Earthquakes, Folds and Faults

1. Explain the relationship between earthquakes and plate tectonics. Why do earthquakes occur at places NOT on plate boundaries ?

Earthquakes happen on the earth were ever there has been enough stored up elastic strain energy to drive factures along a fault plane. As the plates are moving past each other sometimes they lock and this causes them to build up tension until they finally force past each other and cause shaking or earthquakes. When this happens within the continental lithosphere sometimes the plate deformation is spread out over a larger area then the plate boundary itself. The earthquakes away from the plate boundaries are caused by the fact that strain occurs in these continental deformation.


2. Normal Fault:
Reverse Fault:

Overthrust Fault:

Transform Fault:
3. Describe the dangers associated with earthquakes.

The effects of earthquakes are many including:
Shaking and Ground Rupture: Depending on the strength of the earthquake and how close you are to the epicenter this will have different effects. Sometimes you may just feel minor shaking and other times whole cities can be destroyed. On occasion there is visible breaking of the earths surface, which could cause severe damage as well. Most of the time however they have learned where this breaking would occur and make sure to build nothing major in these areas.
Landslides and Avalanches: On steep slopes earthquakes can often cause rock and snow to fall and collect taking anything in its path with it.
Fires: Because of the fact that it causes the earth to shake if often causes power lines to break and this can cause fires in large cities.
Soil Liquefaction: Because of the shaking of the earth it can sometimes cause solid ground material to turn to more of a liquid, and this can cause buildings to sink.
Tsunami: When there are large earthquakes under the ocean it causes large, long period waves to come to the surface. Where there are cities near the ocean this can be devastating.


4. Anticline:
Syncline:

Dome:

Geosyncline:

Structure of the Earth

Lithosphere: This layer includes both the crust, and the upper most part of the mantle. It is about 100 km thick and is able to move and flow over the rest of the upper mantle. This is the zone that creates earthquakes, mountains, volcanoes, and continental drifting. It is broken up into portions called tectonic plates.

Oceanic Plate: The part of the lithosphere that surfaces in the ocean basins. It is rich in iron and magnesium. Though it is denser then the continental plates it is much less thick at about 10 km. The magnetic forces that run along these plates is helpful proof for the fact that there are plate tectonics, as well as the fact that there is a large mountain range under water.

Continental Plate: A layer of sedimentary, igneous and metamorphic rocks which from the continents. It consists mostly of granite rock and is less dense then the oceanic crust, though it is much thick at about 35-40 km. The fact that the size and shape of the continents on these plates has changed over time is solid proof for plate tectonics.

Asthenoshpere: The highly vicious portion of the upper mantle. It is beneath the lithosphere at a depth of 100-200 km below the surface of the Earth. It is involved in plate movements. Pressure and heat help keep it like plastic with a low density meaning that seismic waves are able to easily pass through it. This is the layer on which the lithospheric plates move, causing plate tectonics.

Convection Currents: There are the currents that pass through the asthenosphere that is causing the plates of the lithosphere to move. It is the movement of molecules through liquids.

Movement

1) The ferry terminal in Vesuvius can take you to Crofton in 20 minutes. The ferry terminal in Fulford can take you to Sydney in 35 minutes. The ferry terminal at Long Harbour can get you to the Lower Mainland and Outer Islands in anywhere from 1-3 hours. There are also three sea planes that can take you to the mainland and Vancouver Island. For people who live on the outer islands there is a water taxi to get students to and from school. It also runs in the summer time in order to get outer islanders onto Saltspring.

2) In some rare cases on Saltspring island people receive there energy from solar panels or wind turbines, but it is much more common for people to receive there energy from BC Hydro.

3) I think it would be silly for me to say that we received all of our food from Canada though I think that a lot of it is able to come from Canada, or at least the states. Of course for my exotic fruits and vegetables have to come from countries around the world, or if it is not the right time of year for us to get things then we can get it from the southern hemisphere. However most fish, wheat, common fruits and vegetables such as apples, and other meat can come from BC and Canada. There are many farms on Saltspring Island that are able to provide us with fruits and vegetables, cheeses mostly of the goat variety, lamb and fish.

4) Though Saltspring is not often used for our forest resources, trees are something that are often sent around the world for construction, paper and other things. We also have a lot of fish that we are able to share around the rest of the world. Because of the small size of Saltspring we are not able to share many of our resources of manufacture many things because we mostly need to save these things to sustain ourselves.

