Natural Disasters Flashcards
What are the 2 categories of tectonic plates?
Oceanic
Continental
What are the 3 layers of the earth?
Core
Crust
Mantle
How thick is the crust?
0-60km thick
Whats in the mantle which causes plates to move?
Convection currents
On which boundaries do earthquakes occur?
All of them
What is a conservative plate boundary?
Where they slide past each other
(Earthquakes appear)
What is a constructive plate boundary?
They move away from one another. Earths crust pulled apart to create a path for rising magma to flow. Volcanoes are built like a mountain
What is a destructive plate boundary
Its a convergent boundary where one slide beneath the other which is called subduction. (Many earthquakes occur and volcanoes)
What is a meteorological hazard?
Caused by changes to earths atmosphere (meteor; sky)
Examples are: thunderstorm, hurricane, landslide, earthquake, tsunami, volcano
Whats a geological hazard?
A geological condition causing widespread destruction
Example: volcanoes, earthquakes, avalanches
Features of continental and oceanic
Oceanic more dense
Continental thicker
Oceanic has fe, mg, calcium
Continetal= silicon, 02, Al
Oceanic goes under continetal
Continetal older than oceanic
What is the focus of an earthquake?
Where the earthquake originates from/ where it started its point or origin
What is the epicentre?
Directly above the focus of the earthquake
What does earthquakes measured in now
Moment magnitude scale and richter
What are volcanoes measured in
Volcanic explosivity index (VEI)
