Earthquake Magnitude Conversion Problem

2018 ◽  
Vol 108 (4) ◽  
pp. 1995-2007 ◽  
Author(s):  
Ranjit Das ◽  
H. R. Wason ◽  
Gabriel Gonzalez ◽  
M. L. Sharma ◽  
Deepankar Choudhury ◽  
...  
Keyword(s):  
Earthquake Magnitude ◽  
Magnitude Conversion ◽  
Earthquake Magnitude Conversion

Regional Earthquake Magnitude Conversion Relations for the Himalayan Seismic Belt

2020 ◽  
Vol 91 (6) ◽  
pp. 3195-3207
Author(s):  
Rajiv Kumar ◽  
Ram Bichar Singh Yadav ◽  
Silvia Castellaro
Keyword(s):  
Moment Tensor ◽  
Earthquake Magnitude ◽  
Seismic Belt ◽  
Centroid Moment Tensor ◽  
Moment Tensor Solution ◽  
Magnitude Conversion ◽  
Magnitude Scales ◽  
Regression Relations ◽  
Regional Earthquake ◽  
Earthquake Magnitude Conversion

Abstract We present regional earthquake magnitude conversion relations among different magnitude scales (Mw, Ms, mb, ML, and MD) for the Himalayan seismic belt developed from data of local, regional, and international seismological agencies (International Seismological Centre [ISC], National Earthquake Information Centre [NEIC], Global Centroid Moment Tensor Solution [CMT], International Data Centre [IDC], China Earthquake Administration [BJI], and National Centre for Seismology [NDI]). The intra- (within the same magnitude scale) and inter- (with different magnitude scales) magnitude regression relations have been established using the general orthogonal regression and orthogonal distance regression techniques. Results show that the intra-magnitude relations for Mw, Ms, and mb reported by the Global CMT, ISC, and NEIC exhibit 1:1 relationships, whereas ML reported by the IDC, BJI, and NDI deviates from this relationship. The IDC underestimates Ms and mb compared with the ISC, NEIC, and Global CMT; this may be due to different measurement procedures adopted by the IDC agency. The inter-magnitude relations are established between Mw,Global CMT and Ms, mb, and ML reported by the ISC, NEIC, IDC, and NDI, and compared with the previously developed regional and global regression relations. The duration (MD) and local (ML) magnitudes reported by NDI exhibit a 1:1 relationship. The derived magnitude regression relations are expected to support the homogenization of the earthquake catalogs and to improve seismic hazard assessment in this region.

scholarly journals A seismic hazard analysis considering uncertainty during earthquake magnitude conversion

2013 ◽  
Vol 1 (3) ◽  
pp. 2109-2126
Author(s):  
J. P. Wang ◽  
Y. Xu
Keyword(s):  
Seismic Hazard ◽  
Hazard Analysis ◽  
Analytical Framework ◽  
Earthquake Magnitude ◽  
Seismic Hazard Analysis ◽  
Local Magnitude ◽  
Empirical Relationships ◽  
Magnitude Conversion ◽  
Earthquake Magnitude Conversion ◽  
Earthquake Data

Abstract. The magnitude of earthquakes can be described with different units, such as moment magnitude Mw and local magnitude ML. A few empirical relationships between the two have been suggested, such as the model calibrated with the earthquake data in Taiwan. Understandably, such a conversion relationship through regression analysis is associated with some error because of inevitable data scattering. Therefore, the underlying scope of this study is to conduct a seismic hazard analysis, during which the uncertainty from earthquake magnitude conversion was properly taken into account. With a new analytical framework developed for this task, it was found that there is a 10% probability in 50 yr that PGA could exceed 0.28 g at the study site in North Taiwan.

scholarly journals Frictional properties of anorthite (feldspar): implications for the lower boundary of the seismogenic zone

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Koji Masuda
Keyword(s):  
Dominant Role ◽  
Lower Boundary ◽  
Earthquake Magnitude ◽  
Seismogenic Zone ◽  
Effective Pressure ◽  
Velocity Dependence ◽  
Brittle Deformation ◽  
Frictional Properties ◽  
Depth Extent ◽  
Mineral Constituents

Abstract Earthquake magnitude is closely related to the depth extent of the seismogenic zone, and higher magnitude earthquakes occur where the seismogenic zone is thicker. The frictional properties of the dominant mineral constituents of the crust, such as feldspar-group minerals, control the depth extent of the seismogenic zone. Here, the velocity dependence of the steady-state friction of anorthite, the calcic endmember of the feldspar mineral series, was measured at temperatures from 20 to 600 °C, pore pressures of 0 (“dry”) and 50 MPa (“wet”), and an effective pressure of 150 MPa. The results support previous findings that the frictional properties of feldspar play a dominant role in limiting the depth extent of the seismogenic zone. This evidence suggests that brittle deformation of anorthite may be responsible for brittle fault movements in the brittle–plastic transition zone.

Controlling Induced Earthquake Magnitude by Cycled Fluid Injection

2021 ◽  
Vol 48 (19) ◽  
Author(s):  
J. B. Zhu ◽  
J. Q. Kang ◽  
D. Elsworth ◽  
H. P. Xie ◽  
Y. Ju ◽  
...  
Keyword(s):  
Earthquake Magnitude ◽  
Fluid Injection ◽  
Induced Earthquake
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