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Archive for Glaciers and Ice Caps

Fjords of Western Greenland, Sediments, Phytoplankton and Climate Change

63.8N 52W

February 16th, 2013 Category: Glaciers and Ice Caps, Phytoplankton

Greenland – January 26th, 2013

Greenlandic fjords are located at the junction between the ocean and the Greenland Ice Sheet and therefore sensitive to future climate change. However, little is known about the fjord-glacier link, and fjords are in
general understudied. Furthermore, biological studies and basic ecological understanding remain very incomplete.

However, recent research describes differences in plankton community structure in the offshore West Greenland system towards a glacial outlet fjord, and the results suggest differences in offshore and fjord systems. Results suggest that the high suspended sediment concentrations in the fjord cannot explain the spatial distribution of plankton communities, pointing instead the importance of oceanfjord-glacier interaction. In this image, the lighter blue areas along the coast indicate the presence of sediments and/or phytoplankton (click here for more information).

Early Summer Melting Affecting Fuchs Ice Piedmont, Adelaide Island, Antarctica – January 7th, 2013

67.1S 68.1W

January 7th, 2013 Category: Climate Change, Glaciers and Ice Caps, Image of the day

Antarctica – January 6th, 2013

Small icebergs can be seen breaking off the coast of Antarctica, near Adelaide Island (upper right quadrant). Adelaide Island, also known as  Isla Adelaida and Isla Belgrano, is a large, mainly ice-covered island, 75 miles (121 km) long and 20 miles (32 km) wide, lying at the north side of Marguerite Bay off the west coast of the Antarctic Peninsula. The Ginger Islands lie off the southern end.

Located on Adelaide Island is the Fuchs Ice Piedmont, an ice piedmont (ice covering a coastal strip of low-lying land backed by mountains) that is 70 nautical miles (130 km) long, extending in a northeast–southwest direction along the entire west coast of the island. According to Chilean scientists, the snow-covered surface of the glacier has progressively deteriorated over the years, due to increasingly early summer melting. Crevasses appear on the glacier surface progressively earlier in the summer, presumably due to higher snowmelt and perhaps higher ice velocities, in response to regional atmospheric warming.

Phytoplankton in Foxe Basin and Thinning Barnes Ice Cap, Canada – September 20th, 2012

67.7N 76.2W

September 20th, 2012 Category: Glaciers and Ice Caps, Image of the day, Phytoplankton

Canada – September 3rd, 2012

Foxe Basin is a shallow oceanic basin north of Hudson Bay, in Nunavut, Canada, located between Baffin Island and the Melville Peninsula. For most of the year, it is blocked by ice floes. Here, however, the basin appears mostly ice-free, and sediments can be seen along the shores and phytoplankton are visible in the waters, whose nutrient-rich cold waters are known to be especially favorable to such blooms.

The largest island visible in the basin is Prince Charles Island, with an area of 9,521 km2 (3,676 sq mi). Visible north of the island by the top edge is the bright white Barnes Ice Cap, an ice cap located in central Baffin Island, Nunavut. It covers close to 6000 km2 and has been thinning due to regional warming. Between 2004 and 2006, the ice cap was thinning at a rate of 1 m per year.

Large Iceberg Calving Off Petermann Glacier, Greenland – July 21st, 2012

80.5N 59.5W

July 21st, 2012 Category: Climate Change, Glaciers and Ice Caps, Image of the day

Calving from July 11th-18th, 2012

Petermann Glacier, Greenland

On July 16-17 2012, a 150 km2 (59 square-mile) chunk calved from the northern tip of the Petermann Glacier, a large glacier located in North-West Greenland to the east of Nares Strait. It connects the Greenland ice sheet to the Arctic Ocean.

The animated image shows the glacier before and after the large chunk calved from the end of the glacier, while the detail image contains a sequence of images showing the ice gradually calving off. The images in the sequence, from left to right, are from the 11th, 15th, 17th and 18th (last two images) of July.

Although this is not the first time a large piece of ice has calved off the glacier, nor is it the largest (in 2010 an iceberg with an area of roughly 120 sq km / 46 sq mi, or about half the size of the 2012 piece, broke off), the recent calving event has reignited concerns over climate change. While some express little concern, pointing out that the process of icebergs calving off glaciers has occurred for centuries, others worrying about global warming and say that the real issue is whether or not the frequency of calving events is changing, and why.


Milky Blue Glacier Lakes in Patagonia by Chile-Argentina Border

49.5S 72.6W

February 10th, 2012 Category: Glaciers and Ice Caps, Lakes

Argentina - February 6th, 2012

Glacial lakes appearing bright blue in color can be observed in Patagonia by the Andes Mountains and the border between Chile (west) and Argentina (east). The lakes are, from top to bottom, Lake O’Higgins/San Martín (the former name is used in Chile, the latter in Argentina), Viedma Lake and Argentino Lake.

Lake O’Higgins / San Martín is located between the Aysén Region and the Santa Cruz Province. It has a surface area of 1,058 km², an elevation of 250 metres above mean sea level, and a shoreline length of 525 km. Viewed from above, the lake consists of a series of finger-shaped flooded valleys, of which 554 km² are in Chile and 459 km² in Argentina, although sources differ on the precise split, presumably reflecting water level variability. The lake is the deepest in the Americas with a maximum depth of 836 metres near O’Higgins Glacier, and its characteristic milky light-blue color comes from rock flour suspended in its waters.

Viedma Lake, approximately 50 miles (80 kilometers) long, is a major elongated trough lake formed from melting glacial ice. Lake Viedma is fed primarily by the Viedma Glacier at its the western end. The Viedma Glacier measures 3 miles (5 kilometers) wide at its terminus at Lake Viedma. The brown landscape is a result of ice scouring, which left virtually no vegetation on the steep-walled valleys. Water from lake Viedma flows into Lake Argentino through the La Leona River.

Lago Argentino is the biggest freshwater lake in Argentina, with a surface area of 1466 km2 (maximum width: 20 mi). It has an average depth of 150 m, and a maximum depth of 500 m. The lake lies within the Los Glaciares National Park, in a landscape with numerous glaciers and is fed by the glacial meltwater of several rivers, the water from Lake Viedma brought by the La Leona River, and many mountain streams. Its drainage basin amounts to more than 17000 km2.