Tectonics Flashcards
Accretion Wedge
The accumulation of material at the point of subduction
Aseismic Buildings
Buildings designed to withstand or minimise destruction during an earthquake
Asthenosphere
The upper mantle layer of the Earth - semi molten. And 2000km wide
Ash
Fine particles and ejected during an eruption, which can remain airborne as clouds
Continental crust
Crust that forms the continents of the lithosphere, on average 35km thick
Continental Drift
The movement of tectonic plates, due to varying weights of crust. Slab pull is the driving force of CD
Convection Currents
The circulation of magma within the mantle (asthenosphere) Magma is heated by radioactive process at the core and cools at the surface, causing circulation at the two places
Degg’s model
Model that shows when a hazard becomes a disaster if it affects a vulnerable population.
Epicentre
the point on the surface directly above the earthquakes origin
Focus
The place in the crust where the pressure/ seismic energy is released.
Hazard Mitigation Cycle
Sequence of governance of a natural hazard, involves monitoring and prediction, mitigation and preparedness
Hot Spot
Volcanoes found away from the plate boundary, due to magma plume closer to the surface
Lahar
A combination of ash and rainwater
Lithosphere
The upper crust of the Earth ( 100km thickness)
Love waves
A surface EQ with horizontal displacement
Mid-Ocean ridge
Parting oceanic plates at a constructive plate boundary, creates a ridge, with new land at the base of the oceanic valley
Oceanic crust
Crust, usually thinner than continental crust that forms on the sea floor, (7km thick)
Paleomagnetism
Alternating polarisation of new land created. As magma cools , the magnetic elements within will align with the earths magnetic field, and alternate in a few thousand years
Park’s Model
A model describing the decline and recovery of a country over time, following.a natural disaster.
Primary Waves
An earthquake wave causing compressions within the body of a rock
Pyroclastic Flow
A mixture of gases and rock fragments, st high temperatures travelling at rapid speeds.
Richter Scale
Measure of EQ Intensity
Secondary Waves
An Earthquake waves causing vertical displacement within the body of a rock
Seismic Waves
The energy released during an EQ, in the form of P,S and L waves
Slab Pull
The force contributing to the movement of tectonic plates. Due to the weight of the plate
Subduction
Oceanic plate is forced below continental plate, due to the oceanic plate being more dense than the continental plate
Tsunami
Initial vertical water displacement that creates waves with large destructive power.
Benioff Zone
A region of the subduction plate, most affected by pressure and friction, where most destructive margin EQs originate
