A study of Guptkashi, Uttarakhand earthquake of 6 February 2017 (M w 5.3) in the Himalayan arc and implications for ground motion estimation
Por:
Srinagesh, Davuluri, Singh, Shri Krishna, Suresh, Gaddale, Srinivas, Dakuri, Perez-Campos, Xyoli, Suresh, Gudapati
Publicada:
1 may 2018
Resumen:
The 2017 Guptkashi earthquake occurred in a segment of the Himalayan arc with high potential for a strong earthquake in the near future. In this context, a careful analysis of the earthquake is important as it may shed light on source and ground motion characteristics during future earthquakes. Using the earthquake recording on a single broadband strong-motion seismograph installed at the epicenter, we estimate the earthquake’s location (30.546° N, 79.063° E), depth (H = 19 km), the seismic moment (M 0 = 1.12×10 17 Nm, M w 5.3), the focal mechanism (f = 280°, d = 14°, ? = 84°), the source radius (a = 1.3 km), and the static stress drop ( s s ~22 MPa). The event occurred just above the Main Himalayan Thrust. S-wave spectra of the earthquake at hard sites in the arc are well approximated (assuming ? -2 source model) by attenuation parameters Q(f) = 500f 0.9 , ? = 0.04 s, and f max = infinite, and a stress drop of s = 70 MPa. Observed and computed peak ground motions, using stochastic method along with parameters inferred from spectral analysis, agree well with each other. These attenuation parameters are also reasonable for the observed spectra and/or peak ground motion parameters in the arc at distances = 200 km during five other earthquakes in the region (4.6 = M w = 6.9). The estimated stress drop of the six events ranges from 20 to 120 MPa. Our analysis suggests that attenuation parameters given above may be used for ground motion estimation at hard sites in the Himalayan arc via the stochastic method. © 2018, Springer Science+Business Media B.V., part of Springer Nature.
Filiaciones:
Srinagesh, Davuluri:
CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad, Telangana, India
Natl Geophys Res Inst, CSIR, Uppal Rd, Hyderabad 500007, Telangana, India
Singh, Shri Krishna:
Universidad Nacional Autónoma de México, Instituto de Geofísica, Circuito de la Investigación s/n, Ciudad Universitaria, Coyoacán, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Inst Geofis, Circuito Invest S-N,Ciudad Univ, Mexico City 04510, DF, Mexico
Suresh, Gaddale:
National Centre for Seismology, Noida, India
Natl Ctr Seismol, Noida, India
Srinivas, Dakuri:
CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad, Telangana, India
Natl Geophys Res Inst, CSIR, Uppal Rd, Hyderabad 500007, Telangana, India
Perez-Campos, Xyoli:
Universidad Nacional Autónoma de México, Instituto de Geofísica, Circuito de la Investigación s/n, Ciudad Universitaria, Coyoacán, Mexico City, Mexico
Univ Nacl Autonoma Mexico, Inst Geofis, Circuito Invest S-N,Ciudad Univ, Mexico City 04510, DF, Mexico
Suresh, Gudapati:
National Centre for Seismology, Noida, India
Natl Geophys Res Inst, CSIR, Uppal Rd, Hyderabad 500007, Telangana, India
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