Examination of aperiodicity parameters for the Brownian Passage Time model using intraplate paleoearthquake data in Japan

• Takashi Kumamoto

• Yukiko Hamada

Abstract

When calculating the probability of future earthquake occurrence, it is common to apply stochastic models to paleoearthquake data collected from fault trenching surveys. The Headquarters of Earthquake Research Promotion (HERP,2001) concluded that in terms of fiscal meaning, stability, and ease of comprehension, the best of the stochastic models is the Brownian Passage Time (BPT) model. This model requires two parameters: average recurrence interval and aperiodicity of the mean period between events (coefficient of variation). HERP (2001) derived a value of 0.24 for the common aperiodicity from four paleoearthquake data sets, which is roughly half the value of 0.50 derived by Ellsworthet al. (1999) from 37 worldwide earthquake records. The purposes of this study are (1) to construct a paleoearthquake database of active intraplate faults in Japan based on trenching results conducted after 1995 and (2) to evaluate aperiodicity using the BPT model and this database. Common aperiodicity ( a_c), calculated from 23 paleoearthquake data sets in this study, is 0.49, approximately the same as the result of Ellsworth et al. (1999). This study shows no distinct relations between aperiodicity and active fault type, fault activity, recurrence interval derived from trench results, or distance between trench site and the center of the seismogenic fault system. There is a small positive correlation between the aperiodicities in this study and the number of neighboring faults within 30 km of trench sites. This might be consistent with the BPT model, in that aperiodicity of a given fault can be affected by seismic activity of nearby earthquakes, which alters the recurrence interval and future earthquake probability of the fault under consideration.

Journal

• Active Fault Research

  Active Fault Research 2005 (25), 9-22, 2005

  Japanese Society for Active Fault Studies

Keywords

• active fault recurrence
• trench database
• Brownian Passage Time (BPT) model
• aperiodicity

Details

• CRID: 1390001204429549952
• NII Article ID: 130004844909
• NII Book ID: AN10157356
• DOI: 10.11462/afr1985.2005.25_9
• NDL BIB ID: 7455216
• ISSN: 09181024
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I7455216
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed