EXPLOSION OF THE TOBA VOLCANO – WHEN HUMANS NEARLY VANISHED
There was once a huge and tall volcano known as Mount Toba located on the modern island of Sumatra, at 80 km south of Medan. Its history dates back to million years ago.
Mount Toba erupted 840,000 years ago. It formed a caldera in the east of the region. Another eruption occurred 501,000 years ago forming a caldera in the North of the region.
The last eruption (74,000 years ago) is considered the largest volcanic eruption that happened within the last 25 million years. Its explosivity index (VEI) was 8 (the highest rating on the scale).
Scientists have claimed that the phenomenon was the result of two major plates colliding, beginning during the Eocene Era (about 65 million years ago); namely the Indian Ocean or the Australian plates in the southwest and the Asian Plate in the northeast.
Historians believe that Mount Toba spewed two-thousand times as much ash as Mount St. Helens did. Ash covered all of India to a depth of at least a half foot, and to a depth over twenty feet in some places. The entire world was devastated by the atmospheric ash. The result was a six-year “nuclear winter” followed by a thousand-year ice-age. The entire human species were completely exterminated between Java and the present-day border of Iran.
The Toba eruption is associated with a genetic bottleneck in human evolution. It is believed that the eruption caused a significant reduction in the human population, possibly leading to a near-extinction event. It is not clear how many people had lived before the eruption, but the theory suggests that so many people got killed that the world population only remained 3,000-10,000 individuals following the eruption.
According to the Toba catastrophe theory, most early humans in Europe and Asia didn’t make it, as the climate and environment suddenly changed in the aftermath of the Toba eruption, and only a small group, with limited genetic variability, survived by chance in Africa. But archaeological and palaeoclimate records don’t seem to fit this theory. The exact geographic distribution of anatomically modern human populations at the time of the eruption is not known.
Some historians believe that the few surviving Homo sapiens in Africa were said to have survived by developing sophisticated social, symbolic and economic strategies that enabled them to eventually re-expand and populate Asia 60,000 years ago in a single, rapid wave along the Indian Ocean coastline.
Because Lake Toba lies in an earthquake-prone zone significant volcanic activities took place in the region along its southern shore in 1892, 1916, 1920, 1922, 1987, and 2018. Mount Sinabung is currently active in the region.
Toba is the largest resurgent caldera in the world.
Lake Toba is today an extraordinary natural wonder of the world open to tourism. The enormous crater lake consists of an island almost the size of Singapore in its center. At over 1,145 square km, and a depth of 450 meters, Lake Toba is actually more like an ocean. This is the largest lake in Southeast Asia and one of the deepest lakes in the world. National Geographic mentioned its “striking beauty”.
(Source: UNESCO/Forbes/Wikipedia/Smithsonian Institution/Volcano Live/uh.edu/NASA/laketoba.com/National Geographic – Image: Lake Toba today/Authentic Indonesia)