Image of the Week

Image of the Week — What’s up with the sea-ice leads?

Sophie Berger November 13, 2015

Two polarimetric SAR images Artctic Sea Ice. The colours reflect the different polarimetric channels of the SAR (red = VV, green = HV and blue = HH). Credit: Jakob Grahn.

This illustration shows two Synthetic Aperture Radar (SAR) images taken over sea ice in the Arctic Ocean. Both images are polarimetric and the different colours reflect the different polarimetric channels of the SAR (red = VV, green = HV and blue = HH). The two images are from the two satellites “ALOS-2” and “RADARSAT-2”. These are equipped with radars that operate at wavel ...[Read More]

Image of the Week: Greenland Glacier Seen from a Drone

Nanna B. Karlsson November 5, 2015

UAV on its way back from a mission with Store Glacier, West Greenland, in the background. Credit: Johnny Ryan

The use of drones or Unmanned Aerial Vehicles (UAVs) is one of the most exciting development in glaciology in recent years. The picture was taken during fieldwork conducted in the summer of 2014 by Johnny Ryan and colleague Nick Toberg. The aim was to survey Store Glacier once a day using a fixed-wing UAV, that was equipped with a digital camera, which took photos every two seconds during its dang ...[Read More]

Image of Week: Inside the Greenland Ice Sheet

Nanna B. Karlsson October 23, 2015

Cross-section of the age of the Greenland Ice Sheet from radar data. Credit: NASA's Scientific Visualization Studio and MacGregor et al., 2015.

The image shows a cross section of the Greenland Ice Sheet, where a recent study by MacGregor et al. have mapped the layers imaged by radar. Thanks to ice core measurements the age of the layers have been determined, and in the image the layers from the Holocene period (the past 11.700 years) are shown in green. The ice formed during the last ice age, that spanned 11.700 to 115.000 years ago are c ...[Read More]

Image of the Week: Under a Glacier

Nanna B. Karlsson October 16, 2015

Under the Hochjochferner glacier. Credit: Ilkka Matero.

What is happening under a glacier? This is a difficult questions to answer as accessing the glacier bed is usually not that easy. Here, we are getting a rare glimpse of the different processes and materials that are often found at the ice-bed interface. The photograph shows both sediments and hard rock, clear ice and dirty ice, and of course flowing water. No wonder these processes are complicated ...[Read More]

Image of the Week: Antarctic ice-shelf thickness

Sophie Berger October 9, 2015

Thickness of the Antarctic ice shelves. Credit: M. Depoorter

Thickness of floating ice shelves in Antarctica. Ice thickness is greatest close to the grounding line where it can reach 1000 meters or more (red). Away from the grounding line, the ice rapidly thins to reach a few hundreds of meters at the calving front. Ice thickness varies greatly from one ice shelf to another. Within ice shelves, “streams of ice” can be spotted originating from in ...[Read More]

Image of the Week : SAFIRE team getting ready to drill in Greenland

Sophie Berger October 2, 2015

The SAFIRE team sets up the drilling device on the Store Glacier, Western Greenland. Credit : T.J. Young

How do you get a hot water drill onto an ice sheet? The Subglacial Access and Fast Ice Research Experiment (SAFIRE) uses a hot water drill to directly access and observe the physical and geothermal properties where the ice meets rock or sediment at the glacier-bed interface. Here, SAFIRE principal investigator Bryn Hubbard and post-doc Sam Doyle help fly in the drill spool at the start of the Summ ...[Read More]

Image of the week : formation of an ice rise

Sophie Berger September 25, 2015

Deglaciation and formation of an ice rise with the ice-sheet model BISICLES. The simulation starts with an ice sheet in steady state that overrides a topographic high in the bed, close to the calving front. The sea level is then forced to rise steadily with 1 cm per year during 15 thousand years, and the simulation goes on until the ice sheet reaches steady state. The animation below shows that t ...[Read More]

Image of the Week: Hochjochferner

Nanna B. Karlsson September 18, 2015

The margin at Hochjochferner in the fog. Credit: N. B. Karlsson.

The margin of the glacier “Hochjochferner” on the border between Austria and Italy. This glacier has been monitored with an Automatic Weather Station for several years by the Institute for Marine and Atmospheric research in Utrecth, NL.It is also the destination of the field trip that takes place during the annual Karthaus summer school in ice and climate. Here, students are exploring ...[Read More]

Image of the Week: GISP II Borehole

Nanna B. Karlsson September 11, 2015

The GISP II (Greenland Ice Sheet Project Two) borehole at Summit Station, Greenland. Credit: N. B. Karlsson

Climate records from ice cores have helped scientists understand the past changes in climate.The GISP II (Greenland Ice Sheet Project Two) ice core was more than 3km long and was drilled during a five year period in the 1990s. After the drilling ended the casing of the borehole was extended above the surface, so that the borehole can still be accessed for remeasurements of, for example, temperatur ...[Read More]

Image of the Week: Greenland Ice Streams

Nanna B. Karlsson September 4, 2015

Credit: Copernicus data (2015)/ESA/Enveo

This image is from the west coast of Greenland and it shows several glaciers flowing towards the sea (upper part of the image), transporting ice into the ocean. The colours show the velocity of the ice. As the ice gets nearer to the coast it speeds up reaching speeds over 15m/day. The velocities were calculated using two Sentinel-1A radar scans from 3 and 15 January 2015. You can download a high r ...[Read More]