Tectonics Flashcards
Seismic hazards
Generated when rocks within 700km of the earth’s surface come under stress so they break and become displaced
Volcanic hazards
Hazards associated with eruption events
Intra-plate earthquakes
Occur in the middle or interior of tectonic plates. Much rarer than boundary earthquakes
Volcano
A landform that develops around a weakness in the Earth’s crust from which molten magma, volcanic rock and gases are ejected
Plate tectonics
A theory developed to explain the large- scale movements of the lithosphere
Lithosphere
The surface layer or the earth
Average thickness-100km
Subduction zones
Areas where two plates are moving together with the thinner more dense oceanic plate descending beneath a continental plate
Paleomagnetism
Magma aligning with earths magnetic polarity when it cools
Locked fault
A fault that is not slipping because the frictional resistance on the fault is greater than the stress across the fault
Hypocentre
Point within the ground where the strain energy of the earthquake stored is first released
Soil liquefaction
Water saturated material can temporarily lose normal strength and behave like a liquid under the pressure of strong shaking
Intensity
A measure of the ground shaking
Magnitude
Measure of the size of an earthquake
Epicentre
Location on the earth’s surface that is directly above the earthquake focus/hypocentre
Tsunami
Large waves initiated by earthquakes ,landslides and sometimes volcanic eruptions
