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The Garabogazkol June 14, 2006

Posted by jtintle in Earth, Moderate Resolution Imaging Spectroradiometer, Planets, Satellite, Space Fotos, Terra satellite.
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The Garabogazkol

Credit:

Jeff Schmaltz, MODIS Land Rapid Response Team,
NASA GSFC

Description:

This MODIS Terra image, acquired June 12, 2006, shows the Garabogazkol (also known asthe Kara-Bogaz-Gol) – a shallow depression in the northwestern corner of Turkmenistan. Separated from the Caspian Sea by a thin sandbar, its water volume fluctuates seasonally. At times it becomes a large bay of the Caspian Sea, while at other times its water level drops drastically.

The water is very salty, much more so than the Caspian Sea, and has almost no marine life vegetation! The salt has been both good and bad – the valuable salts have been harvested from the 1950s on. But the salt has also caused health problems and poisoned soil for hundreds of kilometers downwind to the east.

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San Francisco Peaks Volcano Field May 23, 2006

Posted by jtintle in Advanced Spaceborne Thermal Emission and Reflection Rad, Earth, Goddard Space Flight Center, NASA, Planets, Satellite, Space Agencies, Space Fotos, Terra satellite, Volcanoes.
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San Francisco Peaks Volcano Field

Click here to view full image (161 kb)

Northern Arizona is best known for the Grand Canyon. Less widely known are the hundreds of geologically young volcanoes scattered across the southern portion of the Colorado Plateau at the eastern foothills of the San Francisco Peaks. This image from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite shows the numerous cinder cones, hills of volcanic ash and rock fragments, in the San Francisco Volcanic Field in the foreground (bottom part of the scene) with San Francisco Mountain in the background. ASTER image data from October 21, 2003, were draped over topographic data from the U.S. Geological Survey. The picture is oriented as if you were looking generally westward. The large version of the image is centered near 35.3 degrees north latitude and 111.5 degrees west longitude.

The developed areas of the outskirts of Flagstaff, Arizona, appear as bright white flecks against the surrounding vegetation. To the north of the city rises Elden Mountain, separated by a canyon from the larger San Francisco Mountain. The catastrophic result of an eruption at San Francisco Mountain about 400,000 years ago is visible in the collapsed look of the mountain’s eastern flank. Lava and other volcanic material appear purple, and the cinder cone field is tinged with green, as vegetation begins to colonize the newly laid landscape. Among the most dramatic flows is the Bonito Lava Flow.

Native Americans were living in this region when the cinder cone volcano known as Sunset Crater (named for the red-tinged rocks and cinders on its slopes) was born around 900 years ago. Accounts of the volcanic activity, which included several eruptions between A.D. 1064 and 1180, describe earthquakes, fire bombs, billowing ash, falling cinders, forest fires, and lava flows. The region is part of the sacred lands of several modern Pueblo peoples, and Sunset Crater is protected as a National Monument.

NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team

Gilbert Islands, central Pacific Ocean May 14, 2006

Posted by jtintle in Earth, Gilbert Islands, Moderate Resolution Imaging Spectroradiometer, Planets, Space Fotos, Terra satellite.
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Gilbert Islands, central Pacific Ocean
Credit: Jeff Schmaltz
Links: MODIS Land Rapid Response Team,
NASA GSFC

This image, acquired by the MODIS on the Terra satellite, shows the Gilbert Islands, located in the central Pacific Ocean. The Gilbert Islands are a chain of 16 atolls and coral islands, and are one of the island groups that form the Republic of Kiribati. The islands are about 930 miles north of Fiji, and the equator runs through the center of the islands, right through the center of the image.

The islands were discovered by Europeans in the late 18th century; one of the explorers was Captain Thomas Gilbert.

The native population of the Gilberts are Micronesian, similar in many respects to the Marshall Islands, the Carolines, and the Marianas.

