Editing Earthquake prediction (section)

== Notable predictions ==
These are predictions, or claims of predictions, that are notable either scientifically or because of public notoriety, and claim a scientific or quasi-scientific basis. As many predictions are held confidentially, or published in obscure locations, and become notable only when they are claimed, there may be a [[selection bias]] in that hits get more attention than misses. The predictions listed here are discussed in Hough's book<ref name=":3"/> and Geller's paper.<ref>{{Harvnb|Geller|1997|loc=§4}}.</ref>

=== 1975: Haicheng, China ===
{{anchor|Haicheng}}

The M 7.3 [[1975 Haicheng earthquake]] is the most widely cited "success" of earthquake prediction.<ref>E.g.: {{Harvnb|Davies|1975}}; {{Harvnb|Whitham|Berry|Heidebrecht|Kanasewich|1976|p=265}}; {{Harvnb|Hammond|1976}}; {{Harvnb|Ward|1978}}; {{Harvnb|Kerr|1979|p=543}}; {{Harvnb|Allen|1982|p=S332}}; {{Harvnb|Rikitake|1982}}; {{Harvnb|Zoback|1983}}; {{Harvnb|Ludwin|2001}}; {{Harvnb|Jackson|2004|pp=335, 344}}; {{Harvnb|ICEF|2011|p=328}}.</ref> The ostensible story is that study of seismic activity in the region led the Chinese authorities to issue a medium-term prediction in June 1974, and the political authorities therefore ordered various measures taken, including enforced evacuation of homes, construction of "simple outdoor structures", and showing of movies out-of-doors. The quake, striking at 19:36, was powerful enough to destroy or badly damage about half of the homes. However, the "effective preventative measures taken" were said to have kept the death toll under 300 in an area with population of about 1.6 million, where otherwise tens of thousands of fatalities might have been expected.<ref>{{Harvtxt|Whitham|Berry|Heidebrecht|Kanasewich|1976|p=266}} provide a brief report. {{Harvtxt|Raleigh|Bennett|Craig|Hanks|1977}} has a fuller account. {{Harvtxt|Wang|Chen|Sun|Wang|2006|p=779}}, after careful examination of the records, set the death toll at 2,041.</ref>

However, although a major earthquake occurred, there has been some skepticism about the narrative of measures taken on the basis of a timely prediction. This event occurred during the [[Cultural Revolution]], when "belief in earthquake prediction was made an element of ideological orthodoxy that distinguished the true party liners from right wing deviationists".<ref>{{Harvnb|Raleigh|Bennett|Craig|Hanks|1977|p=266}}, quoted in {{Harvtxt|Geller|1997|p=434}}. Geller has a whole section (§4.1) of discussion and many sources. See also {{Harvnb|Kanamori|2003|pp=1210–11}}.</ref> Recordkeeping was disordered, making it difficult to verify details, including whether there was any ordered evacuation. The method used for either the medium-term or short-term predictions (other than "Chairman Mao's revolutionary line"<ref>Quoted in {{Harvtxt|Geller|1997|p=434}}. {{Harvtxt|Lomnitz|1994|loc=Ch. 2}} describes some of circumstances attending to the practice of seismology at that time; {{Harvnb|Turner|1993|pp=456–458}} has additional observations.</ref>) has not been specified.{{efn|1=Measurement of an uplift has been claimed, but that was 185&nbsp;km away, and likely surveyed by inexperienced amateurs.<ref>{{Harvnb|Jackson|2004|p=345}}.</ref>}} The evacuation may have been spontaneous, following the strong (M 4.7) foreshock that occurred the day before.<ref>{{Harvnb|Kanamori|2003|p=1211}}.</ref>{{efn|1=According to {{Harvtxt|Wang|Chen|Sun|Wang|2006|p=762}} foreshocks were widely understood to precede a large earthquake, "which may explain why various [local authorities] made their own evacuation decisions".}}

A 2006 study that had access to an extensive range of records found that the predictions were flawed. "In particular, there was no official short-term prediction, although such a prediction was made by individual scientists."<ref name=":13">{{Harvnb|Wang|Chen|Sun|Wang|2006|p=785}}.</ref> Also: "it was the foreshocks alone that triggered the final decisions of warning and evacuation". They estimated that 2,041 lives were lost. That more did not die was attributed to a number of fortuitous circumstances, including earthquake education in the previous months (prompted by elevated seismic activity), local initiative, timing (occurring when people were neither working nor asleep), and local style of construction. The authors conclude that, while unsatisfactory as a prediction, "it was an attempt to predict a major earthquake that for the first time did not end up with practical failure."<ref name=":13"/>

{{further|1975 Haicheng earthquake}}

===1981: Lima, Peru (Brady)===
{{anchor|Lima}}{{anchor|Brady}}{{anchor|Brady-Spence}}

