ShakeAlert—Earthquake Early Warning System for the West Coast of the U.S. (2020)

Summary

ShakeAlert is an earthquake early warning system designed to provide vital seconds of preparation before the damaging effects of earthquakes hit. The system, operated by the U.S. Geological Survey, issues warnings that enable individuals and infrastructures to take protective actions like dropping, covering, and holding on, slowing trains, or shutting critical systems. Despite its advanced technology, ShakeAlert doesn't predict earthquakes; it alerts about already started seismic activities. While it provides timely alerts to many in danger zones, those near the epicenter may not get the alert in time.

Highlights

• ShakeAlert provides vital seconds of advance warning for earthquake shaking. ⏰
• The system helps individuals and systems to be prepared, potentially saving lives. 🌍
• It relies on detecting seismic waves and issuing alerts before the destructive waves hit. 📶
• Alerts can be sent through apps, public systems like TVs and radios, and FEMA's emergency alert network. 📱
• Those closer to the epicenter may not receive alerts before shaking begins due to the proximity of seismic wave arrival. 🚧

Key Takeaways

• ShakeAlert offers crucial seconds of warning to prepare for an earthquake. ⏳
• It's an early warning system, not a prediction tool. 📡
• Immediate action on receiving an alert can save lives and reduce injuries. 🚨
• Not everyone will receive alerts before the shaking, especially those near the epicenter. 📍
• Automatic systems triggered by ShakeAlert can help minimize infrastructural damage. 🏗️

Overview

Imagine getting a ping on your phone that warns you of imminent shaking from an earthquake, giving you precious seconds to seek cover. That's the power of ShakeAlert, a cutting-edge system designed to keep people safe when the ground beneath them threatens to shift violently. The system isn't a crystal ball predicting when earthquakes will occur, but rather a rapid response network alerting people that a quake is already happening, providing time to DROP, COVER, and HOLD ON.

The technical workings of ShakeAlert are fascinating. It starts when sensors strategically placed along the United States' seismic hotspots detect the fast-moving P waves from an earthquake. These are quickly followed by slower, more destructive waves. At least four sensors need to detect the quake to trigger a ShakeAlert. Once confirmed, notifications are sent out to people and systems, all orchestrated to take protective measures instantly.

However, the proximity to an earthquake's epicenter can determine the efficacy of receiving timely alerts. Close to the origin, P and S waves arrive too swiftly for the alert system to send out a warning before the shaking starts. For those farther away, more warning time can be granted, alerting them to act quickly. ShakeAlert is a tool that enhances preparedness and safety in earthquake-prone zones across the West Coast of the U.S., reminding us to always be ready for the inherent unpredictability of nature's geophysical tantrums.

Chapters

• 00:00 - 00:30: Introduction to Earthquake Risk in the U.S. The chapter 'Introduction to Earthquake Risk in the U.S.' discusses the urgent actions required when an earthquake begins, highlighting the vulnerability of over 143 million people in the United States to potentially damaging shaking. It emphasizes that the highest earthquake risks are concentrated in densely populated regions, particularly along the active plate tectonic boundaries of the west coast. The discussion serves as an introduction to the broader topic of earthquake preparedness and risk concentration in the U.S.
• 00:30 - 01:00: Overview of ShakeAlert System The chapter provides an overview of the ShakeAlert earthquake early warning system operated by the U.S Geological Survey. It is a component of the advanced national seismic system. The text clarifies that ShakeAlert does not predict earthquakes; instead, it issues a shake alert message from the USGS indicating that an earthquake has started and shaking is impending.
• 01:00 - 01:30: Benefits of Early Warning Even a brief advance warning from ShakeAlert can save lives and minimize injuries by prompting people to take protective measures like DROP, COVER, and HOLD ON. It also enhances safety and protects infrastructure through automated responses, such as slowing down trains to avert derailments, opening firehouse doors to prevent them from jamming, and closing valves to safeguard water systems, thus helping to stabilize equipment in life-critical scenarios.
• 01:30 - 02:00: How ShakeAlert Works ShakeAlert operates by detecting seismic waves created during an earthquake. Initially, P waves, which are fast-moving and sound wave-like, are detected followed by the slower S waves and surface waves which often cause more damage. Sensors that identify these seismic waves transmit the data to a ShakeAlert processing center, which mandates inputs from a minimum of four sensors to acknowledge an earthquake. If the seismic event matches specific criteria, the US Geological Survey (USGS) releases a ShakeAlert notification which is then propagated by distribution partners.
• 02:00 - 02:30: Alert Distribution Methods The chapter 'Alert Distribution Methods' explores various ways to deliver alerts to individuals and automated systems before, during, or after seismic activities involving s-waves and surface waves. It discusses the distribution of alerts through mobile apps for cell phones and wireless devices, public address systems, televisions, radios, and FEMA's wireless emergency alert system (WEA), which also provides Amber Alerts. The coverage region for each earthquake alert is considered.
• 02:30 - 03:00: Limitations Near Epicenter The chapter discusses the limitations of earthquake alert systems near the epicenter. It explains that alerts cannot arrive before shaking begins because the P and S waves are too close together, and the ShakeAlert system requires time to estimate the earthquake's magnitude and shaking levels. Consequently, people near the epicenter might not receive alerts before shaking starts, whereas those further away may receive earlier warnings.
• 03:00 - 03:30: Response to Alerts and Precautions ShakeAlert messages may be issued to update the estimated magnitude and expected shaking of an event, resulting in alerts across broader areas.
• 03:30 - 04:00: Preparedness and Safety Tips The chapter titled 'Preparedness and Safety Tips' emphasizes the importance of understanding local hazards and recommended precautions by consulting information available on city, county, or state emergency management websites. It stresses the significance of being aware of your surroundings and practicing protective actions as crucial elements of disaster preparedness. The chapter also highlights the essential response during an earthquake: receiving alerts or experiencing shaking should prompt individuals to DROP, COVER, and HOLD ON until the shaking ceases.

