HAZARDS: Volcanic hazards impacts and responses Flashcards Preview

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Give an example of a volcanic hazard in a LIC:

The eruption of Mt Nyiragongo, Congo in January 2002.


Where is Mt Nyiragongo?

Virunga Mountains in the Democratic Republic of the Congo. 

It is located along the African Rift Valley.


What is the African Rift Valley?

A landform found in the East African Rift system, that has formed because of the diverging Nubian and Somalian plates.


Describe the history of Mt Nyiragona:

Since 19th century, it has erupted over 30 times and is responsible for over 40% of Africa's recorded volcanic activity, alongside its neighbouring volcano Mt Nyamuragira.


What makes the Goma area vulnerable to eruptions from Mt Nyiragona?

  • Fertile agricultural region, so people encouraged to move there.
  • Not particular threat to humans, as lava is slow flowing - but flows can overwhelm agricultural land and built environment. 
    • Economic + environmental vulnerability.
  • HOWEVER, recently CO2 emissions, seeping from ground, has made humans very vulnerable.


Describe the 2002 eruption of Mt Nyiragongo:

  • Largely unexpected - although some seismic activity in area.
  • Large eruption - 13 km fissure on southern flank of volcano.
  • Flowed towards Goma and Lake Kivu.
  • Not violent - only measured 1 on VEI scale.

10 to list.

List the major effects of the eruption of Mt Nyiragongo:

  • Lava flows destroyed 1/3 Goma.
  • Commercial centre of town destroyed - inc. water and power facilities, three health centres and one hospital.
  • Lava covered runway at Goma airport.
  • Death toll reached 147.
  • Over 350,000 people fled to Rwanda - caused issue with providing food and shelter.
  • Sulphurous lava entered Lake Kivu - poisoned major source of drinking water.
  • Feared rise in temperature or Lake Kivu - carbon dioxide and methane releasing form lake bed.
  • Several earthquakes - strong enough to cause structural damage.
  • Thousands required medical attention.
  • Looting from abandoned homes and commercial properties.


How did people die in the eruption of Mt Nyiragongo?

Mainly through inhaling poisonous gases, drinking contaminated water and building collapses.


Many were killed when petrol store they were attempting to loot exploded - it is believed looters were hoping to sell petrol in order to buy food.


Why did so many people require medical attention after the eruption of Mt Nyiragongo?

Firstly, from effects of smoke and fumes from lava - eye irritation and respiratory problems. 

Secondly, from complaints of dysentery linked to drinking contaminated water.


What kept the death toll relatively low after the eruption of Mt Nyiragongo?

The prompt issue of a red warning, which enabled a full evacuation to take place.


Describe the responses to the eruption of Mt Nyiragongo:

  • Red warning issued - full evacuation.


  • UN provided humanitarian aid.
    • Food.
    • Temporary shelter.


What aid did the UN give after the eruption of Mt Nyiragongo?

  • Emergency rations:
    • High energy biscuits.
    • Then, more substantial food like maize, beans and cooking oil.
  • Temporary housing for displaced people.
  • Clean water, sanitation and health care.

Overall they estimated the cost of this aid to be around $15 million.


What have been some longer term impacts of the eruption of Mt Nyiragongo?

  • Damaged infastructure - destroyed many businesses, resulting in increased unemployment in the area.
  • Several children and animals died from inhaling poisonous CO2 gas, which seeped from ground in relatively large amounts.
    • Local people named this phenomenon 'Mazuku'.


Give an example of a volcanic eruption that occured in a HIC:

The eruption of Eyjafjallajokull in Iceland, in April 2010.


When was the eruption of Eyjafjallajokull?


April 2010.


What makes Iceland prone to volcanic hazards?

It lies on the mid-Atlantic ridge and so has a number of active volcanoes.

Eurasion plate and North American plate are moving apart.


What are some of Iceland's major volcanoes?

  • Askja
  • Hekla
  • Katla
  • Grimsvotn
  • Reykjavik
  • Eyjafjallajokull


What are many of Iceland's volcanoes convered by?


What does this mean?

By ice caps feeding glaciers.

This means that when they erupt a lot of ice melts and this results in flooding and huge ash clouds also develop.


Was the 2010 eruption in Iceland predicted?

Seismic activity was detected in the area, which gave geophysicists evidence that magma was pouring from underneath the crust into the volcano's magma chamber.


Describe the eruption of Eyjafjallojokull:

  • Seismic activity detected.
  • Minor eruptions followed.
  • Volcano went quiet for a short period.
  • On April 14th, an explosive eruption occurred in the top crater.


How did the eruption of Eyjafjallajokull measure on the VEI scale?



What were the major effects of the eruption in Iceland?

  • Huge amounts of ice were melted causing floods to rush down the nearby rivers - led to the evacuation of nearly 1,000 people.


  • Large quantities of ash went into the higher levels of the atmosphere - knock on effects for travel.


How did the eruption in Goma measure on the VEI scale?

Only a 1


In Iceland, what were the implications of the large volumes of ash releasing into the atmosphere?

  • Picked up by the jet stream and blown towards Europe.


  • Many European air spaces were shut down - the largest shut down since World War II.


  • Estimated cost to airlines - £130 million per day for the six days of closure.


  • Millions were affected and has knock-on tavel effects across the globe.


Describe the risk and vulnerability regarding the Icelandic eruption:

  • Very little risk to people's lives.
  • Real threat comes from ash cloud - spreads the risk across the globe in terms of ability to travel.


Why is there little threat to people's lives regarding the eruption of Eyjafjallajokull?

So few of them live near this part of the volcano, and so they are not at risk from the eruption itself.

However, some did have to be evacuated after most recent eruption, and millions are left vulnerable to potential ash cloud.


What is hazard mitigation?


What are the three main categories of long term responses?

  • Prevention
  • Prepardness
  • Adaptation


In terms of volcanic hazards, explain the long term response of prevention:

  • It's not possible to prevent volcanic eruptions.


  • However, it is sometime possible to prevent eruptions posing a risk to people - eg authorities preventing development on land surrounding volcano.


In terms of volcanic hazards, explain the long term response of prepardness:

What happens before an eruption to minimise risk or vulnerability:

  • Monitoring systems
  • Education on nearest emergency shelter
  • Community search + rescue teams