Ancient Volcano's Devastating Effects Confirmed. The lack of genetic diversity among humans alive today suggests that humans came very close to extinction after massive volcanic eruption 73 000 years ago killed off much of central India's forests, released 800 cubic kilometers of ash into the atmosphere that blanketed the skies and blocked out sunlight for six years.
Global temperatures dropped by 16 degrees centigrade (28 degrees Fahrenheit) and life on Earth plunged deeper into an ice age that lasted around 1,800 years.
disaster may have forced the ancestors of modern humans to adopt new cooperative strategies for survival that eventually permitted them to replace Neanderthals and other archaic human species. some suspect another supervolcanic eruption will eventually take place.
Though not expected to occur anytime soon, a Yellowstone eruption could coat half the United States in a layer of ash up to 3 feet (1 meter) deep.
