense is a topic with some currency and this is seen in contemporary debates and research work concerning parts of Scotland that have been defined as ‘wild areas’ (in this case by Scottish Natural Heritage). The terms ‘wilderness’, ‘wild land’ and ‘wild areas’ have some ambiguity and are reliant on notions heavily affected by human perception, experiences and subjectivity and hence I always put the terms in quotes to denote this lack of precise definition. Much of the GIS research in this area has explored this ambiguity and this would be a central theme of my dissertation.

Papers such as ‘Using distributed map overlay and layer opacity for visual multi-criteria analysis‘ gave me ideas about building a GIS web-based tool which could explore the concept of ‘wild land’ in a way that hadn’t been done before. These ideas developed more formally with the research project proposal document I had created for the Methods in GIS module towards the end of second year of the course, but the ideas themselves constantly evolved all the time, right up until the dissertation itself was completed and submitted.

The first formal step in the creation of the dissertation was to get my ideas accepted as a coherent piece of valid, justified and original research by the UNIGIS UK team and this was done by submitting a formal MSc project proposal form at the start of the third year. This drew heavily on the research project proposal document I created in the second year and its main purpose was to present a research idea and plan with the potential at that early stage to become a dissertation, before work started in earnest. This is a vital step as it is important that a student does not head down a blind alley of unjustifiable research or take on a task that is beyond the scope of a MSc dissertation or not suitably related to the field of GIS. Once this proposal was accepted, an academic supervisor for the dissertation was allocated to me, and groundwork for the dissertation could start which mostly involved reading previous academic research publications and investigation of GIS-related software packages and web applications.

The research for the dissertation was further developed with the Extended Project Outline (EPO), a 2000-word document that benefited from formative feedback from my supervisor so that the ideas in it had been challenged, discussed and developed until they represented a good preliminary ‘grounding’ for the dissertation research to follow. At this stage the aims and objectives of the research were refined in discussions with my supervisor and altered so that they provided a focused target for the direction of the rest of the dissertation work.An important early outcome of these discussions was that I hadn’t initially intended to focus on the public participation geographic information systems (PPGIS) aspect of the web tool, but this change led to the idea of using only ‘open’ data and free and open-source software (FOSS) in the tool and the ‘accessibility’ of the tool becoming a major requirement.

The text of the aim of the research which defines the entire dissertation is:

‘The aim of this dissertation is the development of a publicly-available web-based GIS mapping tool, and the evaluation of the effectiveness of this tool in supporting a PPGIS approach, using the example of exploring the concept of ‘wild land’ in the Scottish Highlands’.

At this stage also the title of the dissertation was finalised to:

‘A web-based GIS tool to allow public exploration of the concept of ‘wild land’ in Scotland’.

The title and aim provide a good summary of the entire dissertation and everything in it can be considered as flowing from this.

The main research methodology underlining the dissertation was also defined at this early stage, and was to be, broadly speaking, a ‘quantitative’ approach in that it would involve the development of a technical software tool and importantly, an evaluation of that tool. This would be a largely desk-based process involving only my own time and efforts and could be described as ‘prestructured research’ in that it wasn’t open-ended and there was intended to be a clear outcome i.e. a measure of how well the web tool met the research objectives in terms of the ‘quality’ of the spatial data used and the usability of the web tool interface. Some dissertations involve ‘qualitative’ methods such as user surveys, interviews and questionnaires, and I decided at an early stage that this would be outside the scope of the dissertation – although these methods could potentially be used in futher research based on the work in the dissertation.

Once the EPO and the dissertation plan was approved (this document actually contributed 10% of the final dissertation mark), then the full work for the dissertation began, and this process took 4 months. Although this was not much longer than is usual for a dissertation in a traditional one-year full-time MSc course, a lot of the groundwork for the dissertation had been done in the preceding 12 months. The dissertation was required by UNIGIS to be no more than 15,000 words and to conform to established academic formats and styling. My supervisor guided me in the process of writing the dissertation with essential feedback on chapters, and contact was maintained throughout this period with Skype audio meetings and emails.

An important thing that I learned in this process is that it is important to create a research plan that is achievable within the resources available to the student (principally time) and appropriate for the level of a MSc dissertation – it can be easy to fall into the trap of taking on something that is more suitable for a full PhD, for instance. An important consideration also is the data that is required for the dissertation and whether it can be obtained and utilised within the timeframes and resources available to the student (e.g. licencing restrictions). The focus of my proposal on ‘open’ data and FOSS meant that this consideration was not a major hurdle, and indeed ‘accessibility’ of data and services was crucial to the theme of the dissertation which focused on PPGIS.

My plan for the dissertation was always that I should create a relatively sophisticated web-based tool as well as writing the dissertation about the tool so that there were essentially two deliverables involved, potentially requiring a lot of work and effort in the form of software design and development as well as research and writing. My strategy throughout however was always to focus on my strengths and what I knew I could do in terms of developing a web tool involving technologies I was familiar with such as HTML, CSS, JavaScript and a web-based client-server architecture.

One technical problem I faced at an early stage was where to host the various components of the web tool architecture. The client-side aspect of the tool was relatively straightforward, being web pages composed of browser-based technologies such as HTML, CSS and JavaScript, which can be hosted on any standard webhosting service (which I already have with the hosting of my personal website at However, the server-side aspect was more challenging and had several technical requirements: command-line superuser remote SSH access to a linux environment with sufficient user privileges and an environment allowing the installation of third-party applications and libraries; sufficient disk space and CPU power; reliability and 24/7 uptime; HTTP access; sufficient timespan of the hosting service to cover the period of development and presentation of the web tool. Crucially, my personal webhosting service does not support the first of these requirements and this sort of service is usually only available with specialist webhosting services for a fee. Unfortunately UNIGIS UK were not able to provide this level of technical support so I was left to my own devices, and for a while this was a problem that may have stopped the entire dissertation. However, as part of my investigation of technical applications, I became aware of the possibility of usingAmazon Web Services (AWS), something I had previously heard of but did not know much about the details and had never used before. The AWS platform provides all of the technical requirements I needed with its EC2 service and amazingly, offers it free for a year’s trial for non-commercial purposes – a perfect solution for a student’s needs. I ended up implementing my entire web tool architecture on AWS.

