Physical geo

What's the continental drift?

A theory made in 1915 by Alfred Wegener, he stated that he believed continents move. He said 300 million years ago, the continenets formed together into a supercontinent called Pangea and 200 million years ago, they started to drift apart

What are the 4 proofs Alfred Wegener had?

1. Jigsaw fit

2. Fossils

3. Mountains

4. Ice sheets

What's the first proof as to why Alfred believed his continental theory? (Jigsaw fit)

Jigsaw fit: South America and Africa seemed to fit together like a jigsaw puzzle, he thought its likely because they were connected at one point

What's the second proof as to why Alfred believed his continental theory? (Fossils)

Fossils: a variety of plants and animals were found on both South America and Africa and he believed it was impossible they traveled across the Atlantic ocean.

What's the third proof as to why Alfred believed his continental theory? (Mountains)

Mountains on both sides of the Atlantic ocean were the same age and same structure and material.

What's the fourth proof as to why Alfred believed his continental theory? (Ice sheets)

Africa, Australia, South America and india showed evidence of being covered by ice sheets about 250 million years ago. Wegener believed that that such warm places would be covered by ice only if they were closer it the south pole (cold area)

Why didn't scientists believe Alfred Wegener's theory?

1. Wegener couldn't explain how something can be powerful enough to move continents.

2. Some of his logic was incorrect or too crazy to believe

What's John tuzo Wilson's theory?

In 1968, he discovered that the earth’s crust had 20 plates that move

How do the earth's plates move

Convection current

What are convection currents?

1. Core heats up nearby rock, they lose density and rise up

2. Cooler rock near the earth's surface go down and the core heats them

3. The hot rock that rose up cool down and go back down again

4. The cool rocks that went down and got warmer go back up

This creates a pattern

how many tectonic plates does the earth have?

20

What are the seven major plates?

• Pacific

• North American

• Eurasian

• African

• Antarctic

• Indo-Australian

• South American

What makes up the mantle?

Slow moving hot rock

What are plate boundaries?

The space (cracks) between tectonic plates where they meet each other.

What are the 2 types of crust?

1. Oceanic, usually 5-10 km thick and made of very dense rock.

2. Continental, usually 25-70 km thick (40 km on average) and it’s made of less dense rock then oceanic.

What are the 3 types of plate boundaries?

1. Divergent: Move apart

2. Convergent: Collide together

3. Transform: slide past each other

What are divergent plate boundaries?

When 2 plates are separating away from each other in the opposite directions

What are the two types of divergent plate boundaries?

1. Mid-ocean ranges

2. Rift valleys

What are rift valleys?

2 continental plates separate, the cracks stretch and the middle part sinks.

What are mid-ocean ridges? Ex?

1. oceanic plates separate

2. magma rises and cools underwater

3. magma turns into rock and and long, low mountain chains

Ex: mid-atlantic ridge

What are convergent plates?

Plates collide together (3 main types)

How do mountains form? Ex?

Continental-continental convergent plate boundaries happen. Ex: Eurasian and Indian plates collision formed himalayas mountains

How do volcanoes form?

Oceanic-Continental convergent plate boundaries happen. Oceanic plate goes underneath the continental plate (mantle) and melts which forms magma, the magma rises and causes volcanoes

How do earthquakes form?

Oceanic-Continental convergent plate boundaries happen. When the oceanic plate is going underneath the continental plate, the movement isn’t smooth and they get stuck then suddenly they break free and slip away.

What are island arcs?

Chain of islands

How do island arcs form?

1. Oceanic-Oceanic plate boundary collide

2. The denser plate goes underneath the other one (subducts)

3. It forms magma

4. Underwater volcano occurs

5. The magma keeps rising and turns to rock until it reaches the surface and creates an island arc

What are subduction zones? Ex?

The area when a convergent plate boundary occurs and the denser plate goes underneath (subducts) and turns to magma. Example: pacific ring of fire aorund the pacific ocean that has more volcanoes and earthquakes

What are transform plate boundaries?

2 plates slide past each other

What are volcanoes?

A vent where magma, volcanic ash and harmful gases are released deep from the earth to the surface

Where are volcanoes located?

1. Convergent plate boundaries

2. Divergent plate boundaries

3. Hotspots

What are hotspot volcanoes?

