Tectonics Case studies Flashcards
(40 cards)
When was the Montserrat eruption?
1995-1997
What type of plate boundary was the Montserrat eruption?
A destructive plate boundary where the North American plate is subducted under the Caribbean plate
What were some factors effecting the Montserrat eruption?
- It is a British overseas territory so they were able to receive aid
- The population is low income and relies on subsistence farming.
What were some hazards present in the Montserrat eruption?
- 2/3 of the island was covered in ash
- flooding was caused by ash blocking river valleys
- lahars
- pyroclastic flows causing forest fires
What impacts occurred after the Montserrat eruption?
- 23 deaths although these were due to not following evacuation procedures
- 7,000 people displaced
- airport closed causing a rapid decline in tourism and a 50% increase in unemployment.
How were the impacts of the Montserrat eruption managed?
- The eruption had been predicted by the Montserrat volcanic observatory
- Hazard maps were created which declared 60% of the island unsafe
- The UK government sent £17 million in aid.
- Tourism increased in the long term
When was the eruption of Mount Nyiragongo?
2002
What type of plate boundary was the Mount Nyiragongo eruption on?
A constructive plate boundary in the East African rift valley, 50km from the city of Goma.
What hazard were present at the Mount Nyiragongo eruption?
- 3 craters as well as a 3km spilt
- lava flowing at 40mph
What were the impacts of the Mount Nyiragongo eruption?
- 30% of infrastructure in Goma was destroyed including hospitals
- Airport was cut in half by lava flows
- 147 people were killed as government chose to ignore warnings from scientists.
- An unplanned evacuation of half a million people took place into the Rwandan jungle.
What plate boundary did the Iceland eruption happen at?
A constructive plate boundary on the mid Atlantic ridge where the North American plate and Eurasian plates pull apart.
What hazards were present at the Iceland eruption?
- An ash plume 10km into the air
- A 500m long fissure spewing 1000c lava 150m in to the air
- Ice mixing with lava causing explosive eruption
What impacts were there for Iceland?
- Fresh fish exports impacted causing a loss of income
- Water supplies contaminated by ash
- Well managed so no deaths
What were the global impacts of the Iceland eruption?
- Europe lost $2.6 billion due to a drop in air passengers
- An 8-day travel ban cancelled around 100,000 flights
- African countries may have lost $65 million due to perishable exports
What were the responses to the Iceland eruption?
- Iceland was well prepared due to high tech detecting equipment and a text message system to warn residents
- 700 people were evacuated away from areas affected by the ash
When was the Kilauea eruption?
2018
What was the plate boundary of the Kilauea eruption?
At a volcanic hotspot, where the Pacific plate moves over a mantle plume creating a chain of volcanic islands.
What type of lava/eruption was at Kilauea?
Basaltic magma which is very hot, has low levels of gas and silica and erupts in effusive lava fountains.
What were the impacts of the Kilauea eruption?
2,000 people evacuated. A 6.9 magnitude earthquake also occurred. 875 acres of land were added to the island due to lava flowing into the sea and solidifying.
How is the lower quartile calculated?
n + 1 / 4
How is the upper quartile calculated?
(n+1/4) X 3
When was the Haiti earthquake?
2010
What plate boundary was the Haiti earthquake?
A conservative plate boundary between the North American and Caribbean plate located at the Enriquillo fault.
What factors effected the Haiti earthquake?
Haiti is the poorest country in the western hemisphere. The judicial system is corrupt, and there is a lot of gang violence.