An important first stage in the dissertation was undertaking of a critical literature review, and this was essentially done as a parallel process with the design and development of the architecture of the web tool. The literature review involved reading a large amount of previous related research and the two areas fed into each other, with the literature defining the methods that others had used in this area and what hadn’t been done before, and the consideration of available technology defining what was possible and which existing applications, software libraries and technology frameworks were appropriate for the task.

The final choice of FOSS GIS technologies for the tool were GeoServer for the server component of the architecture, and the OpenLayers JavaScript API and library for the client component. These technologies fitted all of the requirements well, which were basically to provide a web-based environment which was completely customisable, supported GIS functionality, and were as ‘accessible’ as possible with minimal licencing restrictions so that the main aim of the web tool and hence the research area of the dissertation, to evaluate the potential of PPGIS methods to analyse and explore the concept of ‘wild land’, could be supported. I also decided to geographically restrict the area that was analysed in the web tool, to simplify and reduce the amount of spatial data to be processed and delivered, making it more manageable and usable. I decided to focus on the area of the Cairngorms National Park which has a defined boundary, is one of the largest areas of ‘wild land’ in the UK, and is an area of Scotland I know very well.

An important first step in developing the web tool and deciding what technologies to use was the building of a basic prototype to discover if the ideas were feasible and to provide a platform on which to build further. The prototype was just the first stage in the process of software development which broadly followed the Rapid Application Development methodology, which I have extensive experience of, and which in this case involved several cycles of feedback from my dissertation supervisor (particularly concerning the usability of the interface of the web tool) and associated iterative development of the web tool.

The actual writing of the dissertation and development of the web tool went largely to plan and allowed me to submit the dissertation on time (at just under the 15,000 word limit) in May 2017. I was able to change the working hours of my job to part-time during this period and this helped greatly. Whilst I spent many hours of my spare time in early 2017 on this, and there were many problems to solve and issues to deal with, things fell into place quite neatly and I am proud of the final product which presented some interesting web technologies and GIS concepts in a novel way within an established research framework. Major outcomes and findings of the research were that the FOSS applications, particularly GeoServer and OpenLayers, and the ‘open’ data, particularly the Ordnance Survey OpenData service (which only became available for the first time in 2010), were very well suited to the objectives of the research and allowed a genuinely useful web tool to be built to investigate what the notion of ‘wild land’ means in a thoroughly-grounded academic GIS research context. The final level of success of the completed web tool was not completely apparent to me at the outset of the process of developing ideas for the dissertation, and even during the development of the web tool and the writing of the dissertation. I believe that the general success of the outcomes of the dissertation reflects the current maturity, sophistication and richness of FOSS GIS applications and ‘open’ data and also shows the new opportunities for research that are available, and that this positive outcome would have been unachievable only a few years ago. The ideas and themes behind the research objectives in my dissertation would have made for a much more difficult undertaking if I had been writing the dissertation in say, 2007 instead of 2017.

The dissertation received a very high mark, and combined with the marks I had obtained in the taught component of the course, I was awarded the MSc degree with distinction by the University of Salford in June 2017. This dissertation won an award for best UNIGIS UK dissertation of 2017 andhas also been nominated for an award in the international UNIGIS academic excellence prize competition.

The completed dissertation is available at (PDF format):

The dissertation is also available on the Figshare service at this DOI URL:

The final version of the web tool can be seen at:

Posted by & filed under IT & the Internet, Mountains & hills, Personal, Science, Software engineering, August 21 2017.

I haven’t written anything in my blog for the last three years, and that is partly due to the fact that during that time I have been directing a lot of my energies to a postgraduate course, a Master of Science (MSc) degree in Geographic Information Science or Systems (GIS). I have now finished the course, which went very well.

The course was delivered by UNIGIS UK (a collaboration between Manchester Metropolitan University and the University of Salford), and one of the things that attracted me to the course is the remote learning nature of the course and the fact that the entire course of study is carried out part-time over a three year period (instead of the more usual one year for a full-time MSc course). This allowed me to continue working full-time and earning money whilst studying in my spare time for the course. Another attractive thing about the course is that a qualification can be awarded at the end of each successfully completed year of study, a Postgraduate Certificate after the first year, a Postgraduate Diploma after the second year, and the full Master of Science degree at the end of the third year. This is unlike traditional one year full-time Masters courses, where a lot of good work can achieve no credit if a student doesn’t complete the entire course (this happened to me on an earlier attempt at a GIS MSc). UNIGIS UK offers its MSc programme in three different ‘pathways’ and I chose to study the Geographical Information Technologies pathway.

The taught component of the course is modular, and is assessed using a mixture of formative and summative assessment methods, with the summative component taking the form of 12 very large pieces of assessed work set in a sequential fashion in the first two years, with two for each module, and which are required to pass the various taught components of the course. These assessed assignments are undertaken by the student at their own pace (although with fixed submission deadlines) in an environment of their own choosing, using their own resources (books, broadband internet connection, computer hardware, software applications, online research etc.) There are no formal summative assessment exams, which I consider to be a major point in favour of this course. Feedback gained from the assessed assignments was very detailed and incredibly useful for advancing my knowledge of GIS as the course proceeded, indicating what I was doing well, and also, crucially, correcting or guiding me in areas where I got things wrong. The 12 assignments I undertook took the form of Word documents comprising a mixture of essays and technical reports in an academic format and style, and are in themselves each major pieces of work. I list them here, along with the modules they formed the assessed components of, and descriptions of the work I carried out for each assignment.

Year 1 Modules:

Foundations of GIS

  • Changing boundaries and definitions – a 2500-word essay covering the historical development of the field of GIS and the debate about whether it can be described as a set of technical methodologies or an actual ‘science’, entitled “From GIS to GISc. The symbiotic development of Geographic Information Systems and Geographic Information Science”.
  • Practical portfolio: 1) working with social data; 2) spatial operations and analysis – a technical document describing the practical application of Markov chain analysis with ONS census and DCLG IMD (Index of Multiple Deprivation) data and a site suitability analysis using multi-criteria evaluation and cartographic modelling techniques with Ordnance Survey, Environment Agency and CORINE land cover data, using the desktop ArcGIS 10 application.

