Oregon activates mobile earthquake warning system

“ShakeAlert,” the earthquake early warning program, is set to deliver alerts to the public in Oregon via mobile devices starting today.

By Mariah C. Hoskins, Ph.D., Science Writer (@DrMCHoskins)

Citation: Hoskins, M.C., 2021, Oregon activates mobile earthquake warning system, Temblor, http://doi.org/10.32858/temblor.159

Ten years ago today, the magnitude 9.0 Tohoku earthquake struck off Japan’s eastern coast, sending tsunami waves across the Pacific. The quake was a wake-up call for the Pacific Northwest — a region that has experienced magnitude 9.0 earthquakes in the past and is likely to again (see Ludwin et al. 2005).

Today, Oregon will activate the “ShakeAlert” earthquake early warning system, enabling individuals to receive earthquake alerts on their mobile devices — a major advancement in preparedness. ShakeAlert is a collaboration between the U.S. Geological Survey (USGS), state agencies and universities. These alerts notify people of impending shaking, giving them a chance to take cover. ShakeAlert is already available in California. Washington will activate alerts later this year.

Today’s launch is a reminder that a Tohoku-scale quake is a real threat to the people of Oregon, says Althea Rizzo, Oregon’s Office of Emergency Management Geologic Hazards Program Coordinator, and Gabriel Lotto, University of Washington’s (UW) Engagement Facilitator for ShakeAlert.

Mobile alerts through ShakeAlert

Mobile devices can receive notifications through official Wireless Emergency Alerts (like Amber alerts), the Android operating system and the QuakeAlertUSA app. Wireless Emergency Alerts are broadcast based on cell tower proximity, whereas the mobile app and Android system use location services. Lotto says the UW ShakeAlert team recommends people get set up to receive alerts in multiple ways, to ensure receipt.

“If all goes well [residents] won’t really notice anything,” Rizzo says of the launch.

Photo of person holding cell phone.
USGS “ShakeAlert” notifications are sent through Wireless Emergency Alerts. Credit: USGS


Earthquake warning, not predicting

ShakeAlert does not predict earthquakes. It is a system that detects earthquakes and rapidly sends warnings to areas likely to feel shaking.

When an earthquake occurs, two types of seismic waves — primary and secondary (P and S) — travel out from where the earthquake started. “P-waves travel faster and are less damaging,” explains Lotto. “P-waves reach our seismic network first, and we try to rapidly calculate … the magnitude, the strength of shaking and area of shaking … and distribute that information before people feel strong shaking from the S wave.”

Key to Oregon’s progress in contributing to and implementing ShakeAlert is federal and state funding to install extensive seismic monitoring. The state’s seismic sensors monitor a large swath of the Cascadia Subduction Zone — the major earthquake threat in the Pacific Northwest — so it is an important area for the early detection of earthquakes along the west coast, says Douglas Toomey, a seismologist at the University of Oregon who is involved in the ShakeAlert program.

As for how much warning to expect, Lotto says, “people can get a few seconds, up to tens of seconds, of warning. And that is actually more useful than you’d think.” What would you do with so little warning? Lotto says, “You don’t want to spend the first few seconds of shaking wondering what’s happening. You want to immediately drop, cover and hold on.” ShakeAlert can give you that time.

There are limitations to ShakeAlert warnings. “If you’re right above where the earthquake started, there’s this zone where you are feeling the waves at basically the same time the sensors are feeling the waves, in which case there is not enough time to process an alert,” Lotto says. “[The alerts are] absolutely not a replacement for doing the seismic retrofit that we so desperately need here in Oregon,” says Rizzo.

schematicdiagram of city and mountains with arcs representing earthquake waves.
Schematic showing how rapid detection of earthquakes using P-waves facilitates sending alerts ahead of strong shaking from S-waves. Credit: USGS


Beyond mobile alerts

Public utilities can use ShakeAlert notifications to automatically shut off water or gas valves. Dan Ervin, an engineer and Executive Vice President at the engineering firm Varius Inc. says that without ShakeAlert, water shortages following a major earthquake could last 30-90 days, due to reservoirs emptying through broken pipes. “That kills people. That’s not just an inconvenience … with earthquake early warning, there is a potential to have no water shortages” he says. Varius develops systems that use ShakeAlert notifications to perform automated responses, like shutting off valves. These kinds of systems are engineered to cause no disruption if no damage occurs. Rizzo says that the adoption of automated responses is likely where the biggest impacts of ShakeAlert will be.

Residents can act now

Rizzo says there are two things that residents should do today. First, take a few moments to make sure you have alerts enabled on your mobile phone. Then think of one preparedness action you can take today, and do it. Some ideas to get you started can be found on the Oregon 2 Weeks Ready site.


Ludwin, R.S., Dennis, R., Carver, D., McMillan, A.D., Losey, R., Clague, J., Jonientz-Trisler, C., Bowechop, J., Wray, J., James, K. (2005). Dating the 1700 Cascadia Earthquake: Great Coastal Earthquakes in Native Stories. Seismological Research Letters; 76 (2): 140–148. doi: https://doi.org/10.1785/gssrl.76.2.140.

“A similar earthquake and tsunami are in our future—The 2011 Japan earthquake and tsunami: Lessons for the Oregon Coast” News and information from the Oregon Department of Geology and Mineral Industries, Winter 2012, https://www.oregongeology.org/pubs/cascadia/CascadiaWinter2012.pdf

“2 Weeks Ready” Hazards and Preparedness https://www.oregon.gov/OEM/hazardsprep/Pages/2-Weeks-Ready.aspx