http://www.redorbit.com/images/1/images-of-the-day/gallery/1/earth-4/ http://www.redorbit.com/media/themes/redorbit/images/logo_160x80.gif http://www.redorbit.com/ 160 80 http://www.redorbit.com/images/pic/77439/earth-skylab-view-of-the-great-salt-lake-051813/ 2013-05-18T11:25:41+0000
The first American space station was launched into orbit on a Saturn V rocket on May 14, 1973. In the nine months that followed, three separate crews made progressively longer stays on Skylab. The astronauts made observations of the Sun—including the first images of solar flares from space—conducted biomedical and microgravity experiments on themselves, and did a lot of maintenance and handy work to keep the converted rocket shell working as a laboratory. They also took photographs and observations of home.

“Between 8 and 10 at night, we had free time,” said astronaut Gerald Carr, who commanded the third crewed mission on Skylab for 84 days. “For the most part, the most fun was looking out the window.”

Astronauts on the Skylab 2 mission (May 25 to June 22, 1973) took this photograph of north central Utah with a Hasselblad camera, using an 80 millimeter lens and Kodak Etkachrome MS film. Note the different colors in the north and south sections of the Great Salt Lake, which are separated by a railroad causeway that restricts the mixing of the waters. The north section is much more salty, and different species of algae give the two sections different hues.

Skylab included several handheld cameras and the Earth Resources Experiment Package (EREP), a series of sensors and cameras that observed the Earth in visible, microwave, and infrared light. In 171 days of Skylab operation, EREP collected more than 350,000 photos and 72,725 meters (238,599 feet) of magnetic data tape, observing Earth’s surface between roughly 50 degrees north and south latitude. The astronauts even observed category 5 Hurricane Ava near Acapulco, Mexico.

Astronaut photograph SL2-6-478 was acquired in the spring of 1973 with a Hasselblad camera using an 80 millimeter lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Skylab 2 crew. It has been cropped and enhanced to improve contrast, and lens artifacts have been removed. Caption by Mike Carlowicz.
]]> 0 http://www.redorbit.com/images/pic/77330/earth-argentina-laguna-verde-sub-basins-051613/ 2013-05-16T11:16:25+0000
Laguna Verde (58 kilometers wide, 36 km long) often appears green, giving rise to its name. This image shows the turquoise tint in the central sub-basin (image center), with a yellow to black tinge to water in the southern sub-basin (left)—also known locally as Laguna Negro. The northernmost basin (right) appears black. The large gray zone comprising much of the rest of Laguna Verde is likely a combination of shallow water—only inches deep—and sunglint reflecting off the water surface. The reason for the color differences is that many different families of salt-loving organisms occupy hypersaline lakes such as Laguna Verde. These microscopic organisms appear as different colors, often bright, depending on the salinity and temperature of each water body or sub-basin.

The rest of the lake floor is dry and appears white from the build-up of thick salt deposits. Parallel lines around the southern subbasin (Laguna Negro) indicate prior shorelines of this shrinking water body. Evaporation removes water but leaves ephemeral shorelines marked with white salt.

Astronaut photograph ISS035-E-25019 was acquired on April 20, 2013, with a Nikon D3S digital camera using a 400 millimeter lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 35 crew. It has been cropped and enhanced to improve contrast, and lens artifacts have been removed. Caption by M. Justin Wilkinson, Jacobs/JETS at NASA-JSC.
]]> 0 http://www.redorbit.com/images/pic/77327/earth-iss-expedition-35-crew-landing-051513/ 2013-05-15T10:55:54+0000
Image Credit: NASA/Carla Cioffi
]]> 0 http://www.redorbit.com/images/pic/77228/earth-australia-new-south-wales-jervis-bay-051413/ 2013-05-14T11:37:13+0000
The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured this natural-color image of Jervis Bay on March 29, 2013. This image has been rotated such that north is to the right.

Bright white sands line the coastline around Jervis Bay. When water erodes rocks and carries them downstream or out to sea, softer minerals slowly erode away. Quartz—composed of clear or white silicon dioxide crystals, or silica—resists erosion longer than other rock types. So the brilliant sands of Jervis Bay owe their color (or lack of it) to the relentless action of water from old rivers, and rising and falling seas over thousands of years. According to the Guinness Book of Records, the sands around Jervis Bay are the whitest in the world. These sands are also finer than typical ocean beach sand.