Spatial Data Infrastructures

  • Spatial data capture, metadata and standards - a technical document describing the creation of a land use map and associated attribute data by manual vectorisation of an aerial image, and the creation of an ISO 19115 metadata record for the created dataset, using ArcGIS 10.
  • Spatial data quality and fitness for purpose - a technical document describing the evaluation of spatial data in terms of ‘fitness for purpose’ and ‘quality’, for the purposes of a site selection analysis, using ONS census, Ordnance Survey and Environment Agency data.


  • NoSQL Databases and ‘Big Data’ – a 3000-word essay describing the advantages and limitations of NoSQL databases, in the contexts of spatial and ‘big data.
  • Development database – a technical document describing the development of a relational database using conceptual and logical models (with an Entity Attribute Relation diagram and normalisation methods), the physical implementation of the database model using the PostgreSQL application (with constraints and indexes), and the querying of the database with SQLqueries incorporating table joins.

Year 2 Modules:

Distributed GIS (option for the GI technologies pathway)

  • Aspects of web GIS practical portfolio: 1) interoperability and standards; 2) the benefits and challenges of distributed GIS – a technical document describing the construction of OGC WMS- and WFS-specification compliant queries to dynamically retrieve PNG maps and XML GML data via REST-styleHTTP GET URLs from a remote server,and also the construction of a map within the QGIS desktop application by retrieving data layers dynamically from a remote WFS server – also a 2250-word essay describing the benefits, limitations and challenges of Distributed GIS, focusing on SDIs, the ‘GeoWeb‘, VGI and disaster/emergency management.
  • Web GIS Project -an interactive, responsive web-based map interface using the Google Maps API v3 with HTML, CSS, the JavaScript jQuerylibrary and the Bootstrap library and KML data layers derived from UK Data Service boundary data, and a technical document describing the development of this interface – the interface can be seen at:

Spatial Databases and Programming (option for the GI technologies pathway)

  • Design, implement, interrogate and visualise a spatial database -a technical document describing the development of a relational spatial database using conceptual and logical models (with an Entity Attribute Relation diagram and normalisation methods) supporting specified requirements including the production of reports and maps to meet queries about distances and locations, the physical implementation of the database model using the PostGIS application (with constraints, spatial attributes and spatial indexes), the populating the database tables with spatial data, the querying of the database with spatial OGC SFSQL queries incorporating subqueries, common table expressions, spatial table joins and spatial measurements, and the creation of PostGIS views to visualise the results of queries as data layers in QGIS.
  • A mini project of GIS application development – a suite of software files that delivers a basic standalone ‘tightly coupled’ Windows desktop GIS application (using Python, the QGIS API/PyQGIS and the Qt4 libraries) to support an interface that allows the importing and map-based visualisation of raster and vector datasets as map layers, the presentation of attributes, and spatial analysis of the data (a calculation of travel accessibility indexes using point locations), and a technical document describing the development of the software incorporating a user manual – a zipfile containing the package of software files can be downloaded at: to run the application, extract the files from the 110Mb zipfile and run the ‘job_app_bat’ file in the ‘PyQGIS_package_release’ directory.

Methods in GIS

  • A research design appraisal – a 2500-word document comprising a GIS research proposal in a strict academic format, using as a model preliminary ideas for an eventual MSc dissertation, outlining the research questions, aims, objectives, approach, methodology, methods to be used, and the expected outcomes, all presented in relation to existing academic literature and research, and incorporating an ethics and risk assessment – the proposal was developed with formative feedback from a tutor as well as a peer review process, and laid the groundwork for the dissertation carried out in the third year of the course.
  • A spatial analysis portfolio: 1) point pattern analysis using ArcGIS; 2) implementing geostatistical analysis with ArcGIS – a technical document describing the usage of spatial analysis techniques in ArcGis 10, including descriptive spatial statistics and calculations of nearest neighbour index/ratio for point locations of a supplied dataset of plant locations, evaluation of the methods and conclusions about whether points are clustered or dispersed, whether a pattern is random or non-random, the statistical significance of this, potential causes for the pattern, also spatial interpolation methods (IDW, Trend Surfaces and Ordinary Kriging) using Met Office data, and evaluation and comparison of spatial interpolation methods using validation and calculation of errors.

A major component of the course is the research-based dissertation, which was undertaken in the third year of the course, and which I have discussed in a later blog posting here.

The nature of this learning and assessment framework means that a student learning about GIS in this way gains a great depth of knowledge and understanding in the 12 areas that the assessed assignments cover, which is very valuable, but other areas outside this do not get anywhere near the same level of attention – however, the 12 assignments cover a huge range of techniques, technologies, ideas, concepts and debates in the field of GIS and the end result I believe is a deeper understanding of GIS than is gained on an equivalent, traditional one-year MSc course that is assessed by exams, a framework which I believe does not allow areas to be explored in the same depth. Although in theory the three-year course contains exactly the same amount of work and required study time as a traditional one-year full-time course (200 hours per module), my experience is that the greater length of time allows for greater scope to think about ideas and concepts and to allow for more extensive research in the various areas. My experience also was that some modules require significantly more work than others, with the Spatial Databases and Programming module requiring an extensive investment of time and effort. Another advantage of this ongoing continuous assessment with feedback is that several ideas can be reinforced throughout the course and developed further with each assignment, such as the employment of ‘critical thinking‘, implementation of good cartographic techniques for map and data visualisations and the usage and incorporation into the assignments of an academic language style and rigourous academic format (background, literature, objectives, methodology, results, assumptions, limitations, conclusions, referencing etc.)

The remote learning nature of the course doesn’t suit all students, although it follows in the more established tradition of the Open University. In three years I never met a single fellow student or tutor in person, and all communication, discussion and delivery of course material such as lecture notes, demonstrations, tutorials, external resources, workshops, example exercises and self-test questions is done by online platforms such as email, instant messaging, videoconferencing, a web-based Virtual Learning Environment (VLE) application (Moodle) and multimedia and document files. A lot of the work is solitary and a student must rely on their own resources and initiative to complete the work, although there are discussion forums on the course VLE to discuss things with other students and the course tutors, and I was also in an ad-hoc Skype group of students which proved to be very useful. The remote student’s learning experience is heavily dependent on the willingness of the course tutors to engage with the online platforms. Much of the course used readily-available Free and Open-Source Software (FOSS) applications such as PostGIS and QGIS, but importantly, a licence is provided as part of the course so that the commercial ArcGIS desktop software can be used. Other things that are available as part of the course (without any extra fees) are web-based live seminars from invited GIS academics and industry professionals, subscriptions to current GIS paper-based periodical publications such as GeoConnexion and GIS professional, and a copy of the standard GIS textbook,Geographic Information Science and Systems, all of which are mailed to a student’s home.

