Tectonics Flashcards
What volcanoes occur at a divergent boundary
Low viscosity
What earthquakes occur at a divergent boundary
Low magnitude
What volcanoes occur at a convergent boundary
high viscosity and high silicia content as large amount of gas released - Philiphenes
What earthquakes occur at a convergent boundary
High magnitude
what earthquakes occur at a collsion boundary
high magnitude
what earthquakes occur at a conservative boundary
high magnitude
4 theories of plate tectonics
Wegners continental drift, sea floor spreading , holmes heat hypothesis,paleo magnitism
4 primary hazards of volcano
ash fall, volcanic gas, pyroclastic flow, lava flow
secondary hazards of volcanos
jokulap , lahars
cause of intra plate volcano
hot spot- rising magma under weakness often cause less viscos eruptions
causes of intraplate earthquakes
ancient faults
4 parts of earth
core, athenosphere , lithosphere , crust
focus
where pressure is released underground
epicentre
point on surface directly above focus
what is a shallow focus
0-70km
what is a deep focus
70-700km
P waves
Fastest wave, least damage
L waves
most damage
S waves
make ground shake
wavelength of tsunami
long at sea, decreases as reaches land
amplitude of tsunami
short at sea, increases as reach land
velocity of tsuanmi
slows as reaches shallow water
Sign a tsuanmi is going to occur
Water is drawn back
Trends of tectonic disasters
remained the same - more people affected
more are being recorded s can look like they are more frequent
trends of hydro meterological disasters
more common - global warming has meant that more of the ocean is above 26.5 degrees
multiple hazard zones are
tectonically active, geologically young
hawaii
Forecasts
percentage chance
Seisometer
records minor earthquakes
tiltmeters
record volcanoes bulging
gas spectrometres
analyse gas emissions
MMS
measures amount of energy released ( 1-10)
Mercalli scale
measures damage affects (1-12)
VEI
meausures volume, duration and column height
low VEI
0-3
High VEI
4-7
6 Features of hazard profile
magnitude, speed of onset, areal extent, duration, frequency , spatial predictability
4 stages of hazard cycle
prevention , prepardness , response , recovery
Urbanisation and vulnreability
higher death toll , more at risk. However better access to hospitals
population density and vulnerability
high population density is hard to evacuate however isolated places are also difficult
HDI
measures inequality
good governance and vulnerability
meets day to day needs , aid reaches those who need it
preparedness and vulnerability
land use zoning, monitoring system, education
risk equation
risk = hazard x vulnerability / capacity to cope
4 stages of PAR model
root causes ,dynamic pressure , unsafe condition , disaster
Christchurch magnitude and date
6.3 - 22nd Feb 2011
primary impacts of christchurch
185 dead, 3000 injured, cathedral collapsed, $28 billion of damge
secondary impacts of christchruch
5 Rugby WC matches cancelled, liquefaction, 2 large aftershocks
Nepal date and magnitude
25th April 2015, 7.8
Primary impacts of Nepal
9000 dead, 19,000 injured
Secondary impacts of Nepal
Himalayan avalanche killed 20, Tourism fell
Why Nepal is so vulnreable
LIC so poor infrastructure and response, mountainous ,
Tokohu Date and magnitude
11 March 2011, 9
primary impacts of Tokohu - Japan HIC
15,000 dead, 9000 injured , nuclear station flooded, $235 billion of damage
secondary impacts of Tokohu
aftershocks, landlsides, liquefaction , tsunami
Boxing day date and magnitude
26th december 2004, 9.1
Countries affected by Boxing day tsuami
Maldives, Malaysia, Indonesia , Thailand , India
primary impacts of boxing day tsuanmi
220,000 dead, 650,000 injured fishing villages destroyed , $9.9billion damage
Secondary impacts of boxing day tsunami
cholorea, lack of food
Date of eyjafjallojokull
March - May 2010
Primary impacts of eyjafjallojokull
large amounts of meltwater reacted with lava to form ash plumes
Ash destroyed crops houses and roads ,
airlines lost $130million a day
Secondary impacts eyjafjallojokull
fresh food wasted , glacier flooded
Good things about eyjafjallojokull
prevented 2.8 million tonnes of carbon being released, Eurostar increased, Plankton boomed ( remove more carbon)
Haiti date and magnitude
12th Jan 2010, 7
Primary impacts Haiti
220,00 dead, port damaged , 300,000 injured
Secondary Impacts Haiti
Cholrea , crime increased , power shortages
Bam magnitude and date
6.6 magnitude 26th december 2003
Bam primary impacts
-26,000 dead many died due to hypethermia as trapped under buidings
- 3 hospitals destroyed
- $1.9billion of damage
- 80-90% of buildings collapsed
what made haiti more vulnreable
only one airport and few main roads so it was difficult to distribute aid
factors affecting volcanic eruption - type
basaltic or effusive
factors affecting volcanic eruption - lava type
type and amount of lava as leads to high levels of pyroclastic flow
human factors affecting impacts of tectonic activity
technology which reduces vulnerability
population density
how are impacts measured
socially - deaths
economically - cost
3 strategies to reduce impact
EWS
land use zoning
infrastructure - (defences and buildings)
2 strategies to reduce loss
aid and insurance
3 strategies to reduce vulnerability
education
monitoring
prepardness
5 reasons that managing impacts of hazards varies between countries
- development
- governance
- physical characteristics of a region
- infrastructure
- EWS
- education ( Japan)
how Japan reduces vulnerability
earthquake day every year where people are educated on how to deal with an eq
constant monitoring linked to peoples phones
