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IUGG XXIV General Assembly July 2-13, 2007 Perugia, Italy
(S) - IASPEI - International Association of Seismology and Physics of the Earth's
Interior
JSS004 1893 - 1904
Symposium
Non-instrumental seismometry - Quantification of past and future
earthquakes: balancing the geological, historical and contemporary strain
records
Convener : Dr. Gianluca Valensise
General scopes related to Symposia on Non-instrumental seismometry. During the past 20 years, the
seismic hazard assessment practice has increasingly relied on the quantification of past and future
seismicity based on non-instrumental disciplines such as active tectonics, paleoseismology, historical
seismology. Over the years, these diciplines have been turned from merely descriptive to progressively
more quantitative. Quantification involves not only significant parameters of the earthquake source for
recent and more distant earthquakes (e.g. fault location, fault length, coseismic slip, rupture
complexity), but also the rate of earthquake production and recurrence properties of a fault, the
development of segmentation models, the description of the geometric conditions leading to dynamic
triggering. The symposium intends to acknowledge the enormous progress achieved in this area of
seismology in recent years and particularly since the mid-1990s, emphasize their mutual relationships
and show how they integrate with conventional instrumental methods. Due to its long-standing tradition
in the analysis of the historical earthquake record and to its contribution to the development of
methodologies in earthquake geology, Italy qualifies as an especially appropriate country to take a
leading role in this symposium. This is the first of four related symposia: JSS004, JSS005, JSS006,
JSS007. Below the scopes of JSS004. One of the outstanding issues in modern seismic hazard
assessment practice is the comparison of the earthquake record with the geologic and geodetic
evidence for ongoing tectonic strain. The correct estimation of past earthquakes on the one hand and of
geologic and tectonic parameters on the other hand forms the basis for assessing the maximum credible
earthquake, the size of impending earthquakes, and the expected rate of earthquake production in any
given region. Significant over- or under-estimations of the earthquake potential may derive from such
diverse conditions as source complexity during historical earthquakes, poor assessment of fault size,
dynamic fault interaction, failed identification of active fault trends, and aseismic creep. This session
intends to draw on scientists from different lines of expertise who are willing to cross conventional
disciplinary boundaries and compare their approaches, results and residual uncertainties. We especially
welcome contributions from these areas, or contributions that combine them into unconventional
schemes: - quantification of the historical earthquake record; - quantification of the geologic record,
including field studies of cumulative tectonic strain and the development of fault segmentation schemes;
- partitioning of geodetically-derived strain onto individually identified or areal active tectonic structures.
Papers are expected to emphasize the impact of the proposed results or approaches in the improvement
of i) the understanding of the seismic cycle of major faults, and of ii) mid- to long-term seismic hazard
estimates.