In 1976, Brian Brady, a physicist, then at the [[U.S. Bureau of Mines]], where he had studied how rocks fracture, "concluded a series of four articles on the theory of earthquakes with the deduction that strain building in the subduction zone [off-shore of Peru] might result in an earthquake of large magnitude within a period of seven to fourteen years from mid November 1974."<ref name=":14">{{Harvnb|Roberts|1983|loc=§4|p=151}}.</ref> In an internal memo written in June 1978 he narrowed the time window to "October to November, 1981", with a main shock in the range of 9.2±0.2.<ref>{{Harvnb|Hough|2010|p=114}}.</ref> In a 1980 memo he was reported as specifying "mid-September 1980".<ref>{{Harvnb|Gersony|1982|p=231}}.</ref> This was discussed at a scientific seminar in San Juan, Argentina, in October 1980, where Brady's colleague, W. Spence, presented a paper. Brady and Spence then met with government officials from the U.S. and Peru on 29 October, and "forecast a series of large magnitude earthquakes in the second half of 1981."<ref name=":14"/> This prediction became widely known in Peru, following what the U.S. embassy described as "sensational first page headlines carried in most Lima dailies" on January 26, 1981.<ref>{{Harvnb|Gersony|1982|loc=document 85|p=247}}.</ref>

On 27 January 1981, after reviewing the Brady-Spence prediction, the U.S. [[National Earthquake Prediction Evaluation Council]] (NEPEC) announced it was "unconvinced of the scientific validity" of the prediction, and had been "shown nothing in the observed seismicity data, or in the theory insofar as presented, that lends substance to the predicted times, locations, and magnitudes of the earthquakes." It went on to say that while there was a probability of major earthquakes at the predicted times, that probability was low, and recommend that "the prediction not be given serious consideration."<ref>{{Harvnb|Gersony|1982|loc=document 86|p=248}}; {{Harvnb|Roberts|1983|p=151}}.</ref>

Unfazed,{{efn|1=The chairman of the NEPEC later complained to the Agency for International Development that one of its staff members had been instrumental in encouraging Brady and promulgating his prediction long after it had been scientifically discredited.<ref>{{Harvnb|Gersony|1982|loc=document 146|p=201}}.</ref>}} Brady subsequently revised his forecast, stating there would be at least three earthquakes on or about July 6, August 18 and September 24, 1981,<ref>{{Harvnb|Gersony|1982|loc=document 116|p=343}}; {{Harvnb|Roberts|1983|p=152}}.</ref> leading one USGS official to complain: "If he is allowed to continue to play this game ... he will eventually get a hit and his theories will be considered valid by many."<ref>John Filson, deputy chief of the USGS Office of Earthquake Studies, quoted by {{Harvtxt|Hough|2010|p=116}}.</ref>

On June 28 (the date most widely taken as the date of the first predicted earthquake), it was reported that: "the population of Lima passed a quiet Sunday".<ref>{{Harvnb|Gersony|1982|loc=document 147|p=422}}, U.S. State Dept. cablegram.</ref> The headline on one Peruvian newspaper: "NO PASÓ NADA" ("Nothing happened").<ref>{{Harvnb|Hough|2010|p=117}}.</ref>

In July Brady formally withdrew his prediction on the grounds that prerequisite seismic activity had not occurred.<ref>{{Harvnb|Gersony|1982|p=416}}; {{Harvnb|Kerr|1981}}.</ref> Economic losses due to reduced tourism during this episode has been roughly estimated at one hundred million dollars.<ref>{{Harvnb|Giesecke|1983|p=68}}.</ref>

=== 1985–1993: Parkfield, U.S. (Bakun-Lindh) ===
{{anchor|Parkfield}}

The "[[Parkfield earthquake]] prediction experiment" was the most heralded scientific earthquake prediction ever.<ref>{{Harvtxt|Geller|1997|loc=§6}} describes some of the coverage.</ref>{{efn|1=The most ''anticipated'' prediction ever is likely [[#1990: New Madrid, U.S. (Browning)|Iben Browning's 1990 New Madrid prediction]], but it lacked any scientific basis.}} It was based on an observation that the Parkfield segment of the [[San Andreas Fault]]{{efn|1=Near the small town of [[Parkfield, California]], roughly halfway between San Francisco and Los Angeles.}} breaks regularly with a moderate earthquake of about M 6 every several decades: 1857, 1881, 1901, 1922, 1934, and 1966.<ref>{{Harvnb|Bakun|McEvilly|1979}}; {{Harvnb|Bakun|Lindh|1985}}; {{Harvnb|Kerr|1984}}.</ref> More particularly, {{Harvtxt|Bakun|Lindh|1985}} pointed out that, if the 1934 quake is excluded, these occur every 22 years, ±4.3 years. Counting from 1966, they predicted a 95% chance that the next earthquake would hit around 1988, or 1993 at the latest. The [[National Earthquake Prediction Evaluation Council]] (NEPEC) evaluated this, and concurred.<ref>{{Harvnb|Bakun|Breckenridge|Bredehoeft|Burford|1987}}.</ref> The U.S. Geological Survey and the State of California therefore established one of the "most sophisticated and densest nets of monitoring instruments in the world",<ref>{{Harvnb|Kerr 1984, "How to Catch an Earthquake"}}; {{Harvnb|Roeloffs|Langbein|1994}}.</ref> in part to identify any precursors when the quake came. Confidence was high enough that detailed plans were made for alerting emergency authorities if there were signs an earthquake was imminent.<ref>{{Harvnb|Roeloffs|Langbein|1994|p=316}}.</ref> In the words of ''[[The Economist]]'': "never has an ambush been more carefully laid for such an event."<ref>Quoted by {{Harvnb|Geller|1997|p=440}}.</ref>

