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MELTING GLACIERS

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Title: MELTING GLACIERS


1
MELTING GLACIERS
2
Global Warming
  • According to the recent IPCC report, the mean
    global surface temperature has increased by
    0.74OC over the last 100 years (1906-2005)
  • 11 of the 12 warmest years have been recorded in
    the past 12 years

3
Findings of the IPCC Assessment Report (2007)
  • There has been a significant decline in the
    mountain glaciers and snow cover, which has
    contributed to the increased sea levels
  • From 1961 to 2003, the global mean sea level rose
    by 1.8 (0.5) mm per year
  • The global temperature of the oceans increased by
    0.10oC from surface to depth of 700m from 1961-
    2003 and 80 of the heat added to the climate
    system is being absorbed by the ocean
  • Other long term climatic changes that have been
    observed include extreme droughts, intensity of
    tropical cyclones, changes in the salinity of the
    ocean and wind patterns

4
Changes in the precipitation pattern IPCC
Report (2007)
  • Precipitation has significantly increased () in
    eastern North and South America, northern and
    central Asia and northern Europe
  • There has been decline (-) in precipitation in
    the Mediterranean, some regions in southern Asia,
    southern Africa and Sahel

5
Melting of the Greenland Ice Sheet
  • According to NASA scientists, the Greenland ice
    sheet is melting faster than it is being
    replaced, contributing to sea level rise
  • The loss of ice from Greenland doubled between
    1996 and 2005
  • From 1996 to 2000, the largest acceleration and
    mass loss came from southeast Greenland
  • From 2000 to 2005, the trend extended to include
    central east and west Greenland
  • It is estimated that 69 per cent of the ice-mass
    loss in recent years came from eastern Greenland

6
Greenland ice is declining faster than expected
  • Between 2003 and 2005 the low coastal areas of
    Greenland lost 155 gigatons of ice per year due
    to excess melting while the high elevation
    interior gained 54 gigatons annually from excess
    snowfall
  • Between 2004 and 2006, the rate of melting
    accelerated, with the massive ice sheet melting
    two and one-half times faster than the previous
    two-year period
  • Greenland lost roughly 164 cubic miles of ice
    from April 2004 to April 2006more than the
    volume of the North American Great Lake Erie

7
Greenland Ice Sheet
  • Dramatic ice mass losses concentrated in the
    low-elevation coastal regions, with nearly half
    of the loss coming from southeast Greenland

NASA Earth Observatory
8
Greenland Ice Sheet
  • Greenland is now losing 20 percent more mass
    than it receives from new snowfall each year.

NASA Earth Observatory
9
Greenland Ice Sheet
University of Colorado, CIRES
10
Melting of ice in Greenland
  • 2001-2003
  • A significant increase in the melting area
    has been observed along the edge of the ice cap
    in Greenland.

NASA Earth Observatory
11
Retreat of Ice and Snow in Greenland
  • Ice loses in Greenland range from 5 to 25
    centimeters of water equivalent per year

NASA Earth Observatory
12
Calving of Helheim Glacier, Greenland
The glaciers peak rate of flow has increased
from 8 km/yr in 2000 to 11 km/yr in 2005
Helheim glacier, located in southeast Greenland,
is now one of the fastest moving glaciers in the
world
1986-2006 These images show the retreat of
Helheim glaciers calving front
  • This May 2005 picture of Helheim Glacier,
    demonstrates high calving activity associated
    with faster glacial flow

13
Dramatic changes in Arctic Sea Ice
Imagine an ice-free Arctic
14
Evidence of extensive snowmelts in West
Antarctica
  • January 2005 Areas of extensive snowmelt (shown
    in yellow and red) have been discovered by a team
    of NASA and university scientists in response to
    warmer temperatures in west Antarctica .
  • The combined area affected is as big as
    California.

NASA Jet Propulsion Laboratory
15
Breakup of Larsen ice shelf (Antarctic Peninsula)
220 metres thick Larsen B shelf existed for at
least 400 years prior to breakup
16
Disintegration of the Larsen B Ice Shelf,
Antarctic Peninsula
  • The ice shelf disintegrated suddenly in March
    2002 due to warm summer temperatures

NASA Earth Observatory
17
Breakup of Antarcticas Ross Ice Shelf
  • An iceberg (B-15J) of size of a small United
    States state cracked off the Antarcticas Ross
    Ice Shelf in March 2000
  • On February 1, 2007, three new icebergs were
    formed due to the break up of the original
    iceberg

NASA Earth Observatory
18
Breaking Off Filchner Ice Shelf Antarctica
Filchner Ice Shelf is the largest ice shelf on
the planet
In 1986 the front edge of Ice Shelf broke off
into three enormous icebergs
19
Calving of Ninnis Glacier Antarctica
22 January 2000 The Ninnis Glacier Tongue soon
after the initial calving
5 February 2002 Iceberg split into two sections
and started moving away from Ninnis Glacier
20
Cracks on Drygalski Ice Tongue Antarctica
The ice tongue was discovered in 1902
21 February 2005 Drygalski calved an iceberg
Image shows cracks formed by time and ocean
currents
21
Shrinking Lake Chad shared by Nigeria, Niger,
Chad and Cameroon
Persistent drought has shrunk the lake to about a
tenth of its former size
  • 1972 Larger lake surface area is visible in
    this image
  • 2001 Due to regionally drying climate and human
    demand for fresh water, Lake Chad is fraction of
    what is once was
  • 2004 In many places, the green of wetlands is
    being replaced by drifting sand dunes (tan
    ripples mixed with green)