Watching the World Rev its Heat Engine April 28, 2006

Posted by jtintle in CERES Science Team, Earth, NASA, Space Fotos, Terra satellite.
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Terra/CERES  

Absorption of solar energy heats up our planet’s surface and the atmosphere and makes life for us possible. But the energy cannot stay bound up in the Earth’s environment forever. If it did then the Earth would be as hot as the Sun. Instead, as the surface and the atmosphere warm, they emit thermal longwave radiation, some of which escapes into space and allows the Earth to cool. This false-color image of the Earth was produced on September 30, 2001, by the Clouds and the Earth’s Radiant Energy System (CERES) instrument flying aboard NASA's Terra spacecraft. The image shows where more or less heat, in the form of longwave radiation, is emanating from the top of Earth’s atmosphere.

As one can see in the image, the thermal radiation leaving the oceans is fairly uniform. The blue swaths across the central Pacific represent thick clouds, the tops of which are so high they are among the coldest places on Earth. In the American Southwest, which can be seen in the upper righthand corner of the globe, there is often little cloud cover to block outgoing radiation and relatively little water to absorb solar energy. Consequently, the amount of outgoing radiation in the American Southwest exceeds that of the oceans. Also, that region was experiencing an extreme heatwave when these data were acquired.

Recently, NASA researchers discovered that incoming solar radiation and outgoing thermal radiation increased in the tropics from the 1980s to the 1990s. (Click to read the press release.) They believe that the reason for the unexpected increase has to do with an apparent change in circulation patterns around the globe, which effectively reduced the amount of water vapor and cloud cover in the upper reaches of the atmosphere. Without the clouds, more sunlight was allowed to enter the tropical zones and more thermal energy was allowed to leave. The findings may have big implications for climate change and future global warming.

“This suggests that the tropical heat engine increased its speed,” observes Dr. Bruce Wielicki, of NASA Langley Research Center. “It’s as if the heat engine in the tropics has become less efficient, using more fuel in the 1990s than in the 1980s.”

Floods on the Danube River April 26, 2006

Posted by jtintle in ASTER, Earth, NASA, Space Fotos, Terra satellite.
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Floods on the Danube River Click here to view full image (3176 kb)

The Danube River spills over into farm fields in the northeastern corner of Serbia in this image, taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite on April 24, 2006. Though water levels on the Danube River in Eastern Europe had been expected to fall by this time, the river was still running high on April 24. Melting snow and spring rain have driven rivers across Central Europe over their banks, causing widespread flooding. High water levels on the Danube forced evacuations throughout Serbia, Romania, and Bulgaria in late April 2006, according to news reports.

In the region shown here, a small village is nestled within a bend in the river. Streets, houses, and exposed earth form a tight grey grid within the village, interrupted by occasional red squares where plants are growing. The rest of the land in the scene is covered with long, rectangular agricultural fields. Bare fields, as yet unplanted, are grey, while those in which crops are growing are red. The river, blue, seeps over its banks and across the fields in the center of the image. Smudges of blue along the banks of the river in the village hint that flooding may be occurring here too, though the darker colors may also be shadows cast by the small clouds overhead. On April 23, Reuters reported that some 225,000 hectares of Serbia’s farm land, about 5 percent of the arable land in the country, had been flooded or threatened by floods.

Numerous images of floods in Central Europe can be found in the Earth Observatory’s Natural Hazards: Floods section.

NASA image created by Jesse Allen, Earth Observatory, using data obtained courtesy of the NASA/GSFC/METI/ERSDAC/JAROS and U.S./Japan ASTER Science Team.

Princess Astrid Ice Shelf December 15, 2005

Posted by jtintle in Earth Observing System (EOS), Antarctica, Aqua, Earth, Moderate Resolution Imaging Spectroradiometer, NASA, National Snow and Ice Data Center, Space Fotos, Terra satellite.
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Princess Astrid Ice Shelf Click here to view full image (77 kb)

Released in the fall of 2005, the MODIS Mosaic of Antarctica (MOA) has offered a new view of the frozen continent with unprecedented detail. The map is compiled from 260 images of Antarctica acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on NASA’s Terra and Aqua satellites. Using images collected between November 20, 2003, and February 29, 2004, MOA includes all land areas covered by the Antarctic Treaty. This MOA image shows part of the Princess Astrid Ice Shelf. Prominent on this ice shelf are features that glaciologists often study in Antarctica: blue ice and melt ponds.

