AQA A-Level Geography 7037
Water and Carbon Cycles
Hot Desert Systems and LandscapesLandscape
Coastal Systems and LandscapesLandscape
Glacial Systems and LandscapesLandscape
HazardsHazards or ecosystems
Ecosystems Under StressHazards or ecosystems
Global Systems and Global Governance
Changing Places
Contemporary Urban EnvironmentsHuman option
Population and the EnvironmentHuman option
Resource SecurityHuman option
Hazards
Volcanic Hazards and Eruption Magnitude
- 4 things to know
- Component 1
Overview
Recall questions on nuées ardentes, lava flows, lahars, pyroclastic fallout and ash, volcanic gases and acid rain, the size classes of ash, lapilli and bombs, the global distribution of volcanoes, the VEI and why eruption frequency varies.
What you need to know
Answer each one before you reveal it.
What is pyroclastic fallout?
What is the size range for lapilli?
Describe the global spatial distribution of volcanoes.
Questions from this subtopic
Each one with the model answer underneath.
- 1
What are nuées ardentes?
Model answer
Fast-moving currents of hot gas and volcanic matter (pyroclastic flows) that travel down volcanic slopes at speeds up to 700 km/h and temperatures exceeding 400°C
- 2
Define lava flows and state three factors that determine how far they travel.
Model answer
Streams of molten rock that move downslope from a volcanic vent; their speed and distance are determined by viscosity, temperature and gradient
- 3
What are lahars and how can they be triggered?
Model answer
Mixtures of volcanic debris and water that flow rapidly down valleys; triggered when eruptions melt ice or snow, or when heavy rain mobilises loose ash deposits
- 4
What is pyroclastic fallout?
Model answer
Fragmented volcanic material ejected into the atmosphere that falls back to the surface, ranging from fine ash to larger bombs and blocks
- 5
State five impacts that ash fallout can have on human populations and infrastructure.
Model answer
Collapse of roofs under its weight, contamination of water supplies, damage to crops, disruption to aviation, and respiratory problems over wide areas downwind
- 6
Name the volcanic gas that is most abundant by volume in volcanic emissions.
Model answer
Water vapour
Other ways to work this
The same content, four other ways.
What is inside Levo
Six ways to work the same material.
Every question in Hazards, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.