Can you predict earthquakes?
No. Neither the USGS nor any other scientists have ever predicted a major earthquake. We do not know how, and we do not expect to know how any time in the foreseeable future. An earthquake prediction must define 3 elements: 1) the date and time, 2) the location, and 3) the magnitude.
Yes, some people say they can predict earthquakes, but here are the reasons why their statements are false:
- They are not based on scientific evidence, and earthquakes are part of a scientific process. For example, earthquakes have nothing to do with clouds, bodily aches and pains, or slugs.
- They do not define all 3 of the elements required for a prediction.
- Their predictions are so general that there will always be an earthquake that fits; such as, (a) There will be a M4 earthquake somewhere in the U.S. in the next 30 days. (b) There will be a M2 earthquake on the west coast of the U.S. today.
If an earthquake happens to occur that remotely fits their prediction, they claim success even though 1-3 of the predicted elements is wildly different than what occurred, therefore a failed prediction.
Predictions (by non-scientists) usually start swirling around social media when something happens that is thought to be a precursor to an earthquake in the near future. The so-called precursor is often a swarm of small earthquakes, increasing amounts of radon in local water, unusual behavior of animals, increasing size of magnitudes in moderate size events, or a moderate-magnitude event rare enough to suggest that it may be a foreshock.
Unfortunately, most such precursors frequently occur without being followed by an earthquake, so a real prediction is not possible. Instead, if there is a scientific basis, a forecast may be made in probabilistic terms. To learn what a probability is and how they work, see the FAQ under Seismic HazardsMaps, Probabilities, and EQ Engineering - Are earthquake probabilities or forecasts the same as prediction?
An earthquake forecast was made in China several decades ago, based on small earthquakes and unusual animal activity. Many people chose to sleep outside of their homes and thus were spared when the main earthquake indeed occurred and caused widespread destruction. However, usually no large earthquake follows this type of seismic activity, and, unfortunately, many earthquakes are preceded by no precursory events whatsoever. The next large Chinese event was entirely unheralded and scores of thousands of Chinese died.
The USGS focuses its efforts on the long-term mitigation of earthquake hazards by helping to improve the safety of structures, rather than by trying to accomplish short-term predictions.
New Audiences, New Products for the National Seismic Hazard Maps
Throughout California April is recognized as Earthquake Preparedness Month. This Thursday's lecture, "Predictable Earthquakes", will provide an update on the current ability of scientists to predict potentially destructive earthquakes and to separate fact from fiction from this intriguing topic.
USGS map displaying potential to experience damage from a natural or human-induced earthquake in 2017. Chances range from less than one percent to 12 percent.
Fairweather fault lidar
Damage from the 1964 Alaskan Earthquake. Credit: USGS
Aerial photo of the San Andreas Fault in the Carrizo Plain. By Ikluft - Own work, GFDL, https://commons.wikimedia.org/w/index.php?curid=3106006
This database contains information on faults and associated folds in the United States that demonstrate geological evidence of coseismic surface deformation in large earthquakes during the Quaternary (the past 1.6 million years).