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Flashcards in 1 - Hazardous Earth Deck (62):
1

Explain Atmospheric Circulation

1. Warm air rises at the ITCZ due to intense heating (low pressure)

2. Air cools and falls (high pressure).

3. The difference in pressure causes trade winds to bring the air back to the ITCZ

2

Why are trade winds curved?

Due to the Coriolanus effect the winds are curved.

3

Why is their intense heating?

The high angle causes the sun’s UV to be concentrated.

4

How are ocean currents powered?

Wind from the atmospheric circulation cells. OR due to differences in pressure.

5

Density and ocean currents.

At Arctic and Antarctic water water is cooled = low density, it sinks. Warmer water is pulled in. The cycle repeats.

6

Effect of global circulation

Transfer heat around the world.

7

Natural Climate Change: 2 periods

Interglacials and Glacials

8

How is past climate data collected?

Using ice-core data.

9

Causes of Natural Climate change.

Milankovich cycle (orbital),
Sun radiation change,
Volcanic eruptions,
Asteroid Collisions,
Ocean currents.

10

Milankovich Cycle

Every 100,000 years the orbit changes shape.

11

Sun radiation change.

Sunspots - more intense
More solar flares.

12

Volcanic eruptions

Pump ash into atmosphere blocking sunlight - cooling.

13

Asteroid collisions.

Debris can block sun - cooling.
Fires release CO2 - global warming.

14

Ocean currents and climate change.

Currents shift directing warm water elsewhere.

15

Human causes of Climate Change.

Industry,
Transport,
Energy Production,
Farming.

16

Explain Greenhouse effect.

1. UV reaches atmosphere, some is reflected.

2. Land and oceans absorb heat.

3. Infrared is emitted, and is trapped because of greenhouse gases.

17

Human climate change and global temperatures

Rising,
2015: +1C from 1850

18

Human climate change and CO2

Rising in parallel with global temperatures.

19

Human climate change and ocean temperature.

Rising by 0.11C per decade (1971 - 2010)

20

Human climate change and arctic sea ice.

Covers 13% less each decade

21

Human climate change and sea levels

Risen by 14cm in 21st century.

22

Human climate change and extreme weather.

5x more common vs a century ago.

23

Consequences of Global Warming.

Coastal flooding, biodiversity loss, extreme weather, pests and disease, loss of glaciers, draughts

24

Tropical cyclone names

Hurricanes, cyclones, typhoons

25

Required water temperature for tropical cyclones

26.5C

26

Latitude where tropical cyclones form.

5 to 30

27

Tropical cyclones and pressure.

Low pressure - As warm air rises it draws in more air.

28

Tropical Cyclones and rotation

Coriolis effect causes a spiral rotation

29

Tropical cyclones and structure

-Cylinder of rising spiralling air (low pressure)

-EYE: descending high pressure air.

30

Tropical Cyclones and size

UP to 640km x 10km high

31

Tropical Cyclones and movement.

Start: Warm tropic water, move westwards.
Some: reach belt of winds blowing west and reverses direction.
Can travel 640km in a day

32

Saffir Simpson scale and wind speed (1->5)

Increases:
1. 119-153km/h
5. 252+km/h

33

Saffir Simpson scale and pressure.

Reduces
1: 980+ millibar
5: <920 millibar

34

Saffir Simpson scale and storm surge.

Increases:
1: 1 -> 1.7m
5: >5.7m

35

Category 5 damage

Catastophic

36

Category 1 damage

Some damage.

37

Cyclone intensifier

Water temperature
Low wind shear (different speeds/directions)
High humidity

38

Cyclone dissipaters

Reach land (no water to power it)
Reaches colder water

Wind shear

39

Formation of Tropical Cyclone

1. Warm sea temperatures
2. High humidity
3. Rapid cooling - condensing causes energy release (latent heat)
4. Coriolis effect causes rotation (not enough at 5)
5. Pre-existing low pressure, storms merge.

40

Layers of the Earth.

Lithosphere, Asthenosphere, outer core, inner core

41

What powers the core

Nuclear decay.

42

Inner core conditions

6000C
High pressure
Solid iron

43

Outer Core

5000C
Liquid
iron and nickel

44

Asphenosphere

Plastic region,
Under enough pressure that rocks flow

45

Lower Mantle

3000C

46

Lithosphere

Solid
Tectonic plates.

47

Convection currents and plate movement

Heat from core causes rising towards surface. The force moves plates. Falls towards core to be reheated.

48

Density and the lithosphere

Continental Crust : Granite (Less dense)
Oceanic Crust: Basalt (more dense)
BOTH less dense than asthenosphere.

49

Convergent Plate boundary

2 plates converge
denser plate subducts

50

Collision plate boundary.

2 plates converge
Equal density, forming fold mountains

51

Divergent plate boundary

Rising magma from convection currents pull apart 2 plates causing volcanic ridge.
Many earthquakes.

52

Conservative

2 plates slide along.
Many earthquakes

53

Shield volcano

Constructive boundary (divergent) OR hotspots.
Basaltic lava.
Gentle sloping sides, wide base
Frequent but effusive eruptions

54

Composite (strato volcano)

Andesic lava
Steep sides, narrow base
Layers from previous eruptions
Infrequent but explosive eruptions

55

Basaltic lava

Low viscosity - travels far
Low silica and gas content

56

Andesic lava

High viscosity - not as far
Less hot
High silica and gas content

57

Epicentre

Point on surface above focus.

58

Focus (hypocentre)

Central point underground

59

Primary impacts of Earthquakes

Death, injury
Destruction of buildings and infrastructure

60

Secondary impacts of earthquakes

Fires from fractured gas pipes and electricity pylons

Landslides

Disease, no sanitation

Tsunami

61

Primary impacts of volcanoes

Death, injury
Destruction of buildings, infrastructure and farmland

62

Secondary impacts of volcanoes

Atmospheric pollution (ash)
Mudflows (lahars)
Landslides
Flooding by diverted river
Tsunamis by landslide or cliff collapse.