Fiber Optics and Earthquake Early Warning

Stanford Researchers Build a ‘Billion Sensors’ Earthquake Observatory with Optical Fibers

Earthquake Early Warning Systems rely on mechanical accelerometers to detect the seismic waves.  But a new approach using a particular characteristic of the fiber optic cables, which carry most of the world’s telephone and Internet traffic, is being developed at Stanford University. The system can detect vibrations that alter slightly the characteristics of the laser light shining down the fiber. An experimental pilot system has detected earthquakes ranging from ones that are local but not felt by anyone to ones that are thousands of miles away, such as the recent quakes in Mexico. Such a system would enable a global warning network to be quickly and inexpensively deployed.

 

 

California is Part of a West Coast Early Warning System

 

The West Coast ShakeAlert system, which includes California, Oregon, and Washington, is being developed by a United States Geological Survey (USGS) led team with the goal of integrating and expanding the regional seismic networks that are part of the Advanced National Seismic System (ANSS),  the California Integrated Seismic Network (CISN), and the Pacific Northwest Seismic Network (PNSN). The USGS is also upgrading the processing software and computers to improve accuracy of the system and speed up response time to warnings. This West Coast-wide system has been designed for reliable operations and includes distributed servers with automatic system recovery. It has been sending alerts to early business users in California since early 2012.

There has been both federal and state funding to support the complete rollout, however the full sensor network has not yet been deployed and system is not fully funded for operations. In anticipation of the full system rollout, the California legislature passed SB 438 in 2016 which created the governance structure for implementation. This work, which is being supervised by CalOES, includes the governance and needed cooperative activities of all participants in all aspects of the EEWS, including system operations and public notification. CalOES will work with the USGS to operate the ShakeAlert system and issue public notifications under collaborative authorities with FEMA, as part of the National Earthquake Hazard Reduction Program.  Trials of the notification service are expected in 2018.

Community Earthquake Early Warning to the Public

 

Earthquake Early Warning – More than Technology

Earthquake Early Warning Systems (EEWS) can save lives and reduce damage to property.  However, even after the EEWS computers have determined the seismic risk, at least two additional capabilities are needed:

  1. The impact information needs to be communicated to the parties that need it
  2. The receiving parties accept the information as valid and know how to act on it

Many early stage EEWS, including those in California, are already connected to some organizations on a trial basis. Mass transit rail systems, airports and power utilities can get early warnings and all of them have response plans designed to use the time-critical information quickly and appropriately. But reaching the mass public, where there is the greatest need and potential benefit, is much harder. And educating the public about what to do when they get the notification is harder still.

Reaching the public in a timely way requires the use of multiple channels: radio, TV, the Web, and perhaps, most importantly, cell phones. Cell phone text and voice notification are the best ways to get the information to the public in a timely manner, but systems to do this are not ubiquitous nor are they fully reliable in reaching 100% of subscribers.

Educating the public about the EEWS and their location specific response is perhaps the toughest challenge in communicating warnings. Success here will require cooperation from schools, the media, and the social media community. And unless people do the right thing to save their lives and property, the technology will not have mattered.

 

Earthquake Early Warning: Its not perfect but it still saves lives and reduces injuries

There are three factors that drive successful, large-scale deployments of EEWS:

  1. There needs to be a commitment from government to support the deployments and fund them.
  2. There needs to be a robust system of notification, including direct notification to critical businesses, such as energy and transport firms, and broadcast media and phone networks for mass notification.
  3. Perhaps most important, there needs to be an understanding by the public that there is no perfection when dealing with complex phenomena like earthquakes, so there may be some false warnings or undetected events. The expectation of perfection and the legal risks of lack of perfection can limit system deployments.

No EEW is perfect and totally reliable. However, millions of people around the world are now protected by EEW systems, and many lives have been saved because of them. Japan’s EEW system has been functional for ten years, and even though there have been false alarms, it has proven to be a valuable tool in reducing loss of life and injuries. It is likely that in the future we will see such systems as ubiquitous in areas with seismic risk, and we will all be safer.

 

 

An Earthquake Warning System in your Hand

Traditional warning systems use dedicated sensors, networks and central computers to generate their estimates of seismic impact and alerts. But in the same way that smartphones have changed our lives since being introduced just ten years ago, researchers in the US, Mexico, Chile, Japan and elsewhere are looking to use a distributed network of personal smartphones connected over cellular networks to create a ‘crowdsourced’ EEWS. Today’s smartphones have high-power computer processors, GPS chips and accelerometers, plus radios to connect with cell networks — in essence, everything you need to do seismic detection. Researchers are testing to see if these devices, especially their built-in accelerometers, are accurate enough to support a warning function. And they are. In Chile, a team of local and US researchers is developing and deploying an early warning system using only smartphones and an inexpensive add-on for greater accuracy. Data collected by the sensor boxes is transmitted through an Android app developed by the researchers and analyzed to produce earthquake source models, which in turn can be used to create ground shaking forecasts and local tsunami warnings. A team at UC Berkeley has also developed an Android app with similar functionality which anyone can download and use as a seismometer. Someday these distributed personal networks may even be linked with the centralized systems to provide enhanced warning data and alerts.

Worldwide Use of Earthquake Early Warning

A statewide earthquake early warning system (EEWS) is being developed for California under the leadership of the California Office of Emergency Services (CalOES). There is a proven capability of these systems to provide vital alerts to businesses and citizens, giving them up to several minutes of warning to enable protecting critical systems, securing transport and permitting preparedness response. In the recent 2017 Mexico earthquakes, citizens were given zero to 20 seconds warning depending on their location to get to safety.

However, EEWS are not new. In fact, some have been active for decades. Japan has had a nationwide system since 2007; Taiwan since 2001. Mexico deployed their system, SASMEX, in the 1990s which has since been expanded. Systems have also been deployed in Chile, Canada and China and they are planned for Europe. All of these systems have elements in common, including sensors, connecting communications links, central processing computers and notification networks, and they have some differences, principally the elements of the software that need to be tailored to the geology of the region.

Most of these systems are local or regional; only the Taiwan and Japan systems are effectively nationwide. But 11 European and Mediterranean countries are planning a multinational system. Starting in 2006 the European Commission funded work on the Seismic Early Warning for Europe (SAFER), designed to alert citizens about seismic risk.