Flashcards in 3.1 Elementary plate tectonics Deck (21)
Narrow zone of deep earthquake foci at a subduction zone.
Part of the Earth's crust that forms the continents.
Theory that the continents have drifted across the surface of the globe.
Convergent plate boundaries
Margins where plates are moving towards each other.
Central part of the Earth below 2900 km from the surface.
Outermost layer of the Earth. It may be divided into continental and oceanic.
Divergent plate boundaries
Plate boundaries in which the plates are moving apart.
Relatively small area where magma rises through a continental or ocean plate. As the plate moves across a hot spot a chain of volcanoes may be formed
Chains of volcanic islands on the continental side of an ocean trench. Associated with a subduction zone.
Molten magma that reached the Earth's surface
Outermost layer of the Earth, comprising the crust and part of the mantle.
Molten rock within the Earth. When it reaches the surface it is called lava.
Scale of earthquake intensity based of descriptive data.
Lines of mainly mountains formed when two ocean plates are separating
Part of the crust underlying the oceans.
Arc-shaped depressions formed at subduction zones where one tectonic plate plunges a less dense continental one.
Largest feature of the ocean floor. They are essentially a linear belt of submarine mountains.
Open ended scale to record the magnitude of earthquakes.
Where ocean floors grow as plates move apart at constructive margins.
Continental area that has not been deformed since Pre-Cambrian times.