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THEMATIC SLIDES. Extreme Events. World Map of Historical Earthquakes. Natural and Human-Induced Extreme Events. GEOHAZARDS. Volcanoes Earthquakes and Tsunamis Landslides/Mudslides. CLIMATIC HAZARDS. Floods Drought Hurricanes/Cyclones. INDUSTRIAL/OTHER HAZARDS. Oil Spills
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Extreme Events World Map of Historical Earthquakes
Natural and Human-Induced Extreme Events GEOHAZARDS • Volcanoes • Earthquakes and Tsunamis • Landslides/Mudslides CLIMATIC HAZARDS • Floods • Drought • Hurricanes/Cyclones INDUSTRIAL/OTHER HAZARDS • Oil Spills • Nuclear Accidents • Meteor Impacts Phuket, Thailand: Before and after the 2004 tsunami
Natural and Human-Induced Extreme Events • Extreme events, whether natural or human-induced, can cause significant environmental change, not to mention their devastating impacts on peoples’ lives • In 2005, there was an 18% rise in disasters that killed 91 900 people • There were 360 natural disasters in 2005 compared to 305 in 2004: the number of floods increased by 57% in 2005 and droughts by about 47% • The 2004 Indian Ocean tsunami accounted for 92%, and the 2005 South Asian earthquake, for 81% of the deaths in each respective year Sources: CRED 2006: UN/ISDR 2006
Volcanoes • About 550 volcanoes have erupted in the Earth’s recorded history and an equivalent number of dormant volcanoes have only erupted in the past 10 000 years • On any given day, about ten volcanoes are actively erupting • Explosive eruptions give little warning, while effusive eruptions, which send out gently flowing lava, allow time for people to escape Sources: Camp 2000; Francis 1993; NGDC 2004
Ecosystem recovers after a major volcanic eruption in Mount St. Helens • 1973: The Mountain Peak 10 years before eruption • 1983: 3 years after eruption • 2000: Vegetation re-growth around the volcano
Lava Flow after Kilauea Volcano Maps of lava-flow field from the Pu`u `O `o and Kupaianaha vents of Kilauea Volcano, Hawaii, January 1983-January 1991 Jan 83-Oct 86 Jan 83-Dec 86 Jan 83-Dec 89 Jan 83-Dec 91
Visible destruction caused by Kilauea Volcano Store and Inn buried by lava
Mapping volcanic risk in Africa In this example, high population densities are also associated with areas with active volcanic activity
Earthquakes and Tsunamis • According to long-term records (since about 1900), we can expect about 18 major earthquakes (7.0 - 7.9 on the Richter scale) and one great earthquake (8.0 or above) in any given year • The number of earthquakes and tsunamis resulting in fatalities has increased approximately in proportion to global populations • The growth of giant urban cities near regions of known seismic hazard is a new experiment for life on the Earth • Tsunamis are a threat to life and property for all coastal residents Sources: NEIC 2003; USGS 2004; UNEP 2005 (GEO 2004/2005)
Indian Ocean Tsunami: Devastated Banda Aceh Serene Banda Aceh Dec. 2004: Tsunami devastated the region of Banda Aceh
Bam, Iran: City destroyed by earthquake A 6.6 magnitude earthquake struck southeastern Iran on 26 December 2003, killing over 40 000 people, injuring 16 000, leaving 70 000 homeless and destroying much of the city of Bam, the earthquake’s epicenter
Earthquake triggers avalanche: Buries Yungay city, Peru Andean glaciers have caused enormous material losses and thousands of casualties Scars of the events of 1962 and 1970 in Yungay are still visible
Avalanche wiped out the city of Yungay 1970: Earthquake wipes out Yungay, claims 18,000 lives
Mapping seismic risk in Africa In this example, high population densities are also associated with areas with active seismic activity
Landslides and Mudslides • Worldwide, thousands of people die every year from landslides and mudslides • In the United Sates alone, they cause an estimated US$1 billion in damage and kill 25 to 50 people every year • Earthquakes, volcanoes, and a number of types of weather events can trigger landslides, which are characterized by lethal mixtures of water, rocks, and mud • The two largest landslides in the world in the 20th century occurred at Mount St. Helens, Washington, in 1980 and at Usoy, Tajikistan, in 1911 • The deadliest landslide in the 20th century was also the result of an earthquake, which occurred in western Iran on 20 June 1990. It caused 40 000–50 000 deaths Sources: NEIC 2003; UNEP 2005 (GEO 2004/2005)
