Hazards Flashcards
(31 cards)
Hazard?
Threat of substantial loss/impact to life or damage to property caused by an event
Slab pull?
At destruction, denser crust forced under. The sinking of the plate edge pulls the rest downwards
Tectonic Plate theories?
Jigsaw, fossils, glacial striations, rock sequences, polarity
Crust width?
5-10km beneath oceans. Up to 70km beneath land
Mantle width?
2900km
Where is the mantle solid?
Upper mantle solid above the asthenosphere
How do plates move?
Convention current, gravitational sliding/ ridge push, slab pull
What occurs when constructive plates separate underwater?
Mid-ocean ridge
What occurs when constructive plates separate beneath land?
Rift valley
Example of a mid-ocean ridge?
Mid-Atlantic ridge
What occurs along mid-ocean ridges?
Transform faults
Can volcanoes be found at rift valleys?
Yes
When can volcanic activity occur at destructive plate boundaries?
Oceanic-oceanic and oceanic-continental
Where can a deep sea trench form?
Oceanic-oceanic and oceanic-continental
Where can island arc form?
When there’s an oceanic plate
Example of fold mountains?
Himalayas
Is there volcanic activity at a conservative boundary?
No subduction=no melting of rock=no volcanic activity
What boundary is the San Andreas fault at?
Conservative
What can magma plumes form?
A chain of volcanoes e.g Hawaii
What measures volcanic activity?
Volcanic Explosive Index
Titles of Volcanic Explosive Index
Ejecta volume, description, plume, frequency, examples
Description range of VEI?
From effusive to mega-colossal
What is tephra?
Solid material ejected into the atmosphere
What are pyroclastic flows?
Very hot, high-velocity flows. A mixture of gas and tephra
