Climate Fact: Earthquakes and Ice
About 0.5 mm of the water that is responsible for the 3.1 mm total rise in global sea level comes from Greenland’s melting ice. As this ice has melted, the number of earthquakes in the Region has grown. Although glacial movement is usually thought of as gradual, glaciers can move quickly. A block of ice as spacious as Manhattan and as tall as the Empire State Building can slide ten meters in less than a minute, which can produce an earthquake registering 5.0 on the Richter Scale. There were 15 earthquakes in Greenland in 2002, which was the highest number ever recorded; in 2003, 2004, and 2005, there were 20, 24, and 32 quakes respectively. There is a distinct seasonality associated with these quakes, as the majority of them occur during the summer when the annual ice melt reaches its peak and there is the greatest amount of glacial melt water, which acts as a lubricant and facilitates glacial movements. Earthquakes produced by the shifting of Earth’s tectonic plates do not follow seasonal patterns.
Season: Summer
(Sources: McCarthy, Michael. “An island made by global warming.” The Independent: 24 April 2007. Accessed Online 28 April 2007 <http://news.independent.co.uk/environment/climate_change/article2480994.ece> and Hecht, Jeff. “Glaciea earthquakes rock Greenland ice sheet.” New Scientist: 24 March 2006. Accessed Online 29 June 2007 <http://environment.newscientist.com/article/dn8889.html> and Ekstrom, G. et al. “Seasonality and Increasing Frequency of Greenland Glacial Earthquakes.” Science: 24 March 2006: Vol. 311. no. 5768, pp. 1756 – 1758.)