Hazardous environments terms Flashcards
Active volcano
A volcano that has had at least one eruption in the last 10,000 years. it might be currently erupting or dormant.
Ash
Very small solid particles ejected from a volcano during an eruption (2mm).
Asthenosphere
The upper part of the Earth’s mantle, where the rocks are more fluid.
Atmospheric pressure
The pressure exerted by the weight of the atmosphere(low or high).
Collision PB
A tectonic margin at which two continental plate come together.
Composite volcano
- A cone-shaped volcano with violent eruptions.
- Found at destructive plate boundaries
Conservative PB
A tectonic margin where two plates slide past each other.
Constructive PB
A tectonic margin where rising magma adds new material to the crust.
Continental curst
The part of the crust dominateed by less dense granitic rocks.
Convection currents
Circulating movements of magma in the mantle caused by heat from the core.
Convergent PB
When two plates move towards each other e.g. destructive, collision.
Core
The central part of the Earth, mostly composed of iron and nickel
Coriolis effect/force
An effect which deflects moving objects to the right in the northern himisphere and to the left in the southern.
Destructive PB
Tectonic plate margins where an oceanic plate is subducted
Divergent PB
Two plates moving apart from each other e.g. constructive plate margin.
Earthquakes
A sudden violent shaking of the ground as a result of earth movement.
Emergency aid
Help and aid provided to an area to prevent immediate loss of life because of shortages of basics, such as water, food and shelter.
Epicentre
The centre of an earthquake on the surface of the Earth.
Evacuation
The removal of people, generally in an attempt to avoid a disaster.
Extinct volcano
A volcano that will not erupt again, perhaps because the hotspot has moved.
Fold mountains
Are formed from sedimentary rock when two plates converge the land is buckled upwards and the rock folded into mountains.
Focus
The centre of the earthquake within the Earth
GIS
Geographic information Systmes allow the layering of data to find correlations.
Hazard mapping
Mapping areas that are affected by or vulnerable to a hazard, to plan/prepare.
Hotspots
Volcanic islands formed from plumes of magma rising through a weak crust away from a plate boundary.
Humid
A high levelof water vapour in the atmosphere
Infrastructure
The physical structures and facilities (e.g. buildings, roads, power supplies)
Lahars
A destructive mudflow on te slopes of a volcano.
Landslides
A collapse of a mass of earth or rock from a mountain or cliff.
Lava flows
Hot molten or semi-fluid rock erupted from a volcano moving downslope.
Magma
Hot fluid or semi-fluid material below the earth’s crust in the mantle.
Mitigation
Altering building design to reduce the impact of a natural disaster
Oceanic crust
The part of the crust dominated by denser basaltic rocks.
Oceanic ridge
An underwater mountain range formed by ridge rush at constructive margins.
Ocean trench
An underwater narrow depression into the sea floor (destructive plate boundaries)
Paleo magnetism
Magnetism in rocks, induced by the earth’s magnetic fiedl at the time of formation.
Plate boundaries
The margin between two tectonic plates
Prediction
Forecasting future changes
Preparation
The process of getting ready for an event
Primary waves
Seismic waves that travel fast to the earth’s surface but do little damage.
Pyroclastic flow
A fast moving cloud of super-heated rock, ash, dust and gas that is deadly
Radioactive decay
The process tha occurred at the creation of the Earth
Remote sensing
The scanning of the earth bu satellite or high-flying aircraft to obtain info about it.
Richter scale
The system used to measure earthquake magnitude/strength
Response
The way in which people react to a situation
Ridge push
The motion of magma ascending at the surface, uplifting plates at their edges.
Risk assessment
A systematic process evaluating potentioal risks involved in an activity
Secondary waves
Transverse waves that reach the earth’s surface second - cause significant damage
Seismic
Relating the earthquakes or other vibrations in the earth’s crust.
Seismograph
The machine used to measure earthquake intensity
Shield volcano
A shallow-sided volcano with regular, gentle eruptions
Slab pull
The downwards movement of oceanic crust at destructive boundaries which drag the rest of the plate behind it.
Soil erosion
The removal of soil by processes caused as water and wind motion
Storm surge
High sea level causing flooding due to storm which has high winds.
Subduction
The process which one tectonic plate moves under another tectonic plate and sinks into the mantle as the plates converge.
Tectonic hazards
Threats posed b earthquakes, volcanoes and other crustal processes.
Tephra
Fragmental material produced by a volcanic eruption
Tropical cyclones
Also called hurricanes (Atlantic ocean) and typhoos (Eastern Pacific ocean)
Volcanoes
A mountain or hill, typically conical, having a crater or vent through which lave, rock gragments, hot vapourm and gas are or have been erupted from the earth’s crust.
VEI
The measure of how severe a volcanic eruption is (Volcanic Explosivity Index)
Wind shear
Variation in wind velocity occurring along a direction at right angles to the wind’s direction and tending to exert a turning force.
