Hazardous Earth Tectonics Flashcards
What is the Inner Core made out of?
Solid iron and nickel 5,000°C
What is the Outer Core made out of?
Liquid iron and nickel 4,000°C-5,000°C
What is the Lower Mantle made out of?
Solid peridotite 1,600°C-4,000°C
What is the asthenosphere made out of?
partially molten peridotite 900°C-1,600°C
What is the lithosphere - continental crust made out of?
solid granite 0°C-900°C (less dense)
What is the lithosphere - oceanic crust made out of?
solid basalt 0°C-900°C (more dense)
How does the convection affect the Plate Motion?
heat rises from the core and creates convection currents in the mantle and outer core - this movement causes the tectonic plates to move as they float on top of the mantle
What is the transform plate boundary?
2 tectonic plates slide past each other creating a shallow earthquake - San Andreas Fault in Haiti
What is the convergent plate boundary?
plates push together due to the convection currents, oceanic plate is subducted beneath the less dense continental plate - Pacific plate subducts beneath the Eurasian plate
What is the divergent plate boundary?
plates pull apart due to convection currents allowing material to rise, often takes the form of basalt - Iceland
What is a hotspot?
mantle plumes away from plate boundaries are columns of heat which expose weaknesses in the crust creating volcanoes - Hawaii
What is a composite volcano?
steap sides formed by layers of ash and lava, eruptions may be pyroclastic flow rather than lava, when they erupt they are explosive and pose a threat to nearby life and property
What is pyroclastic flow?
superheated mixture of hot steam, ash, rock and dust
What is a shield volcano?
low with gently sloping sides formed from layers of lava, eruptions are typically non-explosive, produce fast flowing lava that can flow for many miles, eruptions tend to be frequent but relatively gentle and less destructive
How big was the Haiti 2020 earthquake?
magnitude: 7.0
shallow focus: 13km on conservative plate boundary
What were the primary impacts of the Haiti 2020 earthquake?
220,000 dead with 300,000 injured
1 million homeless
main port, major roads and airport destroyed beyond repair
What were the secondary impacts of the Haiti 2020 earthquake?
water supply destroyed leading to an outbreak of cholera killion 8,000 people
clothing industry factories destroyed leading to 60% decline in exports and 1 in 5 jobs lost
destruction of the main port reduced ability for trad and aid
What was the management of the Haiti 2020 earthquake?
limited event planning
large aid response with many NGOs supporting on the ground
1.6 million people put up in temporary camps
over $1bn raised for reconstruction for buildings that will withstand earthquakes
How big was the Japan 2011 earthquake?
magnitude: 9.0
on a convergent plate boundary
caused tsunami epicentre: 70km from the coast of Sendai
What were the primary impacts of the Japan 2011 earthquake?
£235bn of damage caused
Tohoku motorway network collapsed
Sendai airport closed for the short term
What were the secondary impacts of the Japan 2011 earthquake?
15,900 dead and 2,600 missing caused by tsunami
nuclear reactors at Fukushima went into meltdown local people evacuated have still not returned
What was the management of the Japan 2011 earthquake?
every year Japan has earthquake drills with emergency service practising rescuing people
people have to keep emergency kits at home
most buildings are developed to be earthquake proof
along the coast there are 10m high tsunami walls
