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.
Sierra Madre Fault Zone
The 1971 event was the first in a series (1987 Whittier Narrows, 1991 Sierra Madre, 1994 Northridge) of damaging earthquakes which have occurred on reverse faults in the Los Angeles area. The events triggered discussions concerning the largest magnitude earthquake that could be generated by one of the faults, especially in the Transverse Ranges, but the focal point of earthquake hazard assessments in California are often the San Andreas Fault and other associated dextral faults. Although there is a lack of paleoseismic data on reverse faults in the Los Angeles area, a trench excavation at a site on the Sierra Madre-Cucamonga Fault revealed that two large historic earthquakes occurred in the last 15,000 years.