HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Wu, Y.-M. Articles by Chiao, L.-Y. Search for Related Content GeoRef GeoRef Citation

Seismic Quiescence before the 1999 Chi-Chi, Taiwan, M_w 7.6 Earthquake

¹ Department of Geosciences
National Taiwan University
No. 1, Sec. 4, Roosevelt Road
Taipei 106, Taiwan
drymwu{at}ntu.edu.tw
 (Y.-M.W.)

² Institute of Oceanography
National Taiwan University
Taipei, Taiwan
 (L.-Y.C.)

The Chi-Chi, Taiwan, earthquake of 20 September 1999 was preceded by a notable decrease of the regional seismicity rate. The anomalous period started in January 1999 and lasted about 9 months, up to the occurrence of the mainshock, as revealed from analyzing the Taiwan catalog data from 1 January 1994 to 20 September 1999. Our results indicate that the mean seismicity rate is 435 events per month with a standard deviation of 78 events for earthquakes with magnitude above 2.0. During the anomalous period, seismicity rates fell outside the range of one standard deviation with a mean value of 314 events per month. There was also a consistent trend of decreasing regional b-value as well as notable increases of seismic activity in areas surrounding the Chi-Chi earthquake source region via the Z-test map (ZMAP) analysis.

This article has been cited by other articles:

				Y.-M. Wu, C.-H. Chang, L. Zhao, T.-L. Teng, and M. Nakamura A Comprehensive Relocation of Earthquakes in Taiwan from 1991 to 2005 Bulletin of the Seismological Society of America, June 1, 2008; 98(3): 1471 - 1481. [Abstract] [Full Text] [PDF]

				C.-H. Chang, Y.-M. Wu, L. Zhao, and F. T. Wu Aftershocks of the 1999 Chi-Chi, Taiwan, Earthquake: The First Hour Bulletin of the Seismological Society of America, August 1, 2007; 97(4): 1245 - 1258. [Abstract] [Full Text] [PDF]