22
Shrinking Breidamerkurjökull Glacier Iceland
  • 1973-2000 Images show glacier has receded and
    the glacial lake at its tip has enlarged

23
North America Angangueo
Ice dam in the Hubbard Glacier,United
States
  • 1985 Hubbard Glacier
  • 1986 Images show Degradation of forest area
  • 1986 Hubbard Glacier blocks Russell Fjord
  • 2001 Between 1984 and 1999, 38 per cent of
    forests were degraded
  • 2002 Hubbard Glacier blocks Russell Fjord again
  • 2003 Glacier has retreated

24
Hubbard Glacier advances United States
North America Angangueo
  • 1986 Images show Degradation of forest area
  • 2001 Between 1984 and 1999, 38 per cent of
    forests were degraded

10 Aug 2002
14 Aug 2002
25
North America Angangueo
Retreat of Columbia Glacier, Alaska and Arapaho
Glacier, Colorado, United States
  • Since 1980, the Columbia glacier has retreated
    about 15 kilometers but its retreat has not been
    directly linked to rise in global temperatures
  • Arapaho glacier has thinned by 40 meters since
    1960
  • 1986 Images show Degradation of forest area
  • 2001 Between 1984 and 1999, 38 per cent of
    forests were degraded

NASA Earth Observatory
26
North America Angangueo
Athabasca Glacier, Canada
  • Athabasca glacier has receded more than 1.5
    kilometres in last 125 years
  • It has lost half of its volume
  • 1986 Images show Degradation of forest area
  • 2001 Between 1984 and 1999, 38 per cent of
    forests were degraded

NASA Earth Observatory
  • About 8000 cubic kilometres of ice have been lost
    by glaciers worldwide since 1960.

27
North America Angangueo
Glacier National Park, Montana, United States
  • Only 37 glaciers exist compared to 147 glaciers,
    150 years ago
  • 1986 Images show Degradation of forest area
  • 2001 Between 1984 and 1999, 38 per cent of
    forests were degraded

10 Aug 1972-14 July 1974
  • The glaciers are one-third their size in 1850
  • Scientist predict that all the glaciers will
    disappear by 2030

7 July 2001
NASA Earth Observatory
28
North America Angangueo
Glacier National Park, Montana, United States
  • 1986 Images show Degradation of forest area
  • 2001 Between 1984 and 1999, 38 per cent of
    forests were degraded

29
North America Angangueo
Glacier National Park, Montana, United States
  • 1986 Images show Degradation of forest area
  • 2001 Between 1984 and 1999, 38 per cent of
    forests were degraded

30
North America Angangueo
Ayles Ice Shelf, Ellesmere Island, Canada
  • 1986 Images show Degradation of forest area
  • 2001 Between 1984 and 1999, 38 per cent of
    forests were degraded
  • Ayles Ice Shelf on Ellesmere Island, broke
    free on August 13, 2005 and drifted out to the sea

NASA Earth Observatory
31
Declining Rwenzori Mountain Glaciers in East
Africa
This decline is attributed to increased air
temperature and decreased accumulation and
convective cloud activity
1987-2002 Images show a gradual decrease of the
glacial area, especially on the peaks
32
Disappearing Icecap of Mt. Kilimanjaro, Tanzania
Africas highest mountain with a forest belt
having rich diversity of ecosystems
  • 1976 Glaciers covered most of the summit
  • 2000 The glaciers had receded alarmingly

33
Retreat of Gangotri Glacier, India
  • Gangotri glacier has retreated more than 850
    metres, in the last 25 years
  • It has retreated more than 76 metres from 1996 to
    1999

NASA Earth Observatory
34
Glacial Lakes and Glacial Lake Outburst Floods
  • Glacial lakes are formed due to the melting of
    ice and snow from glaciers
  • Due to the faster rate of melting from the
    glaciers, possibly due to global warming, water
    is accumulating at an increasing rate in these
    lakes
  • Sudden outburst results in Glacial Lake Outburst
    Flood (GLOF) downstream causing destruction of
    life and property

Glacial Lakes in the Bhutan-Himalaya Region
Jeffrey Kargel, USGS/NASA JPL/AGU
35
Retreat of Upsala Glacier, Argentina
January 2004 position
  • The Upsala glacier has retreated more than 4
    kilometres since late 1960s to mid 1990s and
    continues to retreat

NASA Earth Observatory
36
Retreat of San Quintin Glacier, Chile
  • The San Quintin Glacier appears to be losing
    mass and retreating

NASA Earth Observatory
37
MELTING GLACIERS
UNEP Atlas of Our Changing Environment
Thank You!
Free Download www.na.unep.net
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