Tectonics Case Studies Flashcards
Where is the volcano Eyjafajallajokull located?
In the South Coast of Iceland
When did Eyjafajallajokull erupt?
It erupted continuously for most of April and May 2010
Where is Mount Etna situated?
Sicily, Italy
Which volcano is one of the most active in the world, being in an almost constant state of eruption?
Mount Etna
Where is Mount Merapi located?
Java, Indonesia
When was Mount Merapi’s last eruption?
26th of October 2010
Where is Mount St Helens?
Washington State, USA
When did Mount St Helens erupt?
18th May, 1980
What are the physical features of Eyjafajallajokull?
- Stratovolcano
- Constructive plate boundary (European and North American)
- Ice cap covers caldera
- Summit elevation of 1651 metres
- Composed of basalt and andesite lava
- Vent is 1.8 to 2.5 miles across
- VEI = 4
What are the physical features of Mount Etna?
- Active stratovolcano
- Erupts basaltic lava
- Strombolian eruptions
- Destructive plate boundary (African and Eurasian)
- Constant state of activity
- Europe’s highest volcano
- Top elevation is 10, 900 feet
- More than one active centre
- Subsidiary cones on lateral fissures
- VEI = 5
What are the physical features of Mount Merapi?
- Destructive subduction plate boundary (Indo- Australian and Eurasian)
- Part of Pacific Ring of Fire
- Part of an island arc
- Active stratovolcano
- Composed of one layer of hardened lava, tephra and volcanic ash
- Steep profile
- Periodic/explosive eruptions
- Large terrifying force
- Eruptions getting worse over time
- VEI = 4
What are the physical features of Mt St Helens?
- Active stratovolcano
- Destructive subduction boundary (Juan de Fuca and North America)
- Andesitic lava
- Lateral blast
- Frequent earth movements in area
- 2500 years old
- VEI = 5
What are the 3 ecological zones of Mt Etna?
- Lowest zone: fertile, rich in vineyards/olive groves/citrus plants, densely populated
- Above zone: steeper, covered with forests
- Highest zone: Covered with ash/sand/lava, alpine plants and algae
What were the primary impacts of Eyafjallajokull?
- Wind carried the ash southeast towards Europe
- Ash blocked ou the sun
- Infrastructure and homes damaged
- Crops destroyed
- Roads washed away
What were the primary impacts of the eruption of Mt Etna?
- Eruption destroyed the tourist ski resort at Piano Provenzana
- Damage to homes
- Lava caused an explosion at a water tank injuring 30 people
What were the primary impacts of the eruption of Mt Merapi?
- Volcanic bombs and hot gases spread
- Pyroclastic flows spread
- Villages under 30 cm of ash
- Sulphur dioxide blown across Indonesia and as far as South Australia
- 353 people were killed
Primary impacts of Mt St Helens eruption?
- Landslide caused by earthquake
- 57 died
- Pyroclastic flow destroyed everything in path
- 27km wipeout zone
- Planes grounded
- Ash killed wildlife in Toutle River and Spirit Lake
- 12% of crops destroyed
Secondary impacts of Eyjafjallajokull eruption?
Positive impacts?
- Ash was so thick goggles and face masks needed
- Local businesses suffered due to slump in agriculture
- Visibility was lowered to a few metres
- Flights grounded - hundreds of thousands of tourists stranded overseas
- Trading with Kenya stopped
Positive:
- Fertile soil from ash
- Geothermal energy
- Rocks used for building
Secondary impacts of Mt Etna eruption?
Positive impacts?
- Airport forced to close
- Winter tourist industry hit
- Schools and businesses forced to close
- In 2008, earthquakes opened fissures which caused lava to flow down the Valle de Bove
- Highly voluminous gas, dust and ash emissions
Positive:
- Fertile soils
Secondary impacts of Mt Merapi?
Positive impacts?
- Damage to crops meant inflation
- Emergency shelters
- 278, 000 had to flee homes
- Extension of danger area
- Planes grounded in Western Australia
- Lahars
Positive:
- Fertile soils
- Conservation area around volcano
Secondary impacts of Mt St Helens?
Positive impacts?
- High sedimentation in Toutle River
- Flooding
- Lahars - destroyed 200 homes
- Economic loss: $800 million
- Clean up operation: $250 million
- Only 14 species (small mammals survived)
Positive:
- Fertility increased
- Tourism increased to 2 million a year
- Geothermal energy
Immediate and long term responses to Eyjafjallajokull?
Immediate:
- Evacuation
- European airspace shut down
Long term:
- Aid agencies (Oxfam/Christian Aid) involved in food/shelter distribution
- Reconstruction of roads/infrastructure
- Research into finding better ways to manage ash concentration
General info about Kobe earthquake?
