AICE Marine Science AS Chapter 2: Earth Processes - Study Guide Flashcards

Vocabulary flashcards covering Earth's interior structure, plate tectonics, geological features, weathering, erosion, sedimentation, and ocean processes like tides and currents, suitable for AICE Marine Science AS Chapter 2 review.

Crust

The outermost layer of Earth, made of solid rock, varying in thickness beneath oceans and continents.

Oceanic Crust

The thinner, denser part of the crust composed of basaltic rocks, rich in iron and magnesium, which tends to subduct.

Continental Crust

The thicker, less dense part of the crust composed of granite.

Mantle

The layer underneath the crust, consisting of hot, semi-solid rock capable of slow movement; the uppermost part is the asthenosphere where convection currents occur.

Asthenosphere

The viscous, uppermost part of the mantle where convection currents, responsible for plate movement, take place.

Core

The center of the Earth, composed of hot, dense iron and nickel, with an outer liquid layer and an inner solid layer.

Theory of Continental Drift

A theory proposed by Alfred Wegener in 1912, suggesting that all continents were once connected in a supercontinent called Pangaea, based on fossil, geological, and shoreline shape evidence.

Pangaea

The supercontinent believed to have existed over 300 million years ago, where all Earth's continents were connected.

Theory of Plate Tectonics

A revised form of the continental drift theory, proposing that the lithosphere is broken into sections called tectonic plates that move on top of the mantle.

Lithosphere

The rigid outermost layer of Earth, broken into tectonic plates, sitting atop the mantle.

Paleomagnetic Stripes (Magnetic Polarity Reversal)

Evidence for plate tectonics found on the ocean floor, showing alternating stripes of normal and reversed magnetism that began at Mid-Ocean Ridges due to magma pushing through.

Volcanoes

Openings in Earth's crust that allow gases and molten rock to escape from the mantle, found at convergent and divergent plate boundaries.

Ring of Fire

A chain of volcanoes formed at convergent boundaries in the Pacific Ocean.

Earthquakes

Sudden releases of energy from movement in Earth's crust, often caused by stuck convergent or transform plates or volcanic eruptions, releasing seismic waves.

Tsunamis

Large ocean waves with long wavelengths and high energy, caused by a sudden release of energy from movement in the seabed, unrelated to tides.

Abyssal Plains

Flat, sandy regions of the ocean floor found at transform boundaries or between boundaries, formed as a result of sea-floor spreading and covered with sediment.

Convection Currents

The movement of fluids or air based on density differences caused by differing temperatures, driving the movement of tectonic plates in the mantle.

Convergent Boundaries

Plate boundaries where two or more tectonic plates come together, forming subduction zones, trenches, volcanoes, and earthquakes.

Subduction Zones

Areas at convergent plate boundaries where one lithospheric plate, typically a denser oceanic plate, slides beneath another, leading to its destruction by the heat of the asthenosphere.

Divergent Boundaries

Plate boundaries where two or more tectonic plates move away from each other, allowing molten magma to push through and creating mid-ocean ridges and rifts.

Mid-Ocean Ridges

Underwater mountain ranges formed at divergent plate boundaries where new crust is created, often featuring volcanoes and hydrothermal vents.

Transform Boundaries

Plate boundaries where two plates slide laterally next to each other, causing great seismic activity, faults, earthquakes, and tsunamis, with abyssal plains as a common feature.

Hydrothermal Vents

Openings in the ocean floor found in mid-ocean ridge systems, releasing superheated water rich in dissolved minerals, supporting chemosynthesis in extreme environments.

Chemosynthesis

The process by which certain organisms produce food using chemical energy, often at hydrothermal vents where chemicals are the basis of the ecosystem.

Black Smokers / White Smokers

Classifications of hydrothermal vents based on their mineral composition and the temperature of the water released.

Weathering

The chemical and physical processes that break down rock at Earth's surface.

Chemical Weathering

The process where the chemical composition of rock changes through exposure to water, oxygen, or salts.

Physical Weathering

Also known as mechanical weathering, where rocks are broken into smaller pieces without changing their chemical composition, often due to temperature changes or ocean waves.

Biological Weathering

Weathering processes that rely on living organisms, which can be chemical or physical in nature.

Erosion

The process by which water, ice, wind, or gravity moves weathered rock or soil.

Sedimentation (Deposition)

The process in which sediment is laid down in new locations, affected by the speed of water flow and particle size.

Littoral Zone

The intertidal region on a shoreline, located between the highest and lowest spring tide marks.

Rocky Shores

Shorelines with a rocky substrate, resistant to erosion and weathering, where little sedimentation occurs due to high water speed.

Sandy Shores

Shorelines made of loose deposits of sand, gravel, and shells, formed by erosion and sedimentation, constantly in motion due to wind and waves.

Muddy Shores

Shorelines found in protected areas with very shallow or no slope, minimal water movement, and formed primarily by the deposition of fine sediment like silt and organic materials.

Estuaries

Partially enclosed, tidal, coastal bodies of water where freshwater from a river meets the saltwater of the ocean, creating brackish water that is often murky and turbid.

Brackish Water

A mix of fresh and salt water, typically found in estuaries.

Deltas

Low-lying triangular areas at the mouth of a river, formed by the deposition of sediments as the river widens and slows down upon meeting the sea.

Tides

The periodic rise and fall of the surface of the ocean and large lakes, resulting from the gravitational pull of the Moon and the Sun.

Semi-diurnal Tide

Tides that occur twice a day, resulting in two high tides and two low tides.

Diurnal Tide

A tide that occurs once a day, resulting in one high tide and one low tide.

Mixed Semi-diurnal Tide

Tides that occur twice a day, but where the two high tides and two low tides differ in height.

Tidal Range (Tidal Amplitude)

The difference in height between high tide and low tide, influenced by gravitational pull and coastline features.

Spring Tides

Tides that create the greatest tidal range (highest high and lowest low), occurring when the Earth, Sun, and Moon are aligned (new moon and full moon).

Neap Tides

Tides that cause the smallest tidal range, occurring when the Sun and Moon are at right angles to each other (first and third quarter moon phases).

Tidal Surge

A rising of water higher than the predicted tidal level, often caused by high winds and low air pressure during tropical cyclones.

Ocean Current

A continuous physical movement of water caused by wind or density differences, transporting water, dissolved nutrients, gases, and heat.

Coriolis Effect

The apparent deflection of moving objects (like ocean currents) to the right in the Northern Hemisphere and to the left in the Southern Hemisphere due to Earth's rotation.

Surface Currents

Ocean currents primarily driven by wind and influenced by the Coriolis Effect, forming predictable spiral patterns away from the equator.

Deep Currents (Thermohaline Circulation)

Ocean currents driven by differences in water density due to changes in temperature and salinity, forming a slow-moving global conveyor belt along the ocean floor.

Global Conveyor Belt (Thermohaline Circulation)

A slow-moving, large-scale system of deep ocean currents driven by temperature and salinity differences, distributing water and heat around the planet.

Upwelling

The movement of cold, nutrient-rich water from the deep ocean to the surface, caused by warmer surface water being pushed away from the coastline or by water moving over underwater features.

El Nino Southern Oscillation (Normal Conditions)

A climate pattern describing typical conditions where cold, nutrient-rich water upwells along the west coast of South America, with westerly winds pushing warm water towards Australia and Asia.