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

The first decade of the 21 st century has witnessed an increase in the number of large
earthquakes exceeding M 7.0, globally. In 2011 eighteen earthquakes have already
occurred above this magnitude with twenty two occurring in the previous year. Whether,
these earthquakes are related is a question which is being debated in the scientific
community. The Mw 7.7 Bhuj earthquake in 2001 occurred in a Stable Continental Region
(SCR) environment of the Indian Peninsular shield which experienced several moderate to
small size earthquakes recorded by improved digital broadband seismological networks in
the country. The epicentral map shows that earthquakes in the Indian shield occur in the
interior rift systems (Narmada-­‐Son and Godavari), rifted continental margins (Bhuj and the
passive margins) and blind faults in the non-­‐rifted parts (Latur, Coimbatore, Bellary). In
addition, earthquakes also occur near water reservoirs and as swarms. Recent data suggest
several new regions, which are becoming seismically active with smaller earthquakes. The
earthquakes which occur in the rift systems generally have greater depths and show thrust
mechanism while in non-­‐rifted parts, the earthquakes are shallow with either thrust or
strike slip mechanism. There are few exceptions to these observations and thus, in the light
of new data sets and the apriori knowledge of tectonic systems in which earthquakes occur
in the Indian shield, there is an urgent to understand the seismotectonics of the Indian
shield through modeling approach. It is also essential to re-­‐evaluate state of stresses in the
region and provide upper bounds, if possible to make a realistic seismic hazard assessment.
S2.4
3D Static Numerical Modeling of Strike-­‐Slip Fault for Studying Ground Surface
Deformation
Ramancharla Pradeep Kumar (Email:ramancharla@iiit.ac.in)
Associate Professor & Head, Earthquake Engineering Research Centre, IIIT Hyderabad,
Gachibowli, Hyderabad-­‐500 032, India.
This paper contributes to understanding the response of soil deposits due to underlying
bedrock fault displacement in three dimensions. When an active bedrock fault ruptures, the
movement along the fault propagates through the overlying soil and produces zones of
intense shear. Hence, it is important to study the surface behavior based on the fault
characteristics. For this reason, we attempted to develop a new application to Applied
Element Method (AEM) by modeling the fault rupture zone. In this paper, we model the
fault rupture problem in three dimensions. First, a simple model is used to illustrate the