1993 came, and passed, without fulfillment. Eventually there was an M 6.0 earthquake on the Parkfield segment of the fault, on 28 September 2004, but without forewarning or obvious precursors.<ref>{{Harvnb|Kerr|2004}}; {{Harvnb|Bakun|Aagaard|Dost|Ellsworth|2005}}, {{Harvnb|Harris|Arrowsmith|2006|p=S5}}.</ref> While the ''experiment'' in catching an earthquake is considered by many scientists to have been successful,<ref>{{Harvnb|Hough|2010b|p=52}}.</ref> the ''prediction'' was unsuccessful in that the eventual event was a decade late.{{efn|1=It has also been argued that the actual quake differed from the kind expected,<ref name=":10"/> and that the prediction was no more significant than a simpler null hypothesis.<ref>{{Harvnb|Kagan|1997}}.</ref>}}

{{further|Parkfield earthquake}}

=== 1983–1995: Greece (VAN) ===
{{anchor|VAN}}
In 1981, the "VAN" group, headed by Panayiotis Varotsos, said that they found a relationship between earthquakes and 'seismic electric signals' (SES). In 1984 they presented a table of 23 earthquakes from 19 January 1983 to 19 September 1983, of which they claimed to have successfully predicted 18 earthquakes.<ref>{{Harvnb|Varotsos|Alexopoulos|1984b|loc=Table 3|p=117}}.</ref> Other lists followed, such as their 1991 claim of predicting six out of seven earthquakes with {{M|s}} ≥ 5.5 in the period of 1 April 1987 through 10 August 1989, or five out of seven earthquakes with {{M|s}} ≥ 5.3 in the overlapping period of 15 May 1988 to 10 August 1989,{{efn|1={{Harvtxt|Varotsos|Lazaridou|1991}} Table 2 (p. 340) and Table 3 (p. 341) includes nine predictions (unnumbered) from 27 April 1987 to 28 April 1988, with a tenth prediction issued on 26 February 1987 mentioned in a footnote. Two of these earthquakes were excluded from Table 3 on the grounds of having occurred in neighboring Albania. Table 1 (p. 333) includes 17 predictions (numbered) issued from 15 May 1988 to 23 July 1989. A footnote mentions a missed (unpredicted) earthquake on 19 March 1989; all 17 entries show associated earthquakes, and presumably are thereby deemed to have been successful predictions. Table 4 (p. 345) is a continuation of Table 1 (p. 346) out to 30 November 1989, adding five additional predictions with associated earthquakes.}} In 1996 they published a "Summary of all Predictions issued from January 1st, 1987 to June 15, 1995",<ref>{{Harvnb|Varotsos|Lazaridou|Eftaxias|Antonopoulos|1996a|loc=Table 1}}.</ref> amounting to 94 predictions.<ref>{{Harvnb|Jackson|Kagan|1998}}.</ref> Matching this against a list of "All earthquakes with M<sub>S</sub>(ATH)"<ref name=":15">{{Harvnb|Varotsos|Lazaridou|Eftaxias|Antonopoulos|1996a|loc=Table 3|p=55}}.</ref>{{efn|1="M<sub>S</sub>(ATH)" is the M<sub>S</sub> magnitude reported by the National Observatory of Athens (SI-NOA), or VAN's estimate of what that magnitude would be.<ref name=":0">{{Harvnb|Varotsos|Lazaridou|Eftaxias|Antonopoulos|1996a|p=49}}.</ref> These differ from the M<sub>S</sub> magnitudes reported by the USGS.}} and within geographical bounds including most of Greece,{{efn|1=Specifically, between 36° and 41° north latitude and 19° to 25° east longitude.<ref name=":0"/>}} they come up with a list of 14 earthquakes they should have predicted. Here they claim ten successes, for a success rate of 70%.<ref>{{Harvnb|Varotsos|Lazaridou|Eftaxias|Antonopoulos|1996a|p=56}}.</ref>{{efn|1=They have suggested the success rate should be higher, as one of the missed quakes would have been predicted but for attendance at a conference, and in another case a "clear SES" was recognized but a magnitude could not be determined for lack of operating stations.}}

