The Chamoli cluster has been redone using recently-acquired data from a temporary network and making use of differential time data. The chamoli16 cluster contains 546 events, compared to 44 events in chamoli11.
The Chamoli cluster is named after the Chamoli District of Uttarakhand
State, India. The cluster contains two damaging earthquakes in the
district, the Mw 6.8 Uttarkashi earthquake on October 19, 1991 and the
Mw 6.6 Chamoli earthquake on March 28, 1998. This version of the Chamoli
cluster replaces the chamoli11 version previously uploaded to GCCEL.
This version takes advantage of the ability to relocate a much larger
number of events and includes a large number of small events that were
well-observed by two temporary networks, one in 19990328-19990617 (data
provided by Bal Rastogi) and another in 20171127-20211016 (data provided
by Jyotima Kanaujia). The arrival time data for these small events
establishes a very robust direct calibration analysis, using 11,164
arrivals within 0.8° to locate the hypocentroid. Another reason for
retaining these locally-recorded events is to make their data more
widely available for research. All events have depth control from
near-source and local-distance readings, or teleseismic depth phases.
The relocation also utilizes 293 measurements of differential times of
regional and teleseismic phases made by Benjamin Kohl.