Magma inside the mantle erupt as the oceanic plate move over it and it turns into rock and multiple eruptions can make it higher until it forms an island

What are the three types of volcanoes

• Active = erupting or can erupt soon

• Dormant = sleeping, might wake up

• Extinct = dead

Whats magma

Underground melted rock

What is lava

Magma that reached the earth’s surface

What is volcanic ash?

A mixture of rock, minerals and glass particles that come from a volcano eruption

What are some of the gases that erupt from a volcano

Harmful acids such as hydrogen halides. Water vapour and harmful substances such as sulphur dioxide, hydrogen sulphide and carbon dioxide.

What are shield volcanoes?

Fast moving lava that erupts in all directions a lot. Creates many of the major island chains in the ocean

What are strato volcanoes?

Slower moving thick lava that erupts from a steep slope. usually found in convergent plate boundaries

What are earthquakes

The sudden release of pressure in the earth’s crust

Where do the most extreme earthquakes occur?

Convergent boundaries

What are seismographs

Tools all around the world used to detect how strong and where earthquakes are

How do seismographs work?

Shaking of the ground is measured and recorded by sensitive equipment

What’s the moment magnitude scale

A scale that shows how powerful an earthquake is. Each number is 10 times more powerful than the previous number. Ex: value 1= strength 1. value 2= strength 10. value 3= strength 100

What can an 8.8 earthquake do

Kill people, destroy houses, tsunamis and landslides (hill or mountain collapses)

How could a city prepare for an earthquake/volcanic eruption?

1. Have earthquake survival kits consisting of food and water, essential survival gear, hygiene/ health, personal items or important docs.

2. Warning systems to warn people

3. Have flexible buildings where the building moves with the earthquake instead of breaking

Why might two earthquakes of similar power cause very different amounts of damage?

1. Area density: If it’s an open area with less buildings and people it’ll cause less damage compared to a packed area with people and buildings

2. How prepared an area is

Signs of volcanoes

1. small earthquake

2. steam or smoke coming out of vents

3. increased heat around volcanoes

4. Gas coming out of vent with a smell of sulfur or rotten eggs

What are the 4 eras? Period of time

1. Precambrian (4600Ma-570Ma)

2. Paleozoic (570Ma-245Ma)

3. Mesozoic (245Ma- 66Ma)

4. Cenozoic (66-present)

What are the 3 main things that happened in the precambrian era?

1. Formation of major land masses like Canadian, Brazilian, Australian and african shields

2. first single cell

3. first multi cell

What are the 3 main things that happened in the Paleozoic era?

1. First plant and animal (amphibians and fish)

2. Large parts of North America covered by shallow seas

3. Appalachian mountains

What are the 3 main things that happened in the Mesozoic era?

1. Dinosaurs, mammals and birds

2. Shallow seas appeared and disappeared in North america

3. Rocky mountains. ex: Innuitian mountains in Canada

What are the 3 main things that happened in the Cenozoic era?

1. Ice sheets cover large parts of North america

2. Modern continents

3. Human beings development

How old is the earth?

4600 Million years = 4.6 billion years

What are climate graphs?

A graph that summarizes climate info about an area. The most common is average monthly temp and total monthly precipitation.

How does average monthly temp look like on a climate graphs?

Red line of connected dots placed in the middle of columns

How does total monthly precipitation look like on a climate graphs?

Blue side by side bars that fill the entire column

Why are climate graphs helpful?

It can help tell us if an area is maritime or continental

Amount of precipitation to be considered maritime or continental (full year worth of precipitation)

• Greater than 1000mm = maritime

• Less than 1000mm = continental

Difference of lowest and highest temperature to be considered maritime or continental?

Less than 25°C = maritime

Greater than 25°C = continental

Season Distribution of Precipitation (season that contains the most precipitation) to be considered maritime or continental?

• Winter months Oct. - Mar. = maritime (u-shape)

• Summer months Apr. - Sep. = continental (mountain shape)

Effects of volcanoes?

1. Tsunamis

2. Landslides

3. Lava destroys nearby areas and could hurt humans (buildidngs, roads, etc)

4. Volcanic ash collapses house roofs and cause air pollution

Where are rocks found?

• Ocean

• earth’s surface

• under soil

What are the 3 types of rocks?

1. Igneous

2. Sedimentary

3. Metamorphic

How do igneous rocks form?

Magma or lava cools

What are the 2 types of igneous rocks? Ex?

Intrusive: Cools slowly deep in the earth (Granite)

Extrusive: Cools fast on the earth’s surface (Dacite)

How can you tell the difference between intrusive and extrusive rocks?

