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Lake Winnipeg and Nelson River in Manitoba, Canada

52.3N 97.5W

May 21st, 2013 Category: Climate Change, Lakes, Rivers

Canada – May 20th, 2013

Ice covers the northern part of Lake Winnipeg, in Manitoba, Canada, visible at the center of the bottom edge of this image. The shores of the Hudson Bay are also lined with ice (upper right quadrant), and sediments can be seen spilling from the Nelson River into the bay.

Climate change has the potential to affect the ecology and biology of Lake Winnipeg. Climate-forcing scenarios predict increases in mid-summer temperatures through the 21st century, with even greater increases in mid-winter temperatures, extending the open water season.

Sediments and Phytoplankton Near Volga Delta in Northern Caspian Sea

46.1N 50.9E

May 11th, 2013 Category: Lakes, Rivers, Sediments

Russia – May 10th, 2013

 This image shows the Volga Delta and the northern part of the Caspian Sea, bright green and blue from sediments and phytoplankton. The sedimentation rates and the types of recent deposits in the Northern Caspian Sea are governed mainly by the abundant Volga discharge.

Investigations based on a complex of techniques revealed that the modern deposits in the Northern Caspian Sea involve terrigenous sands and aleurites with an admixture of detritus and intact bivalve shells, including coquina. Generally, these deposits overlay dark grayish viscous clays.

A similar geological situation occurs in the Volga delta; however, the local deposits are much poorer in biogenic constituents. Illite prevails among the clay minerals. The heavy transparent minerals are represented in the coarse aleurite fraction mostly by epidotes, while quartz and feldspars represent the lighter minerals. The sedimentary material in the Volga delta is far from completely differentiated into fractions due to the abundance of terrigenous inflows, which exceed the energy potential of the river (click here for more information).

Lakes, Rivers and Wetlands in Botswana, Zimbabwe and Zambia

17.6S 24.9E

April 27th, 2013 Category: Lakes, Rivers, Wetlands

Botswana, Zimbabwe and Zambia – April 27th, 2013

Multiple lakes and wetland areas can be observed in this image that focuses on Botswana, Zimbabwe and Zambia (counter-clockwise from lower left quadrant). Visible near the center left is the Okavango Delta, an inland delta in Botswana, with the salt flats of the Makgadikgadi Pan to the southeast. In the upper left quadrant is the Barotse Floodplain, in Zambia, while in the upper right quadrant is Lake Kariba, on the Zimbabwe-Zambia border.

The area in the center of the image is the Caprivi Strip, a narrow protrusion of Namibia eastwards from the Okavango Region about 450 km (280 mi), between Botswana to the south, and Angola and Zambia to the north. Caprivi is bordered by the Okavango, Kwando, Chobe and Zambezi rivers. 

Lake Ihotry and Mangoky River Delta, Madagascar

21.9S 43.6E

April 26th, 2013 Category: Lakes, Rivers

Madagascar – April 26th, 2013

Visible near the western shores of Madagascar is the green Lake Ihotry, a closed saline lake in semi-arid southwestern part of Madagascar. Its area varies seasonally, from 96 km² to 112 km², as does its salinity. Between the lake and the coast is a rather large, whitish area of sand interspersed with silt-laden ponds.

Visible north of the lake is the mouth of the Mangoky River, through which sediments can be seen pouring into the Mozambique Channel. The river is 564 kilometers (350 mi) long, rising in the Central Highlands and flowing generally in a westerly direction out of them, crossing the southern extension of the Bemaraha Plateau, until it reaches the coastal plain and its delta.

Most of Madagascar has undergone serious deforestation during the last 40 years, chiefly from slash-and-burn practises by indigenous peoples. This loss of forest has led to extreme soil erosion in the Mangoky River basin, as evidenced by the many sandbars located within the river channel.

The southern portion of the Ihotry delta is dominated by successive barrier island and spit formation. In contrast, the northern, protected portion of the delta is dominated by tidal passes and mangrove swamps.

Climate Change’s Potential Effects on Lake Ontario and Saint Lawrence River, Canada and USA

43.6N 78.1W

April 7th, 2013 Category: Climate Change, Lakes, Rivers

USA and Canada – April 6th, 2013

Snow dusts the landscape of part of the northeastern USA and Canada, framing the shores of the Saint Lawrence River. The river traverses the Canadian provinces of Quebec and Ontario and forms part of the international boundary between Ontario and New York in the United States. It is the primary drainage conveyor of the Great Lakes Basin, and in this image can be seen connected to Lake Ontario.

In the opinion of some experts, a temperature increase of 2 to 4°C could lower the average flow from Lake Ontario by 24%. Lake Ontario is the major source for the St. Lawrence River, and a decrease in flow of this magnitude could result in a 1-metre drop in water levels in some areas of the St. Lawrence.

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