Volcanoes of the World

• Perspective on Volcanism
  • Volcanoes form at:
    
    • Hot Spots
      
    • Spreading Centers
      
    • Convergent Plate Boundaries
      
      • Ocean – Ocean
        
      • Ocean–Continental
        
  • Volcanism has occurred throughout geologic time
    
    • Presently concentrated in the Circum-Pacific Belt and across the Mediterranean and through Indonesian
      
    • Miocene volcanism covered 700 sq miles of LA Basin
      
      • Ash left from that period causes many modern landslides
        
  • Volcanism threatens to destroy numerous major cities
    
    • Examples
      
      • Popocatepetl - Mexico City
        
      • Mt. Vesuvius - Naples
        
      • Mt. Merapi - Jogjakarta
        
      • Mt. Rainier - Seattle area
        
      • Mt. Hood - Portland
        
  • Huge Populations have grown in Volcanic Areas
    
  • Volcanoes by state:
    
    • Alaska - 42
      
    • Arizona - 9
      
    • California - 10
      
    • Hawaii - 13
      
    • Idaho - 3
      
    • New Mexico - 10
      
    • Oregon - 22
      
    • South Dakota - 1
      
    • Utah - 2
      
    • Washington - 7
      
    • Wyoming - 2
  • VEI (Volcanic Explosivity Index)
  • Volcanic Hazards
    
    • Direct
      
      • Gas
        
      • Lahars (Volcanic Mudflows)
        
      • Lava flows
        
      • Pyroclastic Flows
        
      • Tsunami
    • Indirect
      
      • Famine
        
  • Benefits of Volcanoes
    
    • Produce great amounts of new land
      
    • Frequently produce very fertile soils
      
    • Provide Geothermal Power
      
    • Recreation
      
      
• Volcanic Hazards in Developing Nations - Africa
  
  • Africa – Geologic Overview
    
    • 200 m.y.a. - Breakup of Pangaea
      
    • ~55 m.y.a. – Afro-Arabian rifting began
      
    • Most African volcanoes are the result of hot spots, rifting, or a combination of the two.
      
  • Cameroon – Mt. Cameroon
    
    • Population: 16,063,678
      
    • Government
      
      • Generally stable, political power is an ethnic oligarchy.
        
    • Natural hazards
      
      • volcanic activity from Lake Nyos and Lake Monoun volcanoes
        
    • Current issues include:
      
      • water-borne diseases prevalent; deforestation; overgrazing; desertification; poaching; overfishing
        
    • Type of volcano: stratovolcano
      
      • Known to locals as Mount Faka and “Chariot of the Gods”
        
      • Eruptions occur on the flanks of the volcano
        
      • Cinder cones and lava flows Cameroon – Mt. Cameroon
        
      • 1999 – 2000 eruption
        
        • Primarily basaltic lava flows
          
        • Many villages threatened, evacuations ordered
          
        • Many roads disrupted
          
  • Cameroon – Lake Nyos
    
    • Type of volcanism: Maar
      
      • A volcanic crater that is produced by an explosion in an area of low relief, is generally more or less circular, and often contains a lake, pond, or marsh. (http://volcano.und.nodak.edu/vwdocs/glossary.html)
        
      • Maars in Oku volcanic field formed during an explosive eruption of carbon dioxide gas
        
      • Lake Nyos formed about 400 years ago
        
    • August of 1986 Lake Nyos
      
      • 1 km of CO2 released
        
      • ~1700 people killed up to 26 km away from the lake
        
    • August of 1984
      
      • smaller gas burst from Lake Monoun
        
      • 37 people killed
        
    • Only three lakes in the world are known to contain high concentrations of dissolved gas in their bottom waters:
      
      • Lakes Nyos and Monoun in Cameroon
        
      • and Lake Kivu in East Africa. Only Lakes Nyos and Monoun are known to have recently released gas resulting in the loss of human life.
        
  • African Rift Zone
    
    • Type of volcanism: Rifting
      
    • Two branches:
      
      • Eastern or Great Rift zone
        
        • Jordan River, the Dead Sea, and the Gulf of Aqaba.
          
        • The Red Sea
          
        • Ethiopian Denakil Plain to Lakes Rudolf (Turkana), Naivasha, and Magadi in Kenya.
          
