This article, written by Charles W. Schmidt, a freelance writer
specializing in science, medicine and technology, appeared first
in Environmental Health Perspectives—the peer-reviewed, open
access journal of the National Institute of Environmental Health
Sciences. The article is a verbatim version of the original and
is not available for edits or additions by Encyclopedia of Earth
editors or authors. Companion articles on the same topic that
are editable may exist within the Encyclopedia of Earth. Out of
Equilibrium? The World's Changing Ice Cover In August 2010 an
iceberg four times the size of Manhattan broke off Greenland’s
northwestern coast and began drifting out to the sea. At nearly
100 square miles, this was the largest iceberg to appear in
Arctic waters since 1962 and a fresh indicator that Greenland’s
frozen landscape is undergoing significant changes.1 Originally
part of the much larger Petermann glacier, which flows down from
Greenland’s interior into a coastal fjord, the iceberg detached
for unkn