Chapter 2 Section 1-2 Vocab Flashcards
Asthenosphere
The lower part of the Earth’s mantle that can flow very slowly.
Continental Crust
Earth’s crust that underlies the continents and is composed of relatively less dense silicate minerals rich in silica and aluminum. The continental crust exceeds a thickness of 50 km in some mountain ranges.
Convergent plate boundary
A region where two (or more) lithospheric plates move toward one another and collide.
Core
The central part of Earth; it is divisible into an outer core that may be liquid and an inner core that may be solid.
Crust
The thin, solid, outermost layer of Earth.
Divergent plate boundary
A region where lithospheric plates are moving away from each other.
Earthquake
A sudden notion or shaking in Earth, caused by the abrupt release of slowly accumulated strain.
Earthquake (seismic) wave
A general term got all elastic waves in Earth produced by earthquakes or generated artificially by explosions.
Epicenter
The point on Earth’s surface directly above the focus of an Earthquake.
Focus (plural: foci)
The point of an earthquake within Earth where rupture first occurs to cause an earthquake.
Geologist
A scientist who studies the materials, processes, and history of Earth.
Geoscientist
A scientist who studies the physical properties of the geosphere, atmosphere, hydrosphere, cryosphere, and biosphere on Earth and other planets.
Global positioning system (GPS)
A satellite-based system scale that moves air thousands of kilometers.
Hot spot
A fixed source of abundant rising magma that forms a volcanic center that has persisted for tens of millions of years.
Lava
Fluid rock that comes of a volcano; magma that reaches the Earth’s surface.
Lithosphere
Earth’s crust and the uppermost part of the mantle.
Lithospheric plate
A rigid, thin segment of the outermost layer of Earth, consisting of Earth’s crust and part of the upper mantle. The plate can be assumed to move horizontally and adjoins other plates.
Magma
Naturally occurring molten rock material generated within Earth.
Mantle
The zone of Earth below the crust and above the core. It is divided into the upper mantle and lower mantle with a transition zone between them.
Mid-ocean ridge
A continuous mountain range extending through the North and South Atlantic Oceans, the Indian Ocean, and the South Pacific Ocean.
Oceanic crust
Earth’s crust that underlies the ocean floor and is composed of relatively dense silicate minerals rich in iron and magnesium. Oceanic crust achieves a thickness of 10-16 km.
Plate tectonics
A theory in which the lithosphere is divided into a number of plates that move relative to one another.
Rift valley (give both definitions)
The deep central cleft in the crest of the mid-ocean ridge; a large, long valley on a continent, formed where the continent is pulled apart by forces produced when mantle material rises up beneath the continent.
Seamount
An elevation of the seafloor, 100m or higher, either flat topped or peaked.
Transform boundary
A region where lithospheric plates are moving horizontally in relation to one another.
Volcano
A vent in the surface of Earth through which magma and associated gases and ash erupt.
