Saturday, April 23, 2016

Melting Land Ice Update -- Greenland and Gulf of Alaska

Scientists have discovered sub-glacial lakes deep in the ice of Greenland.
One lake, described in the journal Cryosphere, once held billions of gallons of water and emptied to form a giant crater – 2 km across and around 70 m deep – in just a few weeks.
Dr Howat and his colleagues detected the crater on a spot about 50 km inland from the southwest Greenland coast earlier in 2014.
“The fact that our lake appears to have been stable for at least several decades, and then drained in a matter of weeks – or less – after a few very hot summers, may signal a fundamental change happening in the ice sheet,” Dr Howat said.
In addition to adding to the increase in sea level:
The melting of Greenland’s glaciers has also added a large boost of freshwater to the North Atlantic which could alter ocean currents and the ocean’s ability to take up carbon dioxide.
 The alteration of the ocean current is likely to be to the Gulf Stream which keeps Europe relatively warm for its latitude, and as a result, ironically, this could bring a winter chill to Europe in the middle of the global warming.

Melting glaciers in Alaska are also having a dramatic effect on the Gulf of Alaska.
Incessant mountain rain, snow and melting glaciers in a comparatively small region of land that hugs the southern Alaska coast and empties fresh water into the Gulf of Alaska would create the sixth largest coastal river in the world if it emerged as a single stream, a recent study shows.

Since it’s broken into literally thousands of small drainages pouring off mountains that rise quickly from sea level over a short distance, the totality of this runoff has received less attention, scientists say. But research that’s more precise than ever before is making clear the magnitude and importance of the runoff, which can affect everything from marine life to global sea level.
The collective fresh water discharge of this region is more than four times greater than the mighty Yukon River of Alaska and Canada, and half again as much as the Mississippi River, which drains all or part of 31 states and a land mass more than six times as large.
“Freshwater runoff of this magnitude can influence marine biology, nearshore oceanographic studies of temperature and salinity, ocean currents, sea level and other issues,” said David Hill, lead author of the research and an associate professor in the College of Engineering at Oregon State University.