provide a sure basis for extrapolation. In the highly nonlinear phenomena involved in earthquake generation, there may be a threshold value of the strain that must be exceeded prior to initiation of a large earthquake. ... The underground explosion could serve as the first domino of the row of dominoes leading to a major earthquake. ... as in the case of earthquakes it is not possible at this time to assess quantitatively the probability of a tsunami following the explosion." In July 1971, a group called the Committee for Nuclear Responsibility filed suit against the AEC, asking the court to stop the test. The suit was unsuccessful, with the Supreme Court denying the injunction by 4 votes to 3, and Richard Nixon personally authorized the $200 million test, in spite of objections from Japan, Peru, and Sweden. The Don't Make A Wave Committee chartered a boat, in which they had intended to sail to the island in protest, but due to postponement of the test and interference from the U.S. Coast Guard, they were unable to observe the test. Cannikin tested Cannikin was detonated on November 6, 1971 , as the thirteenth test of the Operation Grommet (1971–1972) underground nuclear test series. The announced yield was 5 megatons (21 PJ) – the largest underground nuclear test in U.S. history. (Estimates for the precise yield range from 4.4 to 5.2 megatons or 18 to 22 PJ). The ground lifted , caused by an explosive force almost 400 times the power of the Hiroshima bomb. Subsidence and faulting at the site created a new lake, several hundred meters wide. The explosion caused a seismic shock of 7.0 on the Richter scale, causing rockfalls and turf slides of a total of . Though earthquakes and tsunamis predicted by environmentalists did not occur, a number of small tectonic events did occur in the following weeks, (some registering as high as 4.0 on the richter scale) thought to be due to the interaction of the explosion with local tectonic stresses. 1973 and beyond The AEC withdrew from the island in 1973, though scientists continue to visit the island for monitoring purposes. In 2001, the DoE returned to the site to remove environmental contamination. Drilling mud pits were stabilized by mixing with clean soil, covering with a polyester membrane, topped with soil and re-seeded. Concerns have been expressed that new fissures may be opening underground, allowing