Seismicity and monitoring of Canada's volcanic zones

Taimi Mulder, & John Cassidy

Published September 8, 2024, SCEC Contribution #14033, 2024 SCEC Annual Meeting Poster #067

Canada’s volcanic zones are located along the tectonic plate boundary region of western Canada, extending for more than 2000 km from southern British Columbia to the Yukon/Alaska border. Within these zones the two most recently active volcanoes are Tseax Cone (~1700s) and Lava Fork (∼1800s), both in northwestern British Columbia. However, no eruptions have occurred in Canada since the deployment of the earliest seismographs in 1898 (Victoria, BC) and 1904 (Sitka, Alaska). Some regions have seen recent volcanic related activity: the 2007 Nazko Cone earthquake swarm in central BC when ~1000 M < 3 earthquakes occurred over the span of about 2 months. These were all deep earthquakes (∼30 km) near the base of the crust and showed the patterns expected from an injection of magma deep into the crust. Prior to that, at the western end of the Anahim Volcanic Belt, more than 40 felt earthquakes occurred from 1940 to 1943. Seismic monitoring has been challenging across these volcanic zones due to rugged, remote terrain, lack of recent volcanic activity, and consequently a lack of instrumentation close to these volcanoes. Seismic detection levels have improved from M∼7 in 1900 to M∼0–1 in southwestern BC and M2.5-3 throughout the rest of BC, with more than 120 seismic stations currently operating in British Columbia and the Yukon, including ∼20 seismic stations within the volcanic zones. Creative methods of researching these volcanic regions are beginning to be possible. A summary of recent and ongoing studies into seismicity at some of Canada’s volcanic zones will be presented.

Citation
Mulder, T., & Cassidy, J. (2024, 09). Seismicity and monitoring of Canada's volcanic zones. Poster Presentation at 2024 SCEC Annual Meeting.

Related Projects & Working Groups
Seismology