Earthquake Monitoring Network Upgrade Blog
We have been very busy working across Canada to upgrade the network. Sixty–seven stations installed with new seismic sensors!! All that from August 2016 to September 2017. Check out the map – blue diamonds are the sites that have been upgraded.
The next two blog stories will feature northern Ontario’s recent upgrades. In the meantime, a bit more about seismicity in northern Ontario.
Northern Ontario usually has a very low level of seismic activity. The map below shows the location of 176-recorded earthquakes since 1985:
- One event was magnitude 4.2 in 2006 (62km northwest from Cochrane);
- Eighteen events ranged in magnitude 3.0 to 3.8;
- the rest less than magnitude 3;
- Twenty-one of the 176 earthquakes were felt.
In the past, two magnitude 5 earthquakes occurred in northeastern Ontario: northeast of Kapuskasing in 1928 and northern Michigan (United States) in 1905.
Why do we have seismic stations in Northern Ontario if the seismic activity is usually very low? Seismic hazard assessment!
It is important to be able to assess seismic hazard in all parts of the country. Seismic hazard analysis provides information to the National Building Code of Canada. Knowing how to design and build structures to withstand potential seismicity in an area allows for safer building practices.
Back in 1982, Atomic Energy of Canada Limited wanted to look at seismicity rates and patterns in northern Ontario*. This was to study seismic hazard estimates for structures including potential nuclear waste repositories. Many stations are required in order to accurately locate smaller magnitude (M < 3) earthquakes. At that time, there were only three stations (Lakehead, Sudbury and Kirkland Lake; now closed). To do the study, six new stations were installed (Sioux Lookout, Thunder Bay, Geraldton, Kapuskasing, Eldee, Chalk River). More stations permitted the location of smaller earthquakes. As well, having more data on the frequency of smaller earthquakes provides information on frequency of rare larger events.
To view seismicity in northern Ontario during the last 30 days, click here: http://www.earthquakescanada.nrcan.gc.ca/index-en.php?CHIS_SZ=non
Come back next week to read Blog 11: Part 1 - Northern Ontario Station Upgrades!
Additional information and references:
The Pacific Coast is the most earthquake-prone region of Canada. Around 400 earthquakes occur each year in the region from the north end of Vancouver Island, British Columbia (BC), Canada to Seattle, Washington, U.S.
Can you believe it? In January 1700, a magnitude 9 earthquake occurred off the coast of Vancouver Island! There is evidence found in Vancouver Island First Nations’ oral history of a large tsunami destroying a village at Pachena Bay on the west coast of the island. Also, a written record of tsunami damage along the east coast of Japan gives us a date and time for the event.
So far, the largest recorded earthquake in BC occurred in August 1949. It was a magnitude 8.1 earthquake offshore Queen Charlotte Islands.
Students are hired to help Natural Resources Canada (NRCan) staff with construction and installations, as part of the network upgrade. Their support helps the multi-year task of upgrading all the stations in Canada’s seismic network. Here’s a report from one student working from our office in Sidney, BC:
Hello, my name is Erin Greeves. I am a Co-op student working for the Canadian Hazard Information Service under Natural Resources Canada. Over the past seven months I have had the privilege to work with Shayla Brown (Co-op student), Rick Hall and Tim Claydon (NRCan staff).
We have traveled all over Vancouver Island and part of the mainland of British Columbia. Our main focus over the summer and fall was to deploy and upgrade earthquake monitoring stations. We managed to complete five stations over that course of time, three of which were new sites that not only required new instruments, but also concrete foundations, new solar panels, solar panel mounts, kiosks, batteries, etc. The whole kit, starting with building a frame for the concrete!
Take a look at some pictures of the various sites we completed.
We managed to get this site done in two days even with the temperature around 34 degrees Celsius in direct sunlight!
This site was completely infested with ants, who had managed to create a whole series of tunnels through the insulation in the vault. Plus some spiders that managed to co habitat the vault too.
Come back soon to find out how many stations have been upgraded in the 2016 field season!
For more information visit Products, Publications, and Research on Earthquakes Canada website and to see the references for this blog:
GeoFact sheet: Earthquakes in southwestern British Columbia
Significant Canadian earthquakes 1600-2006; Lamontagne, M; Halchuk, S; Cassidy, J F; Rogers, G C. Geological Survey of Canada, Open File 5539, 2007, ; 32 pages; 1 CD-ROM, doi:10.4095/224164
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