Image of the Week

Image of the Week – Satellite Measurements of Arctic Sea Ice

David Docquier September 16, 2016

The map above shows the region around Fram Strait that separates Greenland and Svalbard (Spreen et al., 2009) . The colours show the amount (volume flux) of sea ice that was moving from the Artic Basin and south in October/November 2006 as measured by satellites. The arrows show the direction of sea ice.

Sea ice is an important part of the Earth’s climate system. When sea ice forms, it releases heat and salt. When sea ice melts, it takes up heat and adds freshwater to the salty ocean water. It is also important for the exchange of energy between the atmosphere and the ocean surface, and for the ocean currents that transport warm and cold water from the equator to the poles and back. The main route ...[Read More]

Image of the Week – Yes, you’re looking at one of Peru’s most dangerous glacial lakes!

David Rounce September 9, 2016

Lake Palcacocha is one of Peru’s most dangerous glacial lakes due to the threat of an avalanche entering the lake and causing a glacial lake outburst flood. The siphons installed in 2011 lowered the level of the lake by 3-5 m in an attempt to reduce the flood hazard of the lake. [Credit: David Rounce]

As mountain glaciers melt and recede, they often leave behind large glacial lake that are contained by the glaciers’ old terminal moraines. These glacial lakes are found throughout the world and can pose a significant flood hazard to downstream communities and infrastructure. The image of this week focuses on Lake Palcacocha, a large glacial lake located in Peru’s Cordillera Blanca at an elevation ...[Read More]

Image of the Week – The Journey of a Snowflake

Clara Burgard September 2, 2016

Figure 1: Snowflakes viewed with a low temperature scanning electron microscope (SEM). [ Credit : Agricultural Research Service, United States Department of Agriculture via Wikimedia ]

You remember last winter, when everything was white and you had so much fun building a snowman with your friends? What you see on this image above, is what you would see, if you took a tiny tiny piece of your snowman and put it under a low-temperature scanning electron microscope (SEM). The colours are called “pseudo colours”, they are computer generated based on the number of electron ...[Read More]

Image of the Week — Where do people stay in the “coolest” place on earth?

Sophie Berger August 19, 2016

The 82 research stations in the Antarctic. The world map below shows which countries are operating a station in Antarctica. Source: COMNAP Antarctic Facilities (Updated February 2014) - [Credit: Sophie Berger]. Click here here to enlarge the image.

What word would you use to characterise the Antarctic ? White? Windy? Remote? Empty? Inhospitable? Wild? Preserved? While all of these are true it may surprise you to find out that the Antarctic is occupied by humans all year round with almost half of its 82 research stations operating 365.25 days a year! Just a few hours before the launch of the biennial Antarctic meeting held by the Science Comm ...[Read More]

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]

Image of the week – The winds of summer (and surface fluxes of winter)

Céline Heuzé July 22, 2016

Representation of the (a) summer and (b) winter oceanic circulation within the Adélie region, East Antarctica. MGT = Mertz Glacier Tongue (red dot on the Antarctica map); other acronyms indicate different water masses: Antarctic Surface Waters (AASW), Modified Circumpolar Deep Water (MCDW*), Dense Shelf Water (DSW) and Antarctic Bottom Water (AABW) explained below. [Credit: reprinted with permission from Snow et al. (2016, figure 4) ]. Click here here to enlarge the image.

Antarctica is separated from the deep Southern Ocean by a shallow continental shelf. Waters are exchanged between the deep ocean and the shallow shelf, forming the Antarctic cross-shelf circulation: Very dense waters leave the shelf as Antarctic Bottom Water (AABW) that will then flow at the bottom of all oceans. Meanwhile, relatively warm water from the Southern Ocean, Modified Circumpolar Deep W ...[Read More]

Image of the Week — Arctic porthole, Arctic portal

Sophie Berger July 15, 2016

Isfjorden, Svalbard, through the porthole of a boat, June 2012 [Credit: Dr Fabien Darrouzet (imaggeo )]

No need to be a superhero to momentarily escape your everyday life! For that you, can just rely on the EGU Cryosphere Blog, which cares for taking you on trips to all sorts of remote and cool places (OK, OK we have to admit that some of these places are indisputably cold 🙂). The picture of this week was taken through the porthole of a boat in the middle of Isfjorden, one of the largest fjord in Sv ...[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]

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]