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2014). The Larsen B embayment is now RECENT EVOLUTION OF THE The startling outcome of synthesizing indi-
intermittently a new coastal polynya, LARSEN CRYOSPHERE vidual disciplinary studies is that the rapid-
whose seasonal opening is triggered and Remote sensing, in conjunction with the ity at which the area is changing now is not
maintained by the action of warm foehn automated multi-sensor stations, shows a documented in data from the Holocene, yet
winds. In this new state, the region has dramatic evolution of the remaining section is virtually universal in the recent changes
become an important component of the of the Larsen B Ice Shelf that suggests it is observed in precipitation records, sediment
overall western Weddell Sea marine eco- nearing an unstable state prone to disinte- accumulation rates, ecosystem changes,
system. Its seasonal primary production gration (Khazendar et al., 2015). MODIS isostatic uplift, and, of course, ice cover.
will enable both pelagic and benthic image series show increased bottom As dramatic change continues to charac-
habitat expansion. crevassing, and aerial photos as well as terize the Larsen region, potentially with
Redistribution of chemical-based and Landsat 8 images indicate both fine-scale additional breakup in the next warm year,
light-based biological production following surface fracturing and major new rifts in additional study will provide insight into
the ice-shelf breakup may have caused the the Scar Inlet ice. Loss of the A-54 iceberg the complex evolution of one of the most
demise of the extraordinary cold-seep eco- in February 2006 has led to instability in interesting regions on Earth in a funda-
system discovered in the newly exposed the Starbuck Glacier floating shelf front; mentally integrated way. Knowledge of
sub-ice-shelf area in 2005 (Domack et al., however, cooling climate conditions have how changes unfolded in the Larsen B
2005b; Niemann et al., 2009). Extensive led to the formation of multi-year fast ice in and adjacent areas will serve as a basis for
changes in the structure of benthic commu- the Larsen B embayment, which has been understanding what may occur in larger
nities have occurred in the years following present continuously since early 2012. This drainage basins that will warm in the
the shelf event, as previously absent phyto- fast ice appears to be inhibiting further coming years and whose changes may
detritus materials accumulate on the sea- calving of the Scar Inlet ice front. GPS have a greater effect far afield.
floor (Gutt et al., 2011). Lipid biomarkers in systems installed on the ice as part of the
surface sediments suggest that seasonal AMIGOS stations indicate that while the POSTSCRIPT
sea-ice diatoms are important contributors ice shelf accelerated at a rate of ~5% yr The LARISSA project was in many ways guided
−1
to this flux of organic matter (Shimizu, between 2010 and 2012, since the formation by the scientific vision of Eugene Domack, who
2016). The development of a new paleo‐ of the persistent fast ice in 2012, the shelf dedicated much of his life to studying Antarctica
and its connections to the rest of the world. Gene
productivity index in marine sediments has ceased to accelerate and instead exhib- passed away suddenly during the preparation of this
links ocean productivity measured as its an ~3% seasonal oscillation in flow manuscript. The remaining authors, like colleagues
DMSP (dimethyl sulfonopropionate) and speed, lagging the annual peak and trough around the world, mourn his passing.
MSA (methanesulfonic acid) measured in in air temperature by ~30 days. Given that
ice cores, within time scales of thousands the Scar Inlet ice is already structurally REFERENCES CITED
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