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Archive for Rivers

Sediments from the Flinders River, Australia

17.8S 140.5E

May 24th, 2013 Category: Rivers, Sediments

Australia – May 24th, 2013

Predicted climate change for the Australian tropics includes higher temperatures, a more intense monsoon, general increase in rainfall intensities, possible marked increase in heavy rains, more floods and dry spells, increased potential evaporation and enhanced topographic effects on rainfall. To predict river response to climate change and agricultural development, scientists have studied the condition of existing rivers in the Australian tropics, such as the Flinders River, visible here spilling sediments into the southern part of the Gulf of Carpentaria.

The Flinders River is the longest river in Queensland, Australia at about 1004 km, and the sixth longest river in all of the country. The river rises in the Burra Range, part of the Great Dividing Range, and flows into the Gulf of Carpentaria 25 km west of Karumba, Queensland. The catchment covers 109,000 km², in which anabranching rivers predominate, with confined and constrained rivers also present. (click here for more information).

Fires in Mato Grosso, Brazil

12.9S 54.1W

May 21st, 2013 Category: Fires, Rivers

Brazil – May 21st, 2013

Plumes of smoke can be seen from fires in the state of Mato Grosso, in western Brazil. The two main fires, best observed in the full image, can be seen in the lower left and upper right quadrants, releasing smoke westward. Between the two fires is a tract of heavily forested land through which the Ronuro River flows.

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.

Dust and Desertification in Iraq

33.9N 43.2E

May 19th, 2013 Category: Climate Change, Dust Storms, Rivers

Iraq – May 19th, 2013

Some dust blows over the Tigris and Euphrates River Valley in Iraq. Iraq suffers from desertification and soil salination due in large part to thousands of years of agricultural activity. Water and plant life are sparse. Saddam Hussein’s government water-control projects drained the inhabited marsh areas east of An Nasiriyah by drying up or diverting streams and rivers.

The marshlands were a fine and extensive natural wetlands ecosystem which developed over thousands of years in the Tigris–Euphrates basin and once covered 15–20,000 square kilometers. Between 84% and 90% of the marshes have been destroyed since the 1970s. In 1994, 60 percent of the wetlands were destroyed by Hussein’s regime – drained to permit military access and greater political control of the native Marsh Arabs.

The drying of the marshes led to the disappearance of the salt-tolerant vegetation; the plankton rich waters that fertilized surrounding soils; 52 native fish species; the wild boar, red fox, buffalo and water birds of the marsh habitat.

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).