Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published December 2017 | Published
Journal Article Open

Observations and Simulations of Basin Effects in the Kathmandu Valley During the 2015 Gorkha, Nepal, Earthquake Sequence


The M7.8 Gorkha, Nepal main shock ruptured a segment of the Main Himalayan Thrust (MHT) directly below Kathmandu Valley, causing strong shaking levels across the valley. Strong-motion data reveal an initial 6 s source pulse that was amplified and reverberated within the basin. One of the striking features of the observed ground motions in the valley was the exceptionally low energy of periods less than 2 s, which likely limited the extent and severity of structural damage in Kathmandu compared with alternative rupture scenarios of the same magnitude in the region. Isolated cases of liquefaction and lateral spreading of unconsolidated sediments were also observed, but have not yet revealed a systematic damage pattern. Initial analysis of available data suggests that several different factors, including source and path as well as site effects, were responsible for the unusual ground motions characteristics. In this paper, we provide a short description of the Kathmandu Valley geology and analyze available strong-motion records from the main shock and three strong aftershocks, with the intent to shed light on earthquake reconnaissance observations from this earthquake.

Additional Information

© 2017 Earthquake Engineering Research Institute. Received: January 31, 2017; Accepted: October 6, 2017. The accelerometer record at station KATPN was provided by the USGS. The main shock data at stations KTP, PTN, TVU, and THM can be downloaded from: http://www.strongmotioncenter.org/cgi-bin/CESMD. The aftershock time series should be made available soon through the same portal. We acknowledge partial support of this work from the USGS/Caltech Cooperative Agreement (sponsor award number: G14AC00109), and from the GEER Association.

Attached Files

Published - 013117eqs022m.pdf


Files (1.4 MB)
Name Size Download all
1.4 MB Preview Download

Additional details

August 19, 2023
August 19, 2023