Shockwaves From Russian Meteor Circled Globe Twice: A Study
The 10,000 ton meteor that crashed into a frozen lake in Russia earlier this year created shockwaves so intense they endured two trips around the globe, according to a new study based on information recorded at 20 infrasonic stations belong to the global International Monitoring System (IMS).
Infrason refers to ultra-low frequency acoustic waves and are key to measuring the impact of an event, including earthquakes and avalanches.
Published in the journal Geophysical Research Letters, the researchers explain that, along with the 1908 Tunguska fireball, the event was among them most energetic ever recorded, and marked the first time since the IMS network was established that it recorded multiple arrivals of shockwaves.
According to the study, a preliminary estimate of the meteor's explosive energy devised using empirical period-yield scaling relations gave a value equivalent to that of 460 kilotons of TNT, the equivalent of 30 Hiroshima-sized bombs.
Knowing this, the researchers report, could provide a prominent milestone for studying infrasound propagation in the context of the future verification of the Comprehensive-Nuclear-Test-Ban Treaty (CTBT), as well as for calibrating the performance of the IMS network
All told, approximately 1,500 people were injured as a result of the intensity of the explosion, though the meteor itself did not strike anyone directly.
The Tunguska explosion, meanwhile, is estimated to have been approximatley 1,000 times more powerful than the bomb dropped on Hiroshima, decimating an area of Siberian forest near the Podkemannaya Tunguska River roughly the size Tokyo.
For years, speculation surrounded the location with theories ranging from UFOs to a test run of Nikola Tesla's "death ray." The most widely-accepted theory was that of a meteorite, though the event mysteriously never left a crater.
Then, in May, a Russian scientist named Andrei E. Zlobin published a study in which he reports that a fragment of the object believed to cause the explosion is, in fact, part of a meteorite.
According to Nature, impacts like these - Tunguska and the more recent explosion - are believed to occur on average every 75 years.