Seismic detections of the 15 February 2013 Chelyabinsk meteor from the dense ChinArray

Abstract

ChinArray is a dense portable broadband seismic network to cover the entire continental China, and the Phase I is deployed along the north-south seismic belt in southwest China. In this study, we analyze seismic data recorded on the ChinArray following the February 15, 2013 Chelyabinsk (Russia) meteor. This was the largest known object entering the Earth's atmosphere since the 1908 Tunguska meteor. The seismic energy radiated from this event was recorded by seismic stations worldwide including the dense ChinArray that are more than 4000 km away. The weak signal from the meteor event was contaminated by a magnitude 5.8 Tonga earthquake occurred *20 min earlier. To test the feasibility of detecting the weak seismic signals from the meteor event, we compute vespagram and perform F-K analysis to the surface-wave data. We identify a seismic phase with back azimuth (BAZ) of 329.7°and slowness of 34.73 s/deg, corresponding to the surface wave from the Russian meteor event (BAZ *325.97°). The surface magnitude (M S) of the meteor event is 3.94 ± 0.18. We also perform similar analysis on the data from the broadband array F-net in Japan, and find the BAZ of the surface waves to be 316.61°. With the different BAZs of ChinArray and F-net, we locate the Russian meteor event at 58.80°N, 58.72°E. The relatively large mislocation (*438 km as compared with 55.15°N, 61.41°E by others) may be a result of the bending propagation path of surface waves, which deviates from the great circle path. Our results suggest that the dense ChinArray and its subarrays could be used to detect weak signals at teleseismic distances.

Seismogram Rearrangement as a Perspective Basis for Defining New Attributes

“…Instead of complex fault rupture processes superimposed to create an intricate waveform, here is a simple "fault" mechanism, providing something similar to delta short-impulse excitation. From recording distances, one can infer that the propagation of resulting seismic waves took place mostly through the mantle [41][42][43][44][45][46][47][48][49][50].…”

“…Details about the shockwave 'fault' mechanism can be found in [48]. Apart from the GFZ graphical account of the event [43,45], there are recordings, mostly taken as teleseismic, with arrays in China and the USA [49,50]. This 'fault' mechanism is, by all means, very specific.…”

SEDENOSS: SEparating and DENOising Seismic Signals With Dual‐Path Recurrent Neural Network Architecture

“…There are also studies [e.g., Li et al. (2016)], where authors had pick seismoacoustic signals mixed in with seismic ones. Using a source separation technique, one can potentially separate both seismic and acoustic waves for analysis Ambient noise tomography .…”

“…This problem arises especially in nuclear verification (Hoffmann et al, 1999), where seismic data are used to estimate the location and the yielding mass of the potential nuclear explosion. There are also studies [e.g., Li et al (2016)],…”