Editing Earthquake prediction (section)

===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>