A 7.5 Alaska earthquake prompted officials to issued a tsunami warning early on Sat., Jan. 5, 2013. It struck off the coast at 3:58 a.m. while most locals were sleeping. The tsunami warning was canceled later the same morning. The canceled tsunami warning had been issued for the following areas: British Columbia, the British Columia-Washington border, Canada and southeastern Alaska, according to CNN. Fortunately, the 7.5 earthquake in Alaska did not result in any reported damage.
The Alaska earthquake initially measured 7.7 in magnitude, but it was downgraded to 7.5. According to the U.S. Geological Survey (USGS), the " . . . earthquake off the west coast of southeastern Alaska occurred as a result of shallow strike-slip faulting on or near the plate boundary between the Pacific and North America plates." Although no damage or injuries were reported, an earthquake measuring 7.5 is considered a strong earthquake capable of damaging buildings and producing a significant death toll.
The Richter scale was created by Charles Richter and Beno Gutenberg in 1935. It has largely been replaced by the moment magnitude scale (MMS) in most countries. Russia and former members of the U.S.S.R. continue to use the Richter scale. The numerical values for earthquakes measured by the Richter scale and the MMS are similar. Quite often, when the media reports that an earthquake reached a certain magnitude on the Richter scale, they actually mean the MMS.