Co-seismic spring flow changes attributed to the March 29, 1999 Chamoli earthquake of Garhwal Himalaya

Abstract

The moderate magnitude Chamoli earthquake that occurred on March 29, 1999, in the Garhwal Higher Himalaya produced, among many other observable effects, changes in flow of several artisan springs. Qualitative observations of significant changes in the flow of ten springs located in regions of higher intensity show a strong spatial correlation with our preliminary estimates of perturbing pore pressure field induced in the water saturated shallow rocks of the region by the earthquake its coseismic phase. The results are significant for it is the first successful attempt in the Himalayan region to investigate the response pattern of the local groundwater flow system to perturbations induced to the ambient tectonic stress regime by a major earthquake.