This issue of Earthquakes & Volcanoes focuses on a series of three powerful earthquakes centered near Cape Mendocino, California, on April 25-26, 1992. The sequence began with a magnitude 7.1 mainshock at 11:06 a.m. (local time) on April 25. Strong aftershocks with magnitudes of 6.6 and 6.7 occurred on April 26 at 00:41 a.m. and at 4:18 a.m., respectively.