1C - Hazards - Case Studies Flashcards
Mount Ontake, Japan eruption:
When?
27th September 2014
Mount Ontake, Japan eruption:
Was there warning?
No
Until 1979 it was believed to be dormant.
After a few minor eruptions, it was monitored.
Despite it being monitored, the minor earthquakes which usually signal an impending eruption were not detected.
Mount Ontake, Japan eruption:
Vulcanicity
Eruption was phreatic - water seeped into the volcano and became super heated by the magma
In a phreatic eruption, magma doesn’t actually erupt from the volcano, instead hot ash, rocks and steam do.
The eruption wasn’t particularly explosive - had a Volcano Explosivity Index (VEI) of 3 - but the proximity of the hot ash to the hikers made it dangerous
Mount Ontake, Japan eruption:
Japan’s volcanic activity
Japan is one of the most volcanically active places in the world with 10% of the world’s active volcanoes being on Japanese islands.
This is due to it being the meeting point of 4 major plates - the Pacific, Philippine, Eurasian, and North American.
Mount Ontake, Japan eruption:
Effects
Produced huge pyroclastic flow which trapped 250 people on its slopes
Over 50 deaths (most hikers)
At least 40 others injured - some cuts, bruises, and broken bones, some lung damage
The huge ash cloud billowed down the mountain for more than 3km, engulfing hikers in its path.
Mount Ontake, Japan eruption:
Response
Around 1000 Japanese rescue workers set out to search the peak after the eruption.
Recovery efforts were hampered in the early stages of the rescue due to the volcanic conditions.
The rescue effort was halted as the volcano continued to eject toxic gases, rocks, and ash.
Residents were warned of falling stones.
On 29th September, rescuers had to abandon their mission due to the levels of poisonous hydrogen sulphide becoming too dangerous.
Typhoon Phanfone also hit the region on 5th-6th October which meant that efforts were interrupted.
A month after the eruption, death toll stood at 57 with 6 others still missing.
The search for the missing was continued on 29th July 2015 - 10 months after the eruption due to continued volcanic activity.
Mount Ontake, Japan eruption:
Why was there no warning?
This was an eruption of hot ash and super-heated steam meaning that it was very hard to predict.
There were also no visible signs that an eruption was about to occur.
Hurricane Harvey case study:
When
17th August 2017 - 2nd September 2017
Hurricane Harvey case study:
Details of the hurricane
4
First made landfall over San Jose Island and then near Rockport, in south-central Texas as a Category 4 hurricane, threatening millions of residents with 130-mph winds, heavy rains, and a massive storm surge that swamped coastal areas.
It stalled around southern Texas for days as a weakening hurricane, producing catastrophic flash and river flooding.
The storm dumped more than 27 trillion gallons of rain over Texas - wettest Atlantic hurricane ever measured
1/3 of Houston was completely flooded and the weight of the water also sank the city temporarily by two centimetres
Hurricane Harvey case study:
Primary impacts
4
An estimated 300,000 structures and 500,000 vehicles were damaged or destroyed in Texas alone.
Nearly every structure in Port Aransas was damaged, some severely, while significant damage from storm surge also occurred
In Rockport, entire blocks were destroyed by the hurricane’s violent eyewall winds
About 20 percent of Rockport’s population was displaced
Hurricane Harvey case study:
Socio-economic (secondary) Impacts
4
Damage cost:
Causing about $125 billion in damage
Populated area:
Struck densely populated areas - impedes economic activity to a larger degree as more are displaced
Gulf Coast:
Affected the Gulf Coast - U.S. petroleum refining capacity - played a role in increasing energy prices by 2.8% in August 2017
Mental Health:
Rise in levels of depression and anxiety
Hurricane Harvey case study:
Who was most severely affected and why?
7
No. affected = 13 million
Unemployment:
The no. filing for unemployment benefits jumped to a more than two-year high
Schools:
Several dozen schools remained closed more than a month into the school year
Harris County/insurance:
Since many residents lived outside the flood plain, most people affected were uninsured - 15% of homes in Harris County had flood insurance.
Low-income residents:
Wealthier homeowners are more likely to have flood insurance and be able to pay for clean-up sooner.
Low-income residents face substandard infrastructure and higher exposure to pollution and toxic waste
More affluent people have a greater capacity to evacuate.
Renters + public housing tenants:
Renters and public housing tenants also struggled with finding places to go.
