Our ancestors almost did not survive the toba volcanic eruption c. The caldera is 18 x 60 miles 30 by 100 km and has a total relief of 5,100 feet 1700 m. The toba supereruption was the biggest volcanic blast on earth in the past. Toba here is clearly not at the beginning of a cold period but about halfway through, apparently accelerating and deepening it. According to the toba catastrophe theory, modern human evolution was affected by a recent, large volcanic event. This interpretation is consistent with 1 the type of magmas erupted at pusubukit mostly intermediate to mafic in composition but. Toba, sumatra, 75,000 y ago, which produced voluminous ash deposits found across much of the indian ocean, indian peninsula, and south china sea.
The pumice erupted 75,000 years ago is calcalkalic quartzlatite to rhyolite in composition 68%76% silica. The largest volcanic eruption of the past two million years occurred on the indonesian island of sumatra some 75,000 years ago. It stands as the largest eruption in the past 10,000 years and caused global climate changes over the next three years. Aftermath of supereruption shows toba magma systems great. Mount toba eruption ancient humans unscathed, study. Williams et al, on the mount toba eruption 73,000 years ago, proposes that the destructive aftermath of the event caused widespread deforestation in india, some 3,000 miles distant from sumatra, the island on which the volcano was located. Supervolcano eruptions may not be so deadly after all. The eruption of toba volcano in northern sumatra some 73,000 years ago was the largest explosive eruption of the past two million years, with a volcanic explosivity index of magnitude 8, but its impact on climate has been controversial. The eruption of the toba supervolcano released the energy of a million tons of. Toba catastrophe theory wikimili, the best wikipedia reader. The massive toba volcanic eruption on the island of sumatra about 74,000 years ago did not cause a sixyearlong volcanic winter in east africa and thereby cause the human population in the region to plummet, according to new research from university of arizona geoscientists. Compared to the eruption on the super volcano toba, even krakatoa, with its tens of thousands of deaths in 1883, was a tiny belch. The toba catastrophe theory holds that this event caused a global volcanic winter of six to ten years and possibly a 1,000yearlong cooling episode contents.
Within the last three to five million years, after human and other ape lineages diverged from the hominid stemline, the human line produced a variety of human species. The toba volcano supereruption possibly the largest volcanic explosion in earths young or old history the may 2012 issue of quaternary international see references is devoted to exploring the history and implications of the toba volcano supereruption. The eruption of pinatubo in the philippines, 12 june 1991, the largest volcanic eruption since 1912. Recent advances in dating methods suggest a more accurate identification of 74,000 years ago as the date. The earlier outbreaks were not as large as the colossal eruption of 73,000 years ago which is the only eruption of class vei 8 to have taken place since primates have appeared on planet. And it already had an explosive force of 150 mega tonnes of tnt. The new findings disagree with the toba catastrophe hypothesis, which says the eruption and its. Our discovery of ash from the 75 ka eruption of toba ytt in lake malawi. Toba caldera produced the largest eruption in the last 2 million years. Ash from the toba supereruption in lake malawi shows no. Ash from the toba supereruption in lake malawi shows no volcanic winter in east africa at 75 ka christine s. The most explosive volcanic event of the quaternary was the eruption of mt. Toba supervolcano catastrophe idea dismissed bbc news.
Mount toba, ancient volcano located in the barisan mountains, northcentral sumatra, indonesia. The toba volcanic supereruption, environmental change. Due to the very high discharge rate, the duration of plinian pulses generally ranges between a few hours 3 h for the 1815 tambora eruption, sunda arc, indonesia to days about 48 h for the 1991 cerro hudson eruption. No volcanic winter in east africa from ancient toba eruption. Due to lavas distinctive composition, it can be dated using a radioisotope technique called argonargon dating. Its odd elongate shape is a result of the interactions between the magma chamber and the shearing forces of the sumatran fault along the west that has stretched it out.
This prompted anthropologist stanley ambrose of the university of illinois to advance the notion that the human population came close to extinction in the aftermath of. According to the toba catastrophe theory, it had global. Tobas eruption produced vast quantities of sulphur dioxide, a gas that behaves in the opposite way to a greenhouse gas it cools earth by increasing the atmospheres ability to reflect the. The climatic effects of the paroxysmal toba eruption could have caused the bottleneck, and the event. The toba caldera ronggur nihuta, indonesia atlas obscura. Photo courtesy united states geological survey usgs, photographer d. Pinatubo eruption, have been unable to produce such a prolonged. Ancient volcanos devastating effects confirmed live science. It has been suggested that the toba volcanic eruption, approximately 74 ka bp, was responsible for the extended cooling period and ice sheet advance immediately following it, but previous climate model simulations, using 100 times the amount of aerosols produced by the 1991 mt. The area is seismically active with major earthquakes in 1892, 1916, 19201922, and 1987.
Highly evolved rhyolitic glass compositions from the toba. Prior to the eruption of 73,000 years ago, toba had produced at least two earlier major eruptions 800,000 and 500,000 years ago. This book describes a convergence of human origins and the geological forces. Robbie millen, the times the greatest volcanic eruption of modern times occurred in 1815 on the small island of tambora in the east indies. The very large toba eruption 74,000 years ago may have caused a human genetic bottleneck. Toba volcano caldera 2157 m 7,077 ft sumatra, indonesia, 2. It spawned the most extreme weather in thousands of years. The eruption of toba volcano in northern sumatra some 73,000 years ago was the largest explosive eruption of the past two million years, with a volcanic explosivity index of magnitude 8, but its. Woods book is by far the best on the subject, and most comprehensive.
The rare but spectacular eruptions of supervolcanoes can cause massive. The toba volcano is located near the center of the indonesian island of sumatra. Within the last three to five million years, after human and. The youngest toba tuff ytt is the largest known supereruption in. The 35 x 100 km toba caldera, the earths largest quaternary caldera, was formed during four major pleistocene ignimbriteproducing eruptions beginning at 1. Environmental impact of the 73 ka toba supereruption in. Site of the largest volcanic eruption in the last 25 million years, one which may have nearly wiped out humanity altogether. Helens 1980, and mount pinatubo 1991 were enormous, they are very small compared to ancient eruptions such as wah wah springs, toba. The toba catastrophe theory holds that this event caused a global volcanic winter of six to ten years and possibly a 1,000yearlong cooling episode. The toba supereruption was a supervolcanic eruption that occurred about 75,000 years ago at the site of presentday lake toba in sumatra, indonesia. That study did not focus on human habitation sites, but did find that, at least in the vicinity of lake malawi, the toba eruption was not accompanied by a major change in sediment composition. Image nasa image caption mount tobas eruption crater is now a lake. Evidence suggests toba volcanic winter was less lethal. We observed no obvious change in sediment composition or feti ratio, suggesting that no thermally driven overturn of.
The youngest toba eruption was a supervolcanic eruption that occurred around 75,000 years. Lake toba is the site of a supervolcanic eruption estimated at vei 8 that occurred 69,000 to 77,000 years ago, representing a climatechanging event. A massive eruption sometime between 71,000 and 74,000 years ago expelled an estimated 2,800 cubic km about 670 cubic miles of ash and lava. The volume of ejected material produced by individual plinian pulses ranges typically between 0. As large as the toba eruption was, the reservoir of magma below the caldera is much, much greater, the researchers say. It is one of the earths largest known explosive eruptions. Magma composition is interpreted from the composition of igneous rocks exposed at the. One example was the vei 8 toba eruption in sumatra about 74,000 years ago, which released roughly 800 km3 of ash and aerosols into the atmosphere, which covered much of southeast asia to a depth. The toba eruption was enormous, throwing out roughly times as much rock as the 1980 eruption of mt. Using a modern dating technique, the researchers were able to date the human remains of unknown age to 63,00073,000 years, just in time for the toba.
Mount toba, ancient volcano located in northcentral sumatra, indonesia. Dust trapped in polar ice cores shows that ejected material spread around the globe, indicating that the eruption injected substantial material into the stratosphere, where it can strongly affect climate. The eruption 75,000 years ago produced the young toba tuff. Satellite image of lake toba, the site of a vei 8 eruption c. The spheres in the illustration above represent the volume of erupted tephra for some of the most widelyknown explosive volcanic eruptions. The toba eruption 73,000 years ago would have looked rather similar, only very much larger. About 74,000 years bp, more than 2500 cubic kilometers of magma were erupted. The greatest volcanic eruption of modern times occurred in 1815 on the small island of tambora in the east indies. The eruption that changed the world is an intensely researched and very interesting study of the effects of the volcanic eruption that took place on the island of sumbawa in the dutch east indies in april of 1815. A recent model suggests that transportation of the toba ash westward over africa was. The loss of vegetation meant a shortage of food for all animals, including humans, and a resulting famine. Located on the island of sumatra, in indonesia, lake toba is a beautiful caldera lake, measuring 100 km by 30 km.
The eruption led to the final formation of one of earths largest calderas, the 35x100 km wide toba caldera. Helens and the lives it changed forever 2005 and richard waitts in the path of destruction. But the investigation finds no changes in the composition of the. Distribution of magma beneath the toba caldera complex, north.
The glaring engineering mistake that made wind turbines inefficient massive engineering mistakes duration. Large eruptions occurred 840,000, about 700,000, and 75,000 years ago. Discover the toba caldera in ronggur nihuta, indonesia. Heres the abstract of that paper which is behind a paywall, but commented upon in science daily, to which ill refer shortly. According to the toba catastrophe theory, a massive volcanic eruption changed the course of human history by severely reducing the human population. Early humans may have lived through a supervolcano eruption.
Toba is located near the sumatra fracture zone sfz. The pumice erupted 75,000 years ago is calc alkalic quartzlatite to rhyolite in composition 68%76% silica. A provocative book that confidently leaps from volcanology to lit crit by way of history. The climatic downturn intensified by the toba ytt eruption was a. The black line shows a 10,000year smoothed oxygen isotope profile, representing the climate changes. The latest of these produced the young toba tuff ytt about 74,000 years ago. Humans thrived after historic mount toba eruption psi. Although most people believe that vesuvius 79 ad the pompeii eruption, mount st. Doubt over volcanic winter after toba supereruption. Volcanic hazards and disasters in human antiquity, pp. At about 74,000 years ago, mount toba on the island of sumatra erupted in a massive explosion that supposedly rocked the middle palaeolithic world to its very foundations, bringing contemporary human populations to their knees, reducing the global population level to around 15,000 individuals, thereby precipitating a socalled bottleneck of human evolution, as proposed by. The magmas that erupt from volcanoes on earth originate primarily through partial melting processes. New study documents aftermath of a supereruption, and.
It is the largestknown explosive eruption on earth in the last 25 million years. The researchers also used an electron microprobe to confirm that the chemical composition of the glass shards carried the chemical fingerprint of the toba supereruption or, in. The ytt represents the worlds largest known quaternary eruption, ejecting about 25003000 km3 dense rock equivalent of ignimbrite and. An eruption between 71,000 and 74,000 years ago expelled roughly 2,800 cubic km about 670 cubic miles of ash and lava, which, according to some scientists, plunged the planet into an ice age that nearly caused the extinction of modern humans. What would happen if a super volcanic eruption happens again. Did the mount toba eruption almost wipe out humans. Pdf environmental impact of the 73ka toba super eruption.
Toba the rising super volcano volcano world oregon. Toba volcano has produced the largest known volcanic eruption on earth during the past 2 million years. The magnitude and impact of the youngest toba tuff supereruption. Researchers say toba spewed out a staggering 700 cubic miles 2,800 cubic kilometers of magma. Helens 2015, there is now a third recent book that promises to reveal new details about the catastrophic 1980 eruption of mount st helens. The youngest toba eruption was a supervolcanic eruption that occurred around 75,000 years ago at the site of presentday lake toba in sumatra, indonesia.
The toba eruption, which took place on the island of sumatra in indonesia about 73,000 years ago, released an estimated 800 cubic kilometers of ash into the atmosphere that blanketed the skies and. There have been no eruptions at toba in historical. Supervolcanoes occur when magma in the mantle rises into the crust but is unable to break through it and pressure builds in a large and growing magma pool until the crust is unable to contain the pressure. Aftermath of supereruption shows toba magma systems great size date.