Alaska rocked by 7.1 magnitude earthquake. Is that normal?
A magnitude 6.8 earthquake woke up sleeping residents of southern Alaska at 1:30 am Sunday morning.听
In its initial report, the US Geological Survey (USGS) registered the earthquake as a magnitude 7.1, downgraded it to 6.8, and then raised it back to 7.1. There are no deaths or serious injuries reported. The USGS also says Alaska is not in danger of a subsequent tsunami.
鈥�,鈥� Bob Candopolous of Seward told 2KTUU News. 鈥淚t was tough to get to the front door to get out of the house.鈥澛�
The epicenter was located about 162 miles southwest of Anchorage, in the Cook Inlet region.听
鈥淢y husband came into the bedroom forcefully saying, 鈥楪et up! Get up!鈥� said,鈥� Associated Press reporter Mark Thiessen. 鈥�, trying to figure out what was happening.鈥澛�
The earthquake may have surprised sleeping homeowners, but quakes are common in Alaska, particularly of this magnitude. The US Geological Survey (USGS) reports a magnitude 7 or greater earthquake someone in or offshore Alaska .听
鈥淭his is for this region and depth,鈥� the University of Alaska Earthquake Center reports. 鈥淓arthquakes of similar sizes occurred in the Lower Cook Inlet in 1912 and 1933, but we do not have precise magnitudes and locations for that time period.鈥澛�
Of the who power their homes through Homer Electric Association, almost after the quake. The Matanuska Electric Association and Chugach Electric Association also reported 4,900 and 4,600 outages respectively, but by around 6:30 am Sunday morning the number of outages had been reduced to a little more than 100 each.听
2KTUU News also reports more than聽 due to a possible gas leak.
鈥淲hen it hit, it was just soft at first, ,鈥� Joshua Veldstra, a professional photographer who lives in Homer, told CNN. 鈥淚t was one of those moments where you didn鈥檛 know if it was going to get worse or if it was going to calm down.鈥澛�
The Alaska Earthquake Center recorded about 30 aftershocks in the first two and half hours after the quake, including a 4.3 magnitude earthquake at 3:37 am local time.听
Earthquakes occur in Alaska because of stresses between two tectonic plates: . The Pacific Plate moves about two inches northward each year and it is pushed below, or 鈥渟ubducts,鈥� beneath the North American Plate. The Yakutat block, an irregularity on the top of the Pacific Plate, prevents a smooth subduction.听
While Sunday morning鈥檚 earthquake was damaging, it was far less destructive than , the second largest global earthquake ever recorded. Noted as the largest earthquake in Alaska by the USGS, the Great Quake occurred on March 27 with a magnitude of 9.2. The quake triggered a tsunami that destroyed many towns along the Gulf of Alaska. One hundred thirty-one people were killed by the 1964 quake, 9 from the earthquake itself and another 122 from the ensuing tsunami.听 聽
