Satellites map retreat of glaciers

Edinburgh scientists are using satellite data to map complex changes in ice cover on glaciers in Patagonia.

Image showing Patagonian glaciers

They are part of the European Space Agency’s CryoSat mission.

It has revealed that widespread thinning of the region’s glaciers is causing global sea levels to rise by around 0.06 mm each year.

The team from the University’s School of GeoSciences has developed a new way of analysing satellite radar data.

It allows them to map glaciers in greater detail than ever before.

Ice data

This has revealed complex patterns in the changing height of ice fields in Patagonia, which is home to the largest glaciers in the southern hemisphere outside Antarctica.

The Patagonian ice fields collectively lost mass at a rate of over 21 gigatonnes (Gt) per year between 2011 and 2017. This was an increase of almost 25 per cent compared with the amount of ice lost between 2000 and 2014.

The Jorge Montt glacier retreated 2.5 kilometres and lost around 2.2 Gt each year. By contrast, Pio XI – the largest glacier in South America – advanced and gained mass at a rate of around 0.67 Gt per year.

Some glaciers in Patagonia are retreating faster than those found elsewhere, partly because the weather there is relatively warm.

Luca ForestaSchool of GeoSciences

Glacial changes

It has until now proven difficult to monitor the speed at which glaciers in Patagonia are changing.

Satellite radar readings have been used to map large ice sheets for the past 25 years. Conventional methods do not provide enough information to analyse smaller mountain glaciers effectively.

The new technique enables whole swathes of glacial surfaces to be monitored in detail.

The study is published in the journal Remote Sensing of Environment.

This new technique is yielding more details about this complex environment than we ever thought possible.

Noel GourmelenSchool of GeoSciences

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School of GeoSciences


Image credit: ESA/Planetary Visions