        • Shire River valley and Mozambique Plain to the coast of the Indian Ocean near Beira, Mozambique:
          
    • Western zone
      
      • Extends from Lake Nyasa north through Lakes Rukwa, Tanganyika, Kivu, Edward, and Albert
  • .Nyiragongo, Democratic Republic of Congo (Zaire)
    
    • Population: 58,317,930
      
    • Government
      
      • Dictatorship; ethnic strife and civil war, touched off by a massive inflow of refugees from the fighting in Rwanda and Burundi
        
    • Natural hazards
      
      • periodic droughts in south; Congo River floods (seasonal); active volcanoes in the Great Rift Valley
        
    • Current issues include:
      
      • poaching threatens wildlife populations; water pollution; deforestation; refugees responsible for significant deforestation, soil erosion, and wildlife poaching;
        
    • Type of volcanism: Stratovolcano (in EARZ)
      
      • Formed ~20,000 years ago
        
      • One of the “Decade” Volcanoes
        
    • Recent Eruptions
      
      • 1977
        
        • lava lake in crater drained in <1 hour
          
        • flank eruptions moved at 40 mph
          
        • 70 deaths from one eruption, 2000 deaths total for the year
          
        • Eruption formed a fracture system that led partway down to the city of Goma
          
      • 2002
        
        • Lavas unusually low in SiO2
          
        • Flowed rapidly down the slope, through the city of Goma to Lake Kivu
          
        • 45 people killed
          
        • City of Goma largely destroyed, refugee crisis
          
    • Nyiragongo Volcano Erupts
      
      • Ash and steam were pouring from the Nyiragongo Volcano on July 12, 2004, when the Moderate Resolution Imaging
      • Spectroradiometer (MODIS) onboard NASA’s Terra satellite captured this image.
      • http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=16606
        
  • Questions to ponder . . .
    
    • Many African nations are in a period of civil and political unrest
      
      • Ethnic “cleansing”
        
      • Civil war
        
      • Poverty
        
      • Famine
        
      • Drought
        
    • How might a volcanic eruption affect the population?
      
      
• Volcanic Hazards in Developing Nations – the Middle East
  
  • Harrat Hutaymah, Saudi Arabia
    
    • Population: 25,795,938
      
    • Government
      
      • Generally stable, monarchy.
        
    • Natural hazards
      
      • frequent sand and dust storms
        
    • Current issues include:
      
      • desertification; depletion of underground water resources; lack of perennial rivers or permanent water bodies; coastal pollution from oil spills
        
    • Volcanism is the result of rifting
      
      • "Harrat" is Arabic word which means "stony area volcanic country or lava field."
        
        • Volcanism assymetric Harrat Al Birk, Saudi Arabia
          
        • Dark-colored volcanic cones sprout from an ancient lava field known as Harrat Al Birk along Saudi Arabia's Red Sea coastline.
          
        • Many such lava fields dot the Arabian Peninsula and range in age from 2 million to 30 million years old.
          
        • http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=16517
          
      • Tabah
        
        • Small town in a tuff ring
          
  • Questions to ponder . . .
    
    • While there is not a large population base in the volcanic province of Saudi Arabia, there are several important cities within it.
    • What would happen if volcanic activity commenced near the holy city of Mecca?
      
      
• Volcanic Hazards in Developing Nations – SE Asia
  
  • Indonesia – Geologic Overview
    
    • Comprised of more than 13,000 islands
      
    • Volcanic island arcs
      
      • Sunda Arc - subduction of Australian-Indian Plate beneath the Asian Plate = Java Trench
        
      • Banda Arc - subduction of Pacific Plate beneath the Philippine Sea Plate = Marianas Trench
        
    • Largest number of active volcanoes (76)
      
    • 1,171 dated eruptions (second only to Japan)
      
  • Krakatoa (Krakatau), Indonesia
    
    • Type of volcano: resurgent caldera
      
    • Inactive for 200 years before 1883
      
    • Eruption began in May and climaxed on August 26 & 27
    • VEI = 6
      
      • Lava, ash, and gas erupted
        
      • Ash covered neighboring islands
        
      • Pumice choked the Sunda Strait
        
      • Suddenly 10 sq miles collapsed
        
      • A strong earthquake occurred
        
      • Sound could be heard 3000 miles away
        
      • Tsunami over 100 feet high killed 36,000 people in Java and Sumatra
  • Toba, Sumatra
    
    • Type of volcano: stratovolcano
      
    • Last erupted 74,000 years ago
      
      • The resultant caldera formed Lake Toba, 100 km long, 60 km wide
        
      • 3,000 km3 of ejected material + large quantities of SO2
        
      • Ash and SO2 ejected into the stratosphere reflects solar radiation back into space
        
        • Est. global cooling of 5ºC
          
        • 15 ºC in temperate & high latitudes
          
        • Genetic research on mitochondrial DNA
          
  • Tambora, Indonesia
    
    • Type of volcano: Stratovolcano
      
    • 1815 eruption
      
      • Largest eruption in historic time (VEI = 7)
        
      • Caldera-forming eruption
        
      • Numerous pyroclastic flows
        
        • 10,000 deaths
          
      • Pyroclastic fallout destroyed crops in Indonesia
        
        • 82,000 deaths
          
      • Affected global climate – 1816 “year without a summer
        
  • Kelut, Indonesia
    
    • Type of volcano: Stratovolcano
      
    • Eruptions of 1586 & 1919
      
      • VEI = 5?
      • Large crater lake at summit
        
      • Pyroclastic eruptions + water from lake = lahar
        
      • Eruptions make for fertile soil, so heavily populated
        
    • Last eruption: 1990
      
      • VEI=4
        
      • produced a large cloud and heavy tephra fall
        
      • 32 people killed
        
  • Questions to ponder . . .
    