Elderly:
The elderly population was extremely vulnerable as they have much less mobility, complicated medical conditions, and an unstable income.
Hurricane Harvey case study:
Immediate responses
6
The Federal Emergency Management Agency (FEMA) had pre-positioned supplies and personnel in the state
Within 30 days, more than $1.5 billion in federal funds was paid to Texans impacted by the disaster
The Coast Guard deployed personnel, aircrafts, boats and cutters, rescuing 11,022 people
FEMA assigned 28 Urban Search and Rescue (USAR) teams from across the nation to deploy to Texas to assist state and local agencies with the lifesaving mission.
FEMA supplied 3 million meals, 3 million litres of water to the state to distribute
The American Red Cross provided $45 million
Hurricane Harvey case study:
Longer-term recovery
4
To date, the Center for Disaster Philanthropy awarded grants totalling more than $6 million to support long-term recovery
NGOs helped restore health services for vulnerable survivors; expand health services, especially for stress and trauma; and prepare health facilities for future disasters.
The CDP Hurricane Harvey Recovery Fund raised more than $14 million for medium- to long-term recovery in Texas
U.S. Department of Housing and Urban Development announced Texas would receive just over $5 billion for long-term rebuilding efforts.
Hurricane Harvey case study:
Evaluation of responses - Good
4
Harvey was predicted and allowed for preparation and evacuation, therefore keeping the death toll relatively low
The government was also incredibly fast at paying Texans that were impacted (30 days, more than $1.5 billion in federal funds was paid to Texans impacted)
Rescue missions began very quickly
Overall, the huge amount of money raised massively helped struggling communities and the federal funds were also distributed very quickly
Hurricane Harvey case study:
Evaluation of responses - Bad
4
Of the nearly $1 billion raised for regional recovery, nearly 30% had yet to be distributed by Aug 2018
U.S. Department of Housing and Urban Development announced Texas would receive just over $5 billion for long-term rebuilding efforts, but this hadn’t arrived by November
Many people in Texas didn’t have flood insurance, so they received little to no compensation.
Trump requested $44 bn in aid for recovery for all the hurricanes that had hit (it was estimated that $121bn was needed for full recovery). The Governor of Texas Greg Abbott said this was “inadequate” and the White House responded saying, “Up until this point, Texas has not put any state dollars into this process” - this was disputed by Abbott’s office who claimed they had spent or incurred over $1bn
Cyclone Idai case study:
When + Where
March 2019
Made landfall in Mozambique
Brought strong winds and severe flooding in Madagascar, Mozambique, Malawi and Zimbabwe
Cyclone Idai case study:
Details of cyclone
3
Category 2 hurricane on the Saffir-Simpson scale
maximum sustained winds of 121mph
Rainfall in the city exceeded 200mm, while the heaviest rainfall was more than 600mm near Chimoio
Cyclone Idai case study:
Primary impacts
3
2.5m storm surge that ‘totally destroyed’ around 90% of Beira City.
> 700,000 ha of agricultural land was damaged, compounding food shortages in a country that is already at high risk of famine.
Estimated 1,300 people died from primary impacts
Cyclone Idai case study:
Secondary socio-economic impacts
7
Due to infrastructure damage, sanitation severely worsened - Cholera cases topped 4000 in Mozambique roughly 3 weeks after the cyclone first hit
40 health centres in Mozambique were damaged or destroyed
Mozambique also recorded >3000 cases of diarrhoea within 3 weeks of the cyclone
Over 1 million people were left without electricity - communication and rescue efforts impeded
Total damage to buildings and infrastructure were estimated to be US$2bn
Beira City, which was largely destroyed, is the second most important port for international trade in Mozambique, meaning the country’s ability to earn foreign currency was diminished.
2 HEP plants were destroyed in Malawi - Malawi lost 84% of its HEP
Cyclone Idai case study:
Who was most severely affected?
Poorer people and women were hit harder as they are more likely to be involved in unpaid work
Cyclone Idai case study:
Immediate responses
4
Evacuation:
Some people were evacuated by boat before the cyclone struck, however many people in rural areas didn’t respond to the warnings or were not aware of them.
Foreign military:
The South African air force and the Indian army drove the initial rescue effort
Aid:
The government received support from international donors for a disaster fund of $18.3m, the main source of funding was specifically for search and rescue within the first 72 hours
Reception centres:
More than 130,000 newly homeless people were taken into reception centres
