Why “Drop, Cover, and Hold On” when you get a #ShakeAlert-powered alert📱? How do we know this is the best action to take? Check out this social science research! library.seg.org/doi/10.1190/ge…. Let’s dive in 🧵. @Cal_OES @ShakeOut @waEMD @OregonOEM @CAGeoSurvey @RocketRules1 @ECA For a successful #EEW system to reduce injuries, 3 things should be considered: 1) the people who are alerted and the building types they occupy, 2) demographic variables such as gender, age, as well as quake experience & 3) types of quakes and performance of the EEW system.

A shaky afternoon in Southern California. Hope everyone is safe. Did you feel the M4.9 #earthquake near Westmorland at 5:31 pm PT? The #ShakeAlert system issued a message and passed it along to our delivery partners. If you received a message, share a screenshot with us! .#ShakeAlert powered #earthquake alerts were delivered by the @MyShakeApp and @fema Wireless Emergency Alert System - WEA. You can find this map at: prod-earthquake.cr.usgs.gov/earthquakes/ev… Check out the map - if you are inside the MMI 3 (weak) polygon you might have received an alert.

Did you know that it is National Postdoc Appreciation Week #NPAW? For #ResearchFriday, we are focusing on the great work of our early career researchers! Currently we have four @USGS postdocs working to improve the #ShakeAlert system. Let the shout-outs begin! @USGS_Quakes Dr. Noha Farghal has a Ph.D. in geophysics from @Stanford. Noha is working on incorporating fiber-optic sensors into the #ShakeAlert system. Check out her recent paper: The Potential of Using Dynamic Strains in Earthquake Early Warning Applications pubs.geoscienceworld.org/ssa/srl/articl…

A shaky Friday evening in Southern California. Hope everyone is safe. Did you feel the M4.6 #earthquake about 2 miles west of El Monte just before 11:39 pm PT? The #ShakeAlert system issued a message and passed it along to our delivery partners. More info: earthquake.usgs.gov/earthquakes/ev… Let us know if you got an alert and share screen shots if you want. At this magnitude apps that are Powered by #ShakeAlert can deliver alerts to people who could feel MMI III (weak shaking) or greater. Check out how big the MMI III+ region is on this map. @Cal_OES

Hi everyone, it’s #ResearchFriday! On top of having 60+ physical scientists on #ShakeAlert we have a team of 30+ social scientists who study human interaction with ShakeAlert. Meet the Social Science Working Group (SSWG). Here’s our class picture from 2020! Why is social science important? Apart from sensors in the field, data processing centers, and alert delivery by our partners, people directly interact with #ShakeAlert. Anything that can improve that interaction, which often happens quickly, is critical to keeping people safe.

Happy #ResearchFriday! How does #ShakeAlert work and how do our 60+ partners use it to keep people safe? Here's the latest creation from @IRIS_EPO and the ShakeAlert Education & Outreach team - a new video to explain a pretty complex system. Please share! Even #ShakeAlert animations are based on research. What went into making this new resource? Every detail counts and geologist Jenda Johnson spent hours getting everything just right. Just to animate Drop, Cover, and Hold On took 100+ individual frames! @ECA @waShakeOut @ShakeOut

Meet our newest #ShakeAlert team member, recent @pitzercollege grad Mariah Jenkins. A double major in geology and environmental analysis, she will explore, design, and implement resources and programs that focus on access, inclusion, and diversity in ShakeAlert. Optimizing how 50+ million people interact with earthquake alerts is critical to the success of #ShakeAlert. Mariah is up for the task and she will be working with researchers at @OMSI and @UOsojc to apply what she learns to real world settings. @OregonOEM @waEMD @Cal_OES

Hi everyone! It’s #ResearchFriday! #ShakeAlert is constantly looking for ways to improve the System. One way we learn is to ask “What if?” questions. Today let’s ask: What if the ShakeAlert System had been operating with 2020’s technology during the 1994 Northridge earthquake? At 4:30 am on 1/17/94 a M6.7 earthquake occurred near Northridge, CA. The shaking it generated caused damage throughout Los Angeles County, including the San Fernando Valley. There were 57 deaths, over 9000 injuries, and billions of dollars in property damage.

Hi everyone, it’s #ReseachFriday! This week’s focus is on #ShakeAlert alerting regions! This study looked at using the 2019 Ridgecrest earthquakes to find an optimal alerting strategy. pubs.geoscienceworld.org/ssa/bssa/artic… So, the #ShakeAlert system detects an earthquake, it uses ground motion models (GMMs) to determine the size of the alert region using earthquake source estimates as input (generally, magnitude and location).

Welcome to #ResearchFriday where we highlight how we’re constantly improving the #ShakeAlert System whether it’s about Earth science, technology, alert delivery, or even how people and automated systems interact with alerts. This week, it’s some social science! This study brought together many experts to figure out how to improve communication with people after a #ShakeAlert Message is issued and an alert is delivered to your phone or other wireless device.

