India plans to delve deep for earthquake precursors

Science : The National Geophysical Research Institute (NGRI) in Hyderabad, India, will launch a 30-month project to create an earthquake observatory in Koyna, a region in western India that experiences frequent small to moderately sized earthquakes. An 8-kilometer-deep borehole will be drilled and laced with sensors that measure chemical, electrical, and gravitational perturbations. Koyna’s borehole will be unique because it will be the first intraplate boreholethree similar ones drilled thus far are all on the boundaries of tectonic platesand because it will be near a large dam, where the rise and fall of reservoir water levels often induces earthquakes. Concerns that drilling could increase regional seismicity and thus pose a risk to the nuclear power plant in Maharashtra, 64 kilometers away, have been dismissed as unrealistic: Earthquakes in the region are triggered by water in the many thousands of water-filled cracks in the earth, and seismologists believe that one more hole will not have any significant effect.