Volcanoes at the south end of California’s Salton Sea erupted as recently as the time of Christ, not 30,000 years ago, and may be active today.
Live Science reported the correction about Salton Buttes. It makes the five domes a possible threat for a new eruption.
The buttes last erupted between 940 and 0 B.C., not 30,000 years ago, as previously thought, a new study detailed online Oct. 15 in the journal Geology reports. The new age — which makes these some of California’s youngest volcanoes — pushes the volcanic quintuplets into active status. The California Volcano Observatory, launched in February by the U.S. Geological Survey (USGS), already lists the area as a high threat for future blasts.
Last August, an earthquake swarm alerted the USGS of activity in the area. This was followed by a foul smell of rotten eggs over a wide area that could have come from an outgassing event in the volcanic field, not from a fish die-off as first suggested. This means the volcanoes are active today, not 30,000 years ago.
A new helium-zircon dating technique was used to arrive at the new date. Scientists should have known, though, that the cones were young. If they had been underneath prehistoric Lake Cahuilla (a precursor to Salton Sea), they would have been covered with sediments. Native Americans worked the obsidian between 510 and 640 BC, the article said, but not before–probably because it wasn’t available before the recent eruptions.
What would happen if Salton Buttes erupted again? “The amounts of magma involved are relatively small and the impacts of an explosive eruption, meaning an ash cloud, would most likely be very local,” said UCLA geochronologist Axel Schmitt. The abstract of his paper in Geology states, “The (U-Th)/He eruption age is younger and significantly more precise than previous ages for these volcanoes, and is the first indication that the eruption of obsidian flows coincided with human presence in the region.”
Long ages are a playground for speculation. It’s like giving a packrat vast numbers of closets for storing his junk. Rather than constrain scientific thinking, it produces irresponsible storytelling and puts the burden on others to explain why the tens of thousands of years, or millions, or billions, is unreasonable. When you see the catch-phrase “as previously thought,” always ask, “Who thought that?” If it wasn’t you, don’t let them lump you in with the storytellers.