The Sadyr cluster is named for the town of Sadyr in eastern Kazakhstan,
close to the border with China. Some earthquakes, including the largest
one (6.4 mb), on December 21, 1958, are in China. Many small events that
are only recorded to near-regional distances are included to improve the
statistics for location calibration. The station coverage at local
distances is quite good since ~2003. All events except the large 1958
event (fixed to a depth of 15 km) have depth control, from a combination
of near-source and local-distance readings and teleseismic depth phases.
A few events locate to very shallow depths, usually based on readings at
least 50 km away.
