Earth Science Quiz

• Physical geography deals with the natural environment and the processes that shape it.

Earth's Layers

• The Earth consists of three main layers: the crust, the mantle, and the core.
• The crust is thin, brittle, and made of rock, where we live.
• Continental crust is thicker and less dense than oceanic crust, forming the land we see.
• The mantle is a thick layer of molten lava.
• The core is dense and metallic, with inner and outer layers.
• Each layer has a unique composition affecting the Earth's surface.

Continental Drift

• In 1912, Alfred Wegener proposed the theory of continental drift, suggesting that all continents were once joined in a supercontinent called Pangea.
• Continental drift refers to the movement of the Earth's continents relative to each other, appearing to drift across the ocean.
• Evidence for continental drift includes the jigsaw puzzle fit of continents, glacial deposits, fossils, and mountain ranges found on different continents.
• Canadian John Tuzo-Wilson observed that plates move over hotspots in the mantle, forming volcanic island chains like Hawaii.
• Tuzo-Wilson also discovered transform faults, the third type of plate boundary.
• Plate tectonics is the more complete theory explaining that the Earth's outer shell consists of individual plates that move.

Plate Tectonics

• Plate tectonics explains earthquakes, volcanoes, mountain formation, and the creation of new crust.
• Harry Hess proposed the theory of seafloor spreading, supported by evidence from the mid-Atlantic Ridge.
• Canada's west coast is situated on a plate boundary between the North American and Juan De Fuca plates, resulting in earthquakes, tsunamis, and volcanic eruptions when plates collide.

Tharp-Heezen Map

• The Tharp-Heezen Map uses sonar and water depth to reveal underwater mountains.

Divergent Boundaries

• At divergent boundaries, two oceanic plates tear apart, and magma fills the gap, hardening to form underwater volcanoes like the mid-ocean ridge.
• The mid-ocean ridge is the largest underground mountain range, discovered in the 1950s, leading to the theory of seafloor spreading.
• Seafloor spreading is the creation of new crust on the ocean floor through volcanic activity, where magma rises, cools, and reaches the oceanic crust.
• Iceland was once part of the underwater ocean ridge that was pushed upwards over time.
• Convergent plate boundaries occur when two plates collide, creating mountain ranges.
• Transform plate boundaries occur when plates rub against each other.
• Convection currents explain plate movement.
• Convection currents involve the rising, spreading, and sinking of gas, liquid, or molten material when heat is applied, creating waves within the mantle.
• A fault line is where plates meet, and Canada is located on a fault line.

Natural Disasters

• Natural disasters are events that cause changes to the landscape, destruction, and death.
• These disasters occur naturally but can be worsened by human activity, including avalanches, tornadoes, floods, landslides, and severe storms.
• In 2011 Fukushima experienced massive earthquakes in Japan, which were the 4th most powerful recorded since the 1900s.
• This caused massive tsunamis, which originated from the earthquakes.
• The tsunami damaged the Fukushima Daiichi nuclear plant, resulting in over 20,00 deaths, making it one of the most devastating disasters in recent history.

Glaciers

• Glaciers contain 2% of all of Earth's water and are considered "world air conditions."
• Glaciers reflect sunlight, moderating temperatures, helping water crops, and generating hydroelectric power.
• About 70% of all freshwater on Earth is trapped in glaciers, playing a significant role in the development of life.
• Water from glaciers flows into rivers worldwide.

Landforms

• Landforms are natural features on the Earth's surface, including mountains, hills, plateaus, and plains.
• Landforms affect where people live and are connected to the rock cycle and glaciation.
• Landforms are formed through tectonic plates.
• Canada's landform regions are divided into different areas with distinct characteristics due to the countrys diverse landscape.
• A landform region is a geographic location with distinct characteristics that impacts the climate, vegetation, and soil.

