Hector Mine

A M7.1 earthquake occurred at 2:46 a.m. local time on 10/16/1999. The event was located in a remote, sparsely-populated part of the Mojave desert, approximately 47 miles east-southeast of Barstow and 32 miles north of Joshua Tree. The initial magnitude estimate of 7.0 was upgraded to 7.1 on October 18, 1999, based on in-depth analysis of "teleseismic" data recorded worldwide. Like music, earthquake waves include both "high tones" and "low tones"--the latter, which are recorded by sensitive seismic instruments around the globe--are crucial in constraining the magnitude of large events, but are not analyzed quite as quickly as data from the immediate southern California region. The Hector Mine earthquake is not considered an aftershock of the M7.3 Landers earthquake of 1992, although subsequent analysis will explore the relationship between these two events. Info Courtesy of SCIGN On average, an earthquake of M7.0 is expected to generate approximately seven aftershocks of M5 or larger within the first week.