indo–us workshop on “intraplate seismicity” - The CERI Blog

INTRODUCTION
ABOUT THE WORKSHOP
The scientific issues associated with the earthquakes that strike away from active plate
boundaries are of paramount importance for understanding earthquake hazard in both India and the
United States. The potentially devastating consequences of such earthquakes were illustrated by
the severe damage and loss of life caused by the 2001 Bhuj earthquake in Gujarat. The issue is of
significant concern in the US as well, in part due to the critical need to understand hazard associated
with the New Madrid, central U.S., seismic zone, which produced a series of large earthquakes in
1811-­‐1812. Topics covered will include lectures on intraplateseismicity, seismic hazard, and tectonic
models, with emphasis on key recent theoretical and observational advances, as well as
identification of key data sets that could be collected and/or made available to address outstanding
issues. The <strong>workshop</strong> will focus on scientific issues that are relevant for hazard assessment. The goal
of <strong>workshop</strong> is to improve our understanding of earthquake science as well as our understanding of
earthquake hazard in India and the United States.
BACKGROUND, CONCEPT AND PURPOSE
In recent years scientists have recognized that stable continental regions (SCR) are more vulnerable
to earthquakes than was once thought. The Himalayan front is an active plate boundary, with high
rates of earthquakes generated by the ongoing collision of the Indian subcontinent into Eurasia.
Peninsular India is characterized by a much lower strain rate; large earthquakes are therefore
expected to be less frequent. Similarly low strain rates are observed throughout central/eastern
North America. However, large earthquakes have struck SCRs at a number of locations, including
the New Madrid Zone, United States; Tennant Creek, Australia; Ungava, Canada; and Kachchh,
Koyna, Latur, and Jabalpur, India. In several developing countries, such as India, the hazard
associated with SCR earthquakes has become very serious because of high population density and
the proliferation of structures not built to withstand earthquake damage. Devastating SCR
earthquakes have also struck the US in historical times: in 1811-­‐1812, three earthquakes with
estimated magnitudes of at least 7.0 occurred within just 53 days in the New Madrid, Central U.S.,
Seismic Zone. The need to understand hazard associated with the New Madrid Seismic Zone has
provided the impetus for focused research that has led to improved understanding of hazard and
intraplate earthquake processes.
Devastating earthquakesin the SCR regions of India include the 1993 Killari earthquake (mb 6.3,
intensity VIII), 1997 Jabalpur earthquakes (mb 6.0, intensity VIII) in the central part of peninsular
India shield area, and the 2001 Bhuj earthquake (Mw 7.7, intensity X) in the western part of shield