The VAN predictions have been criticized on various grounds, including being geophysically implausible,<ref>{{Harvnb|Jackson|1996b|p=1365}}; {{Harvnb|Mulargia|Gasperini|1996a|p=1324}}.</ref> "vague and ambiguous",<ref>{{Harvnb|Geller|1997|loc=§4.5|p=436}}: "VAN's 'predictions' never specify the windows, and never state an unambiguous expiration date. Thus VAN are not making earthquake predictions in the first place."</ref> failing to satisfy prediction criteria,<ref>{{Harvnb|Jackson|1996b|p=1363}}. Also: {{Harvtxt|Rhoades|Evison|1996|p=1373}}: No one "can confidently state, except in the most general terms, what the VAN hypothesis is, because the authors of it have nowhere presented a thorough formulation of it."</ref> and retroactive adjustment of parameters.<ref name=":16">{{Harvnb|Kagan|Jackson|1996|p=1434}}.</ref> A critical review of 14 cases where VAN claimed 10 successes showed only one case where an earthquake occurred within the prediction parameters.<ref>{{Harvnb|Geller|1997|loc=Table 1|p=436}}.</ref> The VAN predictions not only fail to do better than chance, but show "a much better association with the events which occurred before them", according to Mulargia and Gasperini.<ref>{{Harvnb|Mulargia|Gasperini|1992|p=37}}.</ref> Other early reviews found that the VAN results, when evaluated by definite parameters, were statistically significant.<ref>{{Harvnb|Hamada|1993}} 10 successful predictions out of 12 issued (defining success as those that occurred within 22 days of the prediction, within 100&nbsp;km of the predicted epicenter and with a magnitude difference (predicted minus true) not greater than 0.7.)</ref><ref>{{Harvnb|Shnirman|Schreider|Dmitrieva|1993}}; Nishizawa et al. 1993{{full citation needed|date=May 2020}} and Uyeda 1991{{full citation needed|date=May 2020}}</ref> Both positive and negative views on VAN predictions from this period were summarized in the 1996 book ''A Critical Review of VAN'' edited by Sir James Lighthill<ref>{{Harvnb|Lighthill|1996}}.</ref> and in a debate issue presented by the journal [[Geophysical Research Letters]] that was focused on the statistical significance of the VAN method.<ref>{{cite journal|title=Table of contents|journal=Geophysical Research Letters|volume=23|issue=11|date=27 May 1996|doi=10.1002/grl.v23.11}}; {{Harvnb|Aceves|Park|Strauss|1996}}.</ref> VAN had the opportunity to reply to their critics in those review publications.<ref>{{Harvnb|Varotsos|Lazaridou|1996b}}; {{Harvnb|Varotsos|Eftaxias|Lazaridou|1996}}.</ref> In 2011, the ICEF reviewed the 1996 debate, and concluded that the optimistic SES prediction capability claimed by VAN could not be validated.<ref name=":5"/> In 2013, the SES activities were found<ref>{{Harvnb|Varotsos|Sarlis|Skordas|Lazaridou|2013}}</ref> to be coincident with the minima of the fluctuations of the order parameter of seismicity, which have been shown<ref>{{Harvnb|Christopoulos|Skordas|Sarlis|2020}}</ref> to be statistically significant precursors by employing the event coincidence analysis.<ref>{{Harvnb|Donges|Schleussner|Siegmund|Donner|2016}}</ref>

