Impact of Natural Disasters on the Biosphere Flashcards
1
Q
Impact on the biosphere
- Effusive eruptions
A
- The outgassing of carbon dioxide suffocates humans and animals
- Plants are poisoned with carbon dioxide, as it saturates the soil and enters their roots
- The extreme heat of mafic lava destroys crops and vegetation
2
Q
Impact on the biosphere
- Explosive eruptions
A
- Ash causes asphyxiation and asthma attacks
- Ash contaminates and acidifies water supplies
- Death by burial under thick deposits of ash
- Pyroclastic flows flatten forests and directly burn humans and animals
- Lahars trap and bury living things
3
Q
Impact on the atmosphere
- Effusive eruptions
A
- Warming effect due to the outgassing of water vapour and carbon dioxide
- Short term poor air quality
- Depletion of ozone as chlorine is released into the atmosphere
4
Q
Impact on the atmosphere
- Explosive eruptions
A
- Solid ash particles block sunlight, reducing local temperatures
- Sulfur dioxide is released into the atmosphere and reacts with water to form droplets that reflect heat
- When these droplets reach the stratosphere, they freeze to form sulfuric acid aerosols that suspend and disperse around the globe
- This produces a layer that reflects radiation, reducing global climate
5
Q
Deccan traps (global warming and global cooling)
A
- The largest basaltic flows in the world, where 1.5 million km3 of lava was produced
- The effusive eruption ejected a large amount of greenhouse gases into the atmosphere, including methane, carbon dioxide and water vapour, increasing temperatures
- However, the Deccan traps may have entered a prolonged explosive stage and cooled the globe; sulfur dioxide would have created a layer of reflective aerosols in the stratosphere, decreasing global temperatures
6
Q
Siberian traps (global warming)
A
- The effusive eruption produced 1 million km3 of lava and a large amount of gases, including methane, carbon dioxide and water vapour, were released into the atmosphere, increasing global temperatures
7
Q
Mount Pinatubo
– Impact on the biosphere
A
- Volcanic ash covered 100 000 hectares of agricultural land and 20 000 hectares of forests
- Ash travelled around Earth and caused breathing issues outside of the Philippines
- Pyroclastic flows killed those who didn’t evacuate
- 1 000 000 farm animals were left behind and died
- Lahars destroyed marine communities and flooded rivers
- 900 people died and 6 million people were impacted
8
Q
Mount Pinatubo
– Impact on the atmosphere
A
- Ash was projected 40km into the atmosphere
- 20 million tonnes of sulfur dioxide were projected into the stratosphere and reacted with water to form aerosols, which remained there for 5 years
- The temperature dropped by 0.5°C from 1991-1993.
- From the 11th to the 17th of June, typhoon Yunya struck the Philippines with wind speeds of 195km/hr, further dispersing the ash