Microearthquake survey of the Miramichi, New Brunswick, epicentral region, 1985

A survey of the continuing microearthquake activity in the 1982 Miramichi earthquake epicentral region of central New Brunswick took place between July 3 and August 19, 1985. MEQ-800 analog seismographs were deployed at six recording stations for the 47 day period of the survey. Three BakPak digital seismographs were added to the network on July 23, two at the same locations as analog units and one at a seventh site.Three hundred and twenty-five microearthquakes were recorded during the survey. The activity was episodic, with days of few earthquakes being followed by periods when events clustered together in miniswarms. Coda-magnitude relationships for five stations were established from regression analysis of scaled coda lengths of events on the MEQ 800 records and Nuttli magnitudes determined at an Eastern Canadian Telemetered Network station KLN. Only 21 of the events had coda magnitudes (Mc) greater than 0, the largest being 2.0. The larger magnitude earthquakes occurred in zones where there had been ...