Snow is composed of tiny ice crystals with many facets that reflect light like a mirror. Light shining into snow is bounced back largely unaltered, so snow appears white. Over time, however, compressed layers of snow turn to ice, and wind can expose this ice by sweeping away or evaporating lighter layers of snow. Compressed ice has big, clear crystals that allow light to travel through more of the ice before reflecting back. Ice absorbs a tiny amount of red light from the spectrum, so the light coming out of the ice appears blue to human eyes. Although MOA imagery is grayscale, blue ice nevertheless has a unique appearance in the imagery. In this image, windswept blue ice appears as swirling patchwork patterns of dark gray.

Melt ponds also appear in this image, showing up as curving lines of charcoal gray. Melt ponds have attracted the scrutiny of glaciologists because of the effects they have on ice shelves and glaciers. Warm summers can cause ponds of melt water to collect on the ice surface, and these ponds may eventually fill small cracks in the ice. Depending on the depth of a crack and the amount of water filling it, the water may deepen the crack, eventually carving all the way through the thick plate of ice. On a glacier, melt ponds can lead to water flow on the glacier’s underside, loosening it from the bedrock and accelerating flow. On an ice shelf, melt ponds can lead to ice shelf disintegration.

Image courtesy the National Snow and Ice Data Center, based on data from NASA’s Aqua and Terra MODIS sensors.

Hurricane Epsilon December 7, 2005

Posted by jtintle in Earth Observing System (EOS), Earth, Goddard Space Flight Center, Hurricane Epsilon, Moderate Resolution Imaging Spectroradiometer, NASA, Space Fotos, Terra satellite.
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Hurricane Epsilon Click here to view full image (4237 kb)

Explanation:
The official hurricane season in the Atlantic Ocean runs from June 1 to November 30 each year, but on very rare occasions, tropical storms and even hurricanes form outside the season. In 150 years of records, a hurricane has formed outside of the season on only four other occasions. But with so many records broken by the 2005 Atlantic hurricane season, it seems almost unsurprising to find Hurricane Epsilon ushering in December and bumping that out-of-season-hurricane record up to five storms. Epsilon formed in the Central Atlantic about halfway between the Azores Islands and Bermuda on November 29, 2005.

This image shows Hurricane Epsilon in the mid-Atlantic, as observed by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite on December 4, 2005, at 13:30 UTC (10:30 a.m. local time). At that time, the hurricane had peak sustained winds of 140 kilometers per hour (85 miles per hour). That intensity appears to be the strongest the storm will achieve, according to forecasts from early on December 5, 2005. The storm had been sustaining winds from 120-140 kilometers per hour (75-85 mph) for roughly 48 hours at that time. This longevity ensures that Epsilon, despite having four other storms for company in the out-of-season-hurricane neighborhood, will nevertheless go down alone in the record books in at least one respect: it has broken a new record for the longest-lived December hurricane.

Image Credit: Jeff Schmaltz, MODIS Rapid Response Team,Goddard Space Flight Center

Karthala Volcano Erupts December 1, 2005

Posted by jtintle in Earth Observing System (EOS), Earth, Karthala, Moderate Resolution Imaging Spectroradiometer, NASA, Space Fotos, Terra satellite.
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Karthala Volcano Erupts Click here to view full image (298 kb)

On November 24, 2005, Americans celebrated Thanksgiving. Halfway around the world, some 2,000 people fled their homes, hoping to escape the latest eruption of the Karthala Volcano. The volcano covered nearby villages in ash, and locals had little means of protecting their lungs besides covering their faces with scarves. As of November 28, one casualty (an infant) had been reported.

Karthala is one of two volcanoes that make up Grand Comore (or Ngazidja) Island in the Comoros archipelago. These islands lie in the Indian Ocean, between Africa and Madagascar. The Moderate Resolution Imaging Spectroradiometer (MODIS) flying onboard the Terra satellite captured this image on November 25, 2005. In this image, Grand Comore appears only in outline as material from the eruption completely obscures the satellite’s view of the land surface. The volcanic ash ranges in color from tan to beige. It has spread out around the volcano in all directions, but moves primarily eastward.