17th Jan 1995
Caused by subduction of Phillipine plate under Eurasian plate
7.2 magnitude
Japan demographic data?
GDP: $5.334 trillion
Stage in DTM: 4
HDI: 0.941
Life Expectancy: 79.54
Primary impacts of Kobe earthquake?
- Over 6000 died
- Hanshin Expressway collapsed
- Pancaking of houses
- Liquefaction
- Gas mains broke = fires
- Dock closed
Secondary impacts of Kobe earthquake?
- 700 aftershocks
- Temporary accommodation
- Port out of action for 3 months
- Dock not back into full use for 2 years
- $100 million in damage
Immediate responses to Kobe earthquake?
- Osaka Earthquake Observatory monitored
- Thermal imaging, sniffer dogs used in rescue
- Effective medical services
- 3000 army sent to rescue
Long term responses to Kobe earthquake?
- Retro engineering- govt. funds rebuilding of roads/buildings
- Home insurance - people can rebuild homes
- Seismologists monitor area
- Emergency services trained in earthquake response
- National Hazard Prep day
- $6.8 million to rebuild port
General info about Haiti earthquake?
12th January 2010
Magnitude 7
Caused by conservative boundary of Caribbean and North American plates - reactivated fault line under Port Au Prince
Haiti demographic data?
GDP: $6.623 billion
Stage in DTM: 2
HDI: 0.483
Life Expectancy: 61.87
Primary impacts of Haiti earthquake?
- 250,000 killed
- 1 million homeless
- 1 in 3 buildings collapsed
- People buried in rubble
- 4000 criminals escaped
- Violence and social unrest
Secondary impacts of Haiti earthquake?
- Disease - 7000 died from cholera
- Cholera due to water contamination from sewage in river running past city
- Only 132 saved
- Temporary shelters
- 80,000 evicted from camps
Immediate responses to Haiti earthquake?
- Slow response - slow aid from world
- Only 1 ambulance
- Haitians had to dig up rubble themselves
- Port closed for 5 days and airport for 2 days
Long term responses to Haiti earthquake?
- Still not rebuilt within 2 years
- Relocation to up to an hour away
- No electricity/water in shelters
- Weak response to disease
- 1 million still in camps in 2011
- NGOs spent $2 billion
General info about Sendai tsunami?
11th March 2011
Caused by mega thrust quake 9.0 on subduction boundary of Pacific under Eurasian plate
P waves at 6km/s and S waves at 3km/s
Wave was 10m tall
Primary impacts of Sendai tsunami?
- 10 billion tonnes of water
- Breached 10m tsunami wall
- Fukushima flooded
- 138,000 buildings destroyed
- Shortages in food/water/shelter/medicine
- 4.4 million houses without electricity and 1.5 million without water
Secondary impacts of Sendai tsunami?
- Fires
- Flooding
- Hundreds of aftershocks
- Total of 20,000 dead
- Mud volcanoes
- Cracks in ground
- Radiation from Fukushima after explosion
- $360 billion in damage
Immediate responses to Sendai tsunami?
- Warnings across country gave some areas 20 mins to escape
- Tokyo had a minute warning
- Reactors at Fukushima shut down
- UK sent search teams
- Planes dumped water on Fukushima
Long term responses to Sendai tsunami?
- Seismometers
- Temporary shelters
- Red Cross donated $1 million
- NGOs helped
General info about Banda Aceh tsunami?
Boxing Day 2004
Affected Sumatra, the Maldives, Thailand, Sri Lanka
Magnitude 9.1 earthquake caused by subduction of Australian plate under the Indonesian plate
500mph wave
Primary impacts of Banda Aceh tsunami?
- 250,000 dead
- Debris moved at 40mph
- Buildings collapsed
- None saved in Sumatra- 75% of total deaths here
- Land destroyed in Thailand
- 45,000 killed in Sumatra
- Wetlands damaged
Secondary impacts of Banda Aceh tsunami?
- Shifted earth
- Aftershocks for months
- 9000 tourists lost
- Impact on fishing communities
- Tourism badly affected
- Sri Lanka and Maldives lost 80% of GDP
- 1 million homeless in Sri Lanka
Immediate responses to Banda Aceh tsunami?
- Pacific warning system in Pacific Ocean
- Pacific Tsunami Warning centre monitored ocean but couldn’t send a warning to the Indian ocean
- No tsunami education
Secondary responses to Banda Aceh tsunami?
- 26 new buoys in Pacific Ocean to help monitor
- Permanent housing
- Charity ‘World Renew’ restored 37,000 livelihoods
- Early warning system now in Indian Ocean
- UK govt sent £32 million in funds
