Glossary: Restless Earth Flashcards
Collision boundary/ margin
Where two plates are moving together (destructive) and upward, creating mountains.
Conservative boundary/ margin
Where two plates pass alongside each other.
Constructive boundary/ margin
Where two plates move apart.
Continental drift
The theory that describes how plates have moved over millions of years.
Convention current
Movement of magma within the Earth’s mantle, formed by radioactive decay creating heat.
Crust
The outermost layer of the Earth.
Earthquake
A sudden and violent shaking of the Earth’s crust.
Fold mountains
Mountains formed by plate collision, crumpling rock layers.
Hot spot
Where magma plumes rise away from plate boundaries, breaking through the crust.
Magma
Molten rock within the Earth’s mantle.
Outer core
An inner section of the Earth - liquid comprising mostly of iron, at 10-12 g/cm cubed.
(Tectonic) Plate
A huge section of the Earth’s crust.
Plate boundary/ margin
Where any two plates meet.
Plate tectonics
The theory of the distribution of earthquakes, volcanoes, fold mountains and plate movement.
Richter scale
Measures the strength/magnitude of an earthquake - 0 to 10.
Subduction
The sinking movement of one plate beneath another at a destructive margin.
Tectonic activity
Changes taking place in the structure of the Earth.
Tsunami
A wave, often generated by an earthquake, which displaces water and causes devastation.
Vent
The opening of a volcano.
Volcano
Cone-shaped mountain created by lava from repeated eruptions.
Basic lava
Thin ‘runny’ lava, low silica content, flows long distances.
Caldera
The depression of a supervolcano, marking the collapsed magma chamber
Composite volcano
Steep-sided cone with successive layers of ash and lava
Epicentre
The point at the Earth’s surface directly above the focus of an earthquake
