Structure of the Earth

Please define/ explain the significance of these in regards to plate tectonics:

1. Lithosphere: outer part of the earth consisting of crust and the mantle. This is what the plates are made out of, what moves.
2. Oceanic Plates: tectonic plates that are underneath the water, still moving, and made up of more sulphur than continental plates. This makes them less dense and easier to submerge under the continental plates.
3. Continental Plates: The tectonic plates that are above sea water. They are denser than oceanic ones.
4. Asthenosphere: This lays underneath the lithosphere, it consists of molten rock. This is what the lithosphere (tectonic plates) move on top of.
5. Convection currents: This is the process of the heat movement in the asthenosphere that generates the tectonic plates movement.

Plate tectonics

PLATE TECTONICS STUDY GUIDE

1. CONTINENTAL DRIFT

Main idea – Pangea once existed, a super-continent where all the continents were one, until something happened to make them crack and drift apart.

Evidence – Mountain ranges, volcano chains, similar plant and animal fossils, “jigsaw-like fit” of continents, weather patterns (history of erosion and opposite weathering from the current ie. Glacier erosion in a tropical place)

Why was Alfred Wegener laughed at ? He proposed the idea of continental drift without much evidence, other than the “jigsaw-like fit” of all the continents. The argument against Wegener was that it was not “possible for some of the earths crust to be solid, and some to be liquid, or molten.”

2. PLATE MOVEMENT

What is the lithosphere ? The hard and rigid outer layer of the earth. The upper mantle and crust.

Explain the differences between a oceanic plate and a continental plate

An oceanic plate is the plate underneath the water, and a continental plate is one of which is exposed above the water. The continental plate is much thicker and made of granite, and they have also been around for much longer. Whereas the oceanic plate is composed of mainly basalt, making them thinner.

What is the asthenosphere ? The asthenosphere is a molten zone located beneath the lithosphere and is composed of plastic properties.

How does it make plates move ? Convection currents make the plates move, where the molten earth is moving in such a way that it makes the lithosphere on top roll along (very slowly.)

How fast do the plates move ? Very slowly, some plates only move two centimeters per year. In some cases, when there is pressure built up between two subducting plates, when the pressure is released, it results in an earthquake.

Name two natural disasters/phenomenon associated with plate boundaries and movement.

Subduction plate boundaries result in earthquakes, whereas diverging plate boundaries result in volcanoes and trenches.

3. Evidence of plate movement

coastline fit – West coast of Africa and East Coast of South America seem to fit together.

geologic fit – The Himalayas continue from one continent to another in a broken mountain chain range.

Paleoclimatology – The climate change on the continent. A once polar place ( complete with glacier and ice erosion from millions of years ago) can now be a tropical place. This can also deal with tree rings, ocean sediments, radiocarbons in organic material...etc.

fossil correlation – Fossils of plants and animals have been discovered oceans away from eachother.

age of sea floor – the different rock minerals and compositions and changes due to the magnetic polar shifts throughout time.

paleomagnetism – The polar shifts create a pattern along the sea floor, in the magnetic minerals.

What was PANGAEA ? - A super continent millions of years ago, before it split and the continents moved.

4. TYPES OF PLATE BOUNDARIES - labeled diagrams - NAME AN EXAMPLE

Divergent boundaries -

a) seafloor spreading: hot spots

b) continental rifting: Great East African Rift Valley, the Nubian Plate and Somali Plate

Convergent Boundaries -

a) continent/continent: The Juan De Fuca plate beneath the North American plate is an example. This is a transfom boundary, where one continental plate grinds against another and pushes the crust upwards. This creates mountain chains and volcanoes.

b) ocean/continent: This is where an ocean plate submerges beneath a continental plate, creating trenches and such.

c) ocean/ocean: This is where one of the oceanic plates submerges under the other and creates deep trenches.

Big Important summary question - How has plate tectonics affected Canada and its landforms ?

Plate tectonics are affecting Canada and other countries massively. In Canada, there are many mountains and volcanoes that are the result of moving plate tectonics. Although dormant, Mount Garibaldi and Mount Meager are caused by a subduction zone. There is a spreading ridge just off the coast of Vancouver Island (The Juan De Fuca Plate). The Northwestern corner of Canada is going through some stretching due to a spreading ridge as well. This is weakening the earths crust. There are also hot spots along the coast of Canada- such as the Nazko Cone in British Columbia.

Volcanoes pt. 1

GEOGRAPHY 12

Volcanoes and Volcanic Landforms

TEXTS Videos

Knapp Worral pp. 6 - 22 Volcanic Landforms of B.C.

