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.
Frederick S. Lyman
Letters to his brother David Brainerd Lyman (1840–1914) describe a massive eruption of Mauna Loa on their ranch accompanied by a series of earthquakes from March 27 to March 31. His eyewitness observations, sometimes called the "best account" of the events, has been used by scientists for many years.
A few days later the powerful April 2, 1868 Hawaii earthquake, destroyed their house and most others in the area. A massive landslide triggered by the shock killed much of his livestock. From one of the letters:
"It was impossible to stand, we had to sit on the ground, bracing with hands and feet to keep from rolling over. In the midst of it we saw burst out... what we supposed to be an immense river of molten lava (which afterwards proved to be red earth), which rushed down its headlong course and across the plain below, ... swallowing up everything in its way, trees, houses, cattle, horses, goats and men. ... After the hard shaking had ceased, all along the sea-shore the sea was boiling and foaming furiously, all red, for about an eighth of a mile from the shore, and the shore was covered by the sea."
The resulting tsunami killed many of the witnesses who were living at lower elevations. It was the largest earthquake in modern recorded history of the Hawaiian Islands.
This convinced the family to return to town, where he looked for whatever employment he could.