A crucial issue is the large and often indeterminate parameters of the predictions,<ref>{{Harvnb|Mulargia|Gasperini|1992|p=32}}; {{Harvnb|Geller|1996a|p=184}} ("ranges not given, or vague"); {{Harvnb|Mulargia|Gasperini|1992|p=32}} ("large indetermination in the parameters"); {{Harvnb|Rhoades|Evison|1996|p=1372}} ("falls short"); {{Harvnb|Jackson|1996b|p=1364}} ("have never been fully specified"); {{Harvnb|Jackson|Kagan|1998|p=573}} ("much too vague"); {{Harvnb|Wyss|Allmann|1996|p=1307}} ("parameters not defined"). {{Harvtxt|Stavrakakis|Drakopoulos|1996}} discuss some specific cases in detail.</ref> such that some critics say these are not predictions, and should not be recognized as such.<ref>{{Harvnb|Geller|1997|p=436}}. {{Harvtxt|Geller|1996a|loc=§6|pp=183–189}} discusses this at length.</ref> Much of the controversy with VAN arises from this failure to adequately specify these parameters. Some of their telegrams include predictions of two distinct earthquake events, such as (typically) one earthquake predicted at 300&nbsp;km "NW" of Athens, and another at 240&nbsp;km "W", "with {{sic|magnitutes|nolink=y}} 5,3 and 5,8", with no time limit.<ref>Telegram 39, issued 1 September 1988, in {{Harvnb|Varotsos|Lazaridou|1991|loc=Fig. 21|p=337}}. See figure 26 (p. 344) for a similar telegram. See also telegrams 32 and 41 (figures 15 and 16, pp. 115-116) in {{Harvnb|Varotsos|Alexopoulos|1984b}}. This same pair of predictions is apparently presented as Telegram 10 in Table 1, p. 50, of {{Harvnb|Varotsos|Lazaridou|Eftaxias|Antonopoulos|1996a}}. Text from several telegrams is presented in Table 2 (p. 54), and faxes of a similar character.</ref>{{efn|1=This pair of predictions was issued on 9/1/1988, and a similar pair of predictions was re-iterated on 9/30/1988, except that the predicted amplitudes were reduced to M(l)=5.0 and 5.3, respectively. In fact, an earthquake did occur approximately 240&nbsp;km west of Athens, on 10/16/1988, with magnitude Ms(ATH)=6.0, which would correspond to a local magnitude M(l) of 5.5.<ref name=":15"/>}} The time parameter estimation was introduced in VAN Method by means of [[Natural time analysis|natural time]] in 2001.<ref name=":6"/>
VAN has disputed the 'pessimistic' conclusions of their critics, but the critics have not relented.<ref>{{Harvtxt|Varotsos|Lazaridou|Eftaxias|Antonopoulos|1996a}} they also cite Hamada's claim of a 99.8% confidence level. {{Harvtxt|Geller|1996a|p=214}} finds that this "was based on the premise that 6 out of 12 telegrams" were in fact successful predictions, which is questioned. {{Harvtxt|Kagan|1996|p=1315}} finds that in Shnirman et al. "several variables ... have been modified to achieve the result." {{Harvtxt|Geller|Jackson|Kagan|Mulargia|1998|p=98}} mention other "flaws such as overly generous crediting of successes, using strawman null hypotheses and failing to account for properly for ''a posteriori'' "tuning" of parameters."</ref> It was suggested that VAN failed to account for clustering of earthquakes,<ref name=":16"/> or that they interpreted their data differently during periods of greater seismic activity.<ref>{{Harvnb|Kagan|1996|p=1318}}.</ref>

VAN has been criticized on several occasions for causing public panic and widespread unrest.<ref>{{Harvtxt|''GR Reporter''|2011}} "From its very appearance in the early 1990s until today, the VAN group is the subject of sharp criticism from Greek seismologists"; {{Harvtxt|Chouliaras|Stavrakakis|1999}}: "panic overtook the general population" (Prigos, 1993). {{Harvtxt|Ohshansky|Geller|2003|p=[https://books.google.com/books?id=tIm-sXDVIiIC&pg=PA318&lpg=PA318 318]}}: "causing widespread unrest and a sharp increase in tranquilizer drugs" (Athens, 1999). {{Harvtxt|Papadopoulos|2010}}: "great social uneasiness" (Patras, 2008). {{Harvtxt|Anagnostopoulos|1998|p=96}}: "often caused widespread rumors, confusion and anxiety in Greece". {{Harvtxt|ICEF|2011|p=352}}: issuance over the years of "hundreds" of statements "causing considerable concern among the Greek population."</ref> This has been exacerbated by the broadness of their predictions, which cover large areas of Greece (up to 240 kilometers across, and often pairs of areas),{{efn|1=While some analyses have been done on the basis of a 100&nbsp;km range (e.g., {{Harvnb|Hamada|1993|p=205}}), {{Harvtxt|Varotsos|Lazaridou|1991|p=339}} claim credit for earthquakes within a radius of 120&nbsp;km.}} much larger than the areas actually affected by earthquakes of the magnitudes predicted (usually several tens of kilometers across).<ref>{{Harvnb|Stiros|1997|p=482}}.</ref>{{efn|1={{Harvtxt|Geller|1996a|loc=6.4.2}} notes that while Kobe was severely damaged by the 1995 {{M|w|6.9}} earthquake, damage in Osaka, only 30&nbsp;km away, was relatively light.}} Magnitudes are similarly broad: a predicted magnitude of "6.0" represents a range from a benign magnitude 5.3 to a broadly destructive 6.7.{{efn|1=VAN predictions generally do not specify the magnitude scale or precision, but they have generally claimed a precision of ±0.7.}} Coupled with indeterminate time windows of a month or more,<ref>{{Harvnb|Varotsos|Lazaridou|Eftaxias|Antonopoulos|1996a|pp=36, 60, 72}}.</ref> such predictions "cannot be practically utilized"<ref>{{Harvnb|Anagnostopoulos|1998}}.</ref> to determine an appropriate level of preparedness, whether to curtail usual societal functioning, or even to issue public warnings.{{efn|1=As an instance of the quandary public officials face: in 1995 Professor Varotsos reportedly filed a complaint with the public prosecutor accusing government officials of negligence in not responding to his supposed prediction of an earthquake. A government official was quoted as saying "VAN's prediction was not of any use" in that it covered two-thirds of the area of Greece.<ref>{{Harvnb|Geller|1996a|p=223}}.</ref>}}

