Mission: Thomas-Jakobshavn 01
Priority: Baseline
This is a repeat of 2009, 2010, 2011, 2012, 2013 and 2014 IceBridge missions. Its purpose is to re- survey the highest-priority lines of the historical ATM 10-km Jakobshavn grid, the main flowline of Jakobshavn. It also extends that grid with a broader array of ICESat ground tracks over the larger Jakobshavn basin. Renamed in 2015 in honor of Robert H. Thomas.
A promising forecast for this mission, with outflow across the Ilulissat region, made for an easy choice today. Because of the less promising forecast for this region later in the week, we opted to fly a longer mission that included two additional ICESat lines upstream of the main set flown today. We flew along the fjord west of Kangerlussuaq for an additional couple of minutes to repeat the snow radar calibration performed yesterday. We were greeted with clear skies across Jakobshavn Isbræ, where we surveyed numerous ATM and ICESat lines, along with the central flowline. No significant clouds were encountered, and laser altimetry surveying was good all day. We spotted a couple of piles of rubble that we suspected to be due to drained subglacial lakes. We passed by a snow-covered Swiss Camp. No instrument issues were reported, and altimetry coverage was 100%. A ramp pass at 2000 ft was performed.
Attached images:
1. Map of today’s mission (John Sonntag / NASA)
2. Snow-filled crevasses near Jakobshavn Isbræ, under P-3 shadow (Joe MacGregor / NASA)
3. The complex southern shear margin of Jakobshavn Isbræ, with an ambiguous grounded-to-floating transition (Joe MacGregor / NASA)
4. The ice prow that separates the main trunk of Jakobshavn Isbræ from the now-stagnant outlet glacier to the north, also demarcating the iceberg supply (Joe MacGregor / NASA)
5. Ice rubble possibly due to drainage of a subglacial lake (Joe MacGregor / NASA)
6. Iceberg in Ilulissat fjord (Joe MacGregor / NASA)
7. Snow-filled bedrock lineations (Joe MacGregor / NASA)
8. Snaking sastrugi (Joe MacGregor / NASA)