Smythe Brown pp. 99 - 108 Earth Alive - Volcanism

Physical Geology pp. 169 - 195 The Volcano Watchers

1. Explain how the folowing terms differ:

LAVA vs. MAGMA

Lava is thick and reaches the earths surface, whereas magma is the molten rock inside the earth which is a little thinner than lava.

DORMANT vs. EXTINCT volcanoes

Dormant volcanoes are inactive, but not extinct. There is still a chance that it may erupt in the future, whereas extinct volcanoes are completely incapable of future eruptions.

INTRUSIVE vs. EXTRUSIVE Volcanism

An intrusive volcano is one which erupts INSIDE the earth. An extrusive volcano has an opening on the earths surface- such as a rift or a cone shaped mountain.

VOLCANOES vs. HOT SPOTS

A volcano has an opening above sea level, such as a composite volcano. A hot spot is where magma pushes its way through the crust to erupt on the sea floor or the ground of the earths crust, which creates a sheild volcano.

2. Explain where volcanoes tend to be located.

Volcanoes tend to be located at the edges of tectonic plates. When a plate is converging and creating a cone-shaped volcano, sometimes lava gets pushed up through the neck of the volcano. At divergent plate boundaries, where the plates are seperating and creating a trench, lava may bubble up, or when one plate is subducting under another, a rift volcano may occur.

3. What and where is the "RING OF FIRE"?

The ring of fire is located in the Pacific, stretching from New Zealand, along the Eastern Edge of Asia, North across some Alaskan Islands and South along the coast of North and South America.

4. Complete the following chart for the 3 main types of volcanoes:

example/

volcano type appearance composition location

Composite /cone shaped/ built up of solidified lava and rock sediments/Subduction zones/ Mount Rainier

Sheild/ massive, broad, gently sloped dome/ build up of hot spot lava/ seafloor, divergent zones/ Hawaii

Compound/ two or more vents/ multiple eruptions from sides, build up of ash and solid lava/ Along plate boundaries/ Homa Mountain, Kenya

5. Define the following terms and create an original diagram showing all of the features.

dike – sheet intrusion that cuts across massive rock formations or compositions.

sill – flat, horizontal mass of igneous rock in between two layers of older sedimentary rock formations.

laccolith – an intrusion of igenous rock (molten magma at the time) in between two layers of sedimentary rock. This intrusion pushes the overlying rock up, creating a dome-like appearance on the crust of the earth.

batholith – A large mass of igenous rock believed to have solidified beneath the earth.

pipe (neck) – The throat inside volcanoes that brings the lava to the surface.

geyser – A spring that discharges hot water and steam.

6. Using the PHYSICAL GEOLOGY text complete the following chart:

HAZARD DANGER POSSIBLE SOLUTION ?

lava flow/ it’s fast, can burn anything./ Run, don’t live near volcanoes, use ocean water to spray onto oncoming lava.

Pyroclastics/ cinders, ash, gas./ Create a synthetic winter, block sun./ Nothing. Don’t live near a volcano.

Nuee Ardentes( pyroclastic flows)/ flow of hot gas, rock and ash./ Get out of it’s way.

Lahars/ Landslide flow of hot mud, water and pyroclastics/ It’s very fast, run.

toxic gases/ The toxic gases released from a volcano/ stay away from the opening of a volcano.

steam explosions/ sometimes accompanied by pyroclastics, toxic gases/ don’t live near a volcano.

The Five Themes of Geography

Saltspring Island







Location-



Absolute: 48 45' /123 30'



Relative: Located in the Southern Gulf Islands, below Kuper Island, Galiano Island, Wallace Island, to the West off the Coast of Vancouver Island, between the Tricomali Channel and the Stuart Channel in the Pacific Ocean. Located to the East is Vancouver Island, to the North is Mainland Vancouver- 20-35 minutes ferry travel to Vancouver Island, and about an hour and a half to mainland Vancouver. Close to the 49th parallel, or the US/Canada border.







Place-



Physical characteristics: Saltspring is 185 sq. km, 72 sq miles. There are several lakes: Saint Mary Lake, Maxwell Lake, Cushion Lake, Stowel Lake, Ford Lake, Roberts Lake, and Bullock Lake. There are many mountains as well: Mount Erskine, Mount Maxwell, Mount Belcher, Mount Sullivan, Mount Tuam, Mount Bruce, Hope Hill, and Reginald Hill. There are 29 beaches in total, 9 swimming beaches: Arbutus Beach, Hudson Point, Fernwood Point, Long Harbour Beach, Churchill, Price Beach, Beddis Beach, Ruckle Beach, Isabella Point, Burgoine Bay, Erskine Bay, Baker Beach and Vesuvius Beach. Other Physical characteristics include: 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 and Yeo Point.