Again, this style of postgraduate study will not suit all students – I believe it suits more mature students who may already have some experience of the field, either in a professional or academic environment, and who are used to working on their own without close direction. The UNIGIS learning environment and approach probably wouldn’t work for a younger person who has just graduated with no knowledge of GIS or things like software engineering or databases. In many ways the course brought together different strands of technical knowledge, skills and experience I have gained from several disparate environments in the 24 years since I graduated and the course allowed me to present them in a formal way to achieve the MSc degree.

The course fees may seem steep, but are reasonable compared to equivalent postgraduate courses and a major attraction of the course is the ability to pay the fees in instalments. A prospective student may well ask what these fees buy them, particularly in the context of remote-learning where a student is expected to rely a lot on their own resources, and a lot of the traditional student university experience is entirely absent. My view is that what a student is essentially buying on this course is access to academic experts from accredited Higher Education Institutions in the field of GIS who can give valuable feedback for the assessed assignments, and monitoring and guidance for the research dissertation, so that a student can gain the MSc qualification in a very flexible environment that can fit in with a lifestyle that may not allow for the more traditional methods of study. An important aspect of the UNIGIS MSc is that it is continually monitored by external examiners so that it meets the academic requirements and standard for this level of study.

Posted by & filed under Mountains & hills, Science, February 25 2014.

New research

Two academic papers have been published recently in the journal ‘The Holocene‘:

The two papers complement each other and describe different techniques to come to the same conclusion, that glaciers existed in corries in the Cairngorm mountains during the ‘late Holocene’, i.e. significantly later than the accepted date for the end of the last period of glaciation in the British Isles, which was the Younger Dryas stadial (also called the Loch Lomond readvance), about 11,500 years ago. They also speculate (and provide some evidence) that this may have been as recently as the period referred to as the ‘Little Ice Age‘ (LIA), corresponding roughly to the period from AD 1550 to AD 1850.

Context and history

This is not a new idea, and there has been some discussion about this question in previous research literature and published articles, some of it going as far back as 1905:

  • In an early article (1905) in Symons’s Meteorological Magazine by the Rev. R.P. Dansey, it is asserted that the high gullies to the east of the summit of Ben Nevis contain two glaciers. In the article he allows that these features are not glaciers in the sense that “they are not fed permanently by high level snows as are real glaciers” but he quotes the Rev. A. E. Robertson (the first person to complete all of the Munro summits in 1901) who says “I think also they would show glacial movement as well, so if that makes it a glacier, then I think you have it on Ben Nevis” (Dansey, R. P. 1905. The Glacial Snow of Ben Nevis. Symons’s Meteorological Magazine 40. 29-32).
  • …it appears probable that the nearest approach to glaciation in the Scottish Highlands was reached in the 1740′s and again about 1809-18;…we cannot claim that a glacier is likely to have established itself” (Manley G. 1949. The Snowline in Britain. Glaciers and Climate: Geophysical and Geomorphological Essays. Geografiska Annaler 31).
  • …it seems that extensive permanent snow beds or even inactive glacier ice existed as recently as the late seventeenth century” (Sugden D E. 1971. The Significance of Periglacial Activity on Some Scottish Mountains. The Geographical Journal 137. 388-392).
  • The original fieldwork in the corries of the Cairngorms that prompted the theory that small glaciers existed relatively recently in these corries was carried out by David Sugden of Aberdeen University Department of Geography in 1964. Sugden’s analysis of his fieldwork results took the form of dating of Rhizocarpon Geographicum lichen growing in the corries, by measuring and comparing relative diameters of lichens – a technique known as lichenometry. Interestingly he says “there are numerous situations in the world where glaciers have crossed weak deposits such as peat without removing them” (Sugden D E. 1977. Did glaciers form in the Cairngorms in the 17th-19th centuries? Cairngorm Club Journal 97. 189-201).
  • This snowfield (Garbh Choire Mòr south of Braeriach) was the source of a Coire Glacier during the previous centuries. Measurements of lichen growth have dated two moraines at 1740 and 1810” (Hudson I C. 1977. Cairngorm snowfield report 1976. Journal of Meteorology 2. 163-166).
  • Sheila Rapson argued that ‘active ice’ cannot have existed in 3 corries with boulder moraine ridges in the Cairngorm mountains since 6000-9000 years ago, as organic sediments retrieved from the lochs in these corries have been radiocarbon dated to those dates (and the assumption is made that ‘active ice’ would have removed this organic material, an assumption that is at odds with what Sugden said in his 1977 CCJ article) – but does say the corries may have contained ‘permanent snow’ during the period of the Little Ice Age (Rapson, S. C. 1985. Minimum age of corrie moraine ridges in the Cairngorm Mountains, Scotland. Boreas, 14. 155-159).
  • Sheila Rapson also subsequently pointed out that David Sugden’s original lichen cover research from the 70s that prompted the theory that glaciers existed in the Cairngorms in the 17th century was not completely negated by her later research, at least in the case of Garbh Choire Mòr of Braeriach. She makes the tentative suggestion that “the coire, because of its high altitude, accommodated a true glacier during the Little Ice Age” (Rapson S C. 1990. The age of the Cairngorm corrie moraines. Scottish Mountaineering Club Journal 34 (no. 181). 457-463).
  • Adam Watson suggests that the ‘moraine’ at the foot of Garbh Choire Mòr, mentioned by Sheila Rapson in her SMC Journal article of 1990 is probably not a moraine formed by a glacier, but instead is a protalus rampart. This would explain the relatively recent date of formation, and would not require the existence of glacial ice to form, instead being formed by rockfall from cliffs onto a large snowpatch at the foot of Garbh Choire Mòr (A snow book, northern Scotland, Paragon Publishing, 2011, Pg. 67).

The two new papers are the most recent contribution to this long-running debate, and have generated a lot of discussion and received some attention in the media. The research was mentioned in an article on the BBC news website here. There is also discussion about this research on the Mountaineering Council of Scotland (MCofS) website here, the website here and the University of Dundee website here.