=== 2008: Greece (VAN) ===
After 2006, VAN claim that all alarms related to SES activity have been made public by posting at [[arxiv.org]]. Such SES activity is evaluated using a new method they call 'natural time'. One such report was posted on Feb. 1, 2008, two weeks before the strongest earthquake in Greece during the period 1983–2011. This earthquake occurred on February 14, 2008, with magnitude (Mw) 6.9. VAN's report was also described in an article in the [[Ethnos (newspaper)|newspaper ''Ethnos'']] on Feb. 10, 2008.<ref>{{Harvnb|Apostolidis|2008}}; {{Harvnb|Uyeda|Kamogawa|2008}}; {{Harvnb|Chouliaras|2009}}; Uyeda 2010.{{full citation needed|date=May 2020}}</ref> However, Gerassimos Papadopoulos commented that the VAN reports were confusing and ambiguous, and that "none of the claims for successful VAN predictions is justified."<ref>{{Harvnb|Papadopoulos|2010}}.</ref> A reply to this comment, which insisted on the prediction's accuracy, was published in the same issue.<ref>{{Harvnb|Uyeda|Kamogawa|2010}}</ref>

=== 1989: Loma Prieta, U.S. ===
{{anchor|Loma Prieta}}

The [[1989 Loma Prieta earthquake]] (epicenter in the [[Santa Cruz Mountains]] northwest of [[San Juan Bautista, California]]) caused significant damage in the [[San Francisco Bay Area]] of California.<ref>{{Harvnb|Harris|1998|p=B18}}.</ref> The [[United States Geological Survey]] (USGS) reportedly claimed, twelve hours ''after'' the event, that it had "forecast" this earthquake in a report the previous year.<ref>{{Harvnb|Garwin|1989}}.</ref> USGS staff subsequently claimed this quake had been "anticipated";<ref>{{Harvnb|USGS staff|1990|p=247}}.</ref> various other claims of prediction have also been made.<ref>{{Harvnb|Kerr|1989}}; {{Harvnb|Harris|1998}}.</ref>

[[Ruth Harris (scientist)|Ruth Harris]] ({{Harvtxt|Harris|1998}}) reviewed 18 papers (with 26 forecasts) dating from 1910 "that variously offer or relate to scientific forecasts of the 1989 Loma Prieta earthquake." (In this case no distinction is made between a ''forecast'', which is limited to a probabilistic estimate of an earthquake happening over some time period, and a more specific ''prediction''.<ref>e.g., {{Harvnb|ICEF|2011|p=327}}.</ref>) None of these forecasts can be rigorously tested due to lack of specificity,<ref>{{Harvnb|Harris|1998|p=B22}}.</ref> and where a forecast does bracket the correct time and location, the window was so broad (e.g., covering the greater part of California for five years) as to lose any value as a prediction. Predictions that came close (but given a probability of only 30%) had ten- or twenty-year windows.<ref>{{Harvnb|Harris|1998|loc=Table 1|p=B5}}.</ref>

One debated prediction came from the M8 algorithm used by Keilis-Borok and associates in four forecasts.<ref>{{Harvnb|Harris|1998|pp=B10–B11}}.</ref> The first of these forecasts missed both magnitude (M 7.5) and time (a five-year window from 1 January 1984, to 31 December 1988). They did get the location, by including most of California and half of Nevada.<ref>{{Harvnb|Harris|1998|p=B10}}, and figure 4, p. B12.</ref> A subsequent revision, presented to the NEPEC, extended the time window to 1 July 1992, and reduced the location to only central California; the magnitude remained the same. A figure they presented had two more revisions, for M ≥ 7.0 quakes in central California. The five-year time window for one ended in July 1989, and so missed the Loma Prieta event; the second revision extended to 1990, and so included Loma Prieta.<ref>{{Harvnb|Harris|1998|loc=figure 5|p=B11}}.</ref>

When discussing success or failure of prediction for the Loma Prieta earthquake, some scientists argue that it did not occur on the [[San Andreas Fault]] (the focus of most of the forecasts), and involved [[Dip-slip fault|dip-slip]] (vertical) movement rather than [[Strike-slip tectonics|strike-slip]] (horizontal) movement, and so was not predicted.<ref>{{Harvtxt|Geller|1997|loc=§4.4}} cites several authors to say "it seems unreasonable to cite the 1989 Loma Prieta earthquake as having fulfilled forecasts of a right-lateral strike-slip earthquake on the San Andreas Fault."</ref>

Other scientists argue that it did occur in the San Andreas Fault ''zone'', and released much of the strain accumulated since the 1906 San Francisco earthquake; therefore several of the forecasts were correct.<ref>{{Harvnb|Harris|1998|pp=B21–B22}}.</ref> Hough states that "most seismologists" do not believe this quake was ''predicted'' "per se".<ref>{{Harvnb|Hough|2010b|p=143}}.</ref> In a strict sense there were no predictions, only forecasts, which were only partially successful.

