PORTLAND, Ore. (KOIN) — Friday’s 4.4 earthquake in Linn County is an excellent reminder for Pacific Northwest residents to prepare for the potential 9.0 “megathrust” earthquake that could occur along the Cascadia subduction zone in our lifetime.
Oregon State University seismology expert Andrew Meigs told KOIN 6 News that the timing of the quake provides an opportunity for people to learn about the “Great Oregon Shakeout,” a statewide earthquake drill that will take place on Oct. 20.
“This is an opportunity to inform and be prepared,” Meigs said.
The drill, which is designed to prepare Oregonians for a Cascadia subduction zone event, is part of a larger annual drill known as International ShakeOut Day. On this day, people in seismically active regions around the world practice and prepare for large, potentially disastrous earthquakes.
“Oregon lies at a convergent continental boundary where two tectonic plates are colliding,” the Oregon Shakeout website, operated by the Oregon Department of Emergency Management and other state and federal agencies, states. “The Cascadia Subduction Zone is actually a 600-mile long earthquake fault stretching from offshore northern California to southern British Columbia. This fault builds up stress for hundreds of years as the Juan de Fuca and North America Plates push against each other. Eventually, the two plates rip apart, creating some of the largest earthquakes and tsunamis on earth.”
The Oregon Department of Emergency Management states that 41 Cascadia subduction zone earthquakes have occured in the last 10,000 years. The most recent of these quakes was an estimated 9.0 that shook on January 26, 1700.
Cascadia subduction zone earthquakes have the potential to occur every 190 to 1,200 years. Scientists predict that there is a 37% chance that a megathrust earthquake of 7.1 magnitude or greater will occur in this fault zone within the next 50 years, and a 10% chance that an event could occur within the next 30 years.
University of Oregon seismology expert Douglas Toomey said that this earthquake is also a good reminder for residents to sign up for ShakeAlert, a USGS earthquake early warning system that can alert people when a serious earthquake is about to occur.
“ShakeAlert uses science and technology to detect significant earthquakes quickly and sends a real-time alert to people on compatible cell phones and other mobile devices through text-like messages, and through apps as they become available,” OEM states.
In addition to performing earthquake drills and signing up for earthquake alerts, Portland State University Professor Emeritus of Engineering Geology Scott Burns said that residents should also prepare their homes for the Big One.
“It is a reminder that we live in earthquake country, and we all need to be prepared for the Big One,” Burns said. “We all need to be prepared for the Big One. We need our food supply, water supply and to be ready to go into a camping mode. My house is ready.”
OEM recommends that people have an emergency plan and enough food, water and supplies to survive unassisted for at least two weeks in the wake of any large-scale disaster. Click here for information on how to prepare for disasters of this scale.
“Disasters can happen anywhere, at any time, and once they occur, it may take days or even weeks for responders to reach everyone who needs help,” OEM states. “This will especially be true in the event of a Cascadia earthquake and tsunami.”