5) Any recycled products that people have can go to the recycling depot, for garbage we have a local dump or garbage is brought off island in order to be disposed of. For sewage most people have septic tanks, though in rare cases on more populated roads there are are other sewage plants to collect waste.

6) Because of the fact that we get so many exchange students here I think that our cultural influences are able to be taken to places such as Germany and Japan by students that have studied here. As well as the fact that we have music shows, theater, and art here that people come to see. The fact that we are a part of western Canada connects us somewhat with native culture as well. The many Japanese settlers that first came here have also had some impact on the culture of saltspring island.

Human/ Environment Interaction

1) - One of the environmental changes Saltspringers have made to the island is draining and filling Swansons pond in order to have more room for residential areas.
- Another one of the changes we have made is adding the aerators in Saint Mary Lake in order to keep the fungi growth to a minimum.
- On one of the roads leading to Fulford Harbour there was a potential land slide cliff, however with some blasting, grass and tree growing the hill is now being contained.
- A lot of foresting being done on the mountains in order to build more houses.
- Paving gravel roads, creating ferry terminals, and adding docks and harbors in order to make transportation more easy.


2) One of the environmental hazards is the potential earthquake along the juan de fuca plate line. Another environmental hazard is forest fires because it always gets very dry here in the summer time and it is very hard to get people over to put them out.

3) Though the problem is very slowly occurring I think that the environmental issue that most threatens Saltspring is the rising sea levels. Seeing as we are very close to the sea level as the ocean rises the island would be completely engulfed in water.

Region

Saltspring Island is part of, The Gulf Islands or to be more specific the Southern Gulf Islands, British Colombia, Western Canada, The Pacific Rim, The Strait of Georgia, The Pacific Northwest, Capital Regional District along with municipalities of Greater Victoria.

Place

Physical Characteristics: Lakes: Saint Mary Lake, Maxwell Lake, Cusheon Lake, Stowel Lake, Ford Lake, Roberts Lake, Weston Lake, Bullock Lake.
Moutains: Mount Erskine, Mount Belcher, Mount Maxwell, Mount Sulivan, Mount Bruce Mount Tuam, Hope Hill and Reginald Hill.
Beaches: Arbutus Beach, Hudson Point, Fernwood Point, Long Harbour, Churchhill, Price Beach, Beddis Beach, Ruckle Park Beach, Isabella Point, Burgoyne Bay, Erskine Bay, Baker Beach, Vesuvius Beach
Other: Eleanor Point, Isabella Point, Cape Keppel, Musgrave Landing, Bold Bluff, Burgoyne Bay, Maxwell Point, Booth Bay, Southey Point, Hudson Point, Athal Peninsula, Nose Point, Scott Point, Yeo Point.
185 square km.
Human Characteristics: Ferry Terminals: Long Harbour, Fulford Harbour, and Vesuvius Harbour
Major Roads: Fulford Ganges, Beaver Point, Steward, Beddis, Lower Gangers, Vesuvius Bay, Long Harbour, North End and many others.
Parks: Ruckle, Arnell, Maxwell, Mouat, Beaver Point, Drummond, and Portlock
Schools: Saltspring Elementary, Fulford Elementary, Fernwood Elementary, Pheonix Elementary, Centre School, Middle School, GISS, and Pheonix High
Other: Library, Fairgrounds, Three Fire Halls, Seven Public Docks, Four Commercial Marinas, Three Post Offices, Seven Community Halls, Movie Theatre, sixteen churches, hospital, two golf courses, swimming pool, tennis courts, two major shopping centers, two grocery stores, sixteen restaurants, 15 cafes, hotel, motel, resorts, bed and breakfasts, cottages, four gas stations, two pubs.

Location

Specific Location: The specific location of Saltspring Island is around the coordinates 48 degrees north and 123 degrees west.

Relative Location: Saltspring Island is located in the Southern Gulf Islands, along side Galiano, Pender, Mayne and Saturna. It is to the West of the lower mainland and divided from Vancouver by the Stuart Channel. Located to the East is Vancouver Island, in The Pacific Ocean. The travel time to get to Vancouver Island is about 20 - 35 minutes by ferry. And to get to the mainland takes about an hour and a half by ferry. Very close to the 49th parallel or the US/Canada border.