Residual heat from volcanic activity may be causing a river of ice to flow in Greenland, a new study indicates. Geologists have found that the region directly above a stream of relatively fast moving ice is thinner than a simple model of glacier change would predict. This observation, described in a report published today in the journal Science, may help researchers pin down the contribution ice sheets have made to sea level changes.
Glaciers are built up from layers of fused snow that spread out under their own weight as they accumulate, leaving a frozen record of their life history behind. Studying ice-penetrating radar images to piece together the ages of different layers in the Greenland sheet, researchers found that only significant melting could explain the thickness of an area resting above a lengthy ice flow. The old crust beneath this 600-square-kilometer region should melt about a few millimeters of ice each year; instead, up to 10 centimeters liquify. Although its true nature and duration are not clear, the hotspot is comparable in size and strength to the Yellowstone caldera, a place where the crust collapsed after a volcanic eruption. "The rates of melting are a surprise," lead author Mark Fahnestock says, "and the fact that it’s localized in the right place [to cause the ice flow]."
Ice sheets and flows are important stores and sources of water, he adds, so understanding where they come from should improve glaciologists’ understanding of glacier behavior and corresponding changes in sea level. In an accompanying article, geologist Christina Hulbe of Portland State University notes that water melting from the base of a glacier can alter the way it moves and stores energy. This unexpected new finding, she writes, "reminds us that basal melt water matters and that it may be important in places we never suspected."
JR Minkel | Scientific American
Wandering greenhouse gas
16.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Unique Insights into the Antarctic Ice Shelf System
14.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences