Plate Tectonics & Earth’s Interior Key Terms

1. Force exerted on ocean lithosphere due to rising material below the mid-ocean ridge

Ridge Push

1. Instrument that measures small changes in magnetic fields

Magnetometer

1. Relatively steep portion of continental margin connecting the shallow continental margin with the deep ocean basin

Continental slope

1. Relatively flat area of the deep ocean basin underlain by ocean lithosphere

Abyssal Plain

1. Long, narrow depression with parallel mountains on either side found along developing and mature divergent plate boundaries

Rift Valley

1. Force exerted on ocean lithosphere due to the weight of subducting ocean lithosphere

Slab Pull

1. Conical-shaped underwater volcanic mountain

Seamount

1. Line on a map connecting points of equal age

Isochron

1. Flat-topped seamount

Guyot

1. Ancient super continent made up of all of today’s continents

Pangaea

1. Preserved remains of ancient organisms found in rocks

Fossils

1. Process in which older ocean lithosphere moves away from the mid-ocean ridge as new ocean lithosphere forms along the mid-ocean ridge

Sea floor spreading

1. Boundary between Earth’s crust and mantle

Moho

1. Relatively flat portion of continental margin covered by shallow ocean water

Continental Shelf

1. Process in which ocean lithosphere plunges back into the asthenosphere under other lithosphere

Subduction

1. Long, deep canyon on the ocean floor that forms where ocean lithosphere is subducting, typically the deepest parts of oceans

Trench

1. Large, slow-moving pieces of the Earth’s Lithosphere

Plates

1. Plate boundary where the two plates move toward one another

Convergent

1. The edges of continents, parts of which are under relatively shallow ocean water, and are underlain by continental lithosphere

Continental Margins

1. Chain of volcanic islands bordering an ocean trench and formed by subduction

Volcanic Island Arc

1. Middle part of the mantle below the lithosphere that exhibits the property of plasticity

Asthenosphere

1. Energy waves given off during earthquakes that are used to study the layers of the Earth

Seismic waves

1. Theory describing how the continents move and why there are earthquakes, volcanoes, and mountain ranges in certain areas

Plate tectonics

1. Plate boundary where the two plates move away from one another

Divergent

1. Ability of a solid to flow slowly and change shape

Plasticity

1. Gently sloping pile of sediments at the edge of the continental margin marking the boundary between the continental and ocean lithospheres

Continental Rise

1. Volcanic mountain range along the edge of a continent bordering an ocean trench and formed by subduction

Continental Volcanic Arc

1. Ancient magnetic field of the Earth preserved in igneous rocks when they crystallized from magma

Paleomagnetism

1. Volcanic activity caused by a rising plume of hot material through the asthenosphere such as occurs at Hawaii and Yellowstone

Hot spot

1. Plate boundary where the plates move side-to-side past one another

Transform

1. Solid, rigid top part of the Earth divided into numerous plates that slowly slide around the surface of the Earth

Lithosphere

1. Movement of heat energy through a substance in which the molecules of the substance move from one area to another

Convection

1. Long mountain chain along the ocean floor in which new ocean lithosphere is formed by seafloor spreading

Mid-ocean ridge

1. A 180 degree flip in Earth’s magnetic field

Magnetic Reversal