Homestead Valley, California, aftershocks (March 17-18, 1979) recorded on portable seismographs

On March 15, 1979, four moderate earthquakes (ML 4.9, 5.3, 4.5, 4.8) occurred in the Homestead Valley area of the Mojave Desert (Figure 1). At that time, they were noteworthy for a vigorous aftershock sequence and for off-fault epicentral locations that formed a cruciform pattern (Hutton, et al., 1980; Stein and Lisowski, 1983). More recently, there is renewed interest in the Homestead Valley sequence because of its proximity and possible relationship to the June 28, 1992 Landers earthquake (MW 7.3). The Homestead Valley earthquakes fall within the Landers aftershock zone, and many of the Homestead Valley epicenters align with the Landers surface rupture (Figure 2).