EGU Guest blogger

Image of the week – Our salty seas and how this affects sea ice growth

Chris Horvat August 5, 2016

Lines of constant density for sea water . Black lines show lines of constant density as a function of temperature (y-axis) and salinity (x-axis). The dashed black line indicates, for a given salinity, the temperature at which the water will freeze. Figure adapted from Timmermans and Jayne (2016) - with permission.

Earth’s oceans are not simply just water, they are a complicated multi-component fluid consisting of water and dissolved salts (ask anyone who has tried to drink it!). The existence of these salts has a significant impact on global ocean circulation. Nowhere is this more significant than in the polar oceans where it is one of the key factors influencing sea ice formation. In this week’s imag ...[Read More]

Image of the Week — Looking for ice inside a volcano !

Tommaso Santagata July 29, 2016

A phase of the laser scanning survey of the southernmost ice mass in Europe: the Ice Cave, Mount Etna,. [Credit: Alessio Romeo – Inside The Glaciers Project]

Who would think that one of the world’s most active volcano shelters the southernmost persistent ice mass in Europe!? Yes, you can find ice inside Mount Etna! Located at an altitude of about 2,040 m above sea level, the Ice Cave (Grotta del Gelo) is well known among Mt Etna’s volcanic caves due to the presence of columns of ice on its walls and floor which occupy about the 30% of the ...[Read More]

Fieldwork at 5,000 meters in altitude

David Rounce July 28, 2016

Field Site, Imja Lake, in November 2015 [Credit: D. Rounce]

Imja Lake is one of the largest glacial lakes in the Nepal Himalaya and has received a great deal of attention in the last couple decades due to the potential for a glacial lake outburst flood. In response to these concerns, the UNDP has funded a project that is currently lowering the level of the lake by 3 m to reduce the flood hazard. The aim of our research efforts is to understand how quickly ...[Read More]

Image of the Week – How ocean tides affect ice flow

Teresa Kyrke-Smith July 8, 2016

(a) Shaded relief map of Rutford Ice Stream (West Antarctica) and surrounding area. Red box indicates the region shown in b. (b) Horizontal velocity where colors indicate speed, arrows show flow direction, and grayscale background is horizontal speed from Rignot et al. (2011). (c) Detrended along-flow displacements measured with GPS stations beginning December 2003. Locations of stations are indicated in (b). ( Credit : Brent Minchew )

Ice streams discharge approximately 90% of the Antarctic ice onto ice shelves , and ultimately into the sea into the sea (Bamber et al., 2000; Rignot et al., 2011). Whilst flow-speed changes on annual timescales are frequently discussed, we consider here what happens on much shorter timescales! Previous studies have shown that ice streams can respond to ocean tides at distances up to 100km inland ...[Read More]

Ice on fire at the Royal Society Summer Science Exhibition

Thorbjörg Águstsdóttir July 6, 2016

In 2010 thick ash poured from Iceland's Eyjafjallajökull volcano after an explosive eruption. Find out more about why this happened at the Explosive Earth Exhibit at this weeks Royal Society Summer Science Exhibition. Photo Credit: Eyjólfur Magnússon

The Royal Society Summer Science Exhibition (RSSSE) is a free public event 4-10th July 2016 in London. This is a yearly event that is made up of 22 exhibits, selected in a competitive process, featuring cutting edge science and research undertaken right now across the UK. The scientists will be on their stands ready to share discoveries, show you amazing technologies and with hands-on interactive ...[Read More]

Image of The Week – A Game of Drones (Part 1: A Debris-Covered Glacier)

Matt Westoby July 1, 2016

Figure 1: Down-glacier view of debris-covered Miage Glacier, Italy, taken from a low-altitude lightweight UAV in June 2016 (Credit: M. Westoby). As the summer progresses, the melting of winter snow cover prompts the development of a surface drainage network, characterised as a network of streams and ponds, which are concentrated in intermoraine troughs and drain into open crevasses or moulins. Snowmelt in this area will eventually reveal a glacier surface covered by a continuous mantle of supraglacial debris, comprised predominantly of mica-schist

What are debris-covered glaciers? Many alpine glaciers are covered with a layer of surface debris (rock and sediment), which is sourced primarily from glacier headwalls and valley flanks. So-called ‘debris-covered glaciers’ are found in most glacierized regions, with concentrations in the European Alps, the Caucasus, Hindu-Kush-Himalaya, Karakoram and Tien Shan, the Andes, and Alaska and the weste ...[Read More]

Image of the Week – Canyons Under The Greenland Ice Sheet!

Michael Cooper June 24, 2016

Figure 1: The calculated drainage network for southern Greenland (interpreted from airbourne ice penetrating radar data). It shows an extensive flow network of channels beneath the ice. Which can be interpreted as a possible configuration for water flow pre-glacially, as well as in an ice-free future. The main channel within the catchment area of Jakobshavn Isbræ is marked by the red line. Bed elevation (between 300 and 1300 m above sea level (asl)) is also shown. Inset: location of study area within Greenland.

The Greenland Ice Sheet contains enough water to raise sea level by 7.36 meters (Bamber, et. al. 2013) and much of this moves from the interior of the continent into the oceans via Jakobshavn Isbræ – Greenland’s fastest flowing outlet glacier. An ancient river basin hidden beneath the Greenland Ice Sheet, discovered by researchers at the University of Bristol, may help explain the loca ...[Read More]

Marine Ice Sheet Instability “For Dummies”

David Docquier June 22, 2016

MISI is a term that is often thrown into dicussions and papers which talk about the contribution of Antarctica to sea-level rise but what does it actually mean and why do we care about it? MISI stands for Marine Ice Sheet Instability. In this article, we are going to attempt to explain this term to you and also show you why it is so important. Background The Antarctic Ice Sheet represents the larg ...[Read More]

Image of The Week – Ballooning on the Ice

Nanna B. Karlsson June 17, 2016

One man and his balloon. Field leader Prof. J. P. Steffensen (Centre for Ice and Climate, University of Copenhagen) in front of one of the balloons used in camp. Credit: S. Kipfstuhl.

A curious experiment is taking place in Greenland. An experiment involving very large balloons and – of course – a lot of snow. Read on to discover why balloons are an environmentally friendly tool when constructing an ice core drill camp. Last year, a small team traversed 400km from northwest Greenland to the EastGRIP site (read more about the traverse here). This year another strenuous task is w ...[Read More]

Image of the week — The warming effect of the decline of Arctic Sea Ice

Chris Horvat June 10, 2016

Decreasing sea ice and its effect on the albedo in the Arctic (credit: I. Eisenman, K. Pistone, V. Ramanathan, and NASA/GSFC Scientific Visualization Studio)

One of the most dramatic signals of Earth’s recent warming has been the precipitous decline of the Arctic sea ice. While the sea-ice decline is in response to warming ocean and atmosphere, it also has an important feed-back on the climate itself. Solar radiation and albedo Earth’s main energy source is solar radiation. This solar radiation is either absorbed in the atmosphere or at the ...[Read More]