ShakeAlert—Earthquake Early Warning System for the West Coast of the U.S. (2020) Transcription

• 00:00 - 00:30 What would you do if you have seconds to prepare for shaking from an earthquake that has already begun? More than 143 million people in the united states are exposed to potentially damaging shaking due to earthquakes. Most of our nation's earthquake risk is concentrated in highly populated areas on the active plate tectonic boundaries of the west coast of the continental
• 00:30 - 01:00 united states. The U.S geological survey operates the ShakeAlert earthquake early warning system which is part of the advanced national seismic system. ShakeAlert is not earthquake prediction but a shake alert message issued by the USGS indicates that an earthquake has begun and shaking is imminent. [Teacher "....don't let yourself be convinced to do something that you know is bad and then again..."]
• 01:00 - 01:30 With even a few seconds of warning ShakeAlert can save lives and reduce injuries by alerting people to take a protective action, such as DROP COVER and HOLD ON. ShakeAlert further protects people and infrastructure by triggering automatic actions such as slowing down trains to prevent derailments, opening firehouse doors so they don't jam shut, and closing valves to protect water systems and to stabilize equipment during life critical situations.
• 01:30 - 02:00 How does shake alert work? When an earthquake occurs seismic waves carry energy in all directions away from the epicenter. P waves, similar to sound waves, move quickly through the ground followed by the slower and generally more damaging S waves and surface waves. Sensors detect the seismic waves and send that information to a ShakeAlert processing center which requires that at least four sensors detect the earthquake. If the earthquake fits the right profile, the USGS issues a ShakeAlert message. Distribution partners then produce and
• 02:00 - 02:30 deliver an alert to people, and trigger automated systems. Alert delivery can be before during or after shaking from s waves and surface waves. Alerts can be delivered to people through apps designed for cell phones and other wireless devices, over public address systems, tvs and radios, and by fema's wireless emergency alert system WEA. which is also the source of amber alerts. Dor every earthquake there is a region
• 02:30 - 03:00 near the epicenter where alerts will not arrive before shaking begins. That's because close to the epicenter the P and S waves are too close together and the ShakeAlert ystem needs time, often just seconds, to estimate the earthquake's magnitude and shaking levels before issuing a ShakeAlert message. That means that people close to the earthquake epicenter might not get an alert until after the shaking has already started. those farther away from the epicenter could receive more warning time before shaking arrives. If an earthquake continues to grow in
• 03:00 - 03:30 size, additional ShakeAlert messages might be issued. Updating the estimated magnitude and expected shaking for that event will result in alerts being delivered to a broader area. The USGS recommends that when you receive an alert you should take protective action immediately. Do not wait for shaking to arrive. If you are near the coast in a tsunami prone region it's important to get to high ground quickly but only after shaking stops. Before traveling to a new place
• 03:30 - 04:00 learn about both the local hazards and the recommended precautions to take by reading information found in the city county or state's emergency management websites. Knowledge of your surroundings and practicing protective actions are critical components of preparedness for any disaster, Always remember: if you receive an earthquake alert, or experience shaking DROP, COVER and HOLD ON until all shaking stops