Chapter 2 vocab Marine Science Honors

Chapter 2 vocab Dr. Rodseth

Crust

Thin, solid, outermost layer of the Earth composed of rocks and minerals

Mantle

Thick, semi-solid layer of Earth beneath the crust, making up most of its volume.

Core

Very hot, dense, central part of the Earth, made mainly of iron and nickel

Lithosphere

Rigid outer layer of Earth, consisting of the crust and the uppermost part of the mantle

Asthenosphere

A partly melted, plastic-like layer of the mantle just below the lithosphere

Mesosphere

The lower part of the mantle beneath the asthenosphere, where rocks are solid due to high pressure

Plastic

\ a material that can deform and flow without breaking.

Convection

The transfer of heat by the movement of fluids, driving the movement of mantle material

Divergent

A divergent boundary is where two tectonic plates move apart from each other

Convergent

where two tectonic plates move toward each other and collide

Subduction

The process where one tectonic plate slides underneath another at a convergent boundary

Abyssal plain

A flat and nearly featureless area of the deep ocean floor beyond the continental margin

Island arc

A curved chain of volcanic islands formed above a subducting tectonic plate

Trench

A deep, narrow depression in the ocean floor formed at subduction zones

Mid-ocean ridge

An underwater mountain range formed by divergent tectonic plates and seafloor spreading

Seamount

An underwater mountain that rises from the ocean floor but does not reach the surface

Seafloor spreading

The process where new oceanic crust is formed at mid-ocean ridges and moves outward

Continental margin

The zone where the continent meets the ocean, including the continental shelf, slope, and rise

Continental drift

The gradual movement of Earth's continents across the surface over geological time

Plate tectonics

The theory explaining the movement of Earth's lithospheric plates and the resulting geological activity

Upwelling

The rising of deep, nutrient-rich water to the ocean's surface

Continental crust

The thick, less dense part of Earth's crust that makes up the continents

Ocean crust

The thin, dense part of Earth's crust found under the ocean basins

Basalt

A dark, dense igneous rock formed from cooled lava, commonly found in oceanic crust

Granite

A light-colored, coarse-grained igneous rock, making up most of the continental crust

Half-life

The time required for half of a quantity of radioactive material to decay.

Black smokers

Hydrothermal vents on the ocean floor that emit superheated, mineral-rich water

Sulfides

Compounds formed by sulfur and metals, often found around hydrothermal vents

Pangaea

The supercontinent that existed when all Earth’s land masses were joined together over 200 million years ago

Sediment

Loose particles of rock, mineral, or organic material that accumulate on Earth’s surface