[[Iben Browning]] claimed to have predicted the Loma Prieta event, but (as will be seen in the next section) this claim has been rejected.

{{further|1989 Loma Prieta earthquake}}

=== 1990: New Madrid, U.S. (Browning) ===
{{anchor|New Madrid}}{{anchor|Browning}}
{{further|Tidal triggering of earthquakes}}

[[Iben Browning]] (a scientist with a Ph.D. degree in zoology and training as a biophysicist, but no experience in geology, geophysics, or seismology) was an "independent business consultant" who forecast long-term climate trends for businesses.{{efn|1={{Harvnb|Spence|Herrmann|Johnston|Reagor|1993}} (USGS Circular 1083) is the most comprehensive, and most thorough, study of the Browning prediction, and appears to be the main source of most other reports. In the following notes, where an item is found in this document the pdf pagination is shown in brackets.}} He supported the idea (scientifically unproven) that volcanoes and earthquakes are more likely to be triggered when the tidal force of the Sun and the Moon coincide to exert maximum stress on the [[Earth's crust]] ([[syzygy (astronomy)|syzygy]]).{{efn|1=A report on Browning's prediction cited over a dozen studies of possible tidal triggering of earthquakes, but concluded that "conclusive evidence of such a correlation has not been found". It also found that Browning's identification of a particular high tide as triggering a particular earthquake "difficult to justify".<ref>{{Harvnb|AHWG|1990|p=10}} {{Harv|Spence|Herrmann|Johnston|Reagor|1993|p=54 [62]}}.</ref>}} Having calculated when these tidal forces maximize, Browning then "projected"<ref>{{Harvnb|Spence|Herrmann|Johnston|Reagor|1993|loc=<sup>{{dagger}}</sup> footnote, p. 4 [12]}} "Browning preferred the term projection, which he defined as determining the time of a future event based on calculation. He considered 'prediction' to be akin to tea-leaf reading or other forms of psychic foretelling." See also Browning's own comment on p. 36 [44].</ref> what areas were most at risk for a large earthquake. An area he mentioned frequently was the [[New Madrid seismic zone]] at the southeast corner of the state of [[Missouri]], the site of three very large earthquakes in 1811–12, which he coupled with the date of 3 December 1990.

Browning's reputation and perceived credibility were boosted when he claimed in various promotional flyers and advertisements to have predicted (among various other events{{efn|1=Including "a 50/50 probability that the federal government of the U.S. will fall in 1992."<ref>{{Harvnb|Spence|Herrmann|Johnston|Reagor|1993|p=39 [47]}}.</ref>}}) the Loma Prieta earthquake of 17 October 1989.<ref>{{Harvnb|Spence|Herrmann|Johnston|Reagor|1993|pp=9–11 [17–19]}}, and see various documents in Appendix A, including ''The Browning Newsletter'' for 21 November 1989 (p. 26 [34]).</ref> The National Earthquake Prediction Evaluation Council (NEPEC) formed an Ad Hoc Working Group (AHWG) to evaluate Browning's prediction. Its report (issued 18 October 1990) specifically rejected the claim of a successful prediction of the Loma Prieta earthquake.<ref>{{Harvnb|AHWG|1990|p=III}} {{Harv|Spence|Herrmann|Johnston|Reagor|1993|p=47 [55]}}.</ref> A transcript of his talk in San Francisco on 10 October showed he had said: "there will probably be several earthquakes around the world, Richter 6+, and there may be a volcano or two" – which, on a global scale, is about average for a week – with no mention of any earthquake in California.<ref>{{Harvnb|AHWG|1990|p=30}} {{Harv|Spence|Herrmann|Johnston|Reagor|1993|p=64 [72]}}.</ref>

Though the AHWG report disproved both Browning's claims of prior success and the basis of his "projection", it made little impact after a year of continued claims of a successful prediction. Browning's prediction received the support of geophysicist David Stewart,{{efn|1=Previously involved in a psychic prediction of an earthquake for North Carolina in 1975,<ref>{{Harvnb|Spence|Herrmann|Johnston|Reagor|1993|p=13 [21]}}</ref> Stewart sent a 13 page memo to a number of colleagues extolling Browning's supposed accomplishments, including predicting Loma Prieta.<ref>{{Harvnb|Spence|Herrmann|Johnston|Reagor|1993|p=29 [37]}}.</ref>}} and the tacit endorsement of many public authorities in their preparations for a major disaster, all of which was amplified by massive exposure in the news media.<ref>{{Harvnb|Spence|Herrmann|Johnston|Reagor|1993|loc=throughout}}.</ref> Nothing happened on 3 December,<ref>{{Harvnb|Tierney|1993|p=11}}.</ref> and Browning died of a heart attack seven months later.<ref>{{Harvnb|Spence|Herrmann|Johnston|Reagor|1993|pp=4 [12], 40 [48]}}.</ref>

