Body Wave Crustal Attenuation Characteristics in the Garhwal Himalaya, India.

We estimate frequency-dependent attenuation of P and S waves in Garhwal Himalaya using the extended coda normalization method for the central frequencies 1.5, 2, 3, 4, 6, 8, 10, 12, and 16 Hz, with earthquake hypocentral distance ranging from 27 to 200 km. Forty well-located local earthquake waveforms were used to study the seismic attenuation characteristics of the Garhwal Himalaya, India, as recorded by eight stations operated by Wadia Institute of Himalayan Geology, Dehradun, India, from 2007 to 2012. We find frequency-dependent P and S wave quality factors as defined by the relations Q = 56 ± 8 f and Q = 151 ± 8 f by fitting a power-law frequency dependence model for the estimated values over the whole region. Both the Q and Q values indicate strong attenuation in the crust of Garhwal Himalaya. The ratio of Q/ Q > 1 obtained for the entire analyzed frequency range suggests that the scattering loss is due to a random and high degree of heterogeneities in the earth medium, playing an important role in seismic wave attenuation in the Himalayan crust. [ABSTRACT FROM AUTHOR]