Just offshore from the white sands are the unusually clear waters of Jervis Bay. Nearby streams are too small to carry heavy loads of sediment that would cloud the water, and the surrounding wetlands and forests also trap sediments that might otherwise drain into the bay. Meanwhile, human settlement in the area has been relatively mild, so runoff from agriculture and land disturbance are minimized.

Visitors to Jervis Bay National Park may catch glimpses of humpback whales, southern right whales, and dolphins off the coast. On land, rare plant species thrive within the confines of the park. The park even protects habitat for entire communities that have become endangered, such as saltmarsh and floodplain forest. Plants here enjoy abundant moisture, and monthly rainfall totals peak at more than 130 millimeters (over 5 inches) from April through June. According to the New South Wales National Parks and Wildlife Service, the record for rainfall at Jervis Bay is 316.7 millimeters (12.5 inches) in a single day.

NASA Earth Observatory image by Jesse Allen and Robert Simmon, using EO-1 ALI data provided courtesy of the NASA EO-1 team. Caption by Michon Scott.
]]> 0 http://www.redorbit.com/images/pic/77127/earth-solar-eclipse-casts-its-shadow-051313/ 2013-05-13T10:51:09+0000
NASA\'s Terra satellite didn\'t observe the eclipse directly, but it did see the moon\'s shadow darkening the region northeast of Australia including the Solomon Islands. This image was captured by Terra\'s Moderate Resolution Imaging Spectroradiometer on May 9, 2013, at 23:30 UTC (7:30 p.m. EDT).

Credit: NASA/Goddard/MODIS Rapid Response Team
]]> 0 http://www.redorbit.com/images/pic/77124/earth-sand-sea-namib-desert-kompsat-051113/ 2013-05-11T10:28:52+0000
The Namib is the oldest desert in the world, stretching over 2000 km along Africa’s southwestern coast from Angola, through Namibia to South Africa. Sand dunes dominate the desert – some reaching over 300 m in height.

The blue and white area is the dry river bed of the Tsauchab – which only sees water following rare rainfall in the Naukluft Mountains to the east. Black dots of vegetation are concentrated close to the river’s main route, while salt deposits appear bright white.

This flattened area ends about 15 km to the east at the Sossusvlei salt and clay pan (not shown).

Running through the river valley, a road connects Sossusvlei to the Sesriem settlement. At the road’s 45th kilometer, seen at the lower-central part of the image, a white path shoots off and ends at a circular parking area at the base of a dune. This is Dune 45, a popular tourist stop on the way to and from Sossusvlei.

The 170 m-high dune is often photographed early in the morning or late in the day when one side is completely in shadow. In this image, there appears to be some shadow on the western side. From this we can deduce that the image was acquired during the late morning.

ESA supports Kompsat as a Third Party Mission, meaning it uses its ground infrastructure and expertise to acquire, process and distribute data to users.

Credits: KARI/ESA
]]> 0 http://www.redorbit.com/images/pic/77121/earth-iss-expedition-crew-views-sunrise-of-south-pacific-051013/ 2013-05-10T11:19:58+0000
The space station was at a point above Earth located at 27.4 degrees south latitude and 110.1 degrees west longitude, a few hundred miles east of Easter Island.

Image Credit: NASA
]]> 0 http://www.redorbit.com/images/pic/77085/earth-san-diego-california-and-tijuana-baja-california-iss-050913/ 2013-05-09T11:22:25+0000
The city of San Diego was founded in 1769 by Franciscan friar Junípero Serra. While the valley of Tijuana was explored at this time, the city would not be founded until 1889. Today, the San Diego-Tijuana conurbation also includes the cities of Chula Vista, Carlsbad, San Marcos, and National City in the United States, and Tecate and Rosarito Beach in Mexico. The combined population of the region is approximately 5 million according to 2010 census information from both the USA and Mexico.

The city of Coronado, California, situated on an artificial peninsula across the bay from San Diego, is both a popular beach resort and the location of a U.S. Navy air station and training facilities. Point Loma defines the western boundary of San Diego Bay and is part of the city of San Diego. While the northern half of the Point Loma peninsula hosts various residential communities, the southern half is federal land occupied by U.S. Navy installations, the Fort Rosecrans National Cemetery and the Cabrillo National Monument that marks the landing of the first European on the west coast of the United States.

