A very large crack is forming in the Larsen C Ice Shelf on the Antarctic Peninsula. The crack is up to 1,500 feet wide and will most likely generate one of the largest icebergs on record. Only 6.4 miles of ice are keeping the ice sheet from calving off an iceberg that is basically the size of Delaware. Researchers who have been studying the ice melt (Project MIDAS) estimate that although the exact timing of the calving event in unclear, it could occur easily within the next few months. In fact, scientists noted that the crack spread another approximately six miles during the second half of December 2016. From January 1st to January 19th, the crack expanded again, and now only 6.4 miles of unbroken ice remains. Once the calving event occurs, scientists are concerned that it will destabilize the Larsen C ice sheet to the point of its disintegration.
The current location of the rift on Larsen C, as of January 19, 2017. Labels highlight significant jumps. Tip positions are derived from Landsat (USGS) and Sentinel-1 InSAR (ESA) data. Background image blends BEDMAP2 Elevation (BAS) with MODIS MOA2009 Image mosaic (NSIDC). Other data from SCAR ADD and OSM (update on graphic from Freedman, based on Project MIDAS data).
British Antarctic Survey (BAS) recently captured the following video footage of the immense crack in the Larsen C Ice Shelf:
Dr. James Hansen (Director of Climate Science, Awareness and Solutions Program Earth Institute, Columbia University) and 18 co-authors just published an article – Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming could be dangerous – in the journal AtmosphericChemistry & Physics. Their article is significant because not only does it raise the issues of superstorms and sea level rise that are associated with human forcing of climate change, but their research also suggests that current climate models do not adequately gauge the effects of ice melt runoff from the Antarctic and Greenland ice sheets. The video embeded below is done by Dr. Hansen and his co-authors and is a good abstract of their recent research findings.
The Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) field team drilled through 800 m of ice and intersected Subglacial Lake Whillans on 28 January 2013 at 0500 h. The team sampled mud and water from the floor of the subglacial lake, making this the first time that clean whole samples have been recovered from an Antarctic subglacial lake. Water analyses will be made for dissolved minerals and living cells. Sediment cores taken from the lake bed should provide scientists with data on the lake’s formation history and microbial inhabitants.
The WISSARD project team is also looking at ice dynamics. Live Science posted a quote from Ross Powell of the University of Northern Illinois, one of WISSARD’s 13 principal investigators regarding ice dynamics. “Lake Whillans is just one of a few hundred interconnected lakes,” said Powell, “and radar observations have revealed that it fills and drains in a five-to-10-year cycle. We want to find out what causes these cycles. And knowing more about ice dynamics is important to better understand the effects global warming might have on the Antarctic continent. Thanks to WISSARD, we will be able for the first time to use real field data as input in our glacialogical models.”
DISCOVER Magazine has a science journalist, Douglas Fox, in Antarctica on assignment as the WISSARD Embedded Journalist. Read more of his experience with the project team at: DISCOVER.