Large earthquakes, like the recent M7.8 in Alaska, can be seen at seismometers around the world! When an earthquake occurs, seismic energy travels in all directions, much like ripples in a pond.
This evening’s M7.8 earthquake [7/21/20, 10:12 PM AKDT] occurred on the well-known subduction zone interface off the Alaska Peninsula. Strong shaking has been reported from Perryville and Sand Point to King Cove and Cold Bay.
We use the phrase “magnitude of completeness” often when referring to our understanding of seismicity in a region or following a sequence of earthquakes. This value is a simplistic assessment of a catalog of earthquakes.
“As far as earthquakes go, for everyone in Alaska, there is someone looking out for you 24/7,” said Ken Macpherson, who manages the Alaska Earthquake Center’s data analyst team.
March 19, 2020 update. Like all of you, the Alaska Earthquake Center has quickly reconfigured to adhere to public health guidelines while trying to maintain business and operational continuity.
We are getting questions about current earthquake activity in the western Aleutians—and with good reason. There are actually two different sequences of earthquakes unfolding right now in the Andreanof and Rat Islands.
Seismicity in Alaska had another stand-out year in 2019. With a total of 50,289 reported earthquakes, 2019 finished as a runner up to the record-breaking 2018 (figure 1). The earthquake depths ranged between 0 and 165 miles (265 km).
