Earth Science Lecture Notes

Flashcards covering key concepts related to Earth's interior, plate tectonics, and ocean features.

Inner Core

Solid ball made of iron and nickel at Earth's center, extremely hot due to pressure.

Outer Core

Liquid layer of molten iron and nickel surrounding the inner core, responsible for Earth's magnetic field.

Asthenosphere

Partly solid and molten layer in the upper mantle that flows and causes plate movement.

Lower Mantle

Thick, solid layer in the lower mantle made of dense rock under high pressure.

Continental Crust

Thick, less dense crust that forms continents, composed of igneous and sedimentary rock.

Oceanic Crust

Thinner, denser crust made of basalt, typically found in ocean basins.

Discontinuity

Boundary within Earth where there is a sudden change in physical properties.

Gutenburg Discontinuity

Marks change from core to mantle with a dramatic change in density and composition.

Mohorovicic Discontinuity

Sudden change in density that increases the velocity of seismic waves, marking the change from mantle to crust.

Convection Currents

Process of rising and sinking of mantle material caused by heat from Earth's core.

Ridge Push

Pressure exerted by the excess height of the mid-ocean ridge.

Slab Pull

Force exerted by the weight of the subducted slab on the plate it is attached to.

Mantle Convection/Convection Currents

The pull of the underlying current in the direction of plate movement.

Lithosphere

Broader, more rigid layer composed of the crust and the uppermost portion of the mantle.

Mid-Oceanic Ridge

New magma rises from the mantle due to convection currents, forming a new crust and pushing older crust outwards.

Continental drift

Continents have been moving for billions of years

Mesosaurus

Freshwater reptile fossil found across continents, supporting continental drift.

Glossopteris

Plant fossil found across continents, supporting continental drift.

Seafloor Spreading

Ocean floor at the ridges were young because of magma oozing up, spreading then sinking back down at oceanic trenches, essentially recycling itself

Divergent Boundary

Two plates move apart or away from each other, causing volcanic activity.

Convergent Boundary

Plates move towards each other, causing crust to be destroyed.

Continental-Continent Collision

Continental crust pushes against continental crust, creating high mountain ranges.

Continent-Oceanic Crust Collision

Continental crust pushes against oceanic crust, causing the oceanic crust to sink in a process called subduction.

Ocean - Ocean plate collision

2 oceanic plates collide, one crust over the other which causes it to sink into the mantle forming a subduction zone

Transform Boundary

Plates slide past each other, where lithosphere is neither created nor destroyed.

faults

Faults are smaller scale boundaries

Hot Spot Volcanoes

Hot mantle plumes breaching the surface in the middle of a tectonic plate.

Hot Spot

Fixed point where magma flows through the crust

TOPOGRAPHY

Elevation of land ABOVE sea level

BATHYMETRY

Depth of landforms BELOW sea level

Continental Shelf

The extended perimeter of each continent

Continental slope

The descending slope that connects seafloor to the shelf

Continental rise

A gentle slope with a smooth surface made by buildup of sediments from erosion

Abyssal plains

Flat or gently sloping areas typically considered the ocean floor.

Mid-Ocean Ridge

Underwater mountain range with a rift in the middle, formed by plate tectonics.

Volcanic Fissure

Linear vent where lava erupts, found along rift zones.

Hydrothermal Vent

Fissure on the seafloor where geothermal heated water discharges.

Trench

Long, narrow topographic depression on the ocean floor formed at subduction zones.

Submarine Canyon

Narrow, deep canyon carved into the continental shelf by erosion.

Seamount

Mountain rising from the ocean floor that does not reach the surface, formed from extinct volcanoes.

Guyot

Flat-topped seamount eroded by waves, winds, and atmospheric processes.

atoll

island of coral that surrounds a lagoon, og island is gone

Oceanic Island

Found in volcanic island arcs and arise from volcanoes due to subduction.

coral reef

Tropical shallow water, forms off top of volcanoes