Site response of the Ganges basin inferred from re-evaluated macroseismic, observations from the 1897 Shillong, 1905 Kangra, and 1934 Nepal earthquakes

被引:72
作者
Hough, Susan E. [1 ]
Bilham, Roger [2 ]
机构
[1] US Geol Survey, Pasadena, CA 91106 USA
[2] Univ Colorado, CIRES & Geol Sci, Boulder, CO 80309 USA
基金
美国国家科学基金会;
关键词
Historical earthquakes; site response; seismic hazard;
D O I
10.1007/s12040-008-0068-0
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
We analyze previously published geodetic data and intensity values for the M(s) = 8.1 Shillong (1897), M(s) = 7.8 Kangra (1905), and M(s) = 8.2 Nepal/Bihar (1934) earthquakes to investigate the rupture zones of these earthquakes as well as the amplification of ground motions throughout the Punjab, Ganges and Brahmaputra valleys. For each earthquake we subtract the observed MSK intensities from a synthetic intensity derived from an inferred planar rupture model of the earthquake, combined with an attenuation function derived from instrumentally recorded earthquakes. The resulting residuals are contoured to identify regions of anomalous intensity caused primarily by local site effects. Observations indicative of liquefaction are treated separately from other indications of shaking severity lest they inflate inferred residual shaking estimates. Despite this precaution we find that intensites are 1-3 units higher near the major rivers, as well as at the edges of the Ganges basin. We find evidence for a post-critical Moho reflection from the 1897 and 1905 earthquakes that raises intensities 1-2 units at distances of the order of 150 km from the rupture zone, and we find that the 1905 earthquake triggered a substantial subsequent earthquake at Dehra Dun, at a distance of approximately 150 km. Four or more M = 8 earthquakes are apparently overdue in the region based on seismic moment summation in the past 500 years. Results from the current study permit, anticipated intensities in these future earthquakes to be refined to incorporate site effects derived from dense macroseismic data.
引用
收藏
页码:773 / 782
页数:10
相关论文
共 44 条
[1]   Reevaluated intensities for the great Assam Earthquake of 12 June 1897, Shillong, India [J].
Ambraseys, N ;
Bilham, R .
BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, 2003, 93 (02) :655-673
[2]  
Ambraseys N, 2000, CURR SCI INDIA, V79, P1237
[3]   Magnitude calibration of north Indian earthquakes [J].
Ambraseys, NN ;
Douglas, J .
GEOPHYSICAL JOURNAL INTERNATIONAL, 2004, 159 (01) :165-206
[4]  
[Anonymous], 1981, M EWING SERIES AM GE
[5]  
[Anonymous], 2000, CURR SCI
[6]   Mountain building, erosion, and the seismic cycle in the Nepal Himalaya [J].
Avouac, JP .
ADVANCES IN GEOPHYSICS, VOL 46, 2003, 46 :1-80
[7]   Source parameters of earthquakes in eastern and western North America based on finite-fault modeling [J].
Beresnev, IA ;
Atkinson, GM .
BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA, 2002, 92 (02) :695-710
[8]   Plate motion of India and interseismic strain in the Nepal Himalaya from GPS and DORIS measurements [J].
Bettinelli, Pierre ;
Avouac, Jean-Philippe ;
Flouzat, Mireille ;
Jouanne, Francois ;
Bollinger, Laurent ;
Willis, Pascal ;
Chitrakar, Gyani Raja .
JOURNAL OF GEODESY, 2006, 80 (8-11) :567-589
[9]  
Bilham R, 1998, CURR SCI INDIA, V74, P213
[10]   Plateau 'pop-up' in the great 1897 Assam earthquake [J].
Bilham, R ;
England, P .
NATURE, 2001, 410 (6830) :806-809