geography - natural hazards

crust and top layer of upper mantle

more dense in the upper part of mantle

oceanic plate subducts underneath the continental plate because it is more dense

south american plate over the Nazca plate

they jolt into position, this sudden change causes seismic waves

when plates move apart from each other, this causes magma to come up and form new land

mid atlantic ridge in the atlantic ocean

Plates slide past each other and build up friction, they can get stuck and cause earthquakes

San Andreas Fault in the USA

2 continental plates moving towards each other. As they are the same plate, they are forced upwards to create fold mountains as they are the same density

Himalayas between the indian and eurasian plates

naturally occurring events that pose potential risk and threats to people / or property

the likelihood of harm taking place based on the exposure to the hazard

tourism, volcanoes give fertile land for businesses, frequency etc

below land, less dense, granite rock, cannot sink, can't be renewed or destroyed

below ocean, thinner, more dense, can sink, can be renewed or destroyed, basaltic rock

convection currents in the asthenosphere is caused by heat rising, starts to sink when it gets cooler. change of density allows plates to form

states the gravity and the plates are the ones responsible for the plate tectonics through subduction process

known as the sliding plate force is a proposed driving force for plate motion in plate tetonics

the earths crust is more unstable which causes magma to reach the surface. Volcanoes are usually found at destructive and constructive plate margins.

80% are found at destructive plate boundaries

Constructive plate boundaries

steep slopes,tall cone with a narrow base, made of layers of ash, volcanic gases don't escape the lava easily

gentle slopes, low cone with wide flanks, made of numerous lava flows, low viscosity, mild frequent eruptions

large mantle plume, commonly found at shield volcanoes

volcanic explosive ty index takes the height of the volcano and how long they typically last to predict the frequency of them

they see the pattern of the the years when they erupt and see whether it has gone over that limit and is likely to erupt

thermal scanning shows the events of magma rising

you can't really do much. You can evacuate people from their homes to a safe location, people can wear long sleeves to protect them from ash fall. Sometimes people divert lava into the sea to prevent it from reaching a populated area

Exclusion zones can be designated. People. an practice covering their eyes, nose and mouth to prevent gas fumes.

We can pass magnetic waves through rocks and detect any fractures that could suggest that the plates have gone under pressure which could lead to an earthquake

They are dampers which go between the house and ground to withstand vibrations which could cause lots of damage to property

Uses X shape frames to stiffen the frame of a building and helps resist rocking. They are usually placed around lifts so they don't malfunction when evacuating people

They are made of steel or concrete . When the building starts to vibrate, the weights move in the opposite way to help reduce damage

High value land such as hospitals and office books can be protected. Maps can be produced to show the effects of an earthquake or identify the area of risks from damage. For example, after the Tohoku earthquake, every year on the 1st of september they practice an earthquake drill to prepare them for any more potential earthquakes

In Iceland, the blue lagoon is heated by geothermal energy which attracts 1.5 million tourists a year. Leading to the multiplier effect

Attracts tourists, which creates employment, leading to the multiplier effect