The two papers focus on different areas of the Cairngorm mountains; the Harrison et al. paper describes a computer model that uses local historic and contemporary meteorological records and a Digital Elevation Model (DEM) to generate snow and ice cover models for various temporal and climate parameters, in the specific area of Garbh Choire Mòr (and the other corries of Braeriach as well as the northern corries); the Kirkbride et al. paper describes an isotope ratio dating technique used on rocks in Coire an Lochain, one of the northern corries of the Cairngorms. Two of my photographs of Garbh Choire Mòr (which can be seen here and here) were used in the Harrison et al. paper.

The Harrison et al. paper

The Harrison et al. paper (corresponding author: Stephan Harrison of the University of Exeter) essentially describes ‘desktop science’ using a computer model, and concludes that the snow and ice features that are predicted by the model using climate variables (e.g. precipitation and air temperature) that may have been evident during the period of the LIA, indicate the probable presence of ‘glaciers’ at that time in the corries of Braeriach, and the northern corries of Coire an Lochain and Coire an t-Sneachda.

Despite its very genuine and useful methods of analysis which add concrete quantitative results to the debate, the Harrison et al. paper doesn’t seem to recognise the limitations of this method of scientific enquiry, ignores (or doesn’t have the resources to investigate) the ‘ground truth’ that can only be explored properly with on-site fieldwork, and jumps to conclusions that do not appear to be well-justified.

The model in the paper predicts (strictly speaking that should be ‘postdicts’) relatively large surface areas and depths of snow and ice in the Braeriach and northern corries during the LIA (which is not in disagreement with other researchers, including Adam Watson), but the conclusion the paper makes that these snow and ice features were actually glaciers, appears to rest entirely on the (remote) analysis of the geomorphology of a rock ridge and surrounding topography in Garbh Choire Mòr, and the findings of the rock dating techniques in Coire an Lochain in the Kirkbride et al paper; this is contentious, as explained below.

Another limitation of the model used in the Harrison et al. paper is the resolution of the DEM used, which is 30m. A resolution as coarse as this potentially misses some of the smaller topographical variability of the real landscape which can affect the calculated results – the rock ridge in Garbh Choire Mòr is of the order of 30m in length, and smaller gullies than this in Garbh Choire Mòr ‘funnel’ avalanched snow from the mountain plateau above to locations that correspond to the locations of the current persistent snowpatches in Garbh Choire Mòr. Higher resolution DEM data is available such as NEXTMap data which offers sub-10m resolution data.

Computer-based modelling techniques like this are a bit of a pet interest of mine, and the model described in this paper has a lot in common with the Geographical Information Science (GIS) methods I outlined in one of my blog entries I wrote in 2011 about using GIS techniques to analyse snowpatches ( A paper (Purves R S, Mackaness W A, Sugden D E. 1999. An approach to modelling the impact of snow drift on glaciation in the Cairngorm Mountains, Scotland. Journal of Quaternary Science 14; contributed to by William Mackaness who was my supervisor on my 2010 GIS MSc course) which is referenced by the Harrison et al. paper uses a similar desktop modelling technique and this work was a model for my blog entry (which contains preliminary work carried out for my proposed MSc dissertation, which unfortunately never happened).

The Kirkbride et al. paper

Proposed glacier in Coire an Lochain

Proposed glacier in Coire an Lochain

The Kirkbride et al. paper (corresponding author: Martin Kirkbride of the University of Dundee) describes a dating technique that was used to date rock ridges in Coire an Lochain. This dating technique uses Beryllium isotope ratios in the rocks, which is a proxy measurement for exposure to an ‘unshielded’ environment. Using this dating technique the paper arrives at the conclusion that a glacier existed in the corrie, on the rock face of the Great Slab, much more recently than the end of the Younger Dryas stadial, 11,500 years ago (see the image to the left for an idea of the extent of the glacier on a map of the corrie; this is strictly my own interpretation of the putative glacier discussed in the paper; see also this image from the University of Dundee website which is a mockup of how the glacier might have looked).

The dating of this glacier to the specific period of the LIA is supported by one of the contributing authors of the paper, Alastair Dawson, who wrote the book So Foul and Fair a Day (Dawson, Birlinn Ltd, 2009), about Scotland’s climate.

However, from the details in the Kirkbride et al. paper it’s not clear that the results obtained using this dating method cannot be alternatively (and perhaps more satisfactorily) explained by a large extent and depth of ‘inactive’ perennial snow and ice covering the rocks, which is not necessarily a ‘glacier’, and there doesn’t seem to be any difference in this respect between this dating technique and those used by Sheila Rapson in her 1990 SMC Journal article and 1985 Boreas paper (radiocarbon dating and pollen analysis), or even David Sugden’s 1977 CCJ article and 1971 Geographical Journal article (lichenometry).

Controversy and debate about rock ridge features in Garbh Choire Mòr and Coire an Lochain

Rock ridge feature in Garbh Choire Mòr

Rock ridge feature in Garbh Choire Mòr

There is a rock ridge in Garbh Choire Mòr which is a notable and unusual feature in the corrie (see a photograph of this ridge to the right). A lot of the debate has centred on the geomorphology of this ridge, what its origins are, and whether it is a moraine (formed due to the action of glacial ice) or a protalus rampart (formed from rock debris on a snow surface rather than glacial ice).

Concerning the geomorphology of the rock ridge in Garbh Choire Mòr (and also perhaps the rock ridges in Coire an Lochain) Adam Watson has said “It is not a moraine or fluvioglacial deposit or till unless it shows horizon development. A protalus rampart has no obvious horizon development because of the frequent accumulation of fresh topsoil and vegetation leading to topsoil by decomposition“. Adam Watson has also said that this ridge is more likely to be a protalus rampart rather than a glacial moraine, and has stated “Both the 2014 papers state clearly that there was no soil profile in the supposed morainic ridges that they described. This rules out moraines without further ado“.

The Harrison et al. paper mentions this rock ridge and says “the clearest boulder ridge…is too far from the foot of the talus slope at the backwall of the cirque for it to have formed by pronival processes“.

The Kirkbride et al. paper says (about the rock ridges in Coire an Lochain) “soil cover is thin with no horizon development“, but there is no evidence or explanation for this claim, and no reference to any previous fieldwork or research in the area to support it.

