USS Gridley (DLG-21) the "Spruance"-class destroyer to escort reflagged Kuwaiti oil tankers through the Strait of Hormuz during Operation Earnest Will. While homeward bound, transiting the South China Sea, "Gridley" rescued Vietnamese refugees sighted in a small boat off of the coast of Vietnam. A Vietnamese-speaking crewman aboard "Gridley" was able to translate for those rescued, facilitating the process. "Gridley" returned to San Diego in June 1989. On 17 October of that year, the ship's visit to Naval Station, Treasure Island, California, was interrupted by the 6.9 Loma Prieta earthquake that struck the San Francisco Bay area. "Gridley"s crew provided assistance to victims
Earthquake prediction "resoundingly debunked". Probably the most celebrated seismo-electromagnetic event ever, and one of the most frequently cited examples of a possible earthquake precursor, is the 1989 Corralitos anomaly. In the month prior to the 1989 Loma Prieta earthquake measurements of the earth's magnetic field at ultra-low frequencies by a magnetometer in Corralitos, California, just 7 km from the epicenter of the impending earthquake, started showing anomalous increases in amplitude. Just three hours before the quake the measurements soared to about thirty times greater than normal, with amplitudes tapering off after the quake. Such amplitudes had not been seen in two years