Canadian Land of Lakes
This image, acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite, shows wetlands in the Kitikmeot region of Nunavut Territory, in Canada, a region called “Barrend Grounds” or “Barren Lands”.
6:55 am • 14 July 2012 • 100 notes
In this false-colour image of Mississippi River Delta, land vegetation appears pink, while the sediment in the surrounding waters are bright blue and green (via ESA)
9:13 pm • 25 May 2012 • 154 notes
Ouarkziz Impact Crater in Algeria. This crater (3.5 km wide) was formed by a meteor impact less than 70 million of years ago.
7:22 pm • 7 May 2012 • 194 notes
Linear Dunes of the Caprivi Strip
Natural-color image of the Caprivi Strip northeastern Namibia. On the bottom of the image there is the Okavango River.
Caprivi Strip is a stretch of land that “receives more than 600 millimeters (24 inches) of mean annual rainfall and experiences periodic floods”
The stripes visible in the images are linear dunes:
“[…] some are more than 100 kilometers (60 miles) long. Their presence suggests much drier conditions in the past.
Dunes generally form from wind-blown sand over many years. One characteristic of linear dunes is that they tend to remain intact long after the dry conditions cease. And because they don’t migrate like marching dunes, linear dunes preserve dirt and rocks that geologists can later use to understand past conditions.
A study published in 2000 sampled dunes throughout the Caprivi region and found that they likely formed under arid conditions between roughly 60,000 and 20,000 years ago. A study in 2003 concluded that dune construction may have been especially pronounced between 36,000 and 28,000 years ago. After the dunes formed, conditions in the Caprivi Strip moistened enough for the dunes to support vegetation—woodlands on the dune ridges, and grasses and shrubs in the valleys between.” (via EO)
6:15 am • 11 April 2012 • 85 notes
The Arabian Peninsula’s Empty Quarter, or Rub’ al Khali.
White Sands National Monument, Chihuahuan Desert, New Mexico.
Algodones Dunes, southeastern California.
Badain Jaran Desert, Inner Mongolia.
Namib sand sea, Namib Desert, Namibia.
Issaouane erg, Sahara Desert, Eastern Algeria.
Marzuq sand sea, Sahara Desert, Southwest Lybia.
3:39 pm • 7 April 2012 • 321 notes
Nossob river flows through the Kalahari Desert, in Eastern Namibia. (via EO)
7:34 pm • 22 March 2012 • 40 notes
"Geological Investigation of the Alluvial Valley of the Lower Mississippi River" by Harold Fisk, 1944. (via The Rocks Know)
7:32 pm • 18 March 2012 • 297 notes
Kasatochi Volcano is a spectacular stratocone that forms a small island in Aleutians between Adak and Atka Islands. The summit was destroyed during a large explosive event perhaps only a few hundred years ago, exposing the innards of this dramatic volcano. Records of historic activity are sparse, in part because of the remoteness of Kasatochi. (via Alaska Volcano Observatory)
7:15 pm • 24 February 2012 • 107 notes