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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
•Nuclear Accidents
Phuket, Thailand: Before and after the 2004 tsunami
•Meteor Impacts
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
Extreme Events
One Planet Many People:
Atlas of Our Changing Environment
Thank You!
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www.na.unep.net
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