geography - natural hazards & disasters

a primary effect of a tropical cyclone is…

high wind speeds, which increase the cyclones power and are necessary for it to form

two primary effects of earthquakes are….

the ground shaking from seismic waves

surface faulting from where the two plates interacted

three primary effects of volcanoes are…

pyroclastic flow - very fine ash and debris falling back onto earth’s surface.

volcanic bombs - a big, aerodynamic mass of partially molten rock released from volcanic eruptions of lava

lava flow - the flow of molten magma expelled from the earth that destroys everything in its path

three secondary effects of earthquakes are…

landslides and rock falls from rocks cracking and breaking.

ground failure (landslides)

soil liquefaction (becomes more loose and less firm)

two secondary effects of a volcano are…

acid rainfall (rainfall mixed with, for example, sulfuric or nitric acid)

atmospheric ash fallout (ash falling back after explosion)

two secondary effects of tropical cyclones are…

tornadoes (caused by high wind shear and updrafts)

flooding (large water content pushed towards shore)

two long-term impacts of earthquakes are…

spread of chronic illness

fires

two long-term impacts of volcanoes are…

infrastructure destruction

settlement destruction

two long-term impacts of tropical cyclones are…

loss of life

salination of fresh water

three characteristics of a volcano are…

• crater (this is where the magma is released from)

• magma chamber (where it’s stored)

• main pipe / vent

three characteristics of an earthquake are…

• the epicentre (this is directly above where the focus is)

• seismic waves (waves of energy that are generated from a sudden breaking of rocks within Earth)

• focus (point inside the earth where the earthquake started)

*complete* three characteristics of a tropical cyclone are…

• the eye (this is the calmest spot in the storm and where all the wind is gathered around, clear skies and light winds)

• the eye wall (the harshest part of the storm with heavy rain and intense winds)

• rain bands

three causes of a tropical cyclone are…

• strong coriolis force (the force of the earth spinning)

• wind shear (wind spinning in the same direction, or else the cyclone will be torn apart)

• sea temperatures of at least 27 degrees celcius

volcanoes are caused by…

earth’s crust being pulled away at constructive plate boundaries (← →), allowing for magma to rise through.

an earthquake is caused by…

sudden movements at plate boundaries.

volcanoes are measured using…

the volcanic explosivity index (VEI)

which looks at the viscosity of magma, the type of gas released, and the amount of gas released.

tropical cyclones are measured using…

the saffron simpson scale

earthquakes are measured using…

the richter scale

give and summarise three reasons for living in hazardous areas

• lack of education → underestimating risks/dangers leads to reluctance to leave

• financial constraints → many are stuck in a hazard one as they cannot afford to move

• attachment to place for cultural or social reasons → complacency and unwillingness to leave

four benefits of living in a volcanic region are…

• fertile soil for agriculture → profit from selling produce

• free or extremely cheap geothermal energy

• tourism

• expensive/valuable rocks are created → money from selling

four benefits of living near the costal/delta region are…

• water for agricultural, domestic, and industrial purposes

• flat land for building

• cheap to buy land in floodplains (cus it floods often)

• fishing as source of income

two physical factors affecting vulnerability are…

• physical geography (e.g. coastal lowlands that increase susceptibility to landslides and flooding.)

• natural environment (e.g. warmer ocean surface temperatures can lead to increased wind speeds in tropical storms)

two economic factors affecting vulnerability are…

• levels of wealth/development

• building styles/codes

• access to technology (like warning systems)

• insurance cover

two social factors affecting vulnerability are…

• education

• gender (more men in construction jobs, for example)

• population density (more people affected)

• age (it’s easier for younger to escape)

plates move apart at…

constructive plate boundaries.

plates push into each other at…

collision (convergent) zones.

plates slide past each other at…

conservative plate boundaries.

the denser plate (oceanic) goes under the other (continental) at…

destructive plate boundaries.