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Sentinel satellite spies ice cap speed-up | Sentinel satellite spies ice cap speed-up |
(about 17 hours later) | |
Melting at one of the largest ice caps on Earth has produced a big jump in its flow speed, satellite imagery suggests. | |
Austfonna on Norway's Svalbard archipelago covers just over 8,000 sq km and had been relatively stable for many years. | |
But the latest space data reveals a marked acceleration of the ice in its main outlet glacier to the Barents Sea. | |
The research was presented in Brussels on Thursday to mark the launch of the EU's new Sentinel-1a radar spacecraft. | The research was presented in Brussels on Thursday to mark the launch of the EU's new Sentinel-1a radar spacecraft. |
This satellite has been in orbit barely a month but is already being tasked with a range of science observations and other duties. | This satellite has been in orbit barely a month but is already being tasked with a range of science observations and other duties. |
European Commission officials are keen to showcase the platform's capabilities before it goes into full service, including what it can do at high latitudes. | European Commission officials are keen to showcase the platform's capabilities before it goes into full service, including what it can do at high latitudes. |
Radar is particularly useful in these regions. It senses the surface whatever the weather conditions and even in the darkness of polar winter. | Radar is particularly useful in these regions. It senses the surface whatever the weather conditions and even in the darkness of polar winter. |
Scientists had suspected the Arctic's Austfonna Ice Cap was losing substantially more ice through its major drainage glacier at Cap Mohn, and asked if Sentinel-1a could take some pictures. | Scientists had suspected the Arctic's Austfonna Ice Cap was losing substantially more ice through its major drainage glacier at Cap Mohn, and asked if Sentinel-1a could take some pictures. |
"We've observed Austfonna with various satellite radar datasets over the past 20 years, and it hasn't done very much," explained Prof Andy Shepherd from Leeds University, UK. | "We've observed Austfonna with various satellite radar datasets over the past 20 years, and it hasn't done very much," explained Prof Andy Shepherd from Leeds University, UK. |
"But we've now looked at it again with the new Sentienl-1a spacecraft, and it's clear it has speeded up quite considerably in the last two or three years. It is now flowing at least 10 times faster than previously measured." | "But we've now looked at it again with the new Sentienl-1a spacecraft, and it's clear it has speeded up quite considerably in the last two or three years. It is now flowing at least 10 times faster than previously measured." |
That previous measurement was done using the German national TerraSAR-X radar mission. | That previous measurement was done using the German national TerraSAR-X radar mission. |
The speed of a glacier is judged by how far prominent features such as a big crevasse travel in time. | The speed of a glacier is judged by how far prominent features such as a big crevasse travel in time. |
An "ice cap" is much smaller than an "ice sheet", a term that more properly describes the huge frozen masses covering Greenland and Antarctica. | An "ice cap" is much smaller than an "ice sheet", a term that more properly describes the huge frozen masses covering Greenland and Antarctica. |
An ice cap does, however, share a similarity with its bigger cousin in that it too has glaciers flowing away in many directions. | An ice cap does, however, share a similarity with its bigger cousin in that it too has glaciers flowing away in many directions. |
The Earth's ice caps and glaciers have become a key focus for scientists because these are the ice fields that appear to be experiencing the greatest change currently. | The Earth's ice caps and glaciers have become a key focus for scientists because these are the ice fields that appear to be experiencing the greatest change currently. |
"Although ice caps and glaciers contain less than 1% of the world's ice, they contribute around 50% of the sea-level rise due to ice melting," explained Prof Shepherd. | "Although ice caps and glaciers contain less than 1% of the world's ice, they contribute around 50% of the sea-level rise due to ice melting," explained Prof Shepherd. |
A detailed report on Austfonna and the probable causes of the speed-up is being prepared for publication in a science journal. | A detailed report on Austfonna and the probable causes of the speed-up is being prepared for publication in a science journal. |
Prof Shepherd's team said the quality of the Sentinel data was very impressive, especially since the satellite was still in the process of drifting towards its final operational orbit. | Prof Shepherd's team said the quality of the Sentinel data was very impressive, especially since the satellite was still in the process of drifting towards its final operational orbit. |
It augured well for future studies of the cryosphere - research that will be boosted further when a carbon-copy Sentinel is launched in 18 months to hasten the acquisition of imagery. | It augured well for future studies of the cryosphere - research that will be boosted further when a carbon-copy Sentinel is launched in 18 months to hasten the acquisition of imagery. |
The European Commission used Thursday's event to highlight a variety of other scientific and operational applications for Sentinel-1a data. | The European Commission used Thursday's event to highlight a variety of other scientific and operational applications for Sentinel-1a data. |
These included making rapid charts for mariners to warn them of nearby icebergs, and keeping watch over the seas for illicit oil spills. | These included making rapid charts for mariners to warn them of nearby icebergs, and keeping watch over the seas for illicit oil spills. |
Europe has committed some 7.5 billion euros to the end of the decade to launch a fleet of environmental monitoring satellites. | Europe has committed some 7.5 billion euros to the end of the decade to launch a fleet of environmental monitoring satellites. |
They are all called Sentinels but will have specific roles, viewing the Earth using a range of observing techniques. | They are all called Sentinels but will have specific roles, viewing the Earth using a range of observing techniques. |
The spacecraft will gather scientific data but also information the European Commission needs to design and enforce community-wide policies. | The spacecraft will gather scientific data but also information the European Commission needs to design and enforce community-wide policies. |
The Sentinels and the applications that stem from their data fit within what the EC calls its Copernicus programme. | The Sentinels and the applications that stem from their data fit within what the EC calls its Copernicus programme. |
Its scope and financial outlay makes it the biggest civilian Earth observation project ever envisaged. | Its scope and financial outlay makes it the biggest civilian Earth observation project ever envisaged. |
What is Copernicus? | What is Copernicus? |
Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos | Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos |
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