With an altitude of 2,361 meters (7,746 feet), Karthala is a shield volcano, with smooth slopes built from hardened lava. Comprising the southern portion of Grand Comore Island, Karthala is a regular troublemaker in its neighborhood. The volcano has erupted about 20 times in the last century, most recently in April 2005. The November 2005 eruption caused fears of lava floods and poisonous gases. The volcano had showed signs of trouble for several days before the eruption, and the ground continued to rumble afterwards.

Even after the volcano stopped erupting, trouble for the region was expected to continue. The November eruption fouled drinking water already made scarce by the region’s dry season. According to news reports, the UN Office for the Coordination of Humanitarian Affairs estimated that almost 120,000 people were without clean drinking water after the volcano dropped ash into water cisterns.

NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center

Ireland November 30, 2005

Posted by jtintle in Earth Observing System (EOS), Earth, Moderate Resolution Imaging Spectroradiometer, NASA, Space Fotos, Terra satellite.
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Ireland

Satellite: Terra
Date Acquired: 11/21/2005
Resolutions: 1km (238.2 KB)
500m (912.9 KB)
250m (2.4 MB)
Bands Used: 1, 4, 3
Credit: Jeff Schmaltz
MODIS Land Rapid Response Team,
NASA GSFC

Explanation: The rich and vibrant greens in this image depict the aptly-named “Emerald Isle?. Ireland (also called the ‘Republic of Ireland’) comprises about 5/6 of the island, while Northern Ireland, a region of the United Kingdom, encompasses the remaining portion. The darker colors in this image signify the coastal mountain ranges, while the lighter colors indicate the central lowlands or plains. In the past, forests covered the entire island, but the island was virtually stripped of its trees in the 17th century. Since then, agriculture has dominated the landscape, although currently Ireland’s economy is dominated by the industrial and service sectors. Ireland is located at high latitude (between 51.5 and 55.5 degrees North), but its climate is very mild: the average temperature in Winter is about 4 degrees Celsius (39 degrees Fahrenheit), while the average Summer temperature is about 16 degrees Celsius (61 degrees Fahrenheit). This condition is caused by the North Atlantic Current or Drift (of which the Gulf Stream is a part); warm water from the Gulf of Mexico is carried to the North Atlantic by strong ocean currents. Some of the water evaporates, making the water that remains much saltier and colder, and, therefore, more dense. It then sinks towards the ocean floor and is carried back in the direction from which it came. Recent research by NASA and other scientists indicates that this conveyor belt-like system may have been, and continue to be, disrupted by global warming.

The Caspian Sea November 29, 2005

Posted by jtintle in Earth Observing System (EOS), Earth, Moderate Resolution Imaging Spectroradiometer, NASA, Space Fotos, Terra satellite.
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The Caspian Sea

Satellite: Terra
Date Acquired: 11/21/2005
Resolutions: 1km (434.6 KB)
500m (1.5 MB)
250m (3.8 MB)
Bands Used: 1, 4, 3
Credit: Jeff Schmaltz
MODIS Land Rapid Response Team,
NASA GSFC

The Caspian Sea dominates this image at the crossroads of Europe and Asia. The Caspian is just Southwest of the Ural Mountains, the traditional dividing line between the two continents. It is bordered by Russia and Azerbaijan to the West, Kazakhstan to the North, Turkmenistan to the East, and Iran to the South. The Caspian is the largest inland body of water in the world, measuring over 370,000 square kilometers (143,000 square miles). It is fed by the Volga and Ural Rivers, but it has no natural outlet; instead, water is lost primarily through evaporation. It is relatively shallow, measuring only about a 1 kilometer (0.6 miles) deep; in contrast, the deepest lake in the world (Lake Baikal) is 1.6 kilometers (0.9 miles) deep but only about 31,000 square kilometers (12,000 square miles) in area. The Caspian, although sometimes classified as a lake, is comprised of salt, not fresh, water. The Caspian Sea is a major source of sturgeon, a highly valuable type of fish that produces most of the world’s caviar.

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