Glaciers Seen From Space via WIRED | Glaciers on Mars
Our friends from Wired Science recently shared these amazing images of glaciers all over the world. We can read that the definition of glacier is a perennial mass of ice which moves over land. A glacier forms in locations where the mass accumulation of snow and ice exceeds ablation over many years. As glaciers are among the most exciting features on Earth, Wired Science has dedicated this review to some of the most beautiful glaciers worldwide, let’s take a look:
Above is Heiltskuk Ice Field, British Columbia. Covering nearly 1,400 square miles, the vast Heiltskuk Ice Field lies in the southern Coast Mountains of British Columbia. Taken by an astronaut on the International Space Station, this photo captures the snow-covered mountain slopes as well as several of the ice field’s valley glaciers, which are wide swaths of slowly flowing ice and debris.
From the wiki: Glaciers form where the accumulation of snow and ice exceeds ablation. As the snow and ice thicken, they reach a point where they begin to move, due to a combination of the surface slope and the pressure of the overlying snow and ice. On steeper slopes this can occur with as little as 50 feet of snow-ice. The snow which forms temperate glaciers is subject to repeated freezing and thawing, which changes it into a form of granular ice called firn. Under the pressure of the layers of ice and snow above it, this granular ice fuses into denser and denser firn. Over a period of years, layers of firn undergo further compaction and become glacial ice. Glacier ice has a slightly reduced density from ice formed from the direct freezing of water. The air between snowflakes becomes trapped and creates air bubbles between the ice crystals.
Above: Western Greenland Valley. This natural-color image captured in August shows several small glaciers spilling into a mostly dry valley in western Greenland that itself was formed by a glacier in the past.
Above is a Retreat of the Helheim Glacier, Greenland. This photograph, captured by NASA’s Terra satellite in 2003, shows the calving edge of the Helheim Glacier in Greenland. Comparing similar images from 2001 and 2005 reveals that the solid portion of the glacier has been shrinking rapidly.
Above: Upsala Glacier, Patagonian Argentina. The third largest glacier of the Southern Patagonian Ice Field at around 300 square miles and ends in Lake Argentino.
Above the Bering Glacier, Alaska, combined with the ice field that feeds it, is the largest glacier in North America at 2,000 square miles, as well as the longest at 118 miles. This glacier has retreated around 7.5 miles and thinned by several hundred yards over the last century, though it is still around 2,500 feet thick in some places.
Over geologic time, glaciers have ebbed and flowed with natural climate cycles. Today, the world’s glaciers are in retreat, sped up by relatively rapid warming of the globe. In the Glacier National Park in Montana, only 26 named glaciers remain out of the 150 known in 1850. They are predicted to be completely gone by 2030 if current warming continues at the same rate.
So, let’s try to avoid climate change and start taking care of our glaciers!
What about glaciers on Mars? Surprisingly, while researching to write this post, we found some amazing images at the wiki that we wanted to share:
In Mars: Gullies in a crater in Eridania, north of the large crater Kepler.
Vast Martian glaciers of water ice under protective blankets of rocky debris persist today at much lower latitudes than any ice previously identified on Mars. We can read at geology.com that “the gently sloping aprons of material around taller features have puzzled scientists since NASA’s Viking orbiters revealed them in the 1970s. One theory contended they were flows of rocky debris lubricated by a little ice. The features reminded Holt of massive ice glaciers detected under rocky coverings in Antarctica, where he has extensive experience using airborne geophysical instruments such as radar to study Antarctic ice sheets.”