The Kirkbride et al. paper also says “reconnaissance of several cirques has produced evidence of pronival deposition rather than Holocene moraines“. It would be useful to know which ‘cirques’ these were and how they came to this conclusion – effectively it is saying that the moraines they describe in Coire an Lochain are unique features in the Cairngorms. Does this uniqueness also include Garbh Choire Mòr? If so, this is in direct contradiction to the claims made in the Harrison et al. paper.

Also, the Harrison et al. paper says, somewhat brusquely, and in apparent contradiction to the Kirkbride et al. paper “We dismiss arguments that the small boulder ridges in several high cirques are protalus, pronival or avalanche landforms…“). Again, more detail about these locations and support for these conclusions would be welcome.

The Harrison et al. paper even says of these proposed late-Holocene glaciers “…such glaciers were unlikely to have been dynamic enough to excavate pre-existing material from sub-glacial positions” which seems to imply that the rock ridge features that are being discussed weren’t actually formed or modified by moraine-forming ‘glacial’ ice at all.

Fieldwork and ‘ground truth’

Iain Cameron and Mark Atkinson visited Garbh Choire Mòr in September 2012 to carry out some fieldwork, by digging a small trench in the rock ridge in this corrie, which seemed to confirm Adam Watson’s hypothesis (see photographs and a video of this activity). Iain Cameron has said about this feature “avalanche debris can be often be found as late as August in the hollow which is adjacent to the ridge. Attila’s photo from 2008 shows this well.” and “the explanation given by Sandy Walker (via Adam) as to what to look for did seem to suggest the protalus option“.

It is apparent from reading the Harrison et al. paper that no on-site fieldwork was carried out for the research outlined in the paper (perhaps due to its relative inaccessibility), and this may be a weakness in the research carried out in that paper. The inaccessibility of the Braeriach corries (and Garbh Choire Mòr in particular) is definitely a hurdle to effective scientific research and enquiry. In fact the Kirkbride et al. paper touches on this when it says about Coire an Lochain “The irony is that the elusive landform evidence for recent glacial activity was discovered in one of the most visible locations in the massif“, being as it is, about an hour’s easy walk from the ski centre car park.

The Harrison et al. paper refers to the conclusions of the Kirkbride et al. paper to support its own conclusions. It’s not clear what fieldwork was carried out for the Kirkbride et al. paper, apart from rocks which were removed from the surfaces of the rock ridges in Coire an Lochain for use in the lab-based Beryllium isotope dating technique. The Kirkbride et al. paper, in turn, uses the computer modelling of the Harrison paper to support its conclusions.

It is worth pointing out that two of the authors of the Kirkbride et al. paper have written a detailed rebuttal to Adam Watson’s views here.

It’s a confusing picture, and there is by no means a consensus about this.


There is a lack of depth and clarity in both papers I think, with reference to the term ‘glacial ice’ and what this actually means, and what is meant by referring to a feature as a ‘glacier’. The Harrison et al. paper says “The LIA simulations produced small glaciers within each of the cirques, and perennial snow and ice cover on many of the ridges and headwalls within the model domain“, but seems to use an apparently somewhat arbitrary extent and depth measurement to define a feature as a ‘glacier’ as opposed to an area of ‘snow and ice’.

A ‘glacier’ can be defined as a body of ice that has certain characteristics: it has a minimum depth of layers of annual unmelted snowfall which causes lower layers of snow and ice to be pressurised above a certain density and deformed; this ice flows due to gravity, and the ice modifies the landscape around it as it flows (i.e. moraines). So at the core of this debate is the issue of whether the features that are being discussed display these characteristics – but at what point does a large and perennial snowfield (of which there are small contemporary versions in the Scottish mountains) become a ‘glacier’?

A term I’d like to see popularised is ‘glacieret’ (the term ‘proto-glacier’ has also been used in this context) which has already been used (in academic papers) to describe features in other countries which are relatively large perennial and persistent snowpatches that may contain very old ‘fossil ice’ but which aren’t actually glaciers in the true sense in that they may not contain ‘active’ ice that is deformed, flows, and modifies the surrounding rock topography (e.g. the Calderone ‘glacier’ in Italy, the Snezhnika snowpatch in Bulgaria, the Debeli Namet ‘glacier’ in Montenegro, the Hamaguri-yuki and Kuranosuke ‘snowfields’ in Japan, Saint Mary’s ‘glacier’ in Colorado, I go into detail about this in another blog posting at:

There are lots of examples of these types of features, and it might be more useful (and correct) to say that a feature like these (probably) existed in the Braeriach corries in the period of the LIA, rather than an actual ‘glacier’. A list of relevant academic papers and articles can be seen at the bottom of this page on my website:

Historical eye-witness accounts of snow and ice in the Cairngorms

Another problem with the idea that a glacier existed in Coire an Lochain in the period of the LIA is that this corrie is actually easily visible from the surrounding lower-lying inhabited areas of the Spey Valley such as Nethy Bridge and Grantown-on-Spey (the corrie is well-seen from Loch Morlich, for instance). Eye-witness accounts of persistent and large snowfields in the Cairngorms go back many years, right into this period. A detailed collection of these historical accounts can be seen in the book Cool Britannia (Watson & Cameron, Paragon Publishing, 2010).

The crucial point about these accounts is that they do not mention anything out of the ordinary in Coire an Lochain – the large persistent snowfield of Ciste Mhearad is mentioned in accounts from the 17th to 19th centuries, as well as snowpatches in Garbh Choire Mòr (both of which are not visible from the lower ground in the Spey Valley) – but Coire an Lochain (which is) never merits a mention. If there was a glacier in this corrie at some point in the 17th to 19th centuries it would surely have been mentioned specifically in these historical accounts. In contemporary times, Coire an Lochain contains some relatively long-lasting snowpatches but is not known as one of the main areas of snow in the Scottish mountains that persists into the following winter.

It’s worth stressing also that the Kirkbride et al. paper concludes only that a glacier existed in the corrie later than previously thought (the end of the Younger Dryas stadial) and the period of the LIA is only one option for this (although of course this is the most interesting) – the glacier may well have existed at some other cool period in the last 2800 years, so the lack of historical accounts from the 17th to 19th centuries does not necessarily invalidate the research in this paper, only perhaps making it less interesting to modern and contemporary eyes.


