A Prototype Earthquake Early Warning System for Northern India.

Part of North-Western Himalaya particularly Uttarakhand has been identified by several eminent seismologists as gap area where large size earthquake (greater than magnitude 7) is expected. The region has witnessed two earthquakes having a magnitude greater than 6 in last 25 years (March 28, 1999 Chamoli earthquake and October 20, 1991 Uttarkashi earthquake) both having an epicenter in Gharwal region of Uttarakhand. Several studies have shown that a future large earthquake in central Himalayas can generate severe ground motion in the National capital region of Delhi, which is about 300 km from this expected source. Several densely populated cities and villages having total population of several millions are located between Delhi and Uttarakhand. These towns/cities will be severely affected by a large earthquake having an epicenter in this region. Using advancements in communication technology and real-time seismology, a project to have an earthquake early warning system for Northern India is under progress at Indian Institute of Technology, Roorkee. In this project, a dense network of 84 accelerometers has been installed covering an area of about 100 × 40 km in Garhwal region. This network has an average station to station distance of less than 10 km and all the sensors are streaming data, which is being processed in real time at central server stationed at Roorkee. This paper describes details of the network, sensors, present status of development, performance of instrumentation during recent events, and processing details. [ABSTRACT FROM AUTHOR]