Earthquake sensitivity and earthquake sensitive are pseudoscientific terms defined by Jim Berkland [1] 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". [2] Proponents have speculated [3] 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 [4] 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 [5] (other than foreshocks). [6] Aside from whether such phenomena can be detected (by any means), the "consistent failure to find reliable earthquake precursors" [7] has led many scientists to question whether such precursor phenomena even exist. [8]
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) [9] 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. [10]
On their side, the proponents claim that there have been "many scientific papers" supporting their views, [11] but "most have been totally rejected by the keepers of high wisdom." [12] While scientists are quick to dismiss theories they "know, or have good reason to believe, are not credible", [13] and especially predictions by amateurs on account of their lack of scientific rigor, [14] proponents claim that successful predictions can indicate a significant breakthrough, even if the details are not understood. [15] In this regard Berkland claims "a 75 percent accuracy rate of forecasting quakes." [16] However, these results (besides being disputed) [17] are irrelevant in demonstrating any kind of "earthquake sensitive" effect as Berkland's predictions appear to not involve such effects. [18]
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.
Seismology is the scientific study of earthquakes and the generation and propagation of elastic waves through the Earth or other planetary bodies. It also includes studies of earthquake environmental effects such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, glacial, fluvial, oceanic microseism, atmospheric, and artificial processes such as explosions and human activities. A related field that uses geology to infer information regarding past earthquakes is paleoseismology. A recording of Earth motion as a function of time, created by a seismograph is called a seismogram. A seismologist is a scientist works in basic or applied seismology.
Earthquake prediction is a branch of the science of seismology concerned with the specification of the time, location, and magnitude of future earthquakes within stated limits, and particularly "the determination of parameters for the next strong earthquake to occur in a region". Earthquake prediction is sometimes distinguished from earthquake forecasting, which can be defined as the probabilistic assessment of general earthquake hazard, including the frequency and magnitude of damaging earthquakes in a given area over years or decades.
A foreshock is an earthquake that occurs before a larger seismic event – the mainshock – and is related to it in both time and space. The designation of an earthquake as foreshock, mainshock or aftershock is only possible after the full sequence of events has happened.
The 1976 Tangshan earthquake was a Mw 7.6 earthquake that hit the region around Tangshan, Hebei, China, at 3:42 a.m. on 28 July 1976. The maximum intensity of the earthquake was XI (Extreme) on the Mercalli scale. In minutes, 85 percent of the buildings in Tangshan collapsed or were rendered unusable, all services failed, and most of the highway and railway bridges collapsed or were seriously damaged. The official report claimed 242,769 deaths and 164,851 serious injuries in Tangshan, but when taking into account the missing, the injured who later died and the deaths in nearby Beijing and Tianjin, scholars accepted at least 300,000 died, making it the deadliest earthquake in recorded history and one of the worst disasters in China by death toll.
The VAN method – named after P. Varotsos, K. Alexopoulos and K. Nomicos, authors of the 1981 papers describing it – measures low frequency electric signals, termed "seismic electric signals" (SES), by which Varotsos and several colleagues claimed to have successfully predicted earthquakes in Greece. Both the method itself and the manner by which successful predictions were claimed have been severely criticized. Supporters of VAN have responded to the criticism but the critics have not retracted their views.
Coulomb stress transfer is a seismic-related geological process of stress changes to surrounding material caused by local discrete deformation events. Using mapped displacements of the Earth's surface during earthquakes, the computed Coulomb stress changes suggest that the stress relieved during an earthquake not only dissipates but can also move up and down fault segments, concentrating and promoting subsequent tremors. Importantly, Coulomb stress changes have been applied to earthquake-forecasting models that have been used to assess potential hazards related to earthquake activity.
James O. Berkland was an American geologist who controversially claimed to be able to predict earthquakes, including the 1989 Loma Prieta earthquake and 1994 Northridge Earthquake and who popularized the idea that some people are earthquake sensitive. He was profiled in a popular 2006 book as The Man Who Predicts Earthquakes. The book includes a chapter that notes "Many of Berkland's theories--based on tides, moons, disoriented pets, lost cats and dogs, and magnetic field changes--were factors in the great Indian Ocean quake-tsunami disaster on December 26, 2004." but neither his methods nor his predictions have been published in any scientific journals for peer review. His results have been disputed by peers, with other scientists going so far as calling him a crank and a clown.
Earthquake forecasting is a branch of the science of seismology concerned with the probabilistic assessment of general earthquake seismic hazard, including the frequency and magnitude of damaging earthquakes in a given area over years or decades. While forecasting is usually considered to be a type of prediction, earthquake forecasting is often differentiated from earthquake prediction, Earthquake forecasting estimates the likelihood of earthquakes in a specific timeframe and region, while earthquake prediction attempts to pinpoint the exact time, location, and magnitude of an impending quake, which is currently not reliably achievable.Wood & Gutenberg (1935). Kagan says: "This definition has several defects which contribute to confusion and difficulty in prediction research." In addition to specification of time, location, and magnitude, Allen suggested three other requirements: 4) indication of the author's confidence in the prediction, 5) the chance of an earthquake occurring anyway as a random event, and 6) publication in a form that gives failures the same visibility as successes. Kagan & Knopoff define prediction "to be a formal rule where by the available space-time-seismic moment manifold of earthquake occurrence is significantly contracted ...."</ref> Both forecasting and prediction of earthquakes are distinguished from earthquake warning systems, which, upon detection of an earthquake, provide a real-time warning to regions that might be affected.
