Earthquake Early Warnings- Saving Lives in Earthquake Prone Countries

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Since the time earthquake monitoring began, scientists have wondered if earthquake prediction is possible. Some scientists attempted to link earthquakes with previous seismic activity, radon emissions, changes in the magnetic field and animal behavior. None of these earthquake “prediction” attempts were successful. 

The QuakeGuard Warning System

In the 1990’s, a commercial group began producing QuakeGuard Seismic Warning Systems that use a seismometer placed under a location that detects the harmless, fast moving primary waves of an earthquake, that arrive before more damaging S and Surface waves. The system then alerts the user by setting off an alarm, and sometimes even shutting off the gas supply before the arrival of the damaging Surface waves. QuakeGuard was the first operational version of an earthquake early warning system that was able to alert users tens of seconds ahead of a large earthquake, with no false positives. 

Kobe Earthquake Damage

In the 1990's seismologists in Mexico City created a simple earthquake early warning system that involved seismometers placed on a fault off the coast. When shaking was detected by the seismometers,  sirens in the city would sound, giving precious seconds to evacuate un-reinforced buildings.

On January 17, 1995 at 5:46am (Japan Standard Time), a 6.8 magnitude earthquake struck Kobe, the capital of Hyogo Prefecture in Japan. The quake killed over 140,000 people and caused about 100 billion dollars in damages. 

Following the quake Japan started work on a nation-wide earthquake early warning system to help save lives in the event of another major earthquake. This system implemented 4,235 seismometers throughout the country to estimate the intensity of an earthquake and to deliver an early warning to all of its users in the affected areas. The system was first implemented to slow down bullet trains and finally, on October 1, 2007, was put into place nationally. It was ready to alert millions through text messages, TV alerts, radio broadcasts, sirens, and government approved Earthquake Early Warning compatible products.

The system proved its usefulness when on March 11, 2011 at 2:46pm (Japan Standard Time); a 9.0 megathrust earthquake struck its coast. Eight seconds after the earthquake began, seismometers offshore Miyagi Prefecture recognized the fastest moving (P) waves of earthquake and immediately sent earthquake early warnings to the Tohoku Region of Japan. Earthquake early warning messages interrupted radio and TV broadcasts automatically. Two sets of computer generated chimes rang, followed by a prerecorded announcement of a man saying the following, “緊急地震速報です。強い揺れに警戒して下さい。 (Kinkyu jishin sokuho desu. Tsuyoi yure ni kekai shite kudasai.)” Translated, the passage reads, “This is an earthquake early warning. Please prepare for powerful tremors.” Although the city of Tokyo received up to a minute of warning time, in Sendai (closest to the epicenter) the warning was only fifteen seconds. Although fifteen seconds may not seem like much time, five seconds is a sufficient amount of time to duck and cover under a sturdy desk. Few people died in the earthquake’s shaking, proving the system’s effectiveness. Unfortunately the tsunami that followed killed 15,845 people with 3,380 people still missing, creating a need for larger seawalls and more efficient tsunami warnings.

Seismologists from Caltech, USGS Pasadena, USGS Menlo Park, and UC Berkeley, have teamed together with the California Integrated Seismic Network to create and perfect an earthquake early warning system for California, and later for the entire United States Pacific Coast. In 2011 a rough earthquake early warning system was created, and is currently being tested by selected seismologists, the Bay Area Rapid Transit System, and other companies and government organizations throughout California. 

Like most functioning systems, there are some issues:

1. Point Source Approximation. The system is only able to perceive that an earthquake radiates from  one point, not a rupture along a fault line.
2. Seismometer spacing. There are few seismometers along the Central California and Northern California Coast to detect earthquakes quickly. Seismometer spacing must be reduced to 12 miles apart from each other.

3. Funding. A system along the West Coast would cost approximately one-hundred and fifty-million dollars over five years to perfect, and several million dollars more per year to fund. 

On November 29, 2012 the Gordon and Betty Moore Foundation provided a 6 million dollar grant to help fund the Earthquake Early Warning System. Although a system would cost over $150,000,000, it would, in the long run, lessen costs of damages by earthquakes, by stopping production lines, and other sensitive industries, and will reduce personal injury caused by falling debris.

Update: 1/29/13 In January 2013 a bill was created to possibly fund an $80 million dollar earthquake early warning system for California.

Earthquake Early Warnings have saved lives in many earthquake prone countries over the past few years. Unfortunately it often takes the loss of thousands of lives to fund such a system. Hopefully, a system will be publicly implemented on the West Coast of the United States without another devastating earthquake to catapult its creation.

Information retrieved from:
http://www.jma.go.jp/jma/en/Activities/eew.html 

http://www.eew.caltech.edu/

www.cisn.org/eew/