Key words Flashcards
Hot spot
Surface area located above the plume of rising magma.
E.g. The Hawaiian Islands.
Plate
Lithosphere is divided into 7 main segments.
These rigid slabs float on the underlying asthenosphere. Moved by convection currents.
Plate tectonics
A theory that attempts to explain the formation and distribution of the Earth’s major structural features in terms of a series of plates that make up its surface.
Seismic waves
Shock waves released by the rupture of rock strata at the focus of an earthquake.
Travel through the rocks.
Measured/recorded on a seismograph.
Tsunami
Very large sea waves.
Generated by shallow-focus underwater earthquakes, volcanic eruptions, underwater debris slides and large sea landslides.
Volcano
An opening or vent through which magma, molten rock, ash or volatiles erupt on to the surface of the Earth.
Lithosphere
Crust.
Upper mantle.
Asthenosphere
Highly viscous.
deforming region of the upper mantle.
Lies below the lithosphere.
Crust
Two different types:
Oceanic (denser, newer,)
Continental (older, less dense).
Plate margins
Plates edges.
Two plates are either moving apart, colliding together or sliding past one another.
Moho discontinuity
The junction between the Earth’s crust and the mantle where seismic waves are modified.
Intra-plate
Middle of the plate.
Hotspot volcanoes e.g. Yellowstone.
