TECTONICS PAPER 1 Flashcards
what are hazards?
hazards are potential threats to human life
reasons for experiencing hazards:
- on a plate boundary
- near a hot spot
-intra plate ( fault within tectonic)
what are the layers of the earth?
lithosphere (oceanic and continental plate)
asthenosphere (upper mantle)
lower mantle
outer core
inner core
density increases as you go down
what is Pangea
when all the tectonic plates used to fit together to form one big plate
why do tectonics plates move?
radio active reactions in the core release heat which create convection currents
what are landforms on destructive/ collision plate boundaries?
OCEAN TRENCH
continental and oceanic plate collide
forms a line of where the ocean subjects under continental plate
ISLAND ARCS
- chain of volcanoes formed from benioffzone of 2 plates colliding like a hotspot
FOLD MOUNTAINS
-continental and continental plate collide
- as plates have the same densities they cannot subduct so the material folds over ie alps, Himalayas
what land forms are formed on divergent/ constructive plate boundaries
SEA FLOOR SPREADING
2 oceanic plates moving apart
magma rises and cools increasing surface area of sea floor
RIDGES :
2 plates moving apart
due to convection currents forming gentle slopes which are pushed down due to gravity
RIFT VALLEY
2 continental plates moving apart
breaks up a mountain to form a dip of exposed interior
what is subduction
when 2 plates collide the more dense is pushed under the less dense plate and is pulled down by slab pull ( the force of gravity)
are there any plate boundaries formed at a conservative plate boundary?
no
eathquakes happen as there is a built up pressure
what are earthquakes ?
- seismic waves ( shock waves) are produced due to a fault happening which releases this energy
-happens on conservative plate boundaries
happens on collision as the friction of plates colliding into each other causing faults which release energy of seismic waves
EXAMPLES
nepal 2015 : next to china
-people died
-people homeless
-infrastructure collapsed
-people unemployed
-roads destroyed
what are tsunamis?
- big waves as result earthquakes of volcanic eruptions under the sea
at earthquakes the energy released by seismic waves pushes the water up forming the big energy wave
pressure of volcano erupting can cause a tsunami
what are volcanoes?
form on collision and divergent boundaries
composite volcano:
more destructive
andesitic lava
steep slopes
shield volcanoes:
less destructive
gentles slopes
basaltic lava
super volcanoes- having effects globally
lava:
rhyolite lava- coolest lava
basaltic lava- hottest lava
andesitic lava- blocky lava
impacts of volcanoes:
- lava flows
- pyroclastic flow ( big cloud)
- laha ( mud flow)
- jokulhlaups ( glacial flow)
case study for volcanoes
EYFAJALLAJOKULLUP:
Iceland
- stopped planes in Europe
- stopped tourists ( main source of income)
- water contaminated
- international help
- evacuation
- roads and infrastructure damaged
what is DEGGS model ?
Vulnerable population- disaster- natural hazard
types of vulnerability and risk
risk equation
vulnerability- how susceptible a population is to a natural hazard
types of vulnerability:
-economic
- environmental
- knowledge
- physical ( living in a prone area)
- risk is the likelihood of being affected by a natural hazard
risk equation = vulnerability x natural hazard / capacity to cope
this risk equation is important as some counties have bigger natural hazards but there is less damage as they are more developed compared to an undeveloped country with a smaller natural hazard
what is the pressure and release model?
proposes which should be tackled to reduce the risk.
vulnerabilities:
- root cause: limited access power, resources
- dynamic cause: lack of preparedness
- unsafe conditions : local economy, physical environment
what is used to measure earthquakes?
mercalli scale
Richter scale
moment magnitude scale
what is used to measure volcanoes?
volcanic explosivity index
what is a hazard profile?
the magnitude, speed, duration, frequency of a hazard
what is governance?
governance is how well the government looks after their country
EXAMPLES:
Japan:
- resistance infrastructure to earthquakes and tsunamis
- sea walls to reduce impact of tsunami
- practices of what to do
-
Haiti :
- poor governance
- corrupt governance where they keep money to themselves
- damage of a natural hazard is huge
management and mitigation of tectonic hazards
deaths have overall reduces in recent years but the economy losses have increased
preparation:
- divert lava flows
- evacuation centres
prediction
volcanoes are detected for changing shape, any small eruptions
earthquakes are harder to predict
satellites
what happened in the Philippines
VOLCANOE
mount pinatubo
pyroclastic flow
killed people
infrastructure destroyed
road destroyed
unemployment
homelessness
what is used for prediction of hazards
parks model
how well a country recovers from the beginning of the hazard, once hazard has occurred, during hazard, after hazard, post hazard and rebuilding
Hazard management cycle
preparedness
prediction
mitigation
response
recovery
what is mitigation and adaptation?
mitigation:
- land use zoning
- resistant infrastructure
- diversion of lava flows
- GIS mapping
adaptation:
- education
-crisis mapping- volunteers go to damaged areas and find routes to escape
- technology
who are the key players
PAKISTAN EARTHQUAKE
international governments and aid NGOS, insurers
insurers, pay a certain amount so thy can help cover the cost of different situations
primary aid
- evacuation
- food, blankets
secondary
- building temporary earthquake
tertiary help
building infrastructure such as schools
