Just before 1 o'clock local time yesterday a massive earthquake shook deep beneath the sea floor off the coast of Alaska's Little Sitkin Island, one of the long arc of volcanic Aleutian Islands. The earthquake triggered a tsunami warning for the local area, but all-in-all the huge earthquake, which clocked in at magnitude 7.9, was mostly harmless.
Yesterday's earthquake was powerful, but Alaska is no stranger to such strong quakes. The Aleutian Islands arc is one of the most seismically active places on Earth, says the United States Geological Survey. Between the Aleutian Islands and another inland earthquake hot spot in southwestern Alaska, the state has born the brunt of six of the 89 magnitude 8.0+ earthquakes that have hit around the world since 1900. Open this up to magnitude 7.9 events as well and you'd add another five.
That yesterday's earthquake didn't cause much damage is a reminder that, in natural disasters, location is everything. In 2002 a magnitude 7.9 earthquake hit along Alaska's Denali fault causing shaking and land slides that caused minor damage in nearby towns. Because of Alaska's sparse population, even this one caused little damage.
Update: The headline of this post originally said there were seven magnitude 8+ earthquakes in Alaska since 1900. Instead, there were six.
As far as earthquakes are concerned, though, Alaska hasn't always gotten off so easy. The Great Alaska Earthquake of 1964 was the largest ever seen in the U.S., and the second-largest recorded globally since 1900. That time, the tremblor and its associated tsunami hit right outside Anchorage, killing 131 people. The USGS has a video about that earthquake, and how the then-new idea of plate tectonics helped researchers to make sense of what had happened.