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| Titel |
New insights on the subglacial Recovery Lakes from airborne radar data |
| VerfasserIn |
Anja Diez, Kenichi Matsuoka, Jack Kohler, Tom A. Jordan, Fausto Ferraccioli, Hugh Corr, Arne V. Olesen, Rene Forsberg |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250150101
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| Publikation (Nr.) |
 EGU/EGU2017-14528.pdf |
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| Zusammenfassung |
| The Recovery Region, consisting of Recovery, Bailey and Slessor Glaciers, discharges 5 % of
the total fresh water outflow of Antarctica into the Filchner Ice Shelf. The ice shelf is subject
to extensive sub-shelf melting under ongoing climate change. Several active subglacial lakes
have been identified in the Recovery Region from satellite data, indicating the existence of a
dynamic subglacial hydrologic system. Our recent analysis of airborne radar data
shows topographic as well as hydrologic controls on fast ice flow in this region.
Here, we present new insights on the “giant subglacial Recovery Lakes” located
in the flat basal basin upstream of Recovery Glacier. These four subglacial lakes
were inferred using MODIS satellite imagery, visible due to their anomalously flat
surface and estimated to have a total area of 13300 km2. A following ground based
radar survey found that Lake A and B were not water filled during the survey and
suggest they might have drained recently. We conducted two extensive airborne
radar surveys over the Recovery Lakes. The 2013 survey with 20 km line spacing
concentrated on Lake A and B. A more detailed survey in 2015 was done over
Lake A, B, and C. The 2015 survey includes a repeat of a 2013 flight across Lake
B. From the two data sets, we derive ice thickness and bed elevation, refining the
bed topography map in the region. The bed topography map shows a connection
between the area south of Lake A and B to the deep Recovery trough. Using bed
elevation data and bed return power no distinct giant lakes can be identified but we do
find indication of water in the region of Lake A and B in the form of smaller lakes
and larger “swampy” areas. Differences in our two data sets show that a smaller
lake, present in 2013 in the center of Lake A drained by 2015. We suggest that
the Recovery Lakes are not big lakes comparable to Lake Vostok but are instead
smaller, active water bodies connected by areas of saturated sediments or “swamps”. |
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