Tuesday, January 20, 2009
From the space
The Bear Glacier on the Kenai Peninsula along the Gulf of Alaska seen by the IKONOS satellite took this on August 8, 2005. This image shows the ablation zone where the glacier is primarily losing ice. Upslope from the lake, the foot of the glacier is riddled with crevasses - cracks in the ice caused by the glacier's movement over a rough surface. Down the middle of the glacier run dark gray stripes. As a glacier moves, it picks up dirt and debris from the rocks it passes. When two glaciers merge, as they have here, the dirt and debris they carry form parallel stripes, or medial moraines, on the ice surface. (IKONOS satellite image courtesy GeoEye)
In a post called The Earth (and water) from above I published a collection of wonderful aerial images of our planet where water is interesting in some way. This time I do the same but moving our point of view some kilometers higher: NASA satellites. The source of this image is Earth Observatory a Wonderful NASA website dedicated to satellitar images. Visiting it daily to see their Picture of the day is a good habit!
Two cyclones are seen, after forming in tandem in November 2006. The Moderate Resolution Imaging Spectroradiometer (MODIS) onboard NASA's Terra satellite took this picture of the two cyclones south of Iceland on November 20 (South is up in image). (NASA/Jesse Allen, Earth Observatory)
Even the most snow-covered place on Earth has patches of snow-free ground. In Antarctica, a series of parallel valleys lie between the Ross Sea and the East Antarctic Ice Sheet. Known as the Dry Valleys, they are swept free of snow by nearly relentless katabatic winds - cold, dry air that rolls downhill toward the sea from the high altitudes of the ice sheet. The Dry Valleys harbor a collection of glaciers and ice-covered lakes. This false-color image was captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite on November 29, 2000. (NASA/Jesse Allen, NASA/GSFC/METI/ERSDAC/JAROS,U.S./Japan ASTER Science Team)
During the last ice age, Canada's Akimiski Island was buried under several thousand meters of ice, but since its retreat, the island has rebounded (risen in elevation) and new beach areas have emerged, streams and lakes have formed, and trees and other vegetation have colonized the new territory. This image of Akimiski Island was captured by the Landsat 7 satellite on August 9, 2000. (NASA/Jesse Allen, Landsat,University of Maryland's Global Land Cover Facility)
Steep Antarctic mountains channel the flowing ice sheet into a fast-moving river of ice named Byrd Glacier located near McMurdo Station, the principal U.S. Antarctic Research Base. The glacier plunges through a deep, 15-mile-wide valley in the Transatlantic Mountains to create a 100-mile-long, rock-floored ice stream. This image, captured by the Landsat 7 satellite on December 24, 1999, shows part of the Byrd Glacier flowing through the Transatlantic Mountains. (Jesse Allen, Landsat Image Mosaic of Antarctica,LIMA)
In mid-December 2005, the diminutive Amsterdam Island made waves - not in the Indian Ocean where it resides, but in the clouds overhead. The MODIS instrument aboard NASA's Terra satellite captured this image on December 19, 2005. The island itself is almost too small see in this image, but it serves as the starting point for the clouds that flow toward the northeast in a giant V shape. (NASA/Jeff Schmaltz, MODIS Land Rapid Response Team at NASA GSFC)
This highly detailed image from the Taiwanese Formosat-2 satellite shows the different sizes, shapes, and textures of ice fragments from an ice shelf on the Antarctic Peninsula on March 8, 2008. Several large icebergs float amid a mosaic of smaller pieces of ice. The level of detail in the image is so great that it can seem as though you are standing over a scale model made out of papier-mâché and foam blocks. The detail can make the bergs seem deceptively small. In reality, some of the large bergs are several hundred meters (yards) long. (Formosat image © 2008 Dr. Cheng-Chien Liu, National Cheng-Kung University and Dr. An-Ming Wu, National Space Organization, Taiwan)
Tropical Cyclone Billy, seen off the coast of Western Australia on December 25, 2008 by the MODIS instrument on NASA's Aqua satellite. (NASA/Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center)
This image shows a colorful bloom of phytoplankton throughout the Black Sea on June 4, 2008, along the southern coast near the Turkish cities of Sinop and Samsun. The natural-color image was captured by the MODIS instrument on NASA's Aqua satellite. (NASA/MODIS Rapid Response Team)
The setting sun glints off the Amazon River and numerous lakes in its floodplain in this astronaut photograph from August 19, 2008. About 150 kilometers of the Amazon is shown here, about 1,000 kilometers inland from the Atlantic Ocean. This image was acquired on August 19, 2008 by the by the Expedition 17 crew of the International Space Station. (NASA/JSC)
Dust plumes blew off the coast of Saudi Arabia and over the Red Sea in mid-January 2009. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this image on January 15, 2009. The largest plume blows off the Saudi Arabian coast north of Jiddah (or Jeddah), forming a counter-clockwise arc that barely misses the Sudanese coast. Along the northwestern margin of this plume, tendrils of dust form lines roughly perpendicular to the plume’s arc. These tendrils may arise from different air currents at different altitudes. Another relatively large plume blows over the Red Sea to the north, forming wavy lines that dissipate midway over the Sea.The dust plumes arise from fine sediments along Saudi Arabia’s west coast, and many source points appear in this image. Although these dust plumes are from Saudi Arabia, dust can blow over the Red Sea from either direction. Dust plumes from Sudan also occur regularly in this region. Inland from the coast, the land surfaces of both Saudi Arabia and Sudan appear rugged and rocky, darker in color from the fine sediments that can easily give rise to dust plumes.
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