On February 4, 1975, at 19:36 CST, an earthquake of Ms 7.5 and intensity (MMI) IX hit the city of Haicheng, Liaoning, China. Much of the city was evacuated before the earthquake, so few died from building collapse; however, many died from fire and hypothermia in the subsequent days. The evacuees lived during the deep winter in self-made tents made of tree branches, bed sheets, tarps and straw, 372 froze to death and 6,578 suffered frostbite, while a fire burned 341 to death and 980 suffered non-fatal burns. The fire was one of the most notable earthquake-induced fires in China, triggered from a combination of cooking, winter heating and lighting.
The 1995 Antofagasta earthquake occurred on July 30 at 05:11 UTC with a moment magnitude of 8.0 and a maximum Mercalli intensity of VII. The Antofagasta Region in Chile was affected by a moderate tsunami, with three people killed, 58 or 59 injured, and around 600 homeless. Total damage from the earthquake and tsunami amounted to $1.791 million.
QuakeFinder is a company focused on developing a system for earthquake prediction. QuakeFinder operates as a project of aerospace engineering firm Stellar Solutions, and by subscriptions and sponsorships from the public.
Seismo-electromagnetics are various electro-magnetic phenomena believed to be generated by tectonic forces acting on the Earth's crust, and possibly associated with seismic activity such as earthquakes and volcanoes. Study of these has been prompted by the prospect they might be generated by the increased stress leading up to an earthquake, and might thereby provide a basis for short-term earthquake prediction. However, despite many studies, no form of seismo-electromagnetics has been shown to be effective for earthquake prediction. A key problem is that earthquakes themselves produce relatively weak electromagnetic phenomena, and the effects from any precursory phenomena are likely to be too weak to measure. Close monitoring of the Parkfield earthquake revealed no significant pre-seismic electromagnetic effects. However, some researchers remain optimistic, and searches for seismo-electromagnetic earthquake precursors continue.
Shear wave splitting, also called seismic birefringence, is the phenomenon that occurs when a polarized shear wave enters an anisotropic medium. The incident shear wave splits into two polarized shear waves. Shear wave splitting is typically used as a tool for testing the anisotropy of an area of interest. These measurements reflect the degree of anisotropy and lead to a better understanding of the area's crack density and orientation or crystal alignment. We can think of the anisotropy of a particular area as a black box and the shear wave splitting measurements as a way of looking at what is in the box.
The 2002 Sumatra earthquake occurred at 01:26 UTC on 2 November. It had a magnitude of 7.4 on the moment magnitude scale with an epicenter just north of Simeulue island and caused three deaths. This earthquake is regarded as a foreshock of the 2004 Indian Ocean earthquake, which had an epicenter about 60 km to the northwest.
The 1893 Quchan earthquake occurred at about 19:30 local time on 17 November. It had an estimated magnitude of 6.6 on the surface-wave magnitude scale and a maximum perceived intensity of IX (Violent) on the Mercalli intensity scale. It caused severe damage in Quchan County, particularly to the town of Quchan itself and there were an estimated 18,000 casualties.
The 1895 Quchan earthquake occurred at about 11:30 local time on 17 January. It had an estimated magnitude of 6.8 on the surface-wave magnitude scale and a maximum perceived intensity of VIII (Severe) on the Mercalli intensity scale. It caused severe damage in Quchan County, particularly to the town of Quchan itself and there were an estimated 1,000–11,000 casualties. It was the last in a sequence of major damaging earthquakes that struck the area between 1851 and 1895.
Tidal triggering of earthquakes is the idea that tidal forces may induce seismicity.
Rachel Abercrombie is a seismologist at Boston University known for her research on the process of earthquake ruptures.
The earthquake cycle refers to the phenomenon that earthquakes repeatedly occur on the same fault as the result of continual stress accumulation and periodic stress release. Earthquake cycles can occur on a variety of faults including subduction zones and continental faults. Depending on the size of the earthquake, an earthquake cycle can last decades, centuries, or longer. The Parkfield portion of the San Andreas fault is a well-known example where similarly located M6.0 earthquakes have been instrumentally recorded every 30–40 years.
The 1977 Bob–Tangol earthquake struck Kerman province of Iran on December 20, 1977, at 03:04 Iran Standard Time. The earthquake measured Mw 5.9 and struck at a depth of 22.7 km (14.1 mi). A maximum Modified Mercalli intensity of VII was evaluated based on damage. It had a strike-slip focal mechanism, which was unusual as the source structure was a thrust fault. It was part of a sequence of strong earthquakes along the 400 km (250 mi) Kuh Banan Fault. Between 584 and 665 people perished while a further 500–1,000 were injured; thousands were also made homeless. Casualties from the earthquake was considered moderate due to the sparsely populated area it affected. Preceded by foreshocks the month before, many residents became wary of a larger earthquake and took refuge outside their homes, contributing to the moderate death toll. However, there were none immediately before the mainshock so many were still in their homes when it struck. Aftershocks were felt for several months, some causing additional damage.