Seismoacoustic Signatures from Chelyabinsk Meteor Observed by the Kazakhstan Nuclear Explosion Monitoring Network (Invited)
Abstract
Infrasound and seismic stations of the Kazakhstan Nuclear Explosion Monitoring network recorded high-fidelity seismoacoustic signatures from the Chelyabinsk meteor. Infrasound array I31KZ in Aktyubinsk was the closest IMS infrasound station to the source. This station is in the Northwest Kazakhstan, approximately 520 km southward from the bolide blast. The propitious station position relative to the entry trajectory, coupled with calm weather during the event, permitted a detailed, broadband record of the bolide explosion. All eight I31KZ infrasound array channels show an extremely strong broadband signal at 03:48 UTC and a duration of ~20 minutes. Array processing of the signal with PMCC4 shows that signal contains unprecedented detail on the source characteristics. Another Kazakhstani infrasound array in Kurchatov, Northeast Kazakhstan, also recorded the explosion signals. This is third closest infrasound array to the source. The second one is Russian array I43RU, Dubna. Epicentral distances are 1090 km for Dubna and 1300 km for Kurchatov. Traveltimes are 26 minutes for I31KZ Aktyubinsk and 66 minutes for the Kurchatov array. In addition to infrasound arrays, Kazakhstani seismic arrays belonging to Institute of Geophysical Research also recorded the signals generated by the bolide. The epicentral seismic source location corresponds to the pressure shock wave ground impact, and is under the meteor hypercenter. The seismic signal was recorded by Akbulak, Borovoe, Karatau and Makanchy arrays and other Kazakhstani seismic stations. Akbulak was the station nearest to epicenter, at a range of 630 km southward. The estimated origin time of the seismic event following the bolide explosion is 03:21:59.64 GMT. The difference between ground truth time 3:20:33 GMT provided by NASA and the seismic origin time is in reasonable agreement with the reported hypercenter altitude range of 25-30 km asl. The seismic event had a body wave magnitude of Mb 3.5, with energy class K 8.4. For comparison, the seismic magnitude of the Tunguska meteor was Mb 5.0.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFMNH21D..04S
- Keywords:
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- 6245 PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS Meteors