Whillans Ice Stream
Whillans Ice Stream (Coordinates: ) is a glaciological feature of the West Antarctic Ice Sheet, formerly known as Ice Stream B, renamed in 2001 in honor of Ohio State University glaciologist Dr. Ian Whillans.
Whillans Ice Stream is one of about a half-dozen large, fast-moving rivers of ice pouring from the West Antarctic Ice Sheet into the Ross Ice Shelf. The ice stream is the subject of different glaciological studies, one of which is looking at subglacial lakes that researchers believe may be speeding the movement of the ice as they periodically fill and drain.
Other researchers, also funded by the National Science Foundation, reported in the June 5, 2008 issue of the journal Nature that from seismological and GPS data they discovered the Whillans Ice Stream releases two bursts of seismic waves every day, each one equivalent to a magnitude 7 earthquake. The data show that the river of ice moves about a half-meter within approximately 30 minutes, remains still for 12 hours, then moves another half-meter, seemingly in phase with gravitational tides. Each time it moves, it emits seismic waves that are recorded at seismographs around Antarctica, and even as far away as Australia, a distance of more than 6,400 kilometers.
In 2007 an active subglacial water system consisting of several interconnected subglacial lakes was discovered under Whillans Ice Stream using repeat-track data from the ICESat satellite (Fricker and others, 2007). One of these active lakes, subglacial Lake Whillans, is the subject of a major drilling program funded by National Science Foundation WISSARD which successfully reached the lake on January 28, 2013.
In January 2015, drilling near the grounding line revealed a colony of fish, crustaceans, and jellyfish inhabiting the dark, frigid waters below the ice shelf. Images taken with a remote camera showed fish 20 centimetres (7.9 in) and amphipods.
Notes and references
- "The Antarctic Sun: Subglacial Waterworks".
- Wiens, Douglas; Anandakrishnan, Winberry, King (2008). "Simultaneous teleseismic and geodetic observations of the stick-slip motion of an Antarctic ice stream". Nature 453: 770–774. doi:10.1038/nature06990.
- "The Antarctic Sun: Earthshaking Discovery".
- "Drill reaches Antarctica's under-ice Lake Whillans".
- Bizarre Antarctic fish lives below 2,500 feet of ice, Becky Oskin, Christian Science Monitor, 23 January 2015, accessed 26 January 2015