roughbarked said:
mollwollfumble said:
mollwollfumble said:
No one questioning that it was a supervolcano that drove neanderthal’s towards extinction?
In the news yesterday.
Yellowstone supervolcano eruption. Stop worrying it’s about to blow.
The REAL threat at Yellowstone: Experts say a magnitude 7 earthquake ‘can and will’ hit the area already at risk from a supervolcano eruption.
http://www.dailymail.co.uk/sciencetech/article-6083519/Yellowstone-greater-risk-magnitude-7-earthquake-supervolcano-eruption-experts-warn.html
‘The biggest concern we have for Yellowstone is not with the volcano, it’s with the earthquakes,’ Michael Poland, scientist-in-charge at the Yellowstone Volcano Observatory, told USA Today. ‘This is an underappreciated hazard in the Yellowstone area. There can and there will be in the future magnitude-7 earthquakes.’
The last lava flow was 73,000 years ago. Large earthquakes, on the other hand, are far more common. A magnitude 7.3 earthquake hit the park just 59 years ago on August 17, 1959.
Good video 3-D view of the three magma chambers in above link.
Toba was about 75,000 years ago?
Yes, here’s a recent article suggesting that it only had a localized effect.
https://www.theatlantic.com/science/archive/2018/03/supervolcano-goes-boom-humans-go-meh/555356/
“Around 74,000 years ago, the Toba supervolcano erupted on the Indonesian island of Sumatra. It was the biggest volcanic eruption of the last 2 million years, unleashing 2,800 cubic kilometers of magma. That’s enough to bury the entire United States in a foot-thick layer of ash and rock.”
“If Toba had triggered a major global climate event, Africa probably would have been affected, and they see no evidence of that,”
“Now, into the fray comes a new study from an unlikely location. In a cliff near Mossel Bay, a town on South Africa’s south coast, scientists have discovered a layer of microscopic glass shards. Known as cryptotephra, these shards are the products of Toba’s wrath, created when the volcano superheated the silica within its expunged rock. They drifted in the air over 5,500 miles and fell on southern Africa as the sparsest of drizzles. And they settled among bones, tools, and other signs of human occupation.”
““We showed that after the input of the shards, human occupation at the site actually increased dramatically,” says Curtis Marean, from Arizona State University. “We never expected that.”
“The hobbits of Flores, who all lived far closer to Toba than humans in Africa, survived the eruption.”
“This is a Holy Grail moment in geochronology. It’s so, so rare for us to be able to speak about things at that temporal resolution.”
