natural hazards and ecosytems MINI TEST

Question 1

Why the wind speed of a tropical storm may change as it reaches land?

Answer 1

Rising warm air causes the pressure to decrease at higher altitudes. Warm air is under a higher pressure than cold air, so moves towards the ‘space’ occupied by the colder, lower pressure, air. … As this happens, it reduces the mass of air over the ‘eye of the storm’ - causing the wind speed to increase further.

Question 2

One effect of deforestation on the soils of the rainforest?

Answer 2

• Without forests, the soil erodes and washes away

- Causing farmers to move on and perpetuate the cycle

Question 3

Evidence that climate change took place?

Answer 3

• diaries and paintings, provide written observations, could be unreliable but mostly accurate
• tree rings, if the ring is thick, it means the temperature was warm. If the ring was thin, it means the temperature was cool

Question 4

Increasing the use of fossil fuels and changes in agriculture may have contributed to global changes in temperature?

Answer 4

They both caused the release of more green house gases into the atmosphere

Question 5

How do plate movements cause tectonic hazards in Iceland?

Answer 5

• Iceland is a constructive plate margin, meaning the plates move away from each other, and magma rises through the crust
• Low magnitude earthquakes are caused here
• Volcanoes also form here, called shield volcanoes

Question 6

One natural cause of changes in global temperature?

Answer 6

• Influenced by volcanoes

- E.g, when they erupt and pump out clouds of gas and block sunlight

Question 7

Hot desert adaptations, plants?

Answer 7

• succulent plants store water in fleshy leaves/stems/roots
• water is conserved by reduced surface areas, most succulents have few or no leaves
• some protect themselves by being able to camouflage

Question 8

Hot desert adaptations, animals?

Answer 8

• camels have long eyelashes that protect from sun and blowing sand
• hump stores fat tissues, which is useful for scarcity of food
• lips are thick to prevent cuts when eating prickly shrubs

Question 9

How does human activity cause desertification in a hot desert?

Answer 9

• removal of fuel wood, removing the trees leaves the soil exposed, so more easily eroded
• population growth, puts pressure on the land, leading to more deforestation for fire wood
• over grazing, leads to more soil erosion because the plants are eaten so they no longer hold the soil together

Question 10

Why biomass changes between each level in a food chain?

Answer 10

-less energy and biomass is transferred between organisms than at the previous trophic level

Question 11

Role of decomposers in an ecosystem?

Answer 11

They feed on things, e.g, dead plant materials, feces, carcass’s