EPOW - Ecology Picture of the Week

Ice cap over southern interior Greenland

An ice cap is a broad, moundlike mass of glacial ice that covers mountain valleys, ridges, and peaks.  It spreads under its own weight into periglacial flows and frozen rivers that pour out from the margins.  The picture above shows a local ice cap.  In central Greenland, ice caps coalesce into massive ice sheets that average about 2,300 meters (7,500 feet) thick, covering 1.74 million square kilometers (about 672,000 square miles).  (Only 18 countries are larger than this!)

Ice caps and glaciers are not completely "frozen" but flow and move as snow accumulates above and eventually melts far below.  Watching the fate of ice caps, ice sheets, ice shelfs, ice bergs, and glaciers can serve as early warning signals of climate change, although short-term warming trends may confuse the interpretation.  However, NASA has recently reported that the Greenland ice cap is melting.  The implications of rapid global climate changes ("global warming") for maintaining native, healthy ecosystems throughout the world are staggering and can extend even to tropical rainforests.  

The Arctic and sub-Arctic ice of Earth also may have much to teach us about life elsewhere ... particularly Europa, an intriguing moon of Jupiter.

Here on Earth, what might live on glaciers and ice caps?  We will explore some glacial life forms in an upcoming installment of Ecology Picture of the Week.  Stay tuned, and please buckle your seatbelt.

Information:  Update on Greenland's accelerating glaciers ... Greenland's fastest glacier doubles speed ... Retreating glaciers worrying Greenlanders ... Greenland ice cap thickens slightly despite global warming ...