A series of moderate earthquakes shook the sea floor about 225 miles offshore from Coos Bay early Saturday morning. The swarm averaged around a 5.3 Richter which is not particularly strong but any series of earthquakes means something is going on under the seafloor…in this case about six miles down which is still rather shallow for an earthquake. The notorious Cascadia Subduction Zone, where the Pacific plate is sliding under the North American plate, is a case of an irresistible force against an immovable object. Like Mother Earth having a fight with herself.
The Cascadia Subduction Zone is known to create very powerful earthquakes at intervals of 250 to 350 years according to geo-scientists at Hatfield Marine Science Center. The last big quake was recorded on January 26th, 1700. The coast was inhabited only by Native Americans who made a record of the event. So did the Japanese who witnessed a series of nasty tidal waves that moved clear across the Pacific and wiped out a number of fishing villages on Japan’s west shore.
Coastal Oregon’s first responders want to remind everyone that if “The Big One” hits, everyone in low lying areas should make a bee-line to higher ground and don’t carry anything that will slow you down. Find a spot at least 100 feet higher than the beach and await for emergency services personnel to advise you what to do. But everyone should be prepared to hold-up in place for quite a while.