Indonesia
A massive supervolcano erupted at present-day Lake Toba around 70,000 BCE. It is believed to have caused a global volcanic winter and cooling of the climate, and subsequently led to a genetic bottleneck in human evolution, though this is still debated. The 1815 eruption of Mount Tambora and the 1883 eruption of Krakatoa were among the largest in recorded history. The former resulted in 92,000 deaths and created an umbrella of volcanic ash which spread and blanketed parts of the archipelago, and made much of Northern Hemisphere without summer in 1816. The latter produced the loudest sound in recorded history, and resulted in 36,000 deaths that are attributed to the eruption itself and the tsunamis it created. Significant additional effects were also felt around the world years after the eruption. Recent major disasters due to seismic activity include the 2004 Indian Ocean earthquake and the 2006 Yogyakarta earthquake.
1992 Cape Mendocino earthquakes
The Mendocino Fault is seismically active with mostly small and moderate earthquakes, but the largest event that was unequivocally associated with the fault was the M6.9 earthquake on September 1, 1994, at 125.8 W longitude. Aftershocks of that event with corresponding dextral strike-slip focal mechanisms occurred farther to the east and close to the Mendocino Triple Junction. Another large event (7.3–7.6) occurred on January 31, 1922 (with an aftershock of M7+ the next day) but the sources of these shocks could not be determined with any precision as the first seismographs did not arrive in the area until 1932. Due to their offshore epicenters all of these events caused little damage though were felt across a broad area. Previous Gorda plate events include the July 13 and August 17, 1991, shocks of 6.8 and 7.1 and the M7.3 event on November 10, 1980, west of Arcata.