Hazardous Environment Flashcards
Tropical storm
What is the formation of a tropical storm
- warm surface water evaporates, rises and condenses into clouds.
- The rising air is drown up quickly which creates low pressure, this increases surface winds.
- due to coriolis force (winds moving in specific direction due to earth’s axos) the sorm spins.
- As the storm moves over the ocean, the energy from the warm water supply strengthens the storm, so windspeed increases.
Tropica storm
What is the conditions needed for a tropical cyclone/storm.
- between 5-15 NIS of the equator
- Sea temp 27 or higher
- wind sheer (diff in windspeed) needs to be lower
- corlious force
Earths structure.
What is the earths structure?
- **Inner core: ** A solid layer that is extremley hot at the center of the earth.
- Outer core: A liquid layer that surrounds the inner core, also extermley hot.
- Crust: The outer layer of the earth that is thin/fragile - breaks easily.
Earths structure.
What are Plates & Plate boundaries?
- Plates: large section of earth’s crust.
- Plate boundaries: Where two or more plates meet.
Oceanic and Continetal crust.
What is the difference of the Oceanic crust & Continental crust?
Oceanic crust:
- Newer - most less 200 years old.
- Denser
- can sink
- can be renewed & destroyed
- “subducts”
- Heavier plate
- found on ocean floor.
Continental crust:
- Older most over 1500 mill years old.
- less dense
- cannot sink
- cannot be renewed or destroyed.
- lighter plate
- found under land.
Plate boundaries
What is a conservative plate?
- Earthquakes:
landform: Fault lines
Plates: Pacific, North American.
Plates slide in the same direction, snag, pressure build up, break off.
Aka transform
Plate boundaries
What is a collision plate?
Landforms: mountains
Plates: Indo-austrailian Eurasion.
-Earthquakes
2 Continental plates crash into eachother, trigger earthquakes, rocks pushed up.
Plate boundaries
What is a constructive plate boundary?
Landforms: Sheild volcanoe
Plates: North America
-Eathquakes & Volcanoes
2 continental plates move apart, magma rises to fill the gap, new rocks on sea bed, layers of new rock build up & break through.
Aka divergent
Plate boundaries
What is a destructive plate boundary?
Earthquakes, volcanoe, tsunami
Landforms: Composite volc
plates: South A
2 Plates pushed together, oceanic plate sinks, heat from friction melts the subducted plate, plate turns to magma that rises.
Aka Convergent or subduction
Hazardous Areas
Why do people live in hazardous areas?
- unaware of the risks
- better building design make people feel less at risk.
- other priotites (Eg. Money, food, security)
- Volcanoc benefits (Fertile soil, rocks, minerals, hot water)
- Threats that are less frequent arent seen as a danger
Hazardous Areas
How to reduce the risks at a tectonic hazard?:
- Monitor - keep an eye out for warning signs & activity using scientific equipment.
- Predict - Using historical evidence & monitoring, trying to predict where/when thye may happen in the future.
- Protect - Design buildings to survive earthquakes and think of ways to divert lava.
- plan - Identify & avoid places most a risk
Migrate = To interfere
Volcanoes
Where do volcanoes occur at?
They happen at constructive & destructive plate boundaries.
Volcanoes
What are the 3 types of volcanoes?
- Active: Likely to erupt again.
- Dormant: sleeping, erupted in the past 2000 years
- Extinct: Will not happen again
Volcanoes
What is a pyroclastic flow and Lahar?
-
Pyroclastic flow: Volcano loses pressure so ash cloud falls
2.** Lahar:** Ash from Volcanoes mixes into a river.
Volcanoes
What is the difference between Shield & Composite volcanoe?
Shield:
gentle sides
wide base
gentle eruption
runny magma
layer of lava
found at a constructive plate boundaries
Composite:
steep sides
narroe base
violent eruptions
thick magma
alternate layer of ash + lava
Found at destructive plate boundaries
