The Imphal cluster is named for the city of Imphal in the state of Manipur,
bordering Myanmar in eastern India. The cluster contains four events
with magnitude 6: July 1, 1957 (6.6 Ms), May 6, 1984 (6.0 Mw), December
30, 1984 (6.0 Mw) and January 3, 2016 (6.7 Mw). Most events are between
25 and 75 km deep. Depth constraint for many events comes from
teleseismic depth phases, often in combination with near-source and
local-distance readings. The distribution of seismograph stations for
location calibration is not dense but it provides good azimuthal
coverage.
