Natural Hazards Flashcards
(20 cards)
What are natural hazards?
Natural hazards are a natural event that has a social impact
What are types of natural hazards?
Volcanic eruptions, earthquakes, storms, tsunamis, landslides and floods
Factors increasing risk of natural hazards
Urbanisation, poverty, climate change and farming
Global hazard risks
Hati earthquake (2010), Cyclone Aila (2009, Greek wildfires (2018), Enga landslide (2024)
What are the two types of tectonic plates?
Crust-dense, thin oceanic crust
Less dense, thick continental crust
What happens at constructive plate margins?
Plates move apart. New crust is formed as magma rises towards the surface.
What happens at a destructive collision plate margin?
Plates are moving towards each pother, the denser oceanic plate may sink (subduct) beneath a less dense continental plate. Gravtiyu pulls the oceanic plate into the mantle, dragging the plate away from the constructive margin. (Land between plates is forced upwards)
What is the centre of the earth called?
Inner core
What surrounds the inner core?
The outer core then a Large mass of molten rock called the mantle
At the surface there is a thin “………”
Crust “floating” on the mantle below
What do the plates move in response to?
Rising hot currents within the mantle called convection currents
Example of a conservative margin
San Andreas Fault in California
Which plates it the San Andrea’s fault found on?
Pacific and North American plates are sliding past each other. Moving in the same direction but at different speeds.
What happens at constructive margins
They move apart.Mamga Forbes its way to the surface as it breaks through the overlying crust.
An example of a constructive margin
The Tristan da Cunha
Which plate is the “Tristan da Cunha” found?
mid-Atlantic ridge in Iceland
What happens at a destructive collision plate boundary?
Two continental plates move towards each other, the land between the plates is forced upwards.
An example of collision plate boundary (mountains)
The Indian plate
What happens at destructive subduction plate margins?
Two plates are moving towards each other. Where the two plates etc at a deep ocean trench has formed. As the oceanic plate moves downwards it melts. Creating magma which is less fluid than a constructive margin, breaking through the surface to create composite volcanos.
An example of a destructive subduction?
Fold mountains and nas car plate, South American plate.
