T2 - Case studies Flashcards
CS-2.1
Where is Mt Sinabung and why do people live there?
Indonesia, Sumatra
-too poor to move
-social/family ties
-locals don’t trust government evacuation plans
-used to seeing eruptions
-growing coffee (easy with high altitude + volcanic soil, high crop yield) is only source of income
(collection of islands is known as Indonesia)
CS-2.1
Give the date and causes of the Eyjafjallajökull eruption:
April 2010
-divergent (N. American + Eurasian)
-VEI 4
-mantle plume beneath
-magma build up since 1994
CS-2.1
Describe + draw the process of the eruption at Eyjafjallajökull:
-effusive flank eruption at Fimmvörðuháls
-explosive phreatic eruption at summit beneath 200m thick glacier
phreatic is the same as phreatomagmatic, but phreatic is a better word to use
CS-2.1
What were the local effects of Eyjafjallajökull?
-jökulhlaup (glacial) floods (Markafljot river rose by 3m)
-no deaths
-drinking water contaminated with fluoride
CS-2.1
Name some international effects of Eyjafjallajökull:
-high pressure system kept tephra overhead
-100,000 flights cancelled over 8 days, people stranded
-£1.6 billion total cost to airlines
-increased tourism to Iceland, helped with recovery for Iceland and airlines
CS-2.1
What was the response to the eruption at Eyjafjallajökull?
-700 evacuated
-animals moved indoors (fluoride is toxic to them)
-lava diversion channels dug to save major roads
CS-2.1
Give the date and causes of the Tohoku EQ + draw diagram:
March 2011
-convergent (Eurasian + Pacific subducts)
-mag 9.0
-epicentre 100km east, focus 30km deep
-Eurasian had elastic rebound (causing tsunami)
CS-2.1
What were the primary effects and responses to the Tohoku EQ?
-15,000 deaths, 300,000 buildings destroyed
-1m ground subsidence
-initial response was to clear the roads for emergency access
-2019, 12m high tsunami walls built ($12 billion)
Always talk about the effect of what the many deaths had or the buildings being destroyed, eg a reduction in workforce, businesses closing, etc
CS-2.1
Describe the secondary effects caused by the Tohoku EQ:
-10m tsunami, but got over the 10m tsunami walls due to 1m ground subsidence, resulting in coastal flooding (towns like Miyako flooded)
-$300 billion USD cost to Japan
-Fukushima Daiichi explosion (nuclear plant), 30km exclusion zone
CS-2.1
How were buildings in Japan designed to withstand EQs?
-cross braces to increase strength
-isolated base to reduce energy transfer to building
-teflon pads connect to building and absorb shocks
CS-2.2
Threats of living on the Mississippi Delta:
-rivers are 2m higher so increased flood risks, 1800 miles² lost since 1930’s
-$150 billion spent on property loss + recovery in past 10 years
-harder to maintain levees, higher maintenance costs
CS-2.2
Opportunities of living on the Mississippi Delta:
-wetlands slow/spread storm surge, lowers flood risk
-80% of Louisiana’s economy linked to coastal goods/services
-200 million tonnes of cargo pass through each year (can be taxed)
-provide services worth $12 billion yearly
CS-2.2
What are 4 causes of the River Ahr flash floods 2021?
-record rainfall in Eifel region (100mm in a day) due to low pressure system which didn’t move
-V shaped valleys funneled water to town
-large meanders in valleys, kept water near for longer (higher drainage density)
-river is usually 1m, flooded to 8m
CS-2.2
Why protect the River Derwent catchment area? What is the name of the protection scheme?
Pickering - 7000 people, 500 properties, popular historic tourist town
Malton/Norton - 13,000 people, 1000 properties at risk
-and many health facilities and critical infrastructure across all of the area
Slow the Flow
CS-2.2
What were the methods used to minimise the effects of flooding in the River Derwent catchment area?
Newtondale:
-afforestation (S)
-field storage of water with culvert (S/H)
-leaky dams (S)
Pickering:
-channel straightening (H)
-part-concrete river channels (H)
M+N:
-embankments (H)
-flood walls (H)
-designated floodplains (S)
CS-2.2
Describe the flood that happened at Pickering and Malton/Norton:
-1999, flooded by River Derwent
-caused by 5 days of heavy rainfall, melting previously fallen snow adding to the discharge
-railway line cut off
-140 homes + 40 businesses flooded
-£10 million worth of damage
CS-2.3
What protection methods are used on the Holderness coastline?
-none
-sea walls, groynes, rip-rap
-none
-groynes
-rip-rap
-groynes
CS-2.3
Give the policies and rationale for the upper 3 towns on the Holderness Coastline:
-Flamborough Head (NAI), rock is chalk (below is glacial till)
-Bridlington (HtL), 35,000 pop., protect homes and businesses
-Skipsea (NAI), low land value (farmland + caravan park)
CS-2.3
Give the policies and rationale for the lower 3 towns on the Holderness Coastline:
-Mappleton (HtL), low pop but B1242 is 40m from cliff
-Easington (HtL), gas terminal on cliff edge, important to UK gas supply
-Spurn Head (MR), nature reserve + lifeguard station
CS-2.3
Benefits of the GBR:
-biodiversity (1 million species)
-medical treatments (cancer/HIV treatment in some organisms)
-fisheries (where fish is sold, jobs + income)
-tourism (jobs + income)
-coastal protection
(biomedical fisheries tour the coast)
CS-2.3
What are some threats to the GBR?
-cyclones (rip up coral)
-pollution (litter, toxic waste, algal blooms which attract phytoplankton which attract COTS)
-COTS, eats coral polyps
-tourism
CS-2.3
Describe the process of coral bleaching:
-coral stressed due to change in normal environment (due to climate change, increased temperatures, salinity/acidity from rain)
-zooxanthellae leaves and coral turns white, vulnerable to disease/starvation
-coral dies and turns black
CS-2.3
Where is the Great Barrier Reef?
-Coral Sea
-NE coast of Queensland
CS-2.4
Describe the date, causes and location of Hurricane Florence
September, 2018
-4 on Saffir Simpson scale (goes from 1-5)
-900mm rainfall
-3m storm surge wave
-140mph winds
