- The Barrier
The Barrier is a spectacular lava dam retaining the
Garibaldi Lake system in southwesternBritish Columbia ,Canada . It is over 300 m (1,000 ft) in thickness and about 2 km (1.2 mi) wide where it impounds the lake. [ [http://ilmbwww.gov.bc.ca/bcgn-bin/bcg10?name=11694 BCGNIS Geographical Name Details] ]The area below and adjacent to The Barrier is considered hazardous due to the unstable lava formation.
Formation
The Barrier was formed when large lava flows emanated from a vent on the west shoulder of Mount Price about 9,000 years ago called
Clinker Peak . The large lava flowed towards theCheakamus River valley. At the time of eruption, the valley was filled by glacial ice. The lava flow was stopped by the ice and ponded, eventually cooling. When the ice melted away, the ice-cooled lava-flow front formed a precipitous cliff; water ponded behind the lava dam, forming Garibaldi Lake.Rubble Creek boulder field
The unstable lava formation of The Barrier has in the past unleashed several
debris flow s in the area below Garibaldi Lake, most recently in1855 -1856 forming a large boulder field which givesRubble Creek its name. [ [http://gsc.nrcan.gc.ca/volcanoes/cat/feature_garibaldi_e.php Catalogue of Canadian volcanoes - Garibaldi volcanic belt] Retrieved on2007-09-07 ]Hazards
Concerns about The Barrier's instability due to volcanic, tectonic, or heavy rainfall activity prompted the provincial
government to declare the area immediately below it unsafe for human habitation in1981 . [ [http://cgip.wetpaint.com/page/Fire+and+Ice%3A+Distinctive+landscape+features+of+Garibaldi+Provincial+Park Fire and Ice: Distinctive landscape features of Garibaldi Provincial Park] ] This led to the evacuation of the small resort village of Garibaldi nearby, and the relocation of residents to new recreational subdivisions away from the hazard zone. Should the Barrier completely collapse,Garibaldi Lake would be entirely released and downstream damage in the Cheakamus andSquamish River s would be considerable, including major damage to the town ofSquamish and possibly an impact-wave on thewater s ofHowe Sound that would reachVancouver Island .ee also
*
Garibaldi Lake Volcanic Field
*Garibaldi Volcanic Belt
*Cascade Volcanoes
*Volcanism in Canada
*Garibaldi Provincial Park External links
* [http://www.telemark.net/%7Erandallg/photos/20061021_Kamloops/images/416.jpgAerial view of The Barrier and Garibaldi Lake] from [http://www.telemark.net/%7Erandallg/photos/20061021_Kamloops/ Randall & Kat's Flying Photos]
References
Wikimedia Foundation. 2010.