Information on the recent earthquakes near McAdam, NB

In the last few days, numerous small earthquakes have again been felt by the residents of McAdam and recorded by the regional seismograph network operated by Natural Resources Canada and the University of New Brunswick. These earthquakes are occurring at very shallow depths (in the top 1 to 2 km of the earth’s crust) and are quite close to McAdam (in a cluster within 5 km of the town). Although the earthquakes have been small (the largest as of February 8 being a magnitude 3.3) their frequency and close proximity are unsettling to local residents. These events are considered by seismologists to be a resumption of “earthquake swarm” activity that first affected the town in the spring of 2012, and recurred for a shorter period of time in late November/early December, 2015. The current swarm began on February 3, 2016. A swarm usually has many similar-sized earthquakes within a short period of time occurring in a small area. It is not unusual for swarm activity to start, stop, and restart again. A swarm can last for days, weeks or months. Each swarm is unique and the future size and frequency of earthquake activity in the region cannot be predicted. The current earthquake swarm is a reminder that earthquakes can occur in this region, and a larger earthquake, while unlikely, cannot be ruled out. The best advice, as always, is to know what to do before, during and after an earthquake.

For a full list of located earthquakes in the region, visit our list of recent New Brunswick earthquakes

In light of the continuing seismic activity in McAdam, NB, NRCan is installing four seismometers in the area on 11 February 2016. The instruments will remain in place for several weeks and will transmit data in real-time to NRCan to monitor and help characterize the activity. The closest station of NRCan’s permanent seismograph network is 65 km away in Saint George, NB. The deployment of seismograph stations closer to the activity will enable NRCan seismologists to determine more precise epicenters for smaller earthquakes than is possible with the permanent network, confirm the occurrence of events that are felt or heard but too small to be recorded by the stations of the permanent network and provide better information on the rate of activity. The more precise locations will help seismologists to identify the position of the subsurface fault on which the earthquakes are occurring and help determine the type of faulting.

The installation of the seismographs will not give warning of an earthquake before the shaking is felt nor will they allow prediction of future earthquakes. It is also unlikely in the short-term that their information will determine the “trigger” for these events and what causes them to turn on and off. However, the data will contribute to longer term research projects which may lead to a better understanding of earthquakes in the region.