PHYSICAL GEOGRAPHY - HAZARDOUS ENVIRONMENTS CASE STUDIES
ACTUAL EXAM 2025 TEST COMPREHENSIVE QUESTIONS AND VERIFIED
ANSWERS (DETAILED & ELABORATED) 100% SOLVED 2025!!
Volcanoes - ANSWER✔✔-GASES = lake Nygos ,1986
LAVA= Nyriagongo, 2002
PHYROCLASTIC FLOWS & ACID RAIN = Mt Pinamuntubo, 1991
ASH & FLOODS = EJ, 2010
TSUNAMI = Anak Krakatoa, 2018
LAHARS & LANDSLIDES = Mt St Helens, 1980
SUSTAINABLE MANAGMENT = mosneratt, 1997.
Lake Nyos, Cameroon (1986) - ANSWER✔✔-- GASES
- 1,700 killed.
- co2 rose from the magma and collected at the bottom of the lake.
Eruption triggered a landslide - causing material to fall into the lake
- this triggered the co2 to rise
OLIVIA GREENWAYS© 2025, ALL RIGHTS RESRVED 1
,-c02 formed a dense co2 could which flowed over the lip of the volcano before
becoming so dense it sank down over the village ( Nyos & Subum)
- now have a degassing scheme.
Nyiagongo, DRC ( 2002) - ANSWER✔✔--LAVA
- divergent boundary - east Africa is being pulled apart
- magma rises from deep depths so is balsamic and runny.
- lava lake in crater
- lava destroyers 12,000 homes
- 15% of Goma was submerged
- 200 ppl died.
- 400,000 evacuated.
- looting.
- political civil war/ genocide - Hutus vs Tutis
Mt. Pinamuntubo , phillapines (1991) - ANSWER✔✔-- PHYROCLATIC FLOWS &
ACID RAIN.
- destructive boundary
- had no activity for 600 yrs prior
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, - steam explosion, 20 tonnes of hydrogen sulfide released.
- reacted with water in stratosphere forming a layer of hazy mist/ aerosol particles
- acid rain was caused some of the mist blew across the world dropping temps by
1degree.
- rain mixed with ash forming pyroclastic flows filling the valley up to 200m
- 800 killed.
- air base abandoned for 30 yrs.
- roofs collapsed killing 300 ppl.
- 80,000 hc of farmland destroyed.
- Aetas refused too leave their mountain
Ej, Iceland (2010) - ANSWER✔✔-- ASH & FLOODS
- astride the mid Atlantic ridge.- constructive plate boundary
- 10km height ash bloom , 250mn m3 of ash - caused by meltwater entering the caldera
& mixing with lava
- eruption was 250m below ice glacier - melted it causing a meltwater surge.
- polar jet stream drove ash across uk and eu - 107,000 flights cancelled over 8 days
- meltwater floods rose local rivers by 10m - 800 ppl evacuated
OLIVIA GREENWAYS© 2025, ALL RIGHTS RESRVED 3
ACTUAL EXAM 2025 TEST COMPREHENSIVE QUESTIONS AND VERIFIED
ANSWERS (DETAILED & ELABORATED) 100% SOLVED 2025!!
Volcanoes - ANSWER✔✔-GASES = lake Nygos ,1986
LAVA= Nyriagongo, 2002
PHYROCLASTIC FLOWS & ACID RAIN = Mt Pinamuntubo, 1991
ASH & FLOODS = EJ, 2010
TSUNAMI = Anak Krakatoa, 2018
LAHARS & LANDSLIDES = Mt St Helens, 1980
SUSTAINABLE MANAGMENT = mosneratt, 1997.
Lake Nyos, Cameroon (1986) - ANSWER✔✔-- GASES
- 1,700 killed.
- co2 rose from the magma and collected at the bottom of the lake.
Eruption triggered a landslide - causing material to fall into the lake
- this triggered the co2 to rise
OLIVIA GREENWAYS© 2025, ALL RIGHTS RESRVED 1
,-c02 formed a dense co2 could which flowed over the lip of the volcano before
becoming so dense it sank down over the village ( Nyos & Subum)
- now have a degassing scheme.
Nyiagongo, DRC ( 2002) - ANSWER✔✔--LAVA
- divergent boundary - east Africa is being pulled apart
- magma rises from deep depths so is balsamic and runny.
- lava lake in crater
- lava destroyers 12,000 homes
- 15% of Goma was submerged
- 200 ppl died.
- 400,000 evacuated.
- looting.
- political civil war/ genocide - Hutus vs Tutis
Mt. Pinamuntubo , phillapines (1991) - ANSWER✔✔-- PHYROCLATIC FLOWS &
ACID RAIN.
- destructive boundary
- had no activity for 600 yrs prior
OLIVIA GREENWAYS© 2025, ALL RIGHTS RESRVED 2
, - steam explosion, 20 tonnes of hydrogen sulfide released.
- reacted with water in stratosphere forming a layer of hazy mist/ aerosol particles
- acid rain was caused some of the mist blew across the world dropping temps by
1degree.
- rain mixed with ash forming pyroclastic flows filling the valley up to 200m
- 800 killed.
- air base abandoned for 30 yrs.
- roofs collapsed killing 300 ppl.
- 80,000 hc of farmland destroyed.
- Aetas refused too leave their mountain
Ej, Iceland (2010) - ANSWER✔✔-- ASH & FLOODS
- astride the mid Atlantic ridge.- constructive plate boundary
- 10km height ash bloom , 250mn m3 of ash - caused by meltwater entering the caldera
& mixing with lava
- eruption was 250m below ice glacier - melted it causing a meltwater surge.
- polar jet stream drove ash across uk and eu - 107,000 flights cancelled over 8 days
- meltwater floods rose local rivers by 10m - 800 ppl evacuated
OLIVIA GREENWAYS© 2025, ALL RIGHTS RESRVED 3