So where does all of this leave the debate? The two recent papers have added a lot of new insights and data to the discussion, but do not appear to have provided conclusive evidence or firm conclusions about whether or not glaciers existed in the Scottish mountains within the last few hundred years – there is certainly no consensus about the question or indeed its answer. On either side of the debate, attitudes seem to be fairly entrenched and the debate revolves around the scientific interpretation of data, the methods involved in generating that data and even the semantics of the terminology used (what does the term ‘glacier’ actually mean?) The central question that doesn’t appear to have been satisfactorily resolved is, are the rock ridges in Coire an Lochain and Garbh Choire Mòr (and other places in the Cairngorms) recently-modified glacial moraines or not?

However, the two recent papers can be considered as being a welcome spur and catalyst to further research in this area. It is clear that only further research carried out within the usual academic environment (peer-reviewed papers published in ‘respected’ journals by academics associated with well-regarded research institutions such as HEIs, SNH, BGS and CEH) will advance this debate, but I hope that this can be done in collaboration with, and using the very real advantages that can be obtained from, the ‘citizen science‘ approach, which in this area has been carried out in recent years by a large team of interested amateurs who contribute to the annual Scottish snowpatch report in the Weather journal.

The Harrison et al. paper does list some of these ‘citizen science’ papers and articles as references (and in particular Adam Watson’s book ‘A snow book, northern Scotland‘), but it’s not clear what effect they have had on this paper, other than as a source of conclusions to refute by the research carried out. The Harrison et al. paper says (about Coire an Lochain and Coire an t-Sneachda) “…under present conditions, these contain the longest lying snow patches in the British Isles”, a conclusion which is not borne out by the results of ‘citizen science’, and ignores the snowpatches in Lochaber and in the area directly to the east of the summit dome of Ben Macdui, which are consistently more persistent than those in Coire an Lochain and Coire an t-Sneachda.

The two recent papers have certainly raised public awareness of the issues and the science involved (as can be seen from the BBC news and MCofS website reports) so in this sense, they can be seen as a success.

I should also add that I am not a scientist, I am an interested amateur – I’m prepared to be challenged and corrected on anything I’ve written here, this is what this blog is all about! Please leave any comments you might have below…

Posted by & filed under Books, Mountains & hills, Science, September 24 2013.

A Zoologist on Baffin Island, 1953

A Zoologist on Baffin Island, 1953, by Adam Watson

I have been interested in the Canadian island of Baffin Island since ‘Frozen Fire: a Tale of Courage‘ by James Houston was a set text when I went to school. Baffin Island, which straddles the Arctic Circle in the Canadian Arctic Archipelago is in many ways the archetypal ‘Arctic’ location – it has sea ice, polar bears, mountains, glaciers, icecaps, icebergs, fjords, the fabled ‘Northwest Passage‘, whales and Eskimos (now of course, known as Inuit). So Adam Watson‘s book, published in 2011, about his journey to Baffin Island sixty years ago as a young man in 1953 has been on my reading list for some time.

This book covers chronologically in detail the events of the summer months of 1953 when Adam Watson was part of a large group of scientists and explorers who undertook an expedition organised by the Arctic Institute of North America to Pangnirtung Fiord and the Weasel and Owl valleys (an area now known as Akshayuk Pass) on Baffin Island, now part of Auyuittuq National Park.

On the other side of the world, Mount Everest was first successfully climbed while this expedition was underway – this was still an era of pioneers and the decade of the 1950s was possibly the last time that groundbreaking exploration like this could be carried out. Auyuittuq Park and the area in which this 1953 expedition travelled contains some incredibly dramatic peaks with the highest vertical mountain faces in the world, including Mount Asgard (which was first climbed on this expedition by members of the expedition team), Mount Odin (the highest mountain on Baffin Island) and Thor Peak. The Weasel and Owl valleys are now a playground for BASE jumpers and climbers but back in 1953 the area was largely unexplored and access was difficult. Adam Watson’s book is thus a remarkable journal of a time when the area was awaiting first ascents and scientific discoveries before large-scale tourism and globalisation changed the area and the Inuit way of life.

Adam Watson’s description of this Inuit lifestyle, just as it was on the cusp of change and still with real links remaining to their past and traditions is one of the highlights of the book, particularly the first section that details Adam Watson’s time on a sledge (qamutiq or komatik) on the sea ice of Padle Fiord and the area around Padloping Island with an Inuit guide and his dogs. Also notable are his observations of the way that previous European visitors to the area had influenced the Inuit population, notably Scottish whalers who had left a legacy of Scottish country dancing that was eagerly adopted by the Inuit!

Anyone who has read Adam Watson’s autobiography of the early decades of his life, ‘It’s a Fine Day for the Hill‘, or anyone who has an interest in the Arctic, will enjoy this book. As in his autobiography, Adam Watson’s writing style is engaging and descriptive; his eye for the details of human personalities and the natural environment around him is sharp and this makes for a compelling read. The very real harshness and danger of the place, but also the wild beauty, are presented expertly by Adam Watson, in a restrained style and without hyperbole, but all the time maintaining excitement – he lets the places, events and people speak for themselves.

Adam Watson also includes much information about the primary purpose of the expedition, which was scientific exploration, research and investigation, and his own particular speciality, which was the animal life of the area, particularly birds. He also makes his contribution to the ‘myth busting’ of the commonly-held belief that lemmings in the Arctic periodically commit suicide en masse (a myth popularised by Disney of course). He also laments the current status of scientific research globally, contrasting it with the aims and approach of the 1953 expedition, and it is also interesting to read his perspective on AGW (Anthropogenic Global Warming) – while he doesn’t go so far as to label this a myth, throughout the book he firmly makes the case for ‘real’ scientific enquiry, fieldwork, quantitative analysis, interdisciplinary collaboration, hypothesis testing and scepticism.

The book also highlights Pat Baird, the expedition organiser and leader, who was an interesting character who deserves to be more widely known. The noted zoologist, Vero Copner Wynne-Edwards, also joined the expedition.

A fantastic view of the area that the expedition travelled in was shown in the 2009 ITV series ‘Journey to the Edge of the World‘ in which Billy Connolly (referred to in the book by Adam Watson, somewhat disparagingly, as a show-business Scot!) was transported by helicopter to the summit of Mount Battle (named after a member of the team who died during the expedition in a drowning accident in a partially-frozen pond, Ben Battle).

