Natural Hazards

1. Pyroclastic flow

   Nota:

   • A destructive flow of hot ash, rocks, gases and steam that can travel at speeds of up to 200mph.
2. Ash cloud

   Nota:

   • Causes suffocation and leads to many health problems
3. Lahar

   Nota:

   • Mudslide made of melted snow and volcanic ash
4. Sticky acidic lava escapes form the main and side vents

   Nota:

   • Magma is also viscous
5. Ash erupts before lava, so they are made of alternate layers.
6. Found at destructive boundaries

1. Found at constructive boundaries
2. Eruptions surface basic lava, which forms wide sides and gradual slopes .

   Nota:

   • Basic lava - runny lava that flows quickly and a long way before it cools
3. Eruptions are not explosive because magma is not viscous

   Nota:

   • Viscous lava traps hot gases, the pressure builds and gases are suddenly released in explsove eruptions. 

1. The main ones
   1. North and South American plates
   2. African plate
   3. Eurasian plate
   4. Indo-Australian plate
   5. Caribbean plate
   6. Pacific plate

1. Destructive

   Nota:

   • Denser continental plate subducts oceanic plate, it becomes magma in the mantle. The magma is forces to the surface through volcanoes. The plate also causes friction between the plates which causes earthquakes.
2. Constructive

   Nota:

   • Tectonic plates are moving away from each other, magma rises in the gap or through fissures creating ridges
3. Conservative

   Nota:

   • Two plates moving past each other, or in the same direction at different speeds. They occasionally snag which builds up pressure released in earthquakes.
4. Collision

   Nota:

   • Two continental plates moving towards each other and forcing each other upwards, making fold mountains.

Nota:

• The pint underground where the earthquakes occurs

Nota:

• The point of the surface directly above the focus, where the quakes and damage will be most severe.

Nota:

• Waves of energy released by the quakes that are measure dby seismographs. These come in the form of P and S waves, P waves are faster and spread out first, the S waves follow and are often more destructive.

Nota:

• Smaller tremours in the days after the initial quake. They can slow down rescue efforts and cause extra damage.

1. off Africa
2. Caribbean, Mexico, southern USA
3. August to October

1. water 27°C or higher
2. warm, moist air

   Nota:

   • the air rises and condensates which releases huge amounts of energy and makes the storm very powerful
3. in either the Atlantic or the Pacific

Nota:

• this is because the supply from warm water is cut off

1. spin anti-clockwise
2. circular in shape
3. life span of 7-14 days
4. eye is caused by descending air

   Nota:

   • low pressure, cloud and no rain in here

1. Indian Sea

1. Japan and China

Nota:

• people keep using them but they aren't being replenished by rainfall