A Practical Guide to Glacial Sediments, 2nd edition

The first edition of “A Practical Guide to the study of Glacial Sediments” (Edited by David Evans and Doug Benn) was an essential handbook to all students of glacial geology. It has helped countless undergraduate and MSc dissertation students, and my well-thumbed copy has come with me every time I go into the field.

It is therefore a delight to see the second edition, published in 2021, with numerous updates and full colour.

Practical Guide to the Study of Glacial Sediments, 2nd edition

The second edition is published by the QRA and is available to purchase for £20 (inc. p&p) from the QRA website. QRA members get a discount! See the flyer below for details of the chapters and content.

This comprehensive book promises to be absolutely essential to anyone undertaking practical work with glacial sedimentology, ranging from sediment description and logging, particle size, clast form, shape and orientation in glacial sediments, thin-section analysis of glacial sediments, and till geochemistry, particle lithology and mineral properties.

Each chapter contains detailed instructions and recipes, accompanied by full colour images. Recommend it to your library!

What is the ice volume of Thwaites Glacier?

Thwaites Glacier in West Antarctica is currently the focus of a major scientific campaign. Why is Thwaites Glacier of so much interest, however? How much ice is there, and how much would sea levels rise if it all melted?

Thwaites Glacier is roughly the size of UK (176 x103 km2). The glacier terminus is nearly 120 km wide, and the bed of the glacier reaches to >1000 m below sea level. Pine Island Glacier and Thwaites Glacier together account for 3% of grounded ice-sheet area, but they receive 7% of Antarctica’s snowfall1.

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Choosing the future of Antarctica

In a new article in the journal Nature, Stephen Rintoul and colleagues present two very different visions of Antarctica’s future, from the perspective of an observer looking back from 2070. In one vision, humanity continues to exploit Earth’s natural resources (such as fossils fuels) and does little to protect the environment, and in the other, there is a global movement towards conservation. The article shows how Antarctica will change over the next 50 years, should either of these two situations occur.

Post by Jacob Bendle. Continue reading

Mass balance of the Antarctic ice sheet from 1992 to 2017

A new paper with a whole host of authors has just been published in Nature (IMBIE Team, 2018). It provides a new estimate of mass balance of the entire Antarctic Ice Sheet over the last 25 years, the longest and most thorough estimate of this to date.

This article argues that the Antarctic Peninsula, the smallest ice sheet in Antarctica, has lost an average of 20 Gigatonnes (Gt) of ice per year over the 25 year study. This increased during the study and especially since the year 2000.  The West Antarctic Ice Sheet lost 53±29 Gt yr-1 from 1992-1997, but this accelerated to 159±26 Gt yr-1 from 2012-2017. The East Antarctic Ice Sheet is more stable, with small gains (with large errors) over the study period. Continue reading

The Larsen C Ice Shelf growing rift

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.

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Antarctic Peninsula has strong sensitivity to surface warming

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[4]. Glaciers in the region are accelerating, in response to frontal thinning and recession[5]. In addition, ice shelves are collapsing[6], glacier fronts are retreating[7]. 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

Just published: most comprehensive review ever of the glaciation of Antartica

A major new review of the last glaciation of the entire Antarctic Ice Sheet has just been published by Quaternary Science ReviewsThe 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.

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Is the West Antarctic Ice Sheet collapsing?

Marine ice sheet instability

The West Antarctic Ice Sheet (WAIS) is the world’s most vulnerable ice sheet. This is because it is grounded below sea level, and marine ice sheets such as these are susceptible to rapid melting at their base. Fast-flowing ice streams draining the WAIS (Pine Island Glacier and Thwaites Glacier in particular) into the Amundsen Sea have a grounding line on a reverse bed slope, becoming deeper inland. Recession of the grounding line means that the ice stream is grounded in deeper water, with a greater ice thickness. Stable grounding lines cannot be established on these reverse bed slopes1, because ice thickness is a key factor in controlling ice flux across the grounding line. Thicker ice in deeper water drives increased calving, increased ice discharge, and further grounding-line recession in a positive feedback loop2, 3.  This process is called Marine Ice Sheet Instability4.

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Analysis of www.AntarcticGlaciers.org as a tool for online science communication

Davies, B.J., and Glasser, N.F., 2014. Analysis of www.AntarcticGlaciers.org as a tool for online science communication. Journal of Glaciology 60(220), 399-406.

Download the preprint: Davies_et_al_2014_preprint.

The following is a shorter, simpler version of the published paper.

Science communication for the time-limited academic

Academic research into climate change is driven by pressing human concerns. Because climate change has the potential to seriously affect our society, the effective communication of this research is increasingly important1. As such, increasing numbers of academics and researchers are taking part in public engagement2-4. But a key question is,

How can time-limited academics, who work in full-time positions, implement effective outreach strategies with limited budgets?

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