Earthquake sensitivity and earthquake sensitive are pseudoscientific terms defined by Jim Berkland to refer to certain people who claim sensitivity to the precursors of impending earthquakes, manifested in "dreams or visions, psychic impressions, or physiological symptoms", the latter including "ear tones" (ringing in the ears), headaches, and agitation. It is claimed that "[a] person with a very sensitive body may also have some subtle reaction to whatever animals react to". Proponents have speculated that these may result from: 1) piezoelectric effects due to changes in the stress of the earth's crust, 2) low-frequency electromagnetic signals, or 3) from the emission of radon gas.
Although proponents suggest the possibility that the claimed effects might work through known physical phenomena, and thus be amenable to scientific study, these claims are pseudoscientific in that no evidence of such effects, nor any theory of how such effects might be perceived, has been presented in the scientific literature. What the scientific literature does have is various reports showing that animals do not show disturbed or altered behavior attributable to earthquake precursors (other than foreshocks ). Aside from whether such phenomena can be detected (by any means), the "consistent failure to find reliable earthquake precursors" has led many scientists to question whether such precursor phenomena even exist.
Could "earthquake sensitives" be responding to some kind of "psychic impressions" or other paranormal phenomena as yet unknown to science? After reviewing the scientific literature the International Commission on Earthquake Forecasting for Civil Protection (ICEF) concluded that
there is no credible scientific evidence that animals display behaviors indicative of earthquake-related environmental disturbances that are unobservable by the physical and chemical sensor systems available to earthquake scientists.
On their side, the proponents claim that there have been "many scientific papers" supporting their views, but "most have been totally rejected by the keepers of high wisdom." While scientists are quick to dismiss theories they "know, or have good reason to believe, are not credible", and especially predictions by amateurs on account of their lack of scientific rigor, proponents claim that successful predictions can indicate a significant breakthrough, even if the details are not understood. In this regard Berkland claims "a 75 percent accuracy rate of forecasting quakes." However, these results (besides being disputed) are irrelevant in demonstrating any kind of "earthquake sensitive" effect as Berkland's predictions appear to not involve such effects.
Berkland ceased posting his predictions after June 2010. Though a few others have continued to post their predictions on Berkland's website, there appears to be no effort to correlate "ear tones" or any other physiological effect with subsequent earthquakes.
- Orey 2006, p. 261.
- Reneau Z. Peurifoy, quoted in Orey 2006, pp. 65–66.
- Orey 2006, p. 66.
- Shermer 1997, p. 33.
- In several studies direct observation of animals showed no signs of anomalous animal behavior preceding an earthquake (Lighton & Duncan 2005; Kenagy & Enright 1979; Lindberg, Skiles & Hayden 1981). A study of anomalous animal behavior reported to a hotline prior to an earthquake found no significant increase (Otis & Kautz 1979). A claim that advertisements for missing pets increase prior to an earthquake (also touted by Berkland as a means for predicting earthquakes [Orey 2006, p. 263]) was disproven by Schaal (1988).
Animals have been observed reacting to the P-waves that may arrive some tens of seconds before the more severe, but slower, S-waves. However, the P-waves do not precede the earthquake, but only the arrival of the S-waves at locations distant from an earthquake that has already happened.
- Animals, like humans, do react to foreshocks. However, foreshocks are not reliable earthquake precursors: in some cases they are followed by a larger earthquake, but in many cases they are not, and as yet no way has been found to determine whether any cluster or swarm of small earthquakes will lead to an imminent, larger earthquake (ICEF 2011, p. 336; Brodsky & Lay 2014).
- Zechar & Jordan 2008, p. 723. Geller (1997, p. 425) had previously noted that "[e]xtensive searches have failed to find reliable precursors." A assessment in 2011 again noted that, despite a century of study, "[t]he search for diagnostic precursors has thus far been unsuccessful" (ICEF 2011, p. 338).
- Geller et al. 1997; Matthews 1997.
- A panel of internationally recognized earthquake experts convened at the request of the Italian government after the 2009 L'Aquila earthquake.
- ICEF 2011, p. 336.
- Orey 2006, p. 29. Geller (1997, p. 432) and the ICEF (2011, p. 336) reviewed a number of such papers. Such papers are generally collections of anecdotal reports that lack scientific validity. Geller describes them as "doubly dubious".
- Orey 2006, p. 29. Susan Hough, a seismologist at the U.S. Geological Survey, notes "variations on a drumbeat theme that we are hegemonical, close-minded, unwilling to acknowledge or accept breakthroughs that come from outside the ranks." (Hough 2010, p. 166).
- Hough 2010, p. 165.
- Hough 2010, p. 165. In seismology an earthquake prediction must specify the time, location, and magnitude of a future earthquake with sufficient specificity that measures can be taken that will mitigate serious harm (Geller 1997, p. 425). Any evaluation of a prediction method must specify its failure rate as well as its success rate, with complete documentation of all predictions to avoid "cherry picking" of just the successful cases. To be deemed successful prediction methods must be statistically significant. That is, successful beyond random chance (Mulargia & Gasperini 1992, p. 32). Amateurs seldom understand the need for such rigor, and even scientists are occasionally criticized for being vague and ambiguous (Geller 1996, p. 436), or failing to consider alternative explanations (e.g., McClellan 1980). See Earthquake prediction for more information.
