Posts Tagged ‘Glacier’

Settled science? Karakoram glaciers, polar bear and emperor penguin numbers are all growing – not disappearing

April 16, 2012

A settled science? Global warming was going to melt all the Himalayan glaciers by 2035, polar bears were going to be exterminated and emperor penguins populations were going to be devastated. But the climate models are proving to be just the wishful thinking of an alarmist creed.

1. The Guardian: The glaciers flowing between the towering peaks of the Karakoram range on the Pakistan-China border have grown in size in the last decade, according to new research. The impact of climate change on the ice in the greater Himalaya range has been controversial because of an unfounded claim by the United Nations’ climate science panel over the rate of melting in the region. However the melting of vast volumes of ice into the sea in most other parts of the world has been clearly demonstrated. In March, scientists showed that far less ice was being lost across the Himalayas than had been estimated from sparse ground surveys on the remote slopes.

The new study shows that glaciers in one important part of the mountain range are growing. “We provide a detailed glacier-scale evaluation of mass changes in the central Karakoram,” said Julie Gardelle, at CNRS-Université Grenoble, who led the research published in Nature Geoscience on Sunday. …

2. Polar bear populations have never been as large as they are now.

3. Emperor penguin populations are twice the size they were once thought to be.

It is time for the climate brigade and their hangers-on to develop a little humility and acknowledge that the chaotic, turbulent layer around the earth which creates our climate is far from being understood.

Time to ditch some of the models.

Iceland volcano watch stands down

November 6, 2010

Jökulhlaup from Grímsvötn subsides

The earlier concern about meltwater flooding from the Grimsvotn glacial lake in Iceland which could have signalled that the volcano underneath was about to erupt has subsided.

Bridge over Gígjukvísl

Figure 1. The jökulhlaup from Grímsvötn: image vedur.is

The jökulhlaup (glacial outburst flood) from Grímsvötn that began near the end of October is now coming to an end. The flood reached a maximum level shortly after noon on November 3, and scientists from IMO visited the site on that day to study the effects of the flood on the region adjacent to the ice margin. Two IMO technicians have performed regular discharge measurements on the bridge over the river Gígjukvísl throughout this week (Figure 1) and the results from their measurements are shown in Figure 2.

Figure 2. Discharge (m3/s) measurements at Gígjukvísl bridge: From the curve the total amount of floodwater is estimated 0.45 km3

The discharge curve is typical for jökulhlaups from Grímsvötn that do not result from volcanic activity: Over the course of several days, the amount of water flowing through an ice tunnel at the glacier bed steadily increases. Loss of frictional heat from the floodwater causes melting of the tunnel walls, thereby increasing the flow capacity of the tunnel.

In past centuries, most jökulhlaups from Grímsvötn have entered the course of the river Skeiðará. This time, however, floodwater that emerged from beneath the eastern part of the glacier went westwards along the glacier margin and then entered the river Gígjukvísl. Skeiðará has deposited very large amounts of sediment on the eastern part of Skeiðarársandur plains over the centuries, increasing the elevation of the sandur area there relative to the central part. In addition, the glacier has carved a trench during times of advance. Thus, it was clear that retreat of the glacier over the past 15 years would sooner or later lead to a drastic shift in the direction of meltwater flow from this part of the glacier. In the summer of 2009, this shift occurred and water has ceased to enter the course of Skeiðará.

 

Further proof that glaciers are not well understood

September 16, 2010

http://www.sciencedaily.com/releases/2010/09/100915140119.htm

Glacial armoring

A new paper in Nature shows that glaciers can both help mountains grow as well as cause erosion. The stubborn certainty displayed by Pachauri and the IPCC about glaciers seems all the more ridiculous.

Stuart N. Thomson, Mark T. Brandon, Jonathan H. Tomkin, Peter W. Reiners, Cristián Vásquez, Nathaniel J. Wilson.Glaciation as a destructive and constructive control on mountain buildingNature, 2010; 467 (7313): 313 DOI:10.1038/nature09365

Glaciers can help actively growing mountains become higher by protecting them from erosion, according to a University of Arizona-led research team. The finding is contrary to the conventional view of glaciers as powerful agents of erosion that carve deep fjords and move massive amounts of sediment down mountains. Mountains grow when movements of the Earth’s crust push the rocks up. The research is the first to show that the erosion effect of glaciers — what has been dubbed the “glacial buzzsaw” — reverses on mountains in colder climates.

Glaciers atop mountains in temperate latitudes flow downhill, scouring away the surface of the mountain. Over millennia, such erosion can reduce the height and width of a mountain range by miles. However in very cold climates such as the Patagonian Andes, rather than scraping away the surface of the mountain, the team found that glaciers protect the mountain top and sides from erosion. The team dubs the action of the cold-climate glaciers “glacial armoring.”

“Climate, especially through glaciers, has a really big impact on how big mountains get,” said Reiners, a UA professor of geosciences.


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