Cultural/ man-made characteristics:



Saltspring contains a few ferry terminals and boating ports: Long Harbour Terminal, Vesuvius Terminal, Fulford Harbour as well as several public docks- such as the one located in Ganges. Major roads: Fulford- Ganges Road, Beaver Point Road, Steward Road, Beddis Road, Robbinson Road, Vesuvuis Road, Sunset Drive, Lower Ganges road as well as many others. Saltspring has many parks: Ruckle Park, Arnell Park, Maxwell, Mouat Park, Beaver Point Park, Drummond Park, and Portlock. The schools: Saltspring Elementary, Fulford Elementary, Fernwood Elementary, Pheonix Elementary, Center School, Gulf Islands Middle School, Gulf Islands Senior Secondary School, and Pheonix High. Other: Library, 225 farms, 1 fairground, 7 public docks, 4 commercial marinas, 3 post offices, 3 firehalls, 7 community halls, 1 movie theatre, 16 churches, 1 hospital, 2 golf courses, 1 swimming pool, 5 tennis courts, 2 major grocery stores, 2 major shopping centers, 16 resturaunts, 15 cafes, 2 pubs, 1 hotel, 1 motel, 4 gas stations and many resorts, bed and breakfasts, and cottages.







Region/ Cultural:



North America, Canada, Westcoast, Southern Gulf Islands. Saltspring is a part of the Pacific Rim and is a Southern Gulf Island located in the Strait of Georgia between Vancouver Island and Mainland Vancouver. It is also part of the Capital Regional District along with Municipalities of Greater Victoria.





Human/Environment Interactions:





Saltspring is located on the North American tectonic plate, on top of the submerging Juan De Fuca plate- this is a potential natural earthquake hazard. Forest fires are reoccurant during the summer, and hard to extinguish due to the hardship of getting help over to the island.





One of the environmental changes Saltspringers have made ot the island is draining and filling Swanson's Pond in order to have more space for residential housing developments. The placement of Aeraters into the St. Mary lake to suppress the growth of a certain fungi is another, as well as containing a potential avalanche area with synthetic grass and tree growth along a road leading to Fulford Harbour. Foresting on he mountains to create more residential area, the development of ferry terminals and public docks to make transportation more convenient and the creation of paved or gravel roads for on-island transportation.





One major environmental concern is rising sea levels. Because of global warming, the ice caps could melt and the sea levels would rise significantly, burying Saltspring under a blanket of sea water.





Movement-





The ferry terminal in Vesuvius can take you to Crofton in twenty minutes. The ferry terminal in Fulford can take you to Sidney in thirty five minutes. The ferry terminal in Long Harbour can get you to the Lower Mainland and outer Islands in anywhere from one to three hours. There are also three seaplanes that can take you to the mainland and Vancouver Island. For off island students attending Gulf Islands Senior Secondary, there is a water taxi that runs twice a day picking up and dropping off students from Pender, Galiano, Mayne and Saturna Island. It takes anywhere from thirty mintutes to forty five minutes, and they also run occasionally in the summertime.





Saltspring gets their electricity from BC Hydro, solar power and in some cases- wind power.

There are over 200 farms and greenhouses on Saltspring Island that sell their goods on the side of the road by the honor system, as well as two major grocery markets. A lot of the products we get off the shelves of our grocery store are shipped to the store by vessels from the mainland, but there is some produce, sea food, deli cheeses and meat (such as lamb) that is from the island itself. Things that are shipped to the island are usually from mainland BC or Vancouver Island, from Cowichan Valley.

Because BC is known for it's foresting and fishing, there's not many manafacturing plants for material products. Because of the size of Saltspring, it is hard to share the resources because we use them for our own sustainability. Some local artists may ship or sell their work, but it isn't very common.

For islanders, many houses have their own septic tanks, but on smaller streets houses may share tanks. For recyclable items, the island has a recycling depot and as for industrial waste, there is a dump on the island as well, but most garbage is shipped off island to bigger dumps.

Saltspring Island is very art-oriented. There are many local artists, musicians and authors who share their work on the island. This attracts other cultures and maintains ties with other places as well. We host art shows, we have a small venue called "Beaver Point Hall" where artists come and perform, and there are poetry readings held around Ganges on certain nights. The fact that we are a part of Western Canada connects us to Native culture as well. In the high school, GISS, there are many exchange programs for students through grades 10-12, such as students from Germany, Japan, Austria and many other places. The first Japanese settlers to discover the island have had some impact on it's growth culturally as well.