All terms in this list:

Magma: The molten matter within the earth, the source of the material of lava flows, dikes of eruptive rocks, etc.

mid oceanic ridge: continuous mountain range extending through the North and the south Atlantic ocean and the south pacific ocean

Rift valley: the deep central cleft in the crest of the mid oceanic Ridge.

lava: molten rock that issues from a volcano or fissure.

magma: naturally occurring molten rock material generated within the Earth

hot spot: a fixed source of abundant rising magma that forms a volcanic center that has persisted for ten of millions of years.

map projections: the process of systematically transforming position on the Earth's spherical surface to a flat map .

ring of fire: a area where a large number of earthquakes and volcanos erupt

silica: material with the composition

contour lines: a line on a map that connects points of equal elevation.

contour interval: the vertical distance between the elevations .

topographic map: a map showing the topographic features of the land surface

igneous rock: one of the major groups of rock that makes up the crust of the Earth; formed by the cooling of molten rock, either below the surface (intrusive) or on the surface (extrusive)

viscosity: (physics) A quantity expressing the magnitude of internal friction in a fluid, as measured by the force per unit area resisting uniform flow.

shield volcano: A large volcano, with shallow-sloping sides and a flattened dome, formed of successive eruptions of free-flowing lava; a lava dome

caldera: A large crater formed by a volcanic explosion or by collapse of the cone of a volcano.

Lava Dome: is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano.

Lava flow: an outpouring of molten lava from a vent or fissure also the solidified body of rock so formed .

Lahar: A volcanic mudflow.

ash: fine pyroclastic material
(less then 2 mm in diameter)

pyroclastic flow: A flow of volcanic ash, dust, rocks and debris that cascades down the slope of a volcano during an eruption. Pyroclastic flows are very dangerous, reaching speeds greater than 60 miles per hour and temperatures in excess of 800 degrees Fahrenheit.

plate tectonics: a study of the movement and interaction of the earths lithospheric plates

lithosphere: a outermost layer of the earth consisting of the earths crust and the part of the upper mantle

crust: the thin layer outermost of the earth

rift valley: a large long valley on a continent formed where the continent is pulled apart by forces produced when the mantle material rises up beneathe the cotinent

seafloor spreading: is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away ...

convergent plate boundary: a plate boundary where two plates move toward one another .

divergent plate boundaries: where the plates divide away from eachother

transform plate boundary: where the plates pass eachother

transform fault: A geological fault (a form of strike-slip fault) found in mid-ocean ridges in which displacement undergoes a sudden change in direction

subduction: the action of being pushed or drawn beneath another object.

pangea: super continent

continental drift: the slow movement of continents explained by plate tectonics

oceanic crust: is the part of Earth's lithosphere that surfaces in the ocean basins.

continental crust: is the layer of igneous, sedimentary, and metamorphic rocks which forms the continents and the areas of shallow seabed close to their ...

mantle: is a part of a terrestrial planet or other rocky body large enough to have differentiation by density. The interior of the Earth, similar to the other ...