Plate Tectonics
He proposed the continental drift hypothesis
What is a volcano?
a vent or chimney that connects molten rock (magma) from within the Earth's crust to the Earth's surface
Explain the elastic rebound theory using a diagram
strain builds up, causing plates to deform. plates move suddenly and plates snap back to their shape, new location.
Differentiate between valley and continental glaciers?
valley- separated by valley walls
continental- dome-shaped covering surrounding ground
Differentiate between weathering, erosion and mass wasting
Weathering- the physical breakdown and chemical alteration of rock at or near Earth's surface
Erosion- the physical removal of material by mobile agents such as water, wind, ice or gravity
Mass wasting- the transfer of rock and/or soil downslope under the influence of gravity
What are the 3 pieces of evidence that support the theory of plate tectonics?
The "puzzle"
Fossils and Rock record
Geodetic observation (measuring plate velocities)
Earthquake/volcano location
Age of the ocean floor
Draw and label a volcano including the terms; vent, conduit, cone and magma chamber
Differentiate between body waves and surface waves. What are the 2 types of each
Body- travel from focus through the body of the Earth (primary and secondary)
Surface- travel on surface, not through Earth (love and rayleigh)
Identify 2 factors that resist gravity and 2 that help gravitational forces.
Resist:
materials strength and cohesion
vegetation
internal friction between grains
angle of underlying rock
help:
slope angle, amount of weathering, amount of water, overloading of slopes with new material
Identify 2 things weathering is caused by
atmospheric gases, water, acids, living organisms
a. What are the 3 typoes of plate boundaries?
b. Explain each
Divergent
Convergent (subduction, collision)
Transform
What are the 3 products from an explosive volcanic eruption? (describe each)
Ash fall- the fallout of rock, debris and ash from an explosive eruption
Pyroclastic flow- hot, fast moving, high particle concentration of clouds, rock, ash and gas
Pyroclastic surge- low particle concentration flow of volcanic material, turbulent and fast, do not flow as far
Differentiate between the Mercalli scale and Richter scale
Mercalli- qualitative, how intense it is, what we feel on surface of Earth
Richter-based on ground movements, measures magnitude
Differentiate between fall, slide and flow
fall- a mass movement where singular or multiple blocks of rock plunge from a height
slide- a mass movement that occurs as one unit
flow- a mass movement that is internally chaotic and turbulent
What are the 4 types of mechanical weathering?
Frost wedging, unloading, abrasion and biological activity
What are the 3 hypotheses that cause plate movement?
Explain each.
Ridge push (the hot magma rising at the mid-ocean ridge heats the rocks around it)
Slab pull (the more dense plate sinks underneath the less dense plate at a subduction boundary)
Mantle Convection (heat from both cores is transferred through the mantle via convection currents)
What are the 3 pyroclastic materials?
Ash (very small, solid particles)
Lapilli (rock fragments)
Blocks/bombs (blocks broken from solid rock)
Identify 3 earthquake hazards
building failure, soil liquefaction, aftershocks, fires, tsunamis
Explain the 3 steps of how glacial ice is formed
1. air infiltrates snow
2. snowflakes become smaller, thicker, and more spherical ("firn")
3. air is forced out, forming ice
dissolution, hydrolysis and oxidation
a. Differentiate between a craton and terrane.
b. what are the 3 ways to identify a terrane?
a. craton- ancient rock at the core of each continent
terrane- large block of lithospheric plate that gets moved a huge distance and attached to a continent
b. fault boundary on all sides
rocks/fossils do not match
magnetic record does not match
How do pyroclastic flows cause devastation?
What are 3 ways to prevent damage from an earthquake?
isolators at bases of tall buildings
safer materials
gas shut off valves
monitoring equipment in large buildings
Draw and label a glacier. Include; zone of wastage (ablation), zone of accumulation, cirque basin, crevasse and terminal moraine
What are 3 factors that affect the rate a rock weathers?
surface area, rock characteristics, climate, differential weathering