A huge “fireball” meteor that lit up the sky over western Alaska also triggered newly installed sensors to detect volcanic activity, according to the U.S. Geological Survey (USGS).
The event, which occurred on October 15, triggered six alarms from the sensors at a new monitoring station on the Kenai Peninsula. The sensors are designed to detect low frequency sound waves in the atmosphere during volcanic activity, but in this case they picked up waves from the meteor that had been streaming across the sky about 360 miles away.
In a Facebook posting, the USGS said the meteor also triggered an alarm at Mount Spurr – a large, active volcano about 80 miles from Anchorage that last erupted in 1992. However, since other monitoring systems also picked up the waves, “it quickly became clear that this was not activity at Mount Spurr,” the article said.
Scientists from the USGS Alaska Volcano Observatory worked with researchers from the University of Alaska Fairbanks Geophysical Institute to investigate the cause. They found the meteor over Alaska about 40 miles from the Athabaskan community of Kaltag, which is located on the Yukon River.
In a blog post for the American Geophysical Union, UAF science journalist Ned Rozell said witnesses had reported the fireball in regions hundreds of miles apart. One resident of Ruby described it as a “huge ball of light in the sky” moving from north to south. Another resident said it looked like “fireworks” that split into four points.
David Fee, head of the infrasonic program at UAF’s Geophysical Institute and a researcher at AVO, said he believed the meteor exploded somewhere east of Kaltag. “I don’t usually work on meteorites, but they are often really nice infrasound sources to better understand the performance of our networks, and I think they provide valuable information about meteorites and bolides themselves,” he said.
Meteors are small pieces of rock from outer space that enter the earth’s atmosphere. When they enter the Earth’s atmosphere, they burn up and produce a bright light that scatters across the sky. If a rock survives, it falls to the earth and becomes a meteorite. Fee said they believe that the meteorite from the event probably hit the ground somewhere north of the Innoko River and that the remains are now buried with snow.
It is estimated that over a dozen meteorites are expected to hit the Earth’s atmosphere each day. So far this year, the American Meteor Society has registered more than 570 events in which more than five meteorites have been sighted. This includes a fireball that flew over California on October 23rd and was reported by 81 people. Witnesses described the fireball as almost as bright as the moon. One onlooker said it was the “most amazing” thing they had ever seen.