Abstract
We present subannual observations (2009–2014) of a major West Antarctic glacier (Pine Island Glacier) and the neighboring ocean. Ongoing glacier retreat and accelerated ice flow were likely triggered a few decades ago by increased ocean-induced thinning, which may have initiated marine ice sheet instability. Following a subsequent 60% drop in ocean heat content from early 2012 to late 2013, ice flow slowed, but by < 4%, with flow recovering as the ocean warmed to prior temperatures. During this cold-ocean period, the evolving glacier-bed/ice shelf system was also in a geometry favorable to stabilization. However, despite a minor, temporary decrease in ice discharge, the basin-wide thinning signal did not change. Thus, as predicted by theory, once marine ice sheet instability is underway, a single transient high-amplitude ocean cooling has only a relatively minor effect on ice flow. The long-term effects of ocean temperature variability on ice flow, however, are not yet known.
Original language | English |
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Pages (from-to) | 10,817-10,825 |
Number of pages | 9 |
Journal | Geophysical Research Letters |
Volume | 43 |
Issue number | 20 |
Early online date | 12 Oct 2016 |
DOIs | |
Publication status | Published - 28 Oct 2016 |
Externally published | Yes |
Keywords
- glacier-ocean interactions
- ice dynamics
- ice shelves
- ice streams
- marine ice sheet instability