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Floods in Sudan
| Title |
Floods in Sudan |
| Description |
Though flooding occurs every year in the African country of Sudan, 2007 brought unusually extreme floods that affected at least 400,000 people as of August 29, reported the United Nations. [ http://www.reliefweb.int/rw/rwb.nsf/db900sid/YSAR-76JMJK?OpenDocument&rc=1&emid=FL-2007-000093-SDN ] Apart from destroying buildings, crops, and land, the swollen rivers and pools of standing water increase the risk of water-borne disease such as cholera, acute watery diarrhea, and malaria, said the United Nations. This photo-like image, captured by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite on August 29, 2007, shows flooding around the capital city of Khartoum, the tan-gray area nestled between the converging Blue and White Nile Rivers. To the south, sunlight reflecting off the surface of the water has turned the Blue Nile River silvery white, making it stand out from the surrounding land. Brilliant flecks of silver in the landscape between the two rivers are created by light reflecting off standing water or some other bright surface. The sunlight also highlights the intricate network of canals that run like arteries through squares of green agriculture. In the west, the White Nile River paints a wide, white-brown ribbon down the landscape. The river is several times wider than it is during the dry season, as a comparison with a cloud-free image [ http://rapidfire.sci.gsfc.nasa.gov/subsets/?NAfrica_2_07/2007172/NAfrica_2_07.2007172.terra ] from June 2007 reveals. (The area shown here is in the lower-left corner of the image.) As long as human civilization has clung to the fertile banks of the Nile River, the yearly flood cycle has regulated life. Today, the river is tamed