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Research group studying earthquakes and other disasters

Nature has always been an inspiration to humans from the beginning of time.  Humans have worshipped, adored and learned numerous physical and philosophical lessons from nature. At the same time, nature can be extremely detrimental in the form of earthquakes, tsunamis, volcanoes, etc. There are observatories, laboratories and dedicated resources to study these calamities and prevent or at least forewarn about occurrence of such calamities.

Prof Kusala Rajendran heads one such research group at the Centre for Earth Sciences in the Indian Institute of Science. For over twenty years, the group (initiated while a scientist at Centre for Earthscience Studies, Trivandrum) has been working on many processes intrinsic to the earth. The outer shell of the earth, the lithosphere, is actually made of different 'plates' that fit together like many pieces of a jigsaw puzzle. Movements of these plates leads to the formation of active plate boundaries, which are prone to great earthquakes. Seismic studies of collision/sub-duction zones (such as the Himalaya and the Andaman Nicobar) is the focus of research carried out in Rajendran's lab. They also work on earthquake recurrence, tsunami recurrence and hazard evaluations.

“I work on earthquakes, trying to understand their source process and effects. So my work essentially combines field observations with models developed in the lab. The lab hosts basic facilities for earthquake data processing”, said Rajendran.

Her deep passion to study about Mother Earth inspired her to take up Applied Geophysics as her Major in her master’s degree at IIT Roorkee; she then went on to doing a PhD at the University of South Carolina, USA.

Global earthquake records are used to quantify earthquakes – how big, how deep and the way in which they occurred. The way in which the ground reacts to the earthquake is also an important factor that is studied. “For example, how buildings located on a hard rock or built on a refilled land (softer rocks) would respond to ground shaking. In places where there are no recent earthquakes (but are likely to happen in future) we need to understand this behavior for better building strategies.”

Ambient noise also referred to as micro tremors that recorded by seismic recorders are used to understand the ground vibrations where earthquake signals are not available. Earthquake recorders are used to record them and the signals that are generated are used processed and models are generated to represent site effects, which essentially conveys the range of frequency and corresponding amplitude at specific locations. These are useful for the engineers to design the buildings in order to make it less prone to damage during an earthquake.

Rajendran's work also involved many field visits, where her group travels to earthquake prone areas. They also travel to affected areas in the aftermath of earthquakes, like to Nepal after the 2015 earthquake. “My experiences are about the tragedies that people face at the fury of nature. I have seen how people face tragedies with courage, and how groups come together to put their lives back”, she said. "When the going gets tough, the tough get going. That is what I have learned from my life as well as from those who fight natural disasters like earthquakes”.

In the past decade, there have been tremendous advances in data collection, processing and developing models that explain the observations of the findings during an earthquake. Her efforts have provided insights into earthquake recurrence and fault zones in various Earthquake prone regions of India.

Rajendran has been a principal Investigator for various projects and has written numerous papers on the findings that they have made during the research. She has won the Krishnan Gold Medal, conferred by the Indian Geophysical Union for research contributions in the field of Geophysics and the Tabor award conferred by the Department of Geological Sciences, University of South Carolina.

Her projects are mostly funded by the seismicity program of the Ministry of Earth Sciences(MoES) along with Indian National Centre for Ocean Information Services (INCOIS) and the results are used for earthquake disaster mitigation efforts, tsunami modeling and tsunami warning. Rajendran is keen currently working on improving her understanding the source models of earthquakes along the Himalaya and the Andaman plate boundaries.

For Indian seismology research to make an impact at the global stage, getting more people interested in the field is crucial, feels Rajendran. “We need to strengthen our teaching and research in seismology and have more students interested in geophysics and seismology. One of the things we do in the lab is to have undergraduate students get interested and do small projects and encourage them to study seismology”, she added.

Contact: Dr. Kusala Rajendran

Website: http://ceas.iisc.ernet.in/~kusala/

E-mail: kusala@ceas.iisc.ernet.in

Phone: 91-80-2293-2633(O), 91-80-2360-0126(R)