Unit 4 Topic 1 - cause and effect of earth hazards Flashcards
What is the difference between El Nino and La Nina? (In regards to Australia)
The girl is wet and positive about it.
La Nina has layers of warm water evaporating and can bring floods to australia (high rainfall). Major upwelling in the eastern pacific. Low pressure of Darwin (Positive SOI). Single air cell.
El nino has high pressure over Darwin (Negative SOI) causing it to be dry. Low pressure in Tahiti and the Eastern pacific. Presence of 3 walker cells.
What are cyclones?
A system of winds that circulate a centre of low pressure counterclockwise (towards the equator).
They generally form when sea surface temps are above 26.5C
How are tornadoes formed.
Winds moving in different speeds and directions causes the rising hot air to start spinning.
Gusts of warmer air rise and gusts of cooler air sink as they blow across the land. If there are enough rising and sinking gusts, the air near the ground starts spinning.
The rotating air moves horizontally across the ground and can be titled vertically by the rising air, allowing tornado to form.