Landslide creates natural lake in Tibet • Area before landslide creates a natural dam blocking the Pareechu River • 2004:The water is slowly building behind the dam, creating an artificial lake By 13 August 2004, the lake had spread over 188 hectares and had reached a depth of 35m
Floods • Worldwide, the number of major flood disasters has grown significantly, from 6 cases in the 1950s to 26 in the 1990s • From 1971 to 1995, floods affected more than 1 500 million people worldwide • In the most calamitous storm surge, a flood in Bangladesh in April 1991 killed at least 138 000 people and left 10 million homeless Sources: UN-ISDR 2004; DFO 2004; Wikipedia 2006
Mozambique under water 2000: Due to severe flooding, half a million people were made homeless and 700 lost their lives 22 August 1999: Mozambique under normal conditions 1 March 2000: Mozambique under water
Devastating floods in Haiti and the Dominican Republic 12 May 2004: Flood waters cover much of the area surrounding Gonaives in Haiti 26 Sept 2004: the water has receded, leaving behind a lush green vegetation
Tropical Storm Jeanne submerges Island of Hispaniola 17 September 2000: Gonaives in perfect shape 22 September 2004: Roads visible on 17 September 2000 image have disappeared, as have a number of buildings and adjacent farmlands submerged by water and mud
Dust storms – a global environmental concern • 23 March 2002: a relatively clear day • 8 April 2002: extremely dusty skies; dust obscures most of the surface
Dust traveling over the Pacific Images taken between April 29 and May 5, 2005 shows dust from the Gobi Desert crossing the Pacific, well on its way to North America
Drought • A drought is a period of dryness, especially when prolonged, causing extensive damage to crops or preventing their successful growth • Climate change will potentially increase the likelihood of droughts in dry and semi-arid regions. There is already evidence that a number of such regions have experienced declines in rainfall • Throughout history, various parts of the globe have suffered drought and subsequent famine, resulting in huge humanitarian and economic losses Sources: Wikipedia 2006; UNEP 2005
Drop in water level: Lake Mead Drought in the Western United States 2000 2004 PhotoView 18 meters Hoover Dam and Lake Mead
Golf courses along Lake Mead New Golf Courses since 2001
Drought in Kenya 2004/2005 harvest: 300 000 metric tonnes cereal deficit Green clusters: areas where rainfall was plentiful and vegetation was thriving Brown clusters: dry areas where vegetation is less dense than it has been in the past
Drought in Australia • 2002: Pasture land for livestock was so parched and the price of grain so high, that many farmers sold their livestock and converted their land to crops in 2003 • 2003: Image showing the expanded crop area
Hurricanes and Cyclones • Scientists predict that global warming will cause warmer ocean temperatures and associated increased moisture in the atmosphere - two variables that work to power hurricanes. As a result, more intense hurricanes that can cause even more damage when they hit land are predicted • Large parts of densely populated coastal areas are subject to the inundation caused by hurricane storm surges; on numerous occasions, they have experienced heavy economic losses from these events Sources: Henderson-Sellers et al. 1998
Devastation due to Hurricane Charley • July 28, 2002: Crisp, neat neighborhoods • August 15, 2004: Debris scattered across roads, parking lots, and yards, giving the scene a “messy” appearance
Oil spills and fires in the Persian Gulf In the images, the blue shows water, green shows natural vegetation, light yellow shows desert areas and black shows pollution from oil spills and fires
World’s worst nuclear accident The Chernobyl nuclear accident killed more than 31 people immediately More than 120 000 people from 213 villages and cities were relocated outside the contamination zone Much of the farmland surrounding the plant was heavily contaminated with radioactive nuclides and was subsequently abandoned
Meteor impact generated structure Velingara Crater appears to be a meteor-impact-generated structure • 1975: Image predates the agricultural development • 2001: Intense agricultural systems have appeared near the center of the crater
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