Astronaut photograph ISS035-E-27265 was acquired on April 23, 2013, with a Nikon D3S digital camera using a 400 millimeter lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 35 crew. It has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by William L. Stefanov, Jacobs/JETS at NASA-JSC.
]]> 0 http://www.redorbit.com/images/pic/77082/earth-paluweh-volcano-in-indonesia-landsat-thermal-sensor-050813/ 2013-05-08T11:02:52+0000
Credit: Robert Simmon, NASA\'s Earth Observatory, using data from USGS and NASA

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]]> 0 http://www.redorbit.com/images/pic/77034/earth-black-sea-drainage-with-jewel-toned-blooms-modis-050713/ 2013-05-07T11:28:11+0000
Much of the Black Sea drainage basin, as well land immediately surrounding the Sea, are agricultural areas, and fertilization of the land is frequent. Runoff carries fertilizers into the Sea, spurring the growth of phytoplankton (microscopic plant-like organisms) which can reproduce rapidly in jewel-toned blooms which can be easily seen from space. The milky-blue swirls which color the eastern part of the Sea are typical colors for phytoplankton; however, the green tones near the river outflows may well reflect not only sediment, but also phytoplankton growth.

The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite captured this true-color image on April 28.

Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC
]]> 0 http://www.redorbit.com/images/pic/76930/earth-pacific-ocean-ship-tracks-and-vortices-modis-050613/ 2013-05-06T11:11:05+0000
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image on April 20. The ship-track clouds and cloud vortices occurred inside an area of relatively clear skies inside a larger expanse of marine clouds. The long, thin ship tracks stretched roughly east-west, and appeared slightly brighter than the surrounding marine clouds.

The relative brightness of ship tracks results from the way they are formed. Cloud droplets form as tiny spheres of water around airborne particles, or aerosols. The particles may be natural—such as desert dust or sea salt—or artificial—such as the particles from ship exhaust. Compared to natural aerosols, ship exhaust particles are smaller and more concentrated within a given area, seeding smaller, more numerous cloud droplets. The spheres of water in clouds all reflect sunlight, but some reflect light better than others. Compared to a big sphere, a small sphere has a greater surface-to-volume ratio, and the greater surface area makes for a better reflector. So water droplets in ship-track clouds reflect more light than cloud droplets seeded by natural particles.

Although the ship tracks over the Pacific Ocean in late April 2013 mostly ran east-west, some took on swirling shapes, perhaps caught up in the cloud vortices off the Aleutian Islands. When a moving air mass encounters an obstacle such as a volcanic island, the wind flow is disrupted. Downstream from the obstacle, von Karman vortices sometimes form. These double-row vortices alternate the direction and rotation of air. Clouds make the vortices visible, and the results are beautiful paisley patterns. A line of vortices can be seen stretching southward from Tanaga Island.

Yet another distinct cloud formation is visible in the image above: ship wave clouds. Just as vortices can result from an obstruction to air flow, air that rises and falls can create atmospheric wave patterns. Clouds near the wave tops are brighter than clouds near the wave bottoms. These clouds are named for the waves formed in the wakes of boats.

NASA Earth Observatory image by Jesse Allen, using data from the Land Atmosphere Near real-time Capability for EOS (LANCE). Caption by Michon Scott with information from Steve Platnick, Goddard Space Flight Center.
]]> 0 http://www.redorbit.com/images/pic/76927/earth-wildfires-in-eastern-russia-modis-050413/ 2013-05-04T13:05:50+0000
Agricultural fires are deliberately set by farmers to clear fields of old debris and return nutrients to the soil in preparation for the new planting season. Since this area of Russia is responsible for 60% of soybean production in Russia, some of these fires could definitely be agricultural in nature.

However, the Russia-India Report (indrus.in) reports that \"eight Russian military transport airplanes II-76 were redeployed from central Russia to the Far East on April 30, equipped with special spray tanks to put out the fires in the Amur Region, the Khabarovsk Territory and the Republic of Buryatia.\"

Through the use of these specially equipped transports over 90 fires were put out. These planes are used regularly for the monitoring of fire situations and the extinguishing of wildfires in the Siberian, Trans-Baikal and Far Eastern regions.

This natural-color satellite image was collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite on May 03, 2013. Actively burning areas, detected by MODIS’s thermal bands, are outlined in red.

