The 2013 Russian fireball largest ever detected by CTBTO infrasound sensors

Abstract

On 15 February 2013, a large Earth‐impacting fireball disintegrated over the Ural Mountains. This extraordinary event is, together with the 1908 Tunguska fireball, among the most energetic events ever instrumentally recorded. It generated infrasound returns, after circling the globe, at distances up to ~85,000 km, and was detected at 20 infrasonic stations of the global International Monitoring System (IMS). For the first time since the establishment of the IMS infrasound network, multiple arrivals involving waves that traveled twice round the globe have been clearly identified. A preliminary estimate of the explosive energy using empirical period‐yield scaling relations gives a value of 460 kt of TNT equivalent. In the context of the future verification of the Comprehensive Nuclear‐Test‐Ban Treaty, this event provides a prominent milestone for studying in detail infrasound propagation around the globe for almost 3 days as well as for calibrating the performance of the IMS network.

GPS network observation of traveling ionospheric disturbances following the Chelyabinsk meteorite blast

“…Such a TID was not observed after the blast elsewhere in the world, particularly not in those regions covered by dense GPS networks, such as China (the present work) and Japan (Yang et al, 2013). Although the global propagation of acoustic waves in the troposphere was observed by ground-based in-F. Ding et al: TIDs following a meteorite blast frasound sensors (Pichon et al, 2013), global-scale propagation of TIDs associated with acoustic waves in the ionosphere has not been reported to date. According to theoretical calculation, TIDs characterized by such scales would suffer from considerable dissipation and propagate in a limited range (Hines, 1967;Mayr et al, 1990).…”

“…The propagation of this long-distance infrasound-wave is probably driven by acoustic waveguides below an altitude of 40 km (Pichon et al, 2013). At much higher altitudes, ionospheric disturbances caused by the meteorite blast were observed by the backscatter radar at the ARTI observatory, which is located some 200 km from the blast site (Berngardt et al, 2013).…”

A meteor shockwave event recorded at seismic and infrasound stations in northern Taiwan

“…Taking a bulk density of 3 g/cm 3 and an initial velocity of 20 km/s for the meteor in question, this kinetic energy nominally means a pre-atmospheric mass of ~250 kg and a size of ~0.5 m across. Only moderate in (3) log 10 E 2 = 3.34 log 10 (P) − 2.58, E 2 ≤ 100 kT size compared to previously studied events (Brown et al 2002;Le Pichon et al 2013;Caudron et al 2016), such meteors impinge upon the Earth at the rate of a few tens every year (Silber et al 2009). We should note that our estimation of the pre-atmospheric source energy is rather crude and utterly contingent upon the uncertainty in the measurement of periods at the variable recording sites.…”

A New Journal Serving the Infrasound Community

“…The infrasound network will offer us an unprecedented opportunity to better understand man-made and natural atmospheric phenomena on a global scale. The global network is enhanced in some regions by other infrasound arrays and, notably, in the United States by the Transportable Array [1] that comprises 400 combined seismic and acoustic stations on a Cartesian grid spanning 2,000,000 km 2 . We anticipate that the global network of listening posts that monitor the Earth's atmospheric shell will some day become as indispensable as the global seismic network that monitors Earth's solid interior.…”

“…There have been some noteworthy events recorded recently by these stations including the meteor that entered the Earth's atmosphere above Chelyabinsk Russia in February, 2013. Signals from this event were recorded by infrasound arrays after circling the globe twice [2] and by the Transportable Array. Another recent event that was recorded by a large number of infrasound stations was the eruption of Eyjafjallajökull, Iceland [3].…”