BC Hazards Flashcards
1
Q
British Columbia
A
- Complex area accreted/put together over hundreds of millions of years
- Sea level/shore location changed throughout history
- Insular mountains (Vancouver Island), Coast Mountains (West Coast), Interior plateau, Large scale thrust faults (Rocky Mountains)
2
Q
motion in thrust faults vs. reverse faults
A
- Amount of motion is different between thrust faults and reverse faults
- Thrust faults have much larger displacement (and a different angle)
3
Q
Geological history of BC: Cambrian
A
- ~500 ma
- Passive continental margin
- Shallow seas
- Equatorial
- Early life – trilobites
4
Q
Geological history of BC: Mississippian
A
- ~340 ma
- Initiation of subduction
- Active continental margin
- Volcanic island arcs
- Shallow seas
- Tropical
5
Q
Geological history of BC: Permian
A
- ~280 ma)
- Western subduction
- Volcanic island arcs
- Uplift of interior and early mountain building
- Pangea supercontinent
- Further north
- End of Permian: 95% of all species became extinct over approx. 60,000 years
6
Q
Geological history of BC: Late Triassic
A
- ~200 ma
- Dinosaurs
- Eastward subduction
- Accretion of the volcanic island arcs
- Still part of Pangea
7
Q
Geological history of BC: Late Jurassic
A
- ~150 ma
- Eastward subduction
- Further accretion of exotic terranes
- Pangea breakup
- Drifting north again
8
Q
Geological history of BC: Early miocene
A
- ~23 ma
- Eastward subduction
- Increased inland volcanism
- Cascade arc begins
- World map looks almost the same as today
9
Q
Geological history of BC: present
A
- Eastward subduction
- Active cascade arc volcanism
- Active transform faults in California
10
Q
Cascade chain of volcanoes
A
- Current active arc
- Volcanoes are primarily intermediate (this is common to subduction zone settings) and stratovolcanoes
- Ex. Mt. Baker, Garibaldi, Cayley, Meager
11
Q
earthquakes and subduction zones
A
In subduction zones, plate boundary stores the most energy and would release the most energy during an earthquake -> however, it may not cause the most damage depending on how close the boundary is to us
12
Q
where do landslides occur?
A
anywhere you have slopes
