Global Hazard Patterns 🌍 Flashcards
What is the wind speed cause by an extra-tropical cyclone?
150kmh-1
What latitudes do trop cyclones develop between?
8 & 20
What are the 3 conditions that help to form cyclones?
⬆️ humidity and water vapour
⬇️ winds for ↕️ clouds
SST of 26-27 degrees
What are the 3 hazards that cyclones create?
⬆️ winds
Torrential rain
Storm surges
Why are hazard risks from depressions ⬆️ in NE EU?
Jet stream close
W edge of Eurasian exposed to 5000km of ocean with strong winds that have moisture
⬆️ density pop.
What is the polar front jet stream?
Fast moving air that circles globe in mid-latitudes at the height of 8-10km
What is a depression?
Et cyclones in mid to high latitudes
Where do depressions form?
Polar front jet stream
What hazard occurs when the average rainfall doesn’t occur for up to 3 months?
Drought
Why are floodplains attractive to humans?
Flat land for building in valleys
River has deposited alluvium which is ideal for agriculture
Water for irrigation, industry and domestic
What is the difference between the focus and the epicentre?
Focus = where earthquake forms within crust Epicentre = point immediately above focus
What are the vibrations that cause earthquakes?
Seismic waves
How far below a volcano is the magma chamber located?
3-4km
What is the lithosphere?
The crust and underlying rigid part of the mantle
➡️⬅️
Destructive
⬅️➡️
Constructive
⬆️⬇️
Conservative
Name of the zone created when 2 plates converge
Subduction
How are earthquakes formed from destructive plate boundaries?
Friction between subducted plate and upper mantle
How does a destructive PB cause volcanic activity?
Melting of subducted plate. Viscious and gaseous. Rises to surface. Breaks surface to make vocano. Expolosive
How are volcanic eruptions caused in constructive?
Magma from mantle spread the crust which causes a decrease in pressure
How are earthquakes caused by constructive?
Causes parallel faulting that is caused by tension the crust making shallow earthquakes. Spread along ocean floor - submarine rift valleys
How do conservative PB cause earthquakes?
Slowly past each other in opposite directions with uneven movement. Plates lock, pressure builds and sudden movement causes powerful earthq.
What is a volcanic hotspot?
Magma rises and pushes through tec plate. Erupts at surface. Large eruptions of basaltic lava.
