Editing Earthquake prediction (section)

=== 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>}}