Intrusive: Cools slowly so crystals have time to grow

Extrusive: Cools fast so crystals don’t have time to form

What are sedimentary rocks? Ex?

Rocks that form after millions of years of sediments compaction and cementation. Ex: Sandstone

How do sedimentary rocks form?

Compaction: Sediments become tightly packed from the weight of top layers

Cetementations: Mineral dissolved in water fills up the gaps between the layers of sediments and when it evaporates, the mineral stays behind and acts like cement and the whole thing becomes hard.

What are metamorphic rocks?

Other rocks that change their appearance

How do metamorphic rocks form? Ex?

When rocks are buried under other rocks, the pressure and heat change the appearance of the them. Ex: Slate

What’s weathering?

Breaking of rocks (sediments) through chemical or physical processes

Physical change: changes form

Chemical change: changes composition

What’s erosion?

Sediments moving

What’s deposition?

Dropping of sediments

Explain frost wedging

Water seeps into rocks cracks and when temperature drops, the water freezes, turns into ice and becomes 9% larger. The ice acts as a wedge hammered into the cracks of the rock and keeps adding pressure until the rock splits apart.

Explain exfoliation (physical force that causes weathering)

Deep underground rocks have intense pressure due to the dirt and other rock sitting on top of it. Erosion washes away those top layers of rock and that deep underground rock is finally free to move. The underground rocks are hard and brittle so the surface cracks into large flat layers or curved sheets that slide off

What’s carbonation ( chemical force that causes weathering )

rain mixes with carbon dioxide in the air and makes a weak acid called carbonic acid. When the carbonic acid hits rock, it reacts with the calcium in the rock and the rock dissolves and washes away

Explain Oxidation ( chemical force that causes weathering )

Oxidation is when oxygen reacts with minerals in rocks and it turns to iron oxide which weakens the rock and it crumbles easily.

3 examples of erosion

1. Water currents

2. Wind

Explain water currents erosion

When rocks are being moved by rain (surface runoff) and eventually reach rivers, the rivers move the rocks to the ocean and they stop moving in the ocean

Explain wind erosion

Wind picks up and moves sand, the sand chips the rock and the small chips move with the wind to dry climates

Explain gravity erosion

When rocks at a cliff get weak and become too heavy to stay up, they fall and it creates a pile at the bottom.

Explain water deposition

Water carries sediments and when it loses energy and slows down, it drops those sediments.

Explain glacial deposition

Glaciers carry sediments and drop them when they melt

Main 3 physical regions of canada

1. Canadian shield

2. Lowland

3. Highland

What is the Canadian shield

Big area of old worn down ancient mountains

What are lowlands

• Surrounds the Canadian shield

• Low elevations

What are highlands

• Surrounds lowlands

• High elevations

What are canada’s 7 landform regions

1. Innuitian mountains

2. Arctic and Hudson bay lowlands

3. Western Cordillera

4. Interior plains

5. Canadian shields

6. Appalachians

7. Great lakes-St.lawrence lowlands

What’s the oldest and largest landform region in Canada

Canadian shield

Describe the Canadian shield

• contains fresh water

• Made of rocks and poor soil

• Used to contain many huge mountains but they eroded away

What are the 3 lowland areas? Percentage of Canadians that live there

1. Interior plains 17%

2. Great lakes-St Lawrence lowlands 60%

3. Hudson bay arctic lowland 0%

Describe lowlands

• Canada’s best farmland area

• Contains big amount of canada’s oil and gas

What are the 3 highland areas?

1. Western Cordillera

2. Innuitian mountains

3. Appalachian mountains

What do highlands have a lot of?

Minerals like silver, gold and copper

Parts of Western Cordillera

1. Rockies

2. Coast Mountains

3. Columbia mountains

4. Plateues + foothills (lower highland)

What are the 2 types of glaciers and where are they?

1. Alpine, mountains

2. Continental, land

Explain glaciers erosional effects

It can move a big amount of materials long distance

Canada’s result due to glaciers erosions

1. Soil loss

2. Lakes and rivers: destroyed and made in new locations

Explain glaciers depositional effects

Eroded stuff are depsosited by moving ice or meltwater

Result due to glaciers depositions

1. Meltwater has sorted rocks and deposits heavier rocks first

2. Moving ice has mixed and unsorted rocks of different sizes