Theme 3 - Tectonic Processes and Landforms Flashcards
Crust?
the solid outermost layer of the earth lying above the mantle.
Tectonic plates?
the earth’s crust and upper part of the mantle is split up into large sections.
Plate boundary or margin?
the place where two or more plates in the earth’s crust meet.
What are the two types of crust?
.continental crust, which is on average 35km thick
.oceanic crust, which is on average between 6km and 8km thick
What are the layers of the earth? (starting with the crust)
.crust
.upper mantle
.lower mantle
.outer core
.inner core
Where are earthquakes and volcanoes most likely to occur?
near plate margins.
Earthquake?
a tremor of the surface of the earth resulting from shockwaves generated by the movement of rock masses within the earth, particularly near boundaries of tectonic plates.
Volcano?
a mountain created by the eruption and deposition of lava and ash from a vent in the ground.
Destructive margin?
a plate boundary (sometimes called convergent plate margin) where oceanic and continental plates move towards each other and the oceanic plate goes under the continental plate.
Constructive margin?
a plate boundary (sometimes called divergent plate margin) where the crustal plates move apart from each other.
Convection?
where heat in a gas or liquid is transferred from a warmer to a cooler place by upward movement.
Magma?
molten rock located below the earth’s surface within the mantle or crust.
Subduction?
the process in which an oceanic plate collides with and is forced down under an oceanic plate and drawn back into the mantle.
Why do plates move?
tectonic plates move because of heat inside the Earth. The Earth’s interior is hot, and this heat makes the rock in the mantle move like a slow, circulating conveyor belt. This movement, called mantle convection, pushes and pulls on the plates at the surface, causing them to slowly drift.
Ocean trench?
a long, narrow, deep depression in the oceanic floor formed at a subduction zone where the denser plate is forced below the less dense one.
Fold mountains?
mountains that form by folding layers in the upper part of the earth’s crust.
Ocean ridge?
a narrow, largely continuous underwater mountain system formed by the extrusion of lava at a divergent plate margin.
Rift valley?
a lowland region that forms by the subsidence of land between two parallel faults where the earth’s tectonic plates moves apart or rift.
Where are ocean trenches located and what is an example?
.destructive plate margin
.Mariana Trench
Where are fold mountains located and what is an example?
.destructive plate margin
.Andes Mountains
Where are ocean ridges located and what is an example?
.comstructive plate margin
.Mid-Atlantic Ridge
Where are rift valley’s located and what is an example?
.constructive plate margin
.Thingvellir
Shield volcano?
a volcanic cone with gentle slopes made up of layers of fluid basaltic lava.
Stratovolcano?
a conical volcano with steep sides made up of alternating layers of lava and pryclastic material, such as ash.
Caldera?
a volcanic cone where the original top and centre have been removed, either through a massive eruption or through collapse, leaving the base of the cone as a large ring-shaped ridge.
Cinder cone?
a steepsided conical hill formed by the explosive eruption of cinders (glassy volcanic fragments) that accumulate around a vent.
Lava tube?
a hollow tunnel formed when the outside of a lava flow cools and solidifies and the molten material passing through it is drained away.
Geyser?
a hot spring that is under pressure and erupts, sending jets of water and steam into the air. The heat results from the contact of groundwater with magma bodies.
Hotspot?
a small area of the earth’s crust which has an unusually high amount of volcanic activity.
What are 3 large-scale features?
.shield volcanoes
.stratovolcanoes
.caldera
What are 3 small-scale features?
.cinder cone
.lava tube
.geyser
