ShakeAlert® Earthquake Early Warning System
for the West Coast of the United States
Earthquake early warning (EEW) systems aim to quickly detect earthquakes and alert locations expected to experience significant shaking before the shaking arrives, potentially saving lives and preventing injuries. There are many EEW systems in operation and in development around the world, and the EEW system that is availablein the U.S. West Coast states of California, Oregon, and Washington is called the ShakeAlert system.
The ShakeAlert system is operated by the U.S. Geological Survey (USGS) and is a cooperative project between the USGS, state agencies,and university partners including the California Institute of Technology (Caltech), the University of California, Berkeley (UC Berkeley),the University of Washington (UW), and the University of Oregon (UO).
This site focuses on contributions by the SCSN and Caltech Seismological Laboratory, and serves as a repository of resources for partners and the public.
Expand the sections below to view summaries and link to additional pages with in-depth information and resources.
Overview of EEW algorithms and EEW operations at Caltech
Overview of EEW Research and Development at Caltech
- Improving the FinDer EEW algorithm
- Improving the PLUM EEW algorithm (the APPLES configuration)
- Improving ground-motion modeling in EEW
- Investigating using fiber-optic DAS in EEW applications
- Developing EEW performance visualization tools, performance evaluation methods, and preferred alerting strategies
- Investigating station and network improvements
How did this all start?
While there had been interest and some early research conducted at Caltech pertaining to earthquake early warning as far back as the 1980’s, those efforts weren’t combined and formalized until the 2000’s. Scientists and engineers at the California Institute of Technology (Caltech), USGS Pasadena, UC Berkeley, the Swiss Federal Institute of Technology (ETH), and the University of Southern California (USC/SCEC) started working on earthquake early warning (EEW) research for California in 2007. This included the development and implementation of an early demonstration EEW system for California, called “CISN ShakeAlert” (Boese et al., 2012). The early ShakeAlert made use of the existing infrastructure of the California Integrated Seismic Network (CISN, Caltech/UC Berkeley/USGS), including real-time waveform data streams from at the time ~380 broadband and strong-motion stations throughout California. Now data streams from more than 1100 stations between California, Oregon, and Washington are being ingested by ShakeAlert to support the ShakeAlert Earthquake Early Warning System on the entire west coast of the US.
Initially, the project was funded through the US Geological Survey (USGS) that also has the formal responsibility of earthquake alerting in the US. In early 2012, the Gordon and Betty Moore Foundation provided three years of new funding for EEW research and development for the west coast of the US. Caltech, UC Berkeley, University of Washington, and USGS used these funds to accelerate EEW research and to improve the ShakeAlert system. In particular, the Moore funding enabled the research and development of new algorithms for creating more accurate warnings for finite-source large (M>7) earthquakes as well as enabling work with early-adopters of ShakeAlert and development of probability-based smart engineering applications. With the USGS spearheading the implementation and management of the ShakeAlert Earthquake Early Warning System, research continues at the Caltech Seismo Lab and other partner institutions to constantly improve warning times, accuracy, and the reliability of the system.
