Antarctic Peninsula ice shelves | Ice shelf collapse on the Antarctic Peninsula | Rifting on Larsen C | Impact of calving the large iceberg | Sea level rise following ice-shelf collapse | References | Comments |
Antarctic Peninsula ice shelves
The Antarctic Peninsula is fringed by floating ice shelves. They are floating extensions of the glaciers on land, and receive mass by snowfall and marine freeze-on. They lose mass by melting at their base and by calving icebergs. Larsen C Ice Shelf, the largest ice shelf on the Antarctic Peninsula, is currently being closely watched. Following a series of high-profile ice-shelf collapse events on the Antarctic Peninsula over the last few decades, all eyes are watching Larsen C and wondering when, and if, it will collapse.
A growing rift on Larsen C Ice Shelf
Those concerns are growing more acute as a large rift on Larsen C Ice Shelf is growing rapidly, threatening to soon calve a huge iceberg, equivalent to losing 10% of the area of the ice shelf. This could destabilise the ice shelf, making it more susceptible to a total collapse.
Larsen C rift animation uses #Sentinel1 InSAR to illustrate recent jumps in rift progression. From Prof. Adrian Luckman.
Around 27,000 years ago, ice sheets reached their maximum across the world, after a period of global cooling caused by variations in the Earth’s orbit around the sun. There was a massive ice sheet in North America (the Laurentide Ice Sheet)[1, 2], a large Eurasian Ice Sheet covering Britain, Ireland and Scandinavia as well as northern Europe, an ice sheet in Antarctica, the Himalaya and Patagonia[5, 6]. Land near the ice sheets that escaped glaciation was cold, with tundra vegetation. Northern Europe was frequented by ice-age animals such as mammoth, reindeer and arctic hare. There was a landbridge betweeb Britain and Europe, and animals could walk freely across it. Numerous human artefacts from this time are scattered across the landscape.
Ice sheets at the Last Glacial Maximum worldwide, around 27,000 to 21,000 years ago. From data in Ehlers et al., 2011.
Guest post by Dr Jonathan Day, Department of Meteorology, University of Reading
What is going on with the Antarctic sea ice?
March 2017 was an interesting month for sea ice. Both northern and southern hemispheres experienced record breaking low extents for the time of year. The extent of Arctic sea ice reached the maximum area of its seasonal cycle on March 7th coming in at 14.42 million km2. This was a fraction below the previous record, set in 2015 and is in line with what we expect to see in a warming climate. Meanwhile the other side of the planet Antarctic sea ice continues to confound expectations. Continue reading
There are a number of web and news articles around surrounding the question of whether or not we will enter another ice age. Many of these questions arise from the idea that a collapse or significant melting of the Greenland Ice Sheet will produce enough fresh water to shut down the global thermohaline circulation, dropping us into a new ice age in the next 10,000 years.
Last autumn, I had two great pieces of news. The first was that I had been awarded a small grant to conduct three weeks’ fieldwork in Chile. The second was that I was pregnant.
I was obviously immediately interested in other people’s stories about fieldwork while pregnant. I could find only a few blogs about it on the internet, so I thought I would write about my own experiences of fieldwork while pregnant.
I’m delighted to have been awarded a £3000 Software Sustainability Fellowship by the Software Sustainability Institute. This promises to be a great collaboration and I’m excited to be working with the SSI to promote sustainable software practices.
I plan to use the Fellowship funds to host a Software Carpentry Workshop at RHUL, and to attend a conference where I’ll promote sustainable software practices, including promoting open code.
For more information, please see the Fellowship Programme over at the SSI. You can read the profiles of the current and former Fellows here.
As part of Earth Week 2014, the Geological Society ran a competition to find the UK’s top 100 Geosites. The competition can be followed on Twitter with the #100Geosites hashtag.
The results were published as an online clickable map and the results were highlighted on the BBC. This map is ideal for choosing your next UK holiday destination!
Not to be outdone, the Quaternary Research Association has highlighted, as part of its 50th Anniversary celebrations, the UK’s top 50 Quaternary sites. Again, this is presented as an online clickable map. Continue reading
The Antarctic Peninsula is warming very rapidly, about six times the global average[1-3]. There has been a 95% increase in positive degree day sums since 1948. Glaciers in the region are accelerating, in response to frontal thinning and recession. In addition, ice shelves are collapsing, glacier fronts are retreating. The causes for much of these changes has often been attributed to ocean forcing, with warm ocean waters melting these glaciers from below[8-11]. However, while ocean forcing may dominate further south, such as at Pine Island Glacier, a few recent papers have highlighted the importance of surface processes and surface melt induced by warmer surface air temperatures and longer melt seasons, specifically on the Antarctic Peninsula. Continue reading
Next week is Freshers’ Week and across the country, universities will be welcoming enthusiastic students into their departments. These students will be equipped with notebooks, lever-arch files, reading lists and text books.
But there is more that you can do to prepare for university. Here is my own recommended reading list. These are popular science books that I love. You won’t find them on your termly reading list, but they are well written by science advocates, and they may just remind you of your love of science after a particularly dull lecture. Further, they will broaden your horizons, going beyond the scope of your lecturer course and tying together many different concepts.
A major new review of the last glaciation of the entire Antarctic Ice Sheet has just been published by Quaternary Science Reviews. The special issue of the journal includes a suite of review papers involving an international team of experts regarding the last glaciation of the entire Antarctic Ice Sheet. This review, which comprises six review papers and an overview paper in a special issue of Quaternary Science Reviews, is now complete and all papers have been accepted for publication. As this is the most important, up to date and inclusive review ever to be attempted for the glaciation and recession of the Antarctic Ice Sheet, it represents a major step forward in our understanding of palaeo ice-sheet dynamics, provides a benchmark against which future research needs can be identified and highlighted, and provides a compilation of data unlike anything seen before, which can be used to test and calibrate numerical ice-sheet models.