TY - JOUR
T1 - A surface-wave investigation of the rupture mechanism of the Gobi-Altai (December 4, 1957) earthquake
AU - Okal, Emile A.
N1 - Funding Information:
I thank Prof. Hiroo Kanamori for the use ofhis synthetic surface-wave programs, and for many discussions. I am grateful to Prof. C.R. Allen, editor of the English translation of Flonensov and Solonenko (1963), who gave me permission to adapt figs. 197 and 89 into Figs. 2b and 10 of the present paper. Seismic stations listed in Table I kindly provided originals or copies of the records used. This work was supported ~by NASA Contract NGL 05-002-069 and National Science Foundation Grant No. EAR 74-22489.
PY - 1976/9
Y1 - 1976/9
N2 - Long-period records of multiple Love waves from the 1957 earthquake in Mongolia (MS = 8.0) at Pasadena are analysed and compared to synthetic seismograms, generated by the method of Kanamori. A fit in the time domain shows that the records are not consistent with the previous solution, achieved through a frequency-domain analysis of directivity by Ben-Menahem and Toksöz. The solution asks for a shorter rupture of 270 km at a velocity of 3.5 km/s. The focal parameters are constrained by updating all the reported first motion and are found to be: strike = 103°, dip = 53°, slip = 32°. A seismic moment of 1.8 · 1028 dyn · cm is obtained. These figures are also consistent with a time-domain analysis of Love waves at Palisades and Strasbourg, and of Rayleigh waves at Pasadena, with a directivity study of Love waves at Pasadena, and with static deformation and isoseismal data. A discussion is given of the relation between moment, magnitude and rupture area, and a comparison is made with other events in the same region: it is concluded that this earthquake does not exhibit an "intra-plate" behavior, but rather compares better with "inter-plate" events, such as the great Assam earthquake.
AB - Long-period records of multiple Love waves from the 1957 earthquake in Mongolia (MS = 8.0) at Pasadena are analysed and compared to synthetic seismograms, generated by the method of Kanamori. A fit in the time domain shows that the records are not consistent with the previous solution, achieved through a frequency-domain analysis of directivity by Ben-Menahem and Toksöz. The solution asks for a shorter rupture of 270 km at a velocity of 3.5 km/s. The focal parameters are constrained by updating all the reported first motion and are found to be: strike = 103°, dip = 53°, slip = 32°. A seismic moment of 1.8 · 1028 dyn · cm is obtained. These figures are also consistent with a time-domain analysis of Love waves at Palisades and Strasbourg, and of Rayleigh waves at Pasadena, with a directivity study of Love waves at Pasadena, and with static deformation and isoseismal data. A discussion is given of the relation between moment, magnitude and rupture area, and a comparison is made with other events in the same region: it is concluded that this earthquake does not exhibit an "intra-plate" behavior, but rather compares better with "inter-plate" events, such as the great Assam earthquake.
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U2 - 10.1016/0031-9201(76)90027-3
DO - 10.1016/0031-9201(76)90027-3
M3 - Article
AN - SCOPUS:0010632520
VL - 12
SP - 319
EP - 328
JO - Physics of the Earth and Planetary Interiors
JF - Physics of the Earth and Planetary Interiors
SN - 0031-9201
IS - 4
ER -