Abstract
On 9 January 1982, in the Miramichi region of New Brunswick, Canada, an
earthquake with body-wave magnitude (mb) 5.7 occurred. Itwas followed by
extensive aftershocks and felt throughout eastern Canada and
northeastern USA. Digital seismic stations were not yet commonby 1982.
Fortunately, three stations (KLN, EBN and GGN) produced excellent
waveform records for the larger aftershocksallowingthese aftershocks to
be relocated. For each aftershock,its focal depth was first
determinedusing thedepth phase sPg; then, with depth fixed, the
epicenter was determinedusing a set of arrival times recorded for the
Pg-, Sg-, and Pn-phases at the three stations.Sixty-eight aftershocks
were relocated; mostof them occurred in a 5×5 km areaand with depthsof2
to 6 km. The epicentres formed two linear trends in theNE-SW direction.
The trends were close to the northeast strike of the focal mechanism of
the mainshock and consistent with the topographic trend near the source
region. A gap betweenthe trends separated the epicenters into two
groups. One group representstherupture area caused by themainshock, and
the other groupmight represent the rupture area caused by the mb
5.4principal aftershock.