2. Impact of Natural Disasters on Biosphere

Question 1

What are hailstorms?

Answer 1

Hail is precipitation that falls in the form of ice.

Question 2

What is the cause of hailstorms?

Answer 2

Warm updraughts suck raindrops up into the cloud → hail grows in circulating currents → eventually becomes too large for the cloud to hold and fall

Question 3

What is the physical impact hailstorms have?

Answer 3

• Damage to plants → can strip vegetation from trees
• Damage to livestock and other animals

Question 4

What is a East Coast Low?

Answer 4

East coast lows are intense low-pressure systems that develop on or near the east coast of
Australia.

Question 5

What is the cause of an ECL?

Answer 5

interaction between cold air in the high levels of the atmosphere over the continent, and the surface temperature between the land and the relatively warm Tasman Sea air.

Question 6

What is the physical impact of an ECL?

Answer 6

• Storm force winds → coastal erosion, local coastal
  inundation (flooding)
• Heavy widespread rainfall → flash flooding or major river
  flooding
• Very rough seas → damage to coastlines

Question 7

What are droughts?

Answer 7

Prolonged period with less-than-average amounts of rain or snow in a particular region.

Question 8

What is the cause of droughts?

Answer 8

Drier than normal conditions that eventually lead to water supply
problems

Question 9

What is the physical impact of droughts?

Answer 9

• Freshwater bodies dry up
• Vegetation may dry up and die
• Land dries → substantial increase in wildfire risk.

Question 10

What is the cause of floods?

Answer 10

Prolonged heavy rain when the capacity of the water-holding body is overwhelmed.

Question 11

What are some physical impacts of floods?

Answer 11

waterlogged soils → crop failure
- Infrastructure destruction
- sedimentation and turbidity + litter and toxins → enter water and affect
the health of seagrass and coral communities along the coast, and
those species on which they depend.

Question 12

What is a bushfire?

Answer 12

A fire in scrub or a forest

Question 13

Causes of bushfires?

Answer 13

Natural vegetation and dry climate
lightning strikes
human causes

Question 14

How do explosive eruptions impact the biosphere?

Answer 14

lava/ magma/ pyroclastic flows → kill
life
- Ash can cause plane engines to fail
→ kill humans
- Carbon dioxide and carbon
monoxide can accumulate in
low-lying areas and asphyxiate
livestock and other other animals
- Acifidify streams/ water supplies →
limit water access for living
organisms

Question 15

How do explosive eruptions impact the atmosphere?

Answer 15

Gases in explosive plume may contain
chemical that can break down the
ozone layer → global warming
- Sulfate aerosols act to reflect UV light
→ cool atmosphere
- Rain clouds are often highly acidic
near volcanic eruptions

Question 16

How do effusive eruptions impact the biosphere?

Answer 16

Acid rain → starvation
- Ash covering smothering life
- High fluorine content of the gases
kills livestock
- Breathing air with more than 30%
carbon dioxide can quickly induce
unconsciousness and cause death

Question 17

How do effusive eruptions impact the atmosphere?

Answer 17

Sulfur dioxide can lead to acid rain and
air pollution
- Carbon dioxide gas is heavier than air
and therefore accumulates in low-lying
areas

Question 18

After volcanic eruptions, is the atmosphere warmer or colder

Answer 18

Colder.
Often, eruptions will cause a decrease in temperature by up to 1°C, due to the amount of
sulfur expelled into the atmosphere, reflecting the rays from the sun