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.
Ruth A. M. Schmidt
The Great Alaska Earthquake was the most powerful earthquake recorded in North America, and the second most powerful to be recorded in history. Hitting Alaska about 5:30 PM on March 27, 1964, the earthquake registered 9.2. The damage was immense. The tsunami that followed devastated coastal communities from Alaska to northern California. Landslides demolished entire neighborhoods, railroads and highways were destroyed, and major utilities such as gas mains, electrical grids, and phone systems were obliterated. The USGS estimates that 143 people were killed, and thousands were more displaced. Property damages amounted to $2.3B in 2013 dollars.