Chapter 4 Flashcards
accelerographs
- instruments that record the acceleration of the ground during an earthquake.
fracture zones
-major lines of weakness in oceanic crust; former transform faults.
igneous rocks
- rocks formed by the solidification of magma
intraplate earthquakes
- earthquakes occurring within a tectonic plate, far away form plate boundaries.
intrusion
- the process by which magma forces into fissures of pre-existing rocks and crystallizes below the surface of the earth
- bodies formed by the process of intrusion
seismicity
- the frequency and spatial distribution of earthquakes
seismic zonation
- a geographical delineation of areas having similar damage potential from future earthquakes.
shakemaps
- Macs of Marcalli intensity derived automatically from data recorded by a network of seismographs and computed in near real-time.
Where is the eastern boundary of the North American tectonic plate located?
- along the mid-atlantic ridge
Rank the following cities in order of decreasing seismic risk: Montreal, Quebec City, Vancouver, Victoria.
1) Vancouver
2) Montreal
3) Victoria
4) Quebec City
Why Is seismic hazard difficult to assess in Canada?
- historical data is only available for a few hundred years
What might happen when the Cascade mega thrust fault ruptures?
- a large earthquake of approximately magnitude 9
- a tsunami
What is the dominant deformation force associated with the Queen Charlotte fault?
- shear
The Juan de Fuca plate is a remnant of which ancient plate?
- Farallon plate
Why is the urban seismic risk lower in Victoria than in Vancouver?
- the population of Victoria is lower than that of Vancouver
Rank the following earth materials in order of decreasing seismic risk: hard rock, soft soil, soil vulnerable to liquefaction, stiff soil.
1) soil vulnerable to liquefaction
2) soft soil
3) stiff soil
4) hard rock
What is the largest seismic hazard affecting southern British Columbia?
- crustal earthquakes from the North American plate
What are the epicentres of the earthquakes of the Charlevoix seismic zone located?
- they follow a linear trend in the middle of the St. Lawrence River.
if you were planning to build Canada’s tallest skyscraper, where would you want to build it?
- Saskatoon, SK
In Montreal, seismic hazard is moderate to high, and seismic risk is ____.
- high
What evidence in the natural environment support the occurrence of the 1700 Cascadia earthquake?
- the presence of sediments disturbed by tsunami
What should you do after an earthquake?
- check for fire hazards
- check for damage to your home
Identify the seismic-related hazards affecting the west coast of Vancouver Island
- tsunami
the seismic guidelines of the National Building Code of Canada are an example of
- mitigation
Which Canadian impact crater is associated with seismic activity?
- Charlevoix
Seismic donation studies are an example of
- mitigation
How has the exact date and time of the 1700 Cascadia earthquake in British Columbia been determined?
- from Japanese tsunami records
Why has the Canadian National Seismograph Network detected more earthquakes in the last 20 years than in the same period before?
- the detection capability of the network has improved
What is the difference between an isoseismal map and a shakemap?
- an isoseismal map displays intensity reported by eye witnesses and a shakemap displays computed intensity
What are the epicentres of the Western Quebec seismic zone located?
- they follow a linear trend extending northwest from Montreal
Which technology can be used to track the deformation of the earth’s surface?
- Global Positioning System (GPS)
How has the data displayed on the shakemap of the 2012 Haida Gwaii earthquake been calculated?
- the data has been generated automatically from ground motion data recorded by a seismograph network and knowledge of the regional geology
What are the epicentres of the earthquake of the Charlevoix seismic zone located?
- they follow a linear trend in the middle of the St. Lawrence River