    • Current issues include (from CIA World Fact book):
      
      • Poverty
      • Terrorism
        
      • Political unrest
      • Human rights violations
        
      • Separatist pressures in Aceh and Papua.
    • Indonesia’s volcanoes are very destructive – how might a large volcanic eruption affect the region?
• Volcanic Hazards in Developing Nations – Latin America
  
  • Latin America – Geologic Overview
    
    • Mexico & Central America
      
      • Volcanism due to subduction of the Pacific and Cocos Plates beneath the North American & Caribbean Plates
    • South America
      
      • Volcanism due to subduction of the Nazca Plate beneath the South American Plate
  • Paricutin, Michoacan, Mexico
    
    • Type of volcano: Cinder Cone
      
    • 1943 eruption
      
      • cinder cone developed in a farmer’s field
        
      • Erupted for 9 years, built a cone
        
      • Pyroclastic debris & lava flows buried 100 mi2
        
      • Destroyed the towns of Paricutin and San Juan de Paragaricutiro
  • Popocatépetl, Mexico
    
    • Type of volcano: stratovolcano
      
    • Located ~70 km southeast of Mexico City
      
    • Erupted 36 times since the arrival of the Spanish conquistadors in the 1500s
      
    • Most recent: 1994 – 1997
      
    • 1994 eruption
      
      • Began just before Christmas
        
      • Heavy ashfall = evacuation of 19 villages (31,000 people)
        
      • Increased activity = 75,000 people evacuated
    • Today
      
      • Still erupting some ash and gas
        
  • Colima, Mexico
    
    • Type of volcano: Stratovolcano
      
    • One of the “Decade” Volcanoes
      
    • Comprised of two volcanoes:
      
      • Nevado de Colima
        
      • Volcan de Colima (historically active)
        
    • 125 km (75 miles) south of Guadalajar
      
    • January 20, 1913 eruption
      
      • Only 4 days long
        
      • Produced ash flows and a summit crater
        
    • 1961, 1975, 1980s
      
      • Minor lava flows
        
    • 1987 & 1994
      
      • Explosive eruptions
        
    • 1998 – Present
      
      • Explosive eruptions, ash, formation of lava dome & lava avalanches
        
    • Concern is that the volcano has a history of pyroclastic flows and large avalanches
      
  • Nevado del Ruiz, Columbia
    
    • Type of volcano: Stratovolcano
      
    • Eruptions
      
      • 2 eruptions on Nov 13, 1985 melted the summit glaciers
        
        • Mudflows travelled in all directions from the summit
          
        • Mud traveling 30 mph & 50 feet deep buries Amero 30 miles away
          
        • 25,000 killed
  • Questions to ponder
    
    • Many Latin American countries are experiencing large population growths
      
    • Volcanoes typically have very fertile soils.Should new populations be allowed to live on/near volcanoes?
      
      
      

LINKS

• Cameroon
  • Using Science to Solve Problems: The Killer Lakes of Cameroon
  • Volcanic Lakes and Gas Releases
• Columbia
  • CVO - Nevado del Ruiz, Colombia
  • Nevado del Ruiz, Colombia
• Greece
  • The Eruption of Thera
• Kratatoa
  • THE EXPLOSION OF KRAKATOA MOUNTAIN
  • The Krakatoa Stories
  • Krakatau, Sundra strait
  • What happened in the Krakatoa eruption in the 1800's?
• General
  • Deadliest Volcanic Eruptions Since 1500 A.D.
  • Potentially Active Volcanoes of the Western United States
  • Video Clips on VolcanoWorld
  • Volcanoes in the North and Central American Region
  • World Organization of Volcano Observatories (WOVO) - North America and the West Indies
    • Alaska Volcano Observatory
    • David Johnston Cascades Volcano Observatory
    • The Hawaiian Volcano Observatory
    • Instituto de Geofisica, Mexico
    • Centro Universitario de Investigacion en Ciencias de la Tierra (CUICT) - Colima, Mexico
    • Observatoire Volcanologique de la Soufriere, Guadeloupe
    • Observatoire Volcanologique de la Montagne Pele
    • Seismic Research Unit, University of the West Indies

Perspective On Volcanism | Africa | Middle East | SE Asia | Latin America | top