| REGION XII GLACIAL LAKE DISAPPEARS |
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| Written by Administrator | |
| Friday, 22 June 2007 | |
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Park rangers touring Bernardo O’Higgins National Park in Chile’s Region XII in late May were shocked to find that a five-acre glacial lake had disappeared. Just two months ago, rangers had seen the 100-foot-deep lake straddling the Témpanos Fjord. Scientists are baffled as to how the lake, located at the western tip of the Southern Patagonian Ice Field, dried up almost completely and the once plentiful river it fed slowed to a trickle. Park rangers found some of the large ice floes that used to float on top of the lake lying at the bottom of the fjord.“Locals have reported that the glacial lake had always existed, and through monthly patrols and photographic evidence it is clear the lake had remained relatively the same, independent of seasonal shifts in rain and snowfall,” reported Chile’s National Forestry Service (CONAF), which has monitored the area for the past three years. “This is the first time our park rangers have recorded anything like this. However, we are not specialists, and we prefer not to speculate about the cause at this point,” said CONAF regional director Juan José Romero. In two weeks, a team of geologists and investigators will meet at the site to determine what exactly happened to the lake. Satellite images will also be examined. Residents of the extremely remote area blame the 6.2 magnitude earthquake that hit the neighboring Aysen region last April and caused over 50 landslides (ST, May 22). They suggest that a rift opened up and drained the lake’s water. Chilean glaciologist Gino Casassa, one of the 63 experts who participated in the second UN report on global warming, told the La Tercera newspaper that he believes the lake disappeared due to a relatively common glacial phenomenon: a Glacial Lake Outburst Flood (GLOF). A GLOF is a sudden increase in a lake’s volume due to one of various possible causes, including a volcanic eruption, an earthquake, an avalanche, or a portion of a glacier falling into the lake. Casassa said that the GLOF broke open a tunnel of ice below the lake, which drained the water to the ocean. “In this zone in particular... we have evidence that, in general, the lakes are filling up as the glaciers melt,” Casassa added. Global warming is most likely responsible for this process, as well as for the increase in GLOFs. Although the phenomenon is more commonly observed in the Himalayas, GLOFs have previously been seen in Chile, affecting the Perito Moreno glacier and Lake O’Higgins. SOURCES: CONAF, LA TERCERA, LA NACION By Mike Hager ( This e-mail address is being protected from spam bots, you need JavaScript enabled to view it ) |
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