=== 2004 and 2005: Southern California, U.S. (Keilis-Borok) ===
{{anchor|Southern California}}

The [[#M8|M8]] algorithm (developed under the leadership of [[Vladimir Keilis-Borok]] at [[UCLA]]) gained respect by the apparently successful predictions of the 2003 San Simeon and Hokkaido earthquakes.<ref>{{Harvnb|CEPEC|2004a}}; {{Harvnb|Hough|2010b|pp=145–146}}.</ref> Great interest was therefore generated by the prediction in early 2004 of a M ≥ 6.4 earthquake to occur somewhere within an area of southern California of approximately 12,000 sq. miles, on or before 5 September 2004.<ref name=":11"/> In evaluating this prediction the [[California Earthquake Prediction Evaluation Council]] (CEPEC) noted that this method had not yet made enough predictions for statistical validation, and was sensitive to input assumptions. It therefore concluded that no "special public policy actions" were warranted, though it reminded all Californians "of the significant seismic hazards throughout the state."<ref name=":11"/> The predicted earthquake did not occur.

A very similar prediction was made for an earthquake on or before 14 August 2005, in approximately the same area of southern California. The CEPEC's evaluation and recommendation were essentially the same, this time noting that the previous prediction and two others had not been fulfilled.<ref>{{Harvnb|CEPEC|2004b}}.</ref> This prediction also failed.

=== 2009: L'Aquila, Italy (Giuliani) ===
{{Main|2009 L'Aquila earthquake}}

At 03:32 on 6 April 2009, the [[Abruzzo]] region of central Italy was rocked by a magnitude M 6.3 earthquake.<ref>{{Harvnb|ICEF|2011|p=320}}.</ref> In the city of [[L'Aquila]] and surrounding area around 60,000 buildings collapsed or were seriously damaged, resulting in 308 deaths and 67,500 people left homeless.<ref>{{Harvnb|Alexander|2010|p=326}}.</ref> Around the same time, it was reported that Giampaolo Giuliani had predicted the earthquake, had tried to warn the public, but had been muzzled by the Italian government.<ref>{{Harvnb|Squires|Rayne|2009}}; {{Harvnb|McIntyre|2009}}.</ref>

Giampaolo Giuliani was a laboratory technician at the [[Laboratori Nazionali del Gran Sasso]]. As a hobby he had for some years been monitoring radon using instruments he had designed and built. Prior to the L'Aquila earthquake he was unknown to the scientific community, and had not published any scientific work.<ref>{{Harvnb|Hall|2011|p=267}}.</ref> He had been interviewed on 24 March by an Italian-language blog, ''Donne Democratiche'', about a swarm of low-level earthquakes in the Abruzzo region that had started the previous December. He said that this swarm was normal and would diminish by the end of March. On 30 March, L'Aquila was struck by a magnitude 4.0 temblor, the largest to date.<ref>{{Harvnb|Kerr|2009}}.</ref>

On 27 March Giuliani warned the mayor of L'Aquila there could be an earthquake within 24 hours, and an earthquake M~2.3 occurred.<ref>{{Harvnb|Dollar|2010}}.</ref> On 29 March he made a second prediction.<ref>{{Harvtxt|ICEF|2011|p=323}} alludes to predictions made on 17 February and 10 March.</ref> He telephoned the mayor of the town of Sulmona, about 55 kilometers southeast of L'Aquila, to expect a "damaging" – or even "catastrophic" – earthquake within 6 to 24 hours. Loudspeaker vans were used to warn the inhabitants of Sulmona to evacuate, with consequential panic. No quake ensued and Giuliano was cited for inciting public alarm and enjoined from making future public predictions.<ref>{{Harvnb|Kerr|2009}}; {{Harvnb|Hall|2011|p=267}}; {{Harvnb|Alexander|2010|p=330}}.</ref>

After the L'Aquila event Giuliani claimed that he had found alarming rises in radon levels just hours before.<ref>{{Harvnb|Kerr|2009}}; {{Harvnb|Squires|Rayne|2009}}.</ref> He said he had warned relatives, friends and colleagues on the evening before the earthquake hit.<ref>{{Harvnb|Dollar|2010}}; {{Harvnb|Kerr|2009}}.</ref> He was subsequently interviewed by the International Commission on Earthquake Forecasting for Civil Protection, which found that Giuliani had not transmitted a valid prediction of the mainshock to the civil authorities before its occurrence.<ref>{{Harvnb|ICEF|2011|pp=323, 335}}.</ref>