Is the earthquake coming? Are earthquakes predictable?

Question

I am not superstitious, and, last I heard, earthquakes are not predictable yet (or are they?). But I just got this e-mail announcing a big one for next week, in Central America. Why didn't I just delete the chain e-mail as I usually do? Darn!
So, ten days from now, I hope I'll be laughing off my fears. Meanwhile, I'll watch the ants and any odd behaviour in my pets.
Did earthquakes become predictable while I wasn't reading the news?
I'm such a wimp regarding tremors...

Answer 1

There are literally hundreds of earthquakes every day. Thankfully most are small.

Some faults are well documented and a loose prediction that they will slip sometime in the near to middle future can be made but with very little accuracy.

Answer 2

There's a good possibility that by 2030, scientists will have considerably more knowledge and technology to work with - but because it probably would still not be a proved technology, I doubt a highly populated city would be evacuated based on their findings at any given time. This would be especially true after a few false alarms. On a different note, hopefully California will still be there.

Answer 3

There is normally showing an increase in seismic activity. and they predict it off that but quite often the giant goes back to sleep.

Answer 4

ON THE PREDICTABILITY OF EARTHQUAKES

The dominant cooling mechanism on Earth is "plate tectonics", which involves the movement of 8 large plates and a few dozen smaller plates, the motion driven from beneath by convection within the mantle. On Earth, plate tectonics concentrates most of the volcanoes, earthquakes, and other tectonic features along plate margins rather than scattering them evenly throughout the crust. The San Andreas fault in California, for example, is a strike-slip fault at the interface between the Pacific plate (an oceanic plate) and the North American plate (a continental plate).

Geophysical faulting is a break in rock structure that occurs when pressures in the planet's crust are strong enough to cause fracture and displacement. A strike-slip fault is a movement parallel to the fault plane, the two plates shifting tangentially in opposite directions along their interface. The 2 other major types of faults are 1) the "normal" fault, which consists of a simple vertical shifting at the interface, one plate moving up and the other down, and 2) the thrust fault, which involves the edge of one plate sliding over (overlapping) the edge of the adjacent plate.

The term "dilatancy" refers in general to an increase in the volume of a rock deformed by pressure, the increase in volume caused by the expansion and extension of small cracks within the rock. The effect can be detected in strained rocks just before an earthquake, and is the basis of one type of earthquake prediction.

The following points are made by C.G. Sammis and D. Sornette (Proc. Nat. Acad. Sci. 2002 99:2501):

1) Are earthquakes predictable? The answer, of course, depends on what is meant by a "prediction". In the broadest sense, the plate tectonics paradigm makes predictions. It predicts that earthquakes are far more likely to occur at the boundaries between plates than within their interiors. Actually, plate tectonics theory was in part based on this "in-sample" observation, which is verified continuously "out-of-sample." It also predicts an overall rate to the process. Averaged over time, the summed moments of the earthquakes is consistent with the relative motion between the plates determined from the analysis of magnetic anomalies, correcting for aseismic visco-plastic deformations.

2) The forecasting of individual large events has been more problematical. Although the paleoseismological dating of large prehistoric earthquakes has confirmed the plate tectonics hypothesis, the timing between individual events is extremely erratic. For example, the average recurrence interval for the last ten large earthquakes on the San Andreas Fault north of Los Angeles is approximately 132 years. Because the long-term slip rate on the Southern San Andreas fault is approximately 3 centimeters per year, this corresponds to an average displacement of approximately 4 meters per large earthquake -- a very reasonable value. The problem is that the intervals between events range from 44 to 332 years. This lack of quasiperiodicity in large events is also evident in other predictions, and observations have dimmed the hope that large earthquakes can be forecast based solely on the past history of large events on the same fault.

3) An alternative forecasting strategy is based on physical precursors observed to occur just before macroscopic failure in the laboratory. Most of these precursors are associated with microfracture damage and the associated dilatancy observed to precede the formation of a macroscopic shear failure of rock specimens under compressive loading. These laboratory observations have been incorporated into the "dilatancy-diffusion model" for earthquakes. However, the search for physical precursors before large earthquakes has been disappointing. The high hopes raised by the reports of Chinese success in using physical precursors to forecast the 1975 Haicheng earthquake have dissipated with the worldwide failure to produce additional valid predictions.

4) In the US, current work on earthquake prediction is primarily based on the search for precursors to large events in the seismicity itself. One motivation comes from a statistical physics interpretation of regional seismicity as being characteristic of a system at or near a statistically stationary dynamical critical point dubbed "self-organized criticality". Such a self-organized critical state is characterized by power law distributions of event sizes and long-range spatial correlation of fluctuations around the statistically stationary state. Because earthquakes are indeed characterized by several power laws, the application of this concept of self-organized criticality to earthquakes is now often taken for granted in the seismological community. However, the implication of this self-organized critical (statistically stationary) state for the predictability of large earthquakes remains controversial.