The European Space Agency's (ESA) Space for Shore initiative uses radar data from the Copernicus Sentinel-1 mission to deliver comprehensive, year-by-year insights into glacier retreat and calving intensity. The project focuses on areas like Kongsfjorden, where glaciers have shown substantial changes.
Calving, where ice chunks detach from the end of a glacier, significantly contributes to sea-level rise and increases the risks faced by coastal areas worldwide. Monitoring these Arctic processes is vital for predicting potential future impacts on global sea levels.
A recent phase of the Space for Shore project - conducted by I-SEA in France and NORCE in Norway - utilized more than a thousand images from Sentinel-1 to closely observe changes in Svalbard's coastal glaciers. This analysis, spanning 2015 to 2023, enabled scientists to map glacier front positions and gauge calving activity during the summer months, when such processes peak.
Sentinel-1, a part of the EU's Copernicus program, employs synthetic aperture radar (SAR) technology to provide consistent, high-resolution data even under the Arctic's harsh conditions, ensuring uninterrupted monitoring throughout the year.
One of the main outcomes of this research is the yearly mapping of glacier front positions. By studying imagery collected between July and September, researchers identified summer glacier front lines - areas where glacier extent remains stable 95% of the time during this period.
Additionally, the radar data helped detect the presence of floating icebergs and smaller ice fragments known as growlers. This detection has been used as a proxy for summer calving intensity: an increase in the presence of icebergs and growlers signals more active calving and faster glacier retreat, which are crucial for assessing a glacier's stability and health.
In Kongsfjorden, glaciers such as Kronebreen and Kongsvegen have exhibited significant shifts. Daily Sentinel-1 images allowed for the classification of these areas into glacier, iceberg, and growler zones over multiple summers from 2015 to 2023.
Jorg Haarpaintner from NORCE noted, "Instead of a snapshot of a glacier front position, the Sentinel-1 method provides a statistically defined composite of the summer glacier front positions and calving intensities, revealing the dynamic interactions between ice and ocean over time."
Manon Tranchand, the project's lead researcher, added, "This analysis gives us a clear picture of current changes in Arctic glaciers, and they're crucial for predicting the future impacts of climate change on these sensitive regions."
"Without the consistent, high-resolution data from Sentinel-1, monitoring these dynamic ice-ocean interactions wouldn't be possible. Ongoing warming is likely to accelerate ice loss, and our data show how that could contribute to global sea-level rise. Sentinel-1's capabilities allow us to capture these shifts with unprecedented accuracy," Tranchand explained.
Looking forward, the launch of Sentinel-1C next month is set to enhance the Sentinel-1 mission's capacity. This new satellite will offer improved radar imaging capabilities and ensure continuity in critical climate monitoring. Sentinel-1C's advanced technology will bolster data collection on glacier front movements, calving rates, and ice-ocean interactions, even in the Arctic's extreme conditions.
Related Links
Observing the Earth at ESA
Beyond the Ice Age
| Subscribe Free To Our Daily Newsletters |
| Subscribe Free To Our Daily Newsletters |
