Disappearing Lakes

[Harry Hope]

http://www.newsweek.com/2011/01/01/lakes-disappearing-after-glacial-outburst-floods.html

1/1/11

Disappearing Lakes

Two and a half years ago, the Baker river in Chilean Patagonia suddenly tripled in size, causing a virtual river tsunami. In less than 48 hours, roads, bridges, and farms were severely damaged and dozens of livestock drowned. Residents were in disbelief. Jonathan Leidich, an American whose company regularly leads tourists on treks up to nearby glaciers, hiked to the Colonia Glacier at the eastern flank of the Northern Patagonian Ice Field and discovered the source of the mysterious flood: Lake Cachet 2 had vanished. This enormous, two-square-mile glacial lake had emptied its 200 million cubic meters of water in just a matter of hours. What happened? Glaciologists say it was yet another “glacial lake outburst flood,” or GLOF. An increasing rate of melting at the Colonia Glacier swelled the lake so much so that the resulting water pressure gradually forced the creation of a tunnel beneath the surface of the adjacent ice and drained the lake. Since Cachet 2 emptied in 2008, the lake has “disappeared” six more times.

Such GLOFs don’t necessarily arise because of climate change; indeed, some four decades ago a GLOF occurred on the Baker River. But a clear warming trend over the past decade has taken its toll on the world’s glaciers, and it is widely agreed that climate change is dramatically increasing the frequency and intensity of GLOFs. Last month, the United Nations Environment Programme (UNEP) released a report on mountain glaciers at the climate-change talks in Cancún, Mexico, stating that glaciers on Argentine and Chilean Patagonia are “losing mass faster and for longer than glaciers in other parts of the world.” “Accumulation of science shows us a clear general trend of melting glaciers linked to a warming climate,” said UNEP executive director Achim Steiner.

[Trajan]

1. Fascinating story ...

And only the beginning of these consequences, I suppose ...

Living in Portland, OR, we've learned the northwestern states were regularly deluged when Glacial Lake Missoula broke down between ice ages ... The wall of water, a half mile high, would rush to the sea, and would go on to eventually create the fertile Willamette Valley, a very arable and productive agricultural region ... Signs of it exist everywhere in Idaho, Washington and Oregon ...

In any case: That was part of the natural cycle, with a cause that had nothing to do with mankind ...