ENVIRONMENT

Thousands of South Pacific islanders will leave for permanent resettlement as one of the most active volcanoes in the world gets ready to rumble. (Guardian)

Why is the South Pacific erupting? Use our resource to learn a little about the Ring of Fire.

Teachers, scroll down for a quick list of key resources, including today’s MapMaker Interactive map.

Discussion Ideas

• Manaro Voui is a volcano rising from the seafloor. The part of Manaro Voui that is above water is known as the island of Ambae. Where is Ambae? Take a look at today’s MapMaker Interactive map for some help.
  • Ambae is one of the larger islands that make up the South Pacific island nation of Vanuatu. (On our 1-Page Map, Ambae is labeled Aoba.) Vanuatu is a part of Melanesia, which is itself a part of the continent of Australia and Oceania.
  • Ambae and the islands of Vanuatu are a part of the Ring of Fire, a horseshoe-shaped string of volcanic activity ringing the Pacific Ocean.
    • Major tectonic activity in the Ring of Fire is determined by the mighty Pacific plate subducting beneath the continental plates surrounding it. (Subduction! Subduction! Our favorite geologic process!)
      • Around Vanuatu, the New Hebrides plate, a minor plate associated with the Pacific plate, is subducting beneath the Australian plate. This geologic activity contributes to earthquakes, volcanoes, and the New Hebrides trench, a deep ocean trench just west of the archipelago.
  • Manaro Voui is one of the most active volcanoes in the world. It has been steadily erupting with ash and gases since September 2017. Previous eruptions occurred in 2011 and 2005. Learn more about Manaro Voui from the good folks at the Global Volcanism Program here.

• Scroll down and take a look at the “Volcanic Hazards” section of our reference resource. What volcanic hazards do you think ni-Vanuatu authorities are most concerned about?
  • volcanic ash. Volcanic ash can reduce visibility, prevent air travel, damage infrastructure, and harm human health. Some parts of Ambae have already been blanketed in ash 30 centimeters (1 foot) deep.
    • visibility. Plumes of volcanic ash can spread over large areas of sky, turning daylight into complete darkness and drastically reducing visibility. Take another look at that image up top to see how far ocean winds can carry volcanic ash.
    • air travel. Airborne volcanic ash is especially dangerous to moving aircraft. The small, abrasive particles of rock and glass can melt inside an airplane engine and solidify on the turbine blades—causing the engine to stall. The 2010 eruption of Eyjafjallajökull, Iceland, produced an ash cloud that forced the cancellation of roughly 100,000 flights and affected 7 million passengers, costing the aviation industry an estimated $2.6 billion. Check out that ash cloud here.
    • infrastructure. Ash can enter and disrupt machinery found in power supply, water supply, sewage treatment, and communication facilities. Heavy ash fall can also inhibit road and rail traffic and damage vehicles. When mixed with rainfall, volcanic ash turns into a heavy, cement-like sludge can collapse roofs. This has already happened on Ambae, as these dramatic photos document.
    • crops. Most residents of Ambae practice subsistence agriculture. Volcanic ash has already buried crops and contaminated animal feed.
    • health. Carbon dioxide and fluorine, gases that can be toxic to humans, can collect in volcanic ash. The resulting ash fall can lead to crop failure, animal death and deformity, and human illness. Ash’s abrasive particles can scratch the surface of the skin and eyes, causing discomfort and inflammation. If inhaled, volcanic ash can cause breathing problems and damage the lungs. Inhaling large amounts of ash and volcanic gases can cause a person to suffocate.
      • Ambae’s population are already experiencing “breathing difficulties, skin reactions and illnesses such as chest infections.”
      • Volcanic ash and gases have polluted most of Ambae’s water supply in perhaps the island’s most pressing hazard.
  • displacement. Ambae’s population will be forced to find new homes, schools, jobs, hospitals, community centers, and neighborhoods.
    • The evacuation is estimated to cost about $1.8 million.
    • Local leaders want to remain on the island.

• Are evacuated residents of Ambae considered “environmental refugees”?
  • Yes. Residents have been forced to flee their homes and communities due to changes in the environment.

• Island residents are being permanently evacuated because of an erupting volcano. Is Manaro Voui going to go Krakatoa on us?
  • Unlikely. Volcanologists have categorized the eruption as a Volcanic Alert Three, which the Vanuatu Meteorology and Geo-Hazards Department categorizes as “Danger within caldera, volcanic cone and other specific area, possibility of moderate eruption and also chance of flank eruption.”
    • The evacuation is due to increased emissions of gas, ash, and scoria. The cone at one of the volano’s three crater lakes has also grown significantly.
    • Manaro Voui is a shield volcano. Krakatau is a stratovolcano.
      • Shield volcanoes, like Kilauea in Hawaii, are large, gently sloping mountains that are often characterized by effusive eruptions—a slow, steady outpouring of liquid lava.
      • Stratovolcanoes are steep mountains often characterized by explosive eruptions of gases, ash, rocks, and viscous lava. Pyroclastic flows, the most dangerous of volcanic hazards, are usually associated with the explosive eruptions of stratovolcanoes.
      • Although shield volcanoes are obviously dangerous, they are less likely to erupt with the sort of violent intensity of stratovolcanoes like Krakatau, Vesuvius, or Pinatubo. Learn more about shield and stratovolcanoes with our activity here.

• Where will Ambae’s refugees be relocated?
  • “Negotiations are under way between landowners and central government to acquire land for Ambae evacuees on either Maewo or Pentecost – the two closest islands to Ambae, but a safe distance from the volcano, which is one of the most active in the world.”

TEACHERS TOOLKIT

Guardian: Island of no return: Vanuatu evacuates entire population of volcanic Ambae

Smithsonian Institution Global Volcanism Program: Ambae

Nat Geo: Evacuating Ambae Island

Nat Geo: Vanuatu

Nat Geo: What is the Ring of Fire?

Nat Geo: What is a volcano?

Nat Geo: What is volcanic ash?

Nat Geo: Types of Volcanic Eruptions