NASA image courtesy Jeff Schmaltz LANCE/EOSDIS MODIS Rapid Response Team, GSFC. Caption by Lynn Jenner
]]> 0 http://www.redorbit.com/images/pic/76883/earth-yosemite-national-park-landscape-airborne-snow-observatory-050313/ 2013-05-03T11:23:45+0000
Credits: NASA/JPL-Caltech
]]> 0 http://www.redorbit.com/images/pic/76710/earth-modis-captures-drifting-iceberg-in-the-southern-ocean-050213/ 2013-05-02T10:58:04+0000
A relatively new iceberg, C28 was born in mid-February 2010 when massive iceberg B09B collided with the Mertz Glacier tongue on the George V Coast of East Antarctica. About 80% of the tongue broke off due to impact, and this fragment was called C28. At time of calving, the iceberg measured 78 km long and between 33 and 39 km wide. Over the years the iceberg has drifted from its initial location, and has broken into smaller pieces.

In this image, the large piece known as C28A, as well as several smaller icebergs surrounding it, can be easily distinguished from cloud by the bright white color. This is due to the highly reflective nature of ice.

Credits: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC
]]> 0 http://www.redorbit.com/images/pic/76583/earth-france-bay-of-biscay-springtime-phytoplankton-bloom-050113/ 2013-05-01T10:44:09+0000
The swirling colors indicate the presence of vast numbers of phytoplankton – tiny plant-like microorganisms that live in both fresh and salt water. Although these organisms live year-round in the Bay of Biscay, it is only when conditions are right that explosive blooms occur. In spring, the lengthening sunlight, the increased nutrient load swept into the Bay from ocean currents and from snowmelt carried by freshwater rivers, combined with warming waters create the perfect conditions to spur phytoplankton in to tremendous growth. The result is a swirling, multi-hued discoloration that can be easily seen from space.

Each year, typically from March through April, such blooms occur in the Bay of Biscay. By May, however, conditions are not as favorable and the blooms fade, then disappear.

Image Credit: NASA GSFC
]]> 0 http://www.redorbit.com/images/pic/76483/earth-from-the-iss-south-georgia-island-043013/ 2013-04-30T11:20:12+0000
Glaciers sourced in mountain snow and ice—eleven peaks rise higher than 2,000 meters (6,500 feet) above sea level—can be seen reaching the sea (such as at image lower right). Calving icebergs float away from the ice front at image lower right. The island’s glaciers are a major source of erosion. As the ice grinds over rock and soil, it produces fine sediments, known as glacial flour, that impart a milky color to water. The sediment appears as a lighter-toned zone offshore around the island. (Note that in this image, north is to the lower right.)

South Georgia and the South Sandwich Islands, a British overseas territory, are a remote string of islands in the southern Atlantic Ocean. In 1882–1883, a German scientific expedition stationed at Royal Bay (center left) observed the transit of Venus and, amazingly, recorded waves that originated 12,330 kilometers (7,660 miles) away with the eruption of Krakatau.

South Georgia is 170 kilometers long and by far the largest island in the territory, though the current population is less than 50 people. The main revenue comes from fishing licenses, which allow access to rich fishing grounds. Other revenue comes from tourism, customs and harbor dues, and the sale of postage stamps; most of that revenue is spent on fishery protection and research.

While the ISS only orbits above locations between 52 degrees North and South latitude, astronauts using handheld cameras can take images of regions at higher latitudes by using long focal-length lenses and high viewing angles. Such images tend to highlight topographic relief due to shadowing effects (image left) and look similar to the view you might get out of a commercial airliner window.

Astronaut photograph ISS035-E-18807 was acquired on April 13, 2013, with a Nikon D3S digital camera using a 400 millimeter lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 35 crew. It has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by M. Justin Wilkinson, Jacobs/ESCG at NASA-JSC.
]]> 0 http://www.redorbit.com/images/pic/76374/earth-volcanic-mount-etna-in-sicily-042913/ 2013-04-29T10:57:53+0000
Early in April, Etna had appeared more whimsical, blowing smoke rings composed not of actual smoke, but of steam, volcanic gases, and some volcanic ash. Then ash emissions and Strombolian eruptions started on the evening of April 16 and continued through the following day, according to the Etna Observatory. On the morning of April 18, when the ALI image was acquired, the intensity and frequency of eruptions had increased and the volcano was in the middle of its eleventh paroxysm of 2013.

