Earthquakes
The last megathrust earthquake at the Cascadia subduction zone was the 1700 Cascadia earthquake, estimated to have a moment magnitude of 8.7 to 9.2. Based on carbon dating of local tsunami deposits, it occurred around 1700. As reported in National Geographic on 8 December 2003, Japanese records indicate the quake caused a tsunami in Japan which occurred during the evening of Tuesday, 26 January 1700.
In 2008, small earthquakes were observed within the plate. The unusual quakes were described as "more than 600 quakes over the past 10 days in a basin 150 miles southwest of Newport". The quakes were unlike most quakes in that they did not follow the pattern of a large quake, followed by smaller aftershocks; rather, they were simply a continual deluge of small quakes. Furthermore, they did not occur on the tectonic plate boundary, but rather in the middle of the plate. The subterranean quakes were heard on hydrophones, and scientists described the sounds as similar to thunder, and unlike anything heard previously.
Read more about this topic: Juan De Fuca Plate
Famous quotes containing the word earthquakes:
“For nation will rise against nation, and kingdom against kingdom, and there will be famines and earthquakes in various places: all this is but the beginning of the birth pangs.”
—Bible: New Testament, Matthew 24:7,8.