A bit of a shaky morning in LA. Hope everyone is safe. Did you feel the M4.2 #earthquake about 1 mile north of Pacoima just after 4:29 am PT? The #ShakeAlert system issued a message and passed it along to our delivery partners. More info: earthquake.usgs.gov/earthquakes/ev… If you felt it please fill out a Did You Feel It report at: earthquake.usgs.gov/earthquakes/ev…

Today #WeRemember those affected by the 2019 Ridgecrest earthquakes starting with the magnitude 6.4 quake at 10:33 am. Another stronger magnitude 7.1 quake shook the area about 33 hours later. @CalConservation @Cal_OES @SCEC @EERI_tweets More: earthquake.usgs.gov/earthquakes/ev… (1/4) Feeling the ground shake and seeing the environment around us move can leave one feeling wary of what is to come next. We recognize members of the communities affected and people from different agencies and organizations who focused their energy on emergency response. (2/4)

We want to update you on yesterday’s M5.8 earthquake 11mi SSE of Lone Pine, CA. The #ShakeAlert-powered Apps and @fema WEA delivered alerts to thousands of people in Southern California. #QuakeAlertUSA @MyShakeApp @Cal_OES @EarlyWarningLab
(1/6) Since October of 2019 the Wireless Emergency Alert (WEA) system and Apps have been undergoing the testing of public alerting in California. One advantage of WEA is that it can broadcast a single message to many people without overwhelming the cellular system. (2/6)

Yesterday the #ShakeAlert team was working on code updates to improve Earthquake Early Warning (EEW) alert delivery by the Wireless Emergency Alert (WEA) system. To make sure the updates worked we ran a test using an example from the Ridgecrest/Trona region. 1/4 Unfortunately, due to a technical glitch the test message was incorrectly sent to the communities in and around Ridgecrest and Trona. This is the first time a false alert was delivered to the public. 2/4

Did you feel the M3.7 #earthquake in L.A. just after midnight and wonder, “Hey, where's my alert on my phone?” Apps and @fema WEA didn’t deliver alerts because the event did not meet the minimum #ShakeAlert alerting thresholds for either delivery pathway. earthquake.usgs.gov/earthquakes/ev… Apps only deliver alerts to people who could feel MMI 3+ (weak shaking) or greater for quakes M4.5+ and @fema WEA alerts go to those who could feel MMI 4+ (light shaking) or greater for quakes M 5+.

Learn more about the ShakeAlert message issued for the M 4.9 earthquake - 10.5 mi ESE of Anza, CA at 6:53 pm PT. earthquake.usgs.gov/earthquakes/ev… @Cal_OES @CaltechSeismo @BerkeleySeismo An @fema WEA Alert was distributed for this earthquake. Currently WEA alerts are only delivered for earthquakes M5 and greater and only to those who could feel light shaking (MMI 4) or greater. If this quake was only M 4.9 why was a WEA delivered?

#ShakeAlert focuses on eq shaking which is controlled by 3 main factors: magnitude, distance from the rupturing fault, and local ground conditions. These factors play a role in how hard and for how long a region will shake. (1/5) During an earthquake, loose, soft soil will shake harder and longer than hard rock. Valleys will shake harder than mountains because of their sediment fill. Watch this video from @IRIS_EPO (2/5)

Last night the USGS issued a #ShakeAlert for a M 5.5 quake in the Baja California-Sonora border region. See: earthquake.usgs.gov/earthquakes/ev… Look for the ShakeAlert link to learn more. (1/5) Light shaking (MMI 4) was outside of California so no @fema WEA ShakeAlert was distributed - see color scale for comparison. Even though this earthquake was outside the seismic network and harder to locate #ShakeAlert performed well. (2/5)

In 1868, a magnitude 6.8 earthquake struck Hayward, CA - killing 30 people and causing widespread property damage. Shaking was so severe that nearly every building in Hayward was wrecked. (1/4) This animation shows what might happen in a future scenario of a magnitude 7.0 earthquake hitting the region. Pay attention to how the strongest waves (reddish hue) propagate away from the epicenter. Notice how they race toward the south? (2/4)

Today the @Caltech /USGS Earthquake Research Affiliates hosted the third #ShakeAlert communication & education workshop in Pasadena, CA. A fantastic group outreach experts discussed and gave excellent feedback on the development of EEW materials for WA, OR, and CA. We had representatives from a variety of sectors including health care, academia, city government, entertainment, and transportation. Thanks to all who have participated in the last three workshops. @CaltechSeismo

Learn more about the M4.4 earthquake 13km WNW of Toms Place, CA at 10:36 am on 2/1. A #ShakeAlert was issued. See: earthquake.usgs.gov/earthquakes/ev… Take a look at the #ShakeAlert Post-Alert Summary.
earthquake.usgs.gov/earthquakes/ev…

Would have Apps like #QuakeAlertUSA or @MyShakeApp delivered an alert to cell phones? Look at previous tweets for clues. @Cal_OES @BerkeleySeismo @EarlyWarningLab