When I was a boy and I would see scary things in the news, my mother would say to me, “Look for the helpers. You will always find people who are helping.” To this day, especially in times of “disaster,” I remember my mother’s words and I am always comforted by realizing that there are still so many helpers – so many caring people in this world.
— Mr. (Fred) Rogers
Deadliest in historic times: More than 830,000 people died, according to the United States Geological Survey, in the estimated magnitude 8 earthquake of Shaanxi (Shensi), China, on January 23, 1556.
Biggest in historic times: The magnitude 9.5 Chile earthquake on May 22, 1960.
This one is a bit extensive as volcanoes are quite variable. Note also that crater lakes can sometimes release gas even without a volcanic eruption. Such an event at Lake Nyos in 1986 killed over 1700 people and all other life within a 15-mile/25-km radius.
Deadliest eruption in modern times: Per the USGS, the 1883 eruption of Krakatau/Krakatoa killed over 36,000 people quickly, most from tsunamis; however, Tambora’s eruption in 1815 led to the deaths of some 92,000 people, slowly, from starvation.
Biggest eruption of the 20th century: Novarupta/Katmai in Alaska, starting on June 6, 1912, VEI 6.
Biggest eruption in the last 5000 years: Tambora’s 1815 eruption, as above, was a VEI 7, but so were the “Hatepe” eruption at Taupo caldera (North Island, New Zealand) around 180 AD and the “Tianchi” eruption at Baekdu/Changbaishan (on the China/North Korean border) around 1000 AD.
Last known “supereruption” (VEI 8) in human history: Taupo again, some 27,000 years ago.
Yellowstone: Last “supereruption”: 640,000 years ago. Last “plain old eruption”: 70,000 years ago. For a good look at Yellowstone volcano, check out this 3-part series of videos by the Yellowstone Volcano Observatory’s scientist-in-charge Jake Lowenstern:
Highest measured tsunami wave in historic times: 1700 feet/518 m. This was due to unusual geometry. A huge landslide suddenly fell into small and fairly well-enclosed Lituya Bay on July 9, 1958, in Alaska.
Deadliest flood in historic times: Due to a heavy winter snowfall, followed by heavy rain and then an unusually active tropical cyclone season, three great Chinese rivers flooded between July and August 1931, killing some 3.7 million people either directly (drowning, etc.) or indirectly (starvation and disease); about 1/4 of the country’s population was affected. The Three Gorges Dam, built to prevent such a thing from happening again, holds so much water that its mass will (minutely) change the Earth’s rotation.
Tropical cyclones are larger than tornadoes, but their greatest danger is flooding – already covered.