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| Earth on Jul 08, 2013

Explosion from Russian meteor heard round the world, twice

The meteor that exploded over Chelyabinsk, Russia on February 15, 2013 was so powerful that it sent out soundwaves that traveled around the world twice.

The meteor that exploded over Chelyabinsk, Russia on February 15, 2013 was so powerful that it sent out ultra-low frequency soundwaves that traveled around the world at least twice, according to new research published in the journal Geophysical Research Letters.

The meteor was estimated to be 17 meters (56 feet) in diameter and it weighed about 10,000 metric tons. It entered Earth’s atmosphere and approached Russia traveling at speeds near 20 kilometers per second (45,000 miles per hour). The meteor eventually exploded 19 to 24 kilometers (12 to 15 miles) above Earth’s surface. The shockwave from the explosion shattered windows and damaged buildings in nearby cities.

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Fragment of the Chelyabinsk meteorite. Image Credit: Svend Buhl.

New analyses of data collected by a global network of 20 infrasound sensors indicate that some ultra-low frequency soundwaves from the explosion circled around the globe at least twice. Infrasound refers to low frequency sound that is below 20 Hz (Hertz) or 20 cycles per second. While humans are incapable of hearing infrasound, these soundwaves travel long distances and some animals such as whales and elephants can use this type of sound for communication purposes.

Infrasound from the meteor explosion was detected at sensors as far away as Antarctica. It was the largest event ever recorded by the global infrasound sensor network, which is managed by the Comprehensive Nuclear-Test-Ban-Treaty Organization (CTBTO).

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A sensor array in Greenland that detected infrasound from the Chelyabinsk meteor explosion. Image Credit: CTBTO Preparatory Commission.

Scientists were able to use the infrasound records to determine how much energy was released by the meteor. They estimate that the explosion released 460 kilotons of energy, which is equivalent to about 30 atomic bombs. The new estimate of 460 kilotons was similar to earlier estimates that were put forth by other scientists (e.g., 470 kilotons).

The February 2013 Chelyabinsk meteor explosion now ranks as the second largest known event on Earth since the Tunguska explosion in 1908, according to National Geographic. In 1908, a meteor or comet exploded over Russia releasing 10,000 kilotons of energy. Scientists predict that meteor explosions the size of the one in Chelyabinsk, are likely to occur on Earth once every 50 to 100 years.

Bottom line: The meteor that exploded over Chelyabinsk, Russia on February 15, 2013 was so powerful that it sent out ultra-low frequency soundwaves that traveled around the world twice, according to a new study. Scientists were able to use infrasound records from the explosion to determine how much energy was released by the meteor. They estimate that the explosion released 460 kilotons of energy, which is equivalent to about 30 atomic bombs. The research was published on June 9, 2013 in the journal Geophysical Research Letters.

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