- Berkland has said: "The only real test of the efficiency of a predictive method is: How close do future events correspond to the earlier extrapolations?" (Berkland 1990).
- Orey 2006, p. 45. This statement is problematical. For seismologists forecasting usually means a probabilistic estimate of general earthquake hazard, of the frequency and magnitude of earthquakes in a given area, generally over periods of years or decades. Prediction is distinguished as a definite statement of the time and magnitude of the next earthquake expected in a given area. In this instance it appears that "forecast" is being used in the sense of prediction.
- Hunter (2006) analyzed Berkland's predictions, and found them no better than chance.
- In 1990 Berkland described his method as the "Seismic Window Theory" (based on tidal stresses when the sun and moon are aligned, known as syzygy) (Berkland 1990). Orey (2006, p. 29) described Berkland's method as the"Three Double G" system: 1) "the gravity gradient, or the forces exacted on the earth by the gravitational pull of the Sun and the Moon." 2) "Gone Gatos" – missing cats, as indicated by advertisements in several newspapers. 3) "Geyser Gaps", seen as irregularities in the behavior of a geyser in the Napa Valley. Hunter (2006) found "a hodge-podge of factors", but apparently none of these involve human sensitivities of any kind.
- Berkland, Jim (November 29, 1990), "Bring in the Clowns", Report to the California Commission of Earthquake Preparedness and Natural Hazards, archived from the original on March 7, 2016.
- Brodsky, Emily E.; Lay, Thorne (16 May 2014), "Recognizing Foreshocks from the 1 April 2014 Chile Earthquake", Science, 344 (6185): 700–702, doi:10.1126/science.1255202, PMID 24833379.
- Geller, Robert J. (December 1997), "Earthquake prediction: a critical review.", Geophysical Journal International, 131 (3): 425–450, Bibcode:1997GeoJI.131..425G, doi:10.1111/j.1365-246X.1997.tb06588.x.
- Geller, Robert J.; Jackson, David D.; Kagan, Yan Y.; Mulargia, Francesco (14 March 1997), "Earthquakes Cannot Be Predicted" (PDF), Science, 275: 1616, doi:10.1126/science.275.5306.1616.
- Hough, Susan (2010), Predicting the Unpredictable: The Tumultuous Science of Earthquake Prediction, Princeton University Press, ISBN 978-0-691-13816-9.
- Hunter, Roger (September 2006), "Can Jim Berkland predict earthquakes?", Skeptical Inquirer, vol. 30 no. 5, pp. 47–50.
- International Commission on Earthquake Forecasting for Civil Protection (30 May 2011), "Operational Earthquake Forecasting: State of Knowledge and Guidelines for Utilization", Annals of Geophysics, 54 (4): 315–391, doi:10.4401/ag-5350.
- Kenagy, G. J.; Enright, J. T. (1979), "Animal Behavior as a Predictor of Earthquakes: An Analysis of Rodent Activity", Open-File Report 80-453, U.S. Geological Survey.
- Lighton, John R.B.; Duncan, Frances D. (15 August 2005), "Shaken, not stirred: a serendipitous study of ants and earthquakes" (PDF), Journal of Experimental Biology, 208: 3103–3107, doi:10.1242/jeb.01735.
- Lindberg, Robert G.; Skiles, Durward; Hayden, Page (1981), "Can animals predict earthquakes? A search for correlations between changes in activity patterns of two fossorial rodents and subsequent seismic events" (PDF), Open-File Report 81-385, U.S. Geological Survey.
- Matthews, Robert A. J. (December 1997), "Decision-theoretic limits on earthquake prediction", Geophysical Journal International, 131 (3): 526–529, Bibcode:1997GeoJI.131..526M, doi:10.1111/j.1365-246X.1997.tb06596.x.
- McClellan, Patrick H. (May 1980), "Preearthquake Animal Behavior, A Closer Look for Alternative Causes", Geophysical Research Letters, 5 (5): 333–336, doi:10.1029/gl007i005p00333.
- Mulargia, Francesco; Gasperini, Paolo (1992), "Evaluating the statistical validity beyond chance of 'VAN' earthquake precursors" (PDF), Geophysical Journal International, 111: 32–44, Bibcode:1992GeoJI.111...32M, doi:10.1111/j.1365-246X.1992.tb00552.x.
- Orey, Cal (2006), The Man Who Predicts Earthquakes: Jim Berkland, Maverick Geologist: How His Quake Warnings Can Save Lives, Sentient Publications.
- Otis, Leon; Kautz, William (1979), "Biological premonitions of earthquakes: a validation study", Open-File Report 80-453, U.S. Geological Survey, pp. 225–226.
- Schaal, Rand B. (February 1988), "An evaluation of the animal-behavior theory for earthquake predictions" (PDF), California Geology, 41 (2): 41–45.
- Shermer, Michael (1997), Why People Believe Weird Things: Pseudoscience, Superstition, and Other Confusions of Our Time, W.H. Freeman and Company, ISBN 0-7167-3090-1.
- Zechar, J. Douglas; Jordan, Thomas H. (2008), "Testing alarm-based earthquake predictions" (PDF), Geophysical Journal International, 172 (2): 715–724, Bibcode:2008GeoJI.172..715Z, doi:10.1111/j.1365-246X.2007.03676.x.
- http://www.syzygyjob.com Jim Berkland's earthquake prediction website. (Inactive since June 2010.)