Landform Regions

• Landform regions fall into three categories: highlands, lowlands, and shield.
• Highlands feature mountains and high elevations, including the Appalachian Mountains, Innuitian Mountains, and Western Cordillera.
• Lowlands are low-lying regions with lower elevations, such as the Great Lakes-St. Lawrence Lowlands, Interior Plains, and Arctic and Hudson Bay Lowlands
• The Great Lakes-St. Lawrence Lowlands is where most people live due to the climate, vegetation, and soil.
• The Canadian Shield is the oldest and largest region in Canada, formed 3 billion years ago and created through plate tectonics and erosion.
• The Canadian Shield is mainly rock previously a mountain range.
• Glaciation has left the area with little soil, making it unsuitable for farming but rich in mineral deposits like gold, silver, and nickel.

Climate Regions

• Canada has a wide variety of climates.
• There are 6 main factors that determine the climate, remembered by the acronym LOWERN: Latitude, Ocean Currents, Winds and Air Masses, Elevation, Relief, and Near Water.

Rock Cycle

• The rock cycle is a continuous cycle with no beginning or end, involving three main types of rocks: igneous, sedimentary, and metamorphic.
• Igneous rocks form when magma or lava cools, either below the Earth's surface as intrusive rocks or on the surface as extrusive rocks.
• Sedimentary rocks are created through the compaction and cementation of loose sediments and broken-down rocks, such as limestone and concrete.
• Metamorphic rocks are changed versions of igneous and sedimentary rocks, formed when exposed to heat and pressure, such as marble.

Glaciation

• Glaciation is the process of ice advancing and covering large areas of land.
• A glacier is composed of ice and snow that moves across the land, shaping and changing it.
• Glaciers do not completely melt in the summer but shrink or grow due to temperature changes.
• Glaciers change naturally through temperature, but human intervention (greenhouse gases, climate change) has accelerated this process.
• Glaciation contributes to the creation of landforms.
• Glaciers form through a combination of prolonged cold and the accumulation of snow.
• Main types of glaciers are alpine (high elevation, mountain areas) and continental (old, thick mass, covering larger areas).
• The effects of glaciation are visible across Canada, including erosional and depositional features.
• Erosional features involve scraping away of soil and rocks as glaciers move.
• Glaciers can change where rivers, streams, and lakes drain.
• Depositional features involve glaciers adding sand, minerals, and other materials to an area, creating features like till plains and moraines.
• Deposition by water occurs when meltwater moves debris and leaves particles behind, forming meltwater lakes.
• Erratics are large rocks dropped in unusual places by glaciers.
• It matters if we don't have glaciers in the future because we need freshwater, can affect the Earth's ocean levels and are natural air conditioners.Increased greenhouse gases and fossil fuels = glaciers melting
• Reducing emissions could prevent the majority of the world's glaciers from disappearing by 2100.
• Without GHG reduction efforts, the Arctic could be ice-free in summer 2040.
• Rising sea levels are caused by melting glaciers.
• A complete melt of all glaciers on Earth would raise sea levels by 70 meters, flooding coastal cities, increasing the chance of natural disasters, and affecting 30% of the US population living on the coast.

Other Considerations

• A big issue is algae, which grows when glaciers melt and temperatures rise, causing glaciers to melt faster and leading to less freshwater and extinction of species.
• Soil regions have distinct layers with different characteristics.
• Good quality soil provides decent food.
• Lower quality soil in the Canadian Shield and northern regions is due to glaciation and cold temperatures.
• Rich soil exists where there is an effective combination of geology, climate, and vegetation.

Types of Soil

• Wet-climate soils have excessive precipitation, washing away nutrients and reducing fertility.
• Dry-climate soils lack sufficient precipitation and are infertile.
• Tundra soil freezes and thaws, becoming wet-climate soil.

Vegetation

• Vegetation is the plant life in a specific region.
• Canada has three main vegetation types: tundra, forest, and grassland.
• Tundra has limited plant growth, with only small trees.
• There is a transition zone between each region where vegetation gradually changes.
• There are different regions with varying vegetation, including the West coast forest, Cordilleran vegetation, Boreal and Taiga forest, mixed forest, and Deciduous forest.
• Within Canada, there are two types of trees: coniferous and deciduous.
• Coniferous trees can survive in poor-quality soils, have waxy needles and thick bark, preserve moisture in dry conditions, and produce seeds in cones.
• Deciduous trees lose their leaves in the winter and are typically wide.