Zitat:
"Dass die Ursache für diese Zunahme in der Klimaerwärmung zu suchen
ist, liegt für die Forscher klar auf der Hand, denn Gletscherbeben
entstehen durch Wärme: Dann beginnt der Schnee auf dem Gletscher zu
schmelzen, das Wasser versickert und sammelt sich zwischen Eis und
Stein, wo es als "Gleitmittel" für die Eisblöcke dient, die dann von
der Schwerkraft beschleunigt, ruckartig über das Gletscherbett
abwärts rutschen. Erwärmt sich die Erde, gibt es mehr Gletscherbeben,
vornehmlich dort, wo Gletscher besonders stark schmelzen."
Nun ja - wenn es klar auf der Hand liegt, dann braucht man so eine
Aussage ja auch nicht mehr beweisen, richtig?
Erstaunlich finde ich, daß zumindest der Süden Grönlands seit
mehreren Jahrzehnten kontinuierlich kälter wird:
http://www.agu.org/sci_soc/prrl/jh031003.html
"Greenland cools as the globe warms
Greenland's land and ice sheet have cooled significantly over the
past 40 years, even as much of the rest of the world has warmed in
the recent past. Hanna and Cappelen analyzed temperature records from
southern Greenland, finding evidence of a cooling trend that they
believe is associated with an increased phase of the North Atlantic
Oscillation (NAO) that has been observed over the past 35 years. They
believe that the NAO is likely causing the temperature reductions
along the Greenland coast and is responsible for slowing the island's
ice melting rate, in contrast to evidence of global warming. The
lowered temperatures may also have
significantly added to the island's ice sheet, particularly along its
southern coast, although they note that it is difficult to assess the
long-term ice effects from the current NAO trend.
Title: Recent cooling in coastal southern Greenland and relation with
the North Atlantic Oscillation
Authors:
Edward Hanna, University of Plymouth, UK;
John Cappelin, Danish Meteorological Institute, Copenhagen, Denmark.
Source: Geophysical Research Letters (GRL) paper:
10.1029/2002GL01597, 2003"
Da steht irgendwie im Widerspruch zu diesen Annahmen, die "auf der
Hand liegen", oder?
Was die Situation in der Antarktis angeht:
http://www.newscientist.com/article.ns?id=dn1806
(West Antarctic ice sheet is thickening)
"Net gain
Geologists have previously traced the landward retreat of the line
where the base of the ice in West Antarctica meets the ocean. This
has averaged 120 metres a year since the end of the last ice age. The
studies had estimated the Ross Ice Streams region was losing 20.9
billion tons of ice per year.
But now Ian Joughin of the Jet Propulsion Laboratory and Slawek
Tulaczyk of the University of California at Santa Cruz report a net
gain of 26.8 billion tons per year. This represents about a quarter
of the annual snow accumulation.
Joughin measured flow rates along the ice streams emptying into the
Ross Embayment with the Canadian Radarsat satellite. Then he compared
the outflow volume with other measurements on surface accumulation to
obtain the mass balance.
"It's solid work," says Robert Bindschadler of the NASA Goddard Space
Flight Center. Bindschadler had previously warned that the West
Antarctic ice sheet could melt in 4000 years if long-term trends
continued, leading to significant rises in sea level."
Und jetzt?
"Dass die Ursache für diese Zunahme in der Klimaerwärmung zu suchen
ist, liegt für die Forscher klar auf der Hand, denn Gletscherbeben
entstehen durch Wärme: Dann beginnt der Schnee auf dem Gletscher zu
schmelzen, das Wasser versickert und sammelt sich zwischen Eis und
Stein, wo es als "Gleitmittel" für die Eisblöcke dient, die dann von
der Schwerkraft beschleunigt, ruckartig über das Gletscherbett
abwärts rutschen. Erwärmt sich die Erde, gibt es mehr Gletscherbeben,
vornehmlich dort, wo Gletscher besonders stark schmelzen."
Nun ja - wenn es klar auf der Hand liegt, dann braucht man so eine
Aussage ja auch nicht mehr beweisen, richtig?
Erstaunlich finde ich, daß zumindest der Süden Grönlands seit
mehreren Jahrzehnten kontinuierlich kälter wird:
http://www.agu.org/sci_soc/prrl/jh031003.html
"Greenland cools as the globe warms
Greenland's land and ice sheet have cooled significantly over the
past 40 years, even as much of the rest of the world has warmed in
the recent past. Hanna and Cappelen analyzed temperature records from
southern Greenland, finding evidence of a cooling trend that they
believe is associated with an increased phase of the North Atlantic
Oscillation (NAO) that has been observed over the past 35 years. They
believe that the NAO is likely causing the temperature reductions
along the Greenland coast and is responsible for slowing the island's
ice melting rate, in contrast to evidence of global warming. The
lowered temperatures may also have
significantly added to the island's ice sheet, particularly along its
southern coast, although they note that it is difficult to assess the
long-term ice effects from the current NAO trend.
Title: Recent cooling in coastal southern Greenland and relation with
the North Atlantic Oscillation
Authors:
Edward Hanna, University of Plymouth, UK;
John Cappelin, Danish Meteorological Institute, Copenhagen, Denmark.
Source: Geophysical Research Letters (GRL) paper:
10.1029/2002GL01597, 2003"
Da steht irgendwie im Widerspruch zu diesen Annahmen, die "auf der
Hand liegen", oder?
Was die Situation in der Antarktis angeht:
http://www.newscientist.com/article.ns?id=dn1806
(West Antarctic ice sheet is thickening)
"Net gain
Geologists have previously traced the landward retreat of the line
where the base of the ice in West Antarctica meets the ocean. This
has averaged 120 metres a year since the end of the last ice age. The
studies had estimated the Ross Ice Streams region was losing 20.9
billion tons of ice per year.
But now Ian Joughin of the Jet Propulsion Laboratory and Slawek
Tulaczyk of the University of California at Santa Cruz report a net
gain of 26.8 billion tons per year. This represents about a quarter
of the annual snow accumulation.
Joughin measured flow rates along the ice streams emptying into the
Ross Embayment with the Canadian Radarsat satellite. Then he compared
the outflow volume with other measurements on surface accumulation to
obtain the mass balance.
"It's solid work," says Robert Bindschadler of the NASA Goddard Space
Flight Center. Bindschadler had previously warned that the West
Antarctic ice sheet could melt in 4000 years if long-term trends
continued, leading to significant rises in sea level."
Und jetzt?