Physical Geography - XMAS half term

Primary hazards

occurs during the events, it is a direct consequence of the event

Secondary hazards

occurs after the events, it is a indirect consequence of the event

Pyroclastic flows - primary hazards

dense, fast moving flows of hot gas and rocks that move rapidly downslope all speeds can go over 700km/hr

Lava flows - primary hazards

streams of molten rock flowing on the surface. High silica lava tends to be more viscous and solidifies nearer to source than basaltic lava, which generally flows over distance before solifdfying

Ash and Tephra - primary hazards

airborne particles of material that have been ejected from volcanic vents into the atmosphere then fall back to the surface

Lahars - secondary hazards

Type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water.

Acid rain - secondary hazards

forms through a process between reaction of water and other compounds like nitrogen and sulphur dioxide

What are the 4 hazard management concepts

prevent, mitigate, prepare, adapt

What are the ways volcanoes can be monitored?

thermal imaging, satellite tracking, GPS and tiltmeter 

How does tropical cyclogenesis happen ?

1. sea surface temp greater than 27 degrees

2. pre-existing low level disturbance e.g. pressure difference

3. high humidity in lower to middle troposphere

4. low vertical wind sheer

5. hot air rises leaving low pressure under storm centre, other air moves in to replace air risen

6. entire storm rotates due to Coriolis effect

What are the primary hazards of tropical storms ?

1. High winds - often exceed over 150km/hr

2. Storm surge - 90% of deaths un hurricanes caused by storm surges

3. Heavy rainfall - can exceed to 200 to 300mm

What is the key information needed when tracking tropical storm ?

location, direction, size, wind speed, pressure, sea surface temperature

How to predict tropical systems ?

Joint Polar Satellite System - 500 miles above earth, orbits earth x7 a day

Geostationary Operational Environmental Satellites - 24,000 miles above earth, travel at same speed as Earth