Earth's Great Upheavals, From Mass Extinctions to Modern Disasters

About 251.9 million years ago, Earth's most severe known mass extinction removed an estimated 81 percent of marine species and 70 percent of terrestrial vertebrate species. It is primarily attributed to the Siberian Traps flood basalt eruptions, whose carbon dioxide and sulfur dioxide drove warming, ocean acidification and widespread marine anoxia.

Volcanism again sits at the root, this time the Central Atlantic Magmatic Province, about 201.4 million years ago. Roughly 23 to 34 percent of marine genera and an estimated 42 percent of terrestrial tetrapods disappeared, and the cleared ecological space let dinosaurs rise to dominance through the Jurassic.

The cause changes here. About 66 million years ago an asteroid impact that formed the Chicxulub crater on the Yucatan Peninsula brought a lingering impact winter that halted photosynthesis, and three quarters or more of plant and animal species were lost, including all non-avian dinosaurs. The loss opened space for mammals and birds to diversify.

Not an extinction but a sudden climate reversal, from roughly 12,900 to 11,700 years ago. The North Atlantic region cooled by about 2 to 10 degrees Celsius, in Greenland within as little as three years, and the period ended with dramatic warming over around 50 years as the Pleistocene gave way to the Holocene.

About 6225 to 6170 BCE, roughly 290 kilometers of Norway's continental shelf collapsed, displacing about 3,500 cubic kilometers of debris. The resulting paleotsunami crossed the North Atlantic and reached as far as 29 kilometers inland in Scotland, and it is believed to have killed up to a quarter of Mesolithic Britain's population.

On 1 November 1755 an earthquake, the fires it set and a tsunami destroyed most of Lisbon, with roughly 30,000 to 40,000 dead in the city. Because the Marquis of Pombal ordered a parish-by-parish survey of the damage, it is regarded as the founding event of modern seismology, and it also set Voltaire and Rousseau arguing over its meaning.

Far from any plate boundary, a series of intraplate earthquakes beginning on 16 December 1811 struck near New Madrid in what is now Missouri. The first shock is estimated at moment magnitude 7.2 to 8.2, and the series remains the most powerful in the contiguous United States east of the Rocky Mountains. No reliable casualty count exists for the sparsely settled frontier.

In the 1930s severe drought combined with farming practices that stripped away topsoil, producing dust storms across the American and Canadian prairies. Drought came in three waves, in 1934, 1936 and 1939 to 1940, and the crisis displaced more than 500,000 Americans, a case where human land use turned a natural drought into a disaster.

On 22 May 1960 a megathrust earthquake in southern Chile reached moment magnitude 9.4 to 9.6, the strongest ever instrumentally recorded. Its roughly ten minute rupture produced local tsunamis along the Chilean coast and a Pacific wide tsunami that struck Hawaii, Japan and the Philippines.

Katrina peaked as a Category 5 hurricane with 175 mph winds before making final landfall as a Category 3 in late August 2005. It became the costliest tropical cyclone in United States history at about 125 billion dollars, and most deaths came from flooding after engineering failures in the New Orleans levee system, with about 80 percent of the city flooded.

A magnitude 7.0 earthquake near Leogane on 12 January 2010 affected about three million people and damaged or collapsed around 250,000 residences. It is considered the deadliest natural disaster of the 21st century for a single country, and its toll is disputed, with academic estimates of roughly 100,000 to 160,000 against Haitian government claims of 220,000 to 316,000.

A shallow magnitude 7.5 to 7.6 earthquake on 28 September 2018 triggered a localized tsunami that hit Palu with waves of 5 to 7 meters, compounded by severe soil liquefaction. An estimated 4,340 people died, making it the deadliest earthquake worldwide in 2018.