GEOGRAPHY TEST 2 Flashcards
Continental Drift Theory:
Proposed by:
Key Idea:
Evidence:
Proposed by: Alfred Wegener.
Key Idea: Continents were once part of a single supercontinent called Pangea and have drifted apart over millions of years.
Evidence: Fossil evidence, fit of continental coastlines, geological similarities across continents.
Plate Tectonic Theory:
Developed by:
Key Idea:
Processes:
Difference:
Important Points:
Plate Tectonic Theory:
Developed by: Later scientists like Tuzo Wilson expanded Wegener’s ideas with additional findings.
Key Idea: Earth’s crust is broken into plates that move on the magma below, driven by convection currents in the mantle.
Processes: Explains the cause of earthPlates are in constant motion.
Plate movement can lead to natural events like earthquakes, volcanic eruptions, and the creation of mountains.
Difference: Continental Drift focuses on the continents moving, while Plate Tectonics explains the mechanics of how entire plates (continental and oceanic) move.
Important Points:Oreo Cookie Demonstration: Think of the brittle crust (top cookie) moving over a softer mantle (cream layer). quakes, volcanic activity, mountain formation, and ocean trench formation.
Plate Movement 4 Types of Plate Movements:
Divergent: Plates move apart (e.g., Mid-Atlantic Ridge).
Convergent: Plates move towards each other (e.g., Himalayas).
Transform: Plates slide past each other (e.g., San Andreas Fault).
Subduction: One plate is forced under another (e.g., Mariana Trench).
Geologic Eras
4 Eras
Precambrian: Formation of Earth’s crust; simple life forms like bacteria.
Paleozoic: Marine life diversification; formation of early land plants and animals.
Mesozoic: Age of dinosaurs; formation of Pangea’s breakup.
Cenozoic: Age of mammals; continents moved to their current positions.
Weathering & Erosion
Focus on Glaciers:
Advancing: Glacier grows and moves forward (colder periods).
Retreating: Glacier melts faster than it advances (warmer periods).
Stationary: Glacier remains at the same position.
Types of Erosion:
Examples in Canada: Niagara Falls (caused by water erosion).
Other Types: Wind, ice, and chemical erosion (such as acid rain affecting limestone).
Rocks
3 Types of Rocks
Igneous: Formed from cooled magma (e.g., granite).
Sedimentary: Formed from compressed sediments (e.g., limestone).
Metamorphic: Formed under pressure and heat from existing rock (e.g., marble).
Layers of the Earth
Layers of the Earth: Crust, mantle, outer core, inner core.
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Glaciers that accumulate more snow than what melts away in a warmer season are known as
A glacier is advancing (getting larger) if there is more accumulation of snow than there is melting
Glaciers that are melting more than they grow are known as:
A glacier is in retreat (getting smaller) if there is more melting (at the zone of ablation or “snout” than accumulation
Glaciers that do not appear to be moving are known as:
These are stationary (staying the same size) glaciers.
Pros from Glaciers
Cons from Glaciers
A pro would be that glaciers are able to give countries freshwater!
A con would be if they melt sea levels would rise results in cities to be underwater. We lose freshwater because they will malt into the SALT water ocean
Should Canadians be concerned that the amount of glacial melting seems to be happening at a higher rate than glacial accumulation on a global scale (your own thinking skills!)?
Yes, because rising sea levels threaten Canadian coastal areas with flooding and erosion, disrupt weather patterns, and may reduce freshwater supply for communities relying on glacial melt.
