Thursday, January 3, 2013

Glaciers....





Fed from an icefield high above Juneau, the Mendenhall glacier is a dynamic flowing force, grinding and scouring everything in its path as it carves its way down to the sea. It is about 12 miles long. Mendenhall glacier is one of many in southeast Alaska formed during the Little Ice Age ( which began about 3,000 years ago)


The Juneau Icefield encompasses about 1,500 square miles of ice and is the beginning of many glaciers including Mendenhall, Lemon Creek, Herbert, Eagle, and Taku Glaciers. Annual snowfall on the icefield often exceeds 100 feet and the cold temperatures at higher elevations keep the snow from melting.

The unique climate and geography of this region allowed glaciers to survive long after they began receding from other places in North America. Mendenhall Glacier, has lost much width at the Mendenhall Lake entrance but some scientists say it has grown in height.Some glaciers have been slowly melting for hundreds of years, while others are not.
Loons, gulls, and arctic terns nest along the lake shore. A variety of waterfowl use the lake as a stopover on their spring and fall migrations.
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Breiðamerkurjökull, part of Vatnajökull near Jökulsárlón, Iceland



Vatnajökull

Vatnajökull (English: Glacier of Rivers) It's the largest glacier in Iceland. It is located in the south-east of the island, covering more than 8% of the country. With a size of 8,100 km², it is the largest glacier in Europe in volume (3,100 km³) and the second largest (after Austfonna on Nordaustlandet, Svalbard) in area (not counting the still larger ice cap of Severny Island of Novaya Zemlya, Russia, which is located in the extreme northeast of Europe).
The average thickness of the ice is 400 m, with a maximum thickness of 1,000 m. Iceland's highest peak, Hvannadalshnúkur (2,110 m), is located in the southern periphery of Vatnajökull, near Skaftafell National Park. It is classified as an ice cap glacier.

Under the glacier, as under many of the glaciers of Iceland, there are several volcanoes. The volcanic lakes, Grímsvötn for example, were the sources of a large glacial lake outburst flood in 1996. The volcano under these lakes also caused a considerable but short-time eruption in the beginning of November 2004. During the last ice age, numerous volcanic eruptions occurred under Vatnajökull, creating many subglacial eruptions.

According to Guinness World Records Vatnajökull is the object of the world's longest sight line, 550 km from Slættaratindur, the highest mountain in the Faroe Islands. GWR state that "owing to the light bending effects of atmospheric refraction, Vatnajökull (2119m), Iceland, can sometimes be seen from the Faroe Islands, 340 miles (550km) away". This may be based on a claimed sighting by a British sailor in 1939. The validity of this record is analysed/undermined in mathematical and atmospheric detail by J.C. Ferranti.
(semi quote from wiki)

close-up, then below, further away, to give a sense of the size of the icefield....via google earth of
Vatnajökull


Wonderful Blog here about beautiful waterfalls on Iceland. Check it out... there are some gorgeous pictures here!

1 comment:

  1. those aerial views are just amazing!

    ReplyDelete