Earthquake Scientists Focus on the Southern San Andreas Fault

The Associated Press reported an important story in the field of geological science and technology. In Thermal, California, the southern end of the San Andreas Fault is being wired with high-tech sensors that scientists hope will tell them (in advance) when the next high magnitude earthquake will strike. This examination could prove to be right on time, as a swarm of more than 250 earthquakes has shaken the desert for a week where the first new seismic instruments were installed earlier this year. Scientists are paying the closest attention to the forgotten southernmost section, which has not ruptured in over three centuries and is thought to be the most likely to break next.

The USGS currently maintains an expansive network of 300 seismic stations across the state. They automatically estimate a temblor's size when the ground shakes and send real-time data to a central hub in Pasadena, alerting that an earthquake has hit. Scientists are putting great effort into this section of the fault by adding 11 new seismic stations and update six old ones. The entire southern end upgrade will cost more than $500,000, which is financed by a USGS grant. The instruments cost $40,000 plus an extra $15,000 for solar panels, antennas, construction and labor.

By clustering sensors along the southern edge, scientists hope to get faster readings of when quakes occur on the San Andreas and to better understand the science behind how faults break. Eventually, they hope the sensors could be incorporated into an early warning system in Southern California, but unfortunately, this goal is probably still years away.

California faces a 99.7 percent chance of experiencing a magnitude 6.7 quake or larger in the next 30 years, according to the USGS. A temblor that size would be similar to the 1994 Northridge disaster, which killed 72 people and caused $25 billion in damage. The geological survey put the odds of a "Big One" — a magnitude 7.5 or larger — during the same period at 46 percent. Of all the faults in the state, the southern San Andreas is the most ready to go, scientists say.

Source: Associated Press