earthquakes, volcanoes and tectonic plates Flashcards
constructive margin margin=boundaries
plates moving apart causes mid ocean ridge, rising convection current, shield volcanoes, earthquakes.
destructive margin margin=boundaries
most destructive. plates moving together causes subduction, ocean trenches, fold mountains, island arcs,
composite cones.
passive/collision margin? margin=boundaries
Plates moving past each other causes earthquakes.
collision margin. margin=boundaries
Plates moving together causes fold mountains, earthquakes
convection currents
the movement of magma in the mantle
continental drift
Wegners theory that the continents moved
composite volcano features
on destructive boundaries.
viscous lava (like custard).
explosive reaction.
steep sloping.
shield volcano features
on constructive boundaries. runny lava. gently sloping. gentler eruptions. can be in the ocean.
earthquake definition
a sudden violent shaking of the ground, typically causing great destruction, as a result of movements within the earth’s crust or volcanic action.
earthquakes causes
movements within the earth’s crust (plate boundaries) or volcanic action.
focus
The focus is the place inside Earth’s crust where an earthquake originates.
epicentre
The epicentre is the place on the Earth’s surface where an earthquake originates. directly above the focus.
earthquake distribution
Most earthquake zones are found at, or close to, tectonic plate boundaries, often in clusters. About 70% of all earthquakes are found in the ‘Ring of Fire’ in the Pacific Ocean. The most powerful earthquakes are associated with convergent or conservative boundaries.
richter scale
the scale used to measure the magnitude of an earthquake out of 10.00 out there has never been a 10.00 earthquake.
earthquakes in developed countries
in developed countries earthquakes are handled well and buildings are supported to withstand them. training is given and repairs are swift. loss of life/injury is lower here.
