Microseismic Emission Precursors

This may be of particular interest to those of us living near seismically active areas. Interpretation of microseismic emission precursors may represent a possible breakthrough on earthquake prediction:

Prelude to an Earthquake?

A geophysicist from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has identified possible seismic precursors to two recent California earthquakes, including the 1989 Loma Prieta earthquake that wreaked havoc throughout the Bay Area.

After sifting through seismic data from the two quakes, Valeri Korneev found a spike in the number of micro-earthquakes followed by a period of relative calm in the crust surrounding the quakes’ epicenters — months before the quakes occurred. Although more work needs to be conducted to determine whether other large quakes are foreshadowed by a similar rise and subsequent decline in small-magnitude tremors, Korneev’s analysis suggests that these peaks may be indicative of the total set of geological stresses that affect the timing and location of large earthquakes. Understanding this total stress picture may eventually make it be possible to predict destructive earthquakes within a much shorter time frame than currently possible.

Photo: 1989 Quake Damage to Interstate 880 – S.F. Chronicle

Peaks in seismic activity in the crust surrounding a fault could help signal the arrival of large earthquakes,” says Korneev of Berkeley Lab’s Earth Sciences Division. “These peaks may be a good mid-term precursor and allow authorities to declare alerts several months before earthquakes.”

Read the rest of the article at Science Blog: Prelude to an Earthquake?

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