Perhaps the most remarkable aspect of this book is the copious collection of photographs from the expedition from Adam Watson’s personal collection – the format of the book allows large full-page images to be shown, many of which are in colour, an unusual and unique record of an area which was little-visited and relatively unrecorded in the 1950s, and certainly not with colour photography.

Posted by & filed under Mountains & hills, Science, October 11 2012.

At the Pinnacles snowpatch in Garbh Choire Mòr

At the Pinnacles snowpatch in Garbh Choire Mòr

For several years now, there has been a secretive and remote location in the Scottish mountains that I have been trying to get to. This location is Garbh Choire Mòr, a corrie at the western end of the larger An Garbh Choire in the Cairngorm mountains, between Braeriach and Cairn Toul, and it is notable because it holds the most persistent snowpatches in the Scottish mountains (see my website pages about perennial snowpatches in the Scottish mountains here).

The corrie is perhaps the most inaccessible non-climbing location in the whole of the British Isles. I have tried to reach the location on several previous attempts but the corrie is located in the heart of the Cairngorm mountains many kilometres from any roads, and is surrounded on its north, west and south sides by steep and bouldery ground. It is possible to descend into the corrie from the north, at a point just east of Carn na Criche (OS 10-figure grid ref. NN 94160 98316), and from the south down the Corrie of the Chokestone Gully (OS grid ref. NN 948 976), but these are rocky and steep scrambling routes that require a bit of nerve. The approach from the Lairig Ghru in the east has no steep ground but necessitates a long walk over pathless and difficult terrain.

There is a relatively short window in the year in which visiting the corrie to examine the snowpatches is possible. To examine them when they are at their smallest, and hence most interesting in terms of gauging their persistence and appearance, it is necessary to visit as late in the year as possible. However, this cannot be too late in the year as once they are covered by snow they cannot be seen.

As all approaches to the site are long and difficult, then any visit (unless this involves a two-day trip and an overnight wild camp) must also be before the length of the daylight gets too short. This means that the optimum time for a visit is in autumn, in the second half of September.

The Garbh Choire shelter in An Garbh Choire

Three weeks ago on September 23rd, I finally succeeded in reaching the location. I started at Linn of Dee at 8am, with the sun not long risen and the air very cold, and cycled the 7km through Glen Lui to Gleann Laoigh Bheag. From there I walked to Glen Dee and the Lairig Ghru path, past the impressive vistas of Glen Geusachan and The Devil’s Point, to the entrance to An Garbh Choire. At this point, I left the relatively easy terrain of the Lairig Ghru path and headed westwards through boggy, pathless and undulating terrain and into An Garbh Choire and up to the Garbh Choire shelter (see photo to the right). The shelter itself is small and fairly dilapidated, and probably not a place that I would choose to spend the night.

Garbh Choire Mòr

Further up An Garbh Choire beyond the refuge the walking becomes easier and there are a few areas of relatively flat and grassy ground at the entrance to Garbh Choire Mòr that would be suitable for wild camping, perhaps a more preferable option if I was to revisit the area in the future. The final approach to the snowpatches themselves is over an extensive boulderfield and then a short steep ascent.

I got back to the Linn of Dee just after sunset, 12 hours after I set out, with only about 30 minutes time at the snowpatches to spend examining them and taking photographs. The total round-trip distance was 40km, probably the maximum that can be done in daylight hours at this time of year.

Michaelmas Fare, Sphinx and Pinnacles snowpatches

On my visit to Garbh Choire Mòr there were three snowpatches visible high in the corrie, at an altitude of about 1100m (see photograph to the right) – these are named after climbing routes on the cliffs above them and are known as (from left to right in the photograph) Michaelmas Fare, Sphinx (named after the Sphinx Ridge) and Pinnacles (named after the Pinnacles Buttress). On my visit the Pinnacles snowpatch actually had the remnants of a fourth small snowpatch about a few metres in length next to it.

The Pinnacles snowpatch; the Sphinx snowpatch can just be seen behind it

The Pinnacles snowpatch; the Sphinx snowpatch can just be seen behind it

The Sphinx snowpatch is the most persistent snowpatch in the whole of the Scottish mountains. The snow the Sphinx snowpatch consists of has not fully melted since October 2006 (meaning the snow when I visited it was six years old), and has only disappeared completely six times since observations began in the late 19th/early 20th century, in 1933, 1953 (when the Pinnacles snowpatch survived), 1959, 1996, 2003 and 2006, and then only for a short period in the autumn before winter snowfalls arrive. This means that the ground below the Sphinx snowpatch has probably been completely clear of snow for a combined total of only a few months since the start of the cold climate period in the 16-19th centuries known as the Little Ice Age. This is the closest Scotland comes to having a glacier.

Protalus rampart in Garbh Choire Mòr

Protalus rampart in Garbh Choire Mòr

Below the snowpatches at the foot of the bowl of Garbh Choire Mòr is a feature that has caused much debate in recent years (see photo to the right) – this is a small ridge of boulders and soil that was once thought to be a moraine that may have been modified by glacial ice as recently as the 19th century, thus providing evidence (from lichenometry, pollen analysis and radiocarbon dating) of recent glaciation in the Cairngorms. However, current expert opinion is that this feature is a protalus rampart that does not require glacial ice to form, and is probably still being modified in recent times by rockfall from the surrounding cliffs and wind-blown debris from the Braeriach plateau to the west of Garbh Choire Mòr.

Glaciers have probably not existed in Garbh Choire Mòr since the end of the last widespread period of mountain glaciation, the Younger Dryas or Loch Lomond Stadial, which ended over 10,000 years ago. However, during the Little Ice Age there was almost certainly a large perennial snowpatch in Garbh Choire Mòr that filled the whole corrie. See my previous blog postings for more information about this, ‘The Scottish mountains: on the glacial ‘knife-edge’ and ‘Scottish glaciers‘, particularly the comments.

The appearance of the snow in the Garbh Choire Mòr snowpatches is that of extremely hard and compact ice, and is more accurately described by the term firn. I saw no sign of any melting occurring on my visit, and there was a layer of patchy fresh snow of about 1-2cm thickness from a recent fall in the last week covering the snowpatches (I experienced a shower of snow on the summit of Cairn Gorm on September 19th, four days before my visit to Garbh Choire Mòr, see a photo here).

Since my visit, there has been some further snowfall and low temperatures in the Cairngorms, and the three patches will almost certainly survive into next year.