On April 20, yet another paroxysm began at New Southeast Crater. It was the twelfth of 2013, and the thirty-seventh since the start of the current series of eruptive activity. By April 20, lava fountains reached 800 to 1,000 meters (2,600 to 3,300 feet) into the sky, and a column of gas and volcanic ash blew eastward away from the volcano.

Located roughly 25 kilometers (15 miles) north-northwest of Sicily’s second-largest city, Mount Etna is a stratovolcano composed of layers of rocks, lava, and volcanic ash left by earlier eruptions. The summit reaches an altitude of 3,330 meters (10,925 feet) above sea level. People have lived around Etna for millennia, so scientists have one of the longest documented records of activity of any volcano in the world—dating back to 1500 B.C.

NASA Earth Observatory image by Jesse Allen and Robert Simmon, using EO-1 ALI data from the NASA EO-1 team. Caption by Robert Simmon.
]]> 0 http://www.redorbit.com/images/pic/76370/earth-saunders-island-and-wolstenholme-fjord-with-kap-atholl-042713/ 2013-04-27T12:05:11+0000
In March 2013, NASA\'s Operation IceBridge scientists began another season of research activity over Arctic ice sheets and sea ice. IceBridge, a six-year NASA mission, is the largest airborne survey of Earth\'s polar ice ever flown. It will yield an unprecedented three-dimensional view of Arctic and Antarctic ice sheets, ice shelves and sea ice. These flights will provide a yearly, multi-instrument look at the behavior of the rapidly changing features of the Greenland and Antarctic ice.

Image Credit: NASA / Michael Studinger
]]> 0 http://www.redorbit.com/images/pic/76343/earth-eastern-russia-fires-and-snow-modis-042613/ 2013-04-26T11:26:12+0000
Most of the fires are burning in Zabaykalsky Krai in Siberia, an area where both agriculture and forestry are important sources of income for the population. It is likely that most of these fires have been deliberately set as an agricultural tool, used to ready pastures for grazing or ready land for this year’s crops. Even when fires are deliberately set, dry conditions and heavy wind can cause them to escape control, and resultant wildfires can consume many acres.

Credits: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC
]]> 0 http://www.redorbit.com/images/pic/76222/earth-southern-mexico-fires-and-haze-modis-042513/ 2013-04-25T11:10:04+0000
Red “hotspots” speckle the entire region, each indicating an area where the thermal sensors detected temperatures higher than background. When combined with typical smoke plumes such areas indicate actively burning fires. Most of the hotspots are found at the edge of dark green areas, suggesting they are burning at the edge of forests, potentially as forest is cleared for agricultural purposes, usually farming or logging.

In southern Mexico, as in many parts of the developing world, tropical forests are under intense pressure from forest clearing. Not only do deliberately set fires consume forest acreage, but such fires can escape control, leading to unintentional destruction of huge swaths of forest as well as directly endanger humans, property and livestock until fires can be quenched.

Smoke is another hazard of fires, and is a prime cause of respiratory illness in humans as well as livestock in heavily burned areas – and can affect health far from the source. On April 16, the U.S. Air Quality “Smog Blog” reported that smoke from southern Mexico fires was over the Gulf of Mexico, and expected to move northward. By April 19, several air quality monitoring stations along the Mexico-Texas border reported Unhealthy (Code Red) PM2.5 concentrations. The high values were correlated from fires burning in southern Mexico and Central America.

Credits: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC
]]> 0 http://www.redorbit.com/images/pic/76188/earth-volcano-in-bolivia-altiplano-region-042413/ 2013-04-24T11:31:12+0000
Prior to 12,000 years ago, a large debris avalanche was formed by the collapse of the ancestral Tata Sabaya volcano. Debris from the avalanche swept into the nearby Salar de Coipasa, significantly changing its northwestern coastline. The timing of the event was obtained from tufa deposits formed on debris islands during a high stand of the Coipasa lake. The sequence illustrates the geological principle of crosscutting, in that the debris avalanche had to have occurred before the tufa deposits were formed in the lake.

The Tata Sabaya stratovolcano is located at image center in this photograph from the International Space Station. Several young lava flows are visible on the northwestern and western flanks of the volcano. Peaks visible to the northeast and southwest appear to be volcanoes as well, but unlike Tata Sabaya, there is no record of recent activity from either of them, according to the Smithsonian National Museum of Natural History’s Global Volcanism Program.

As the climate of the Altiplano became more arid and the Coipasa Lake shrank, much of the hummocky terrain of the debris avalanche became exposed (an area of more than 300 square kilometers, or 116 square miles). The hummocky terrain is clearly visible on the left side of the image. White salt deposits of the salar surround many of the individual hummocks, making them “islands” once again.

Astronaut photograph ISS035-E-18006 was acquired on April 8, 2013, with a Nikon D3S digital camera using a 400 mm lens, and is provided by the ISS Crew Earth Observations experiment and the Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 35 crew. The image in this article has been cropped and enhanced to improve contrast. Lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by William L. Stefanov, Jacobs/ESCG at NASA-JSC.
]]> 0 http://www.redorbit.com/images/pic/76053/earth-california-coast-cloud-formation-modis-042313/ 2013-04-23T11:14:33+0000
Bob Cahalan of NASA’s Goddard Space Flight Center explains that the cloudbank consisted of stratocumulus clouds, and the arc was probably a wake caused by an obstacle to air flow, perhaps San Clemente Island. Islands that are tall enough can easily interrupt air flow over the ocean, and when clouds are present, they make such disruptions visible in photo-like imagery. Wakes from the Juan Fernandez Islands off Chile provide another example of this phenomenon.

NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response Team at NASA GSFC. Caption by Michon Scott with information from Bob Cahalan, Goddard Space Flight Center.
]]> 0 http://www.redorbit.com/images/pic/75937/earth-china-taklimakan-desert-dust-storm-modis-042213/ 2013-04-22T11:22:05+0000
Dust storms are a frequent occurrence in the Taklimakan Desert – one of the world’s largest shifting-sand deserts. Sand dunes, which may reach 300 meters (982 feet) high, are in constant motion and easily lifted aloft by strong winds of the region. The dry, shifting dunes re virtually devoid of vegetation, but wherever the sand remains in place, a variety of sturdy, xerophilic plants survive. Along the perimeter of the desert, oases exist and plants are more varied and plentiful.

Credits: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC
]]> 0 http://www.redorbit.com/images/pic/75934/earth-iran-earthquake-arabian-and-eurasian-plates-042013/ 2013-04-20T10:25:21+0000
Earth’s crust is broken into giant plates that cover the surface of the planet like pieces of a puzzle. Individual plates constantly collide and grind against one another as they slide on top of a somewhat fluid layer of the Earth’s interior known as the asthenosphere, causing earthquakes in the process.

The Arabian plate is sliding north-northeast at a speed of about 37 millimeters (1.5 inches) per year relative to the larger Eurasian plate. Where the two plates collide in an area known as the Makran subduction zone, the Arabian plate plunges beneath the larger Eurasian plate. As it descends into the mantle where it will eventually melt, earthquakes occur deep beneath the surface, along the boundary between the two plates.

According to the U.S. Geological Survey, the earthquake was the result of faulting at an intermediate depth in the Arabian plate lithosphere, approximately 80 kilometers (50 miles) beneath Earth’s surface. The descending Arabian plate has caused quakes as deep as 160 kilometers (100 miles) beneath the surface in this area in the past, though most have been at much shallower depths.

This image, based on elevation data acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite, shows the area where the earthquake occurred. Land is shown with shades of green and beige. Higher elevations are lighter in color.

NASA Earth Observatory image by Jesse Allen, using data from NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. Caption by Adam Voiland
]]> 0 http://www.redorbit.com/images/pic/75873/earth-south-sandwich-islands-mount-michael-volcano-plume-041913/ 2013-04-19T11:18:57+0000
The wind also creates interesting wave patterns as it blows past each island. As the fast-moving air hits the high, blunt, mountainous terrain, the forward motion stops, and air flow is directed around the obstacle in turbulent wave patterns. Such turbulence is often written in the cloud patterns - and the ship-waved-shape wave clouds seen here are typical patterns for the turbulence created by the South Sandwich Islands.

The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra Satellite captured this false-color image on April 1. In this image, bands 3,6 and 7 have been combined to create an image that separates the warmer, highly reflective gaseous plume from Mount Michael from the surrounding cold cloud cover. With this combination, ocean water appears dark black, cloud tops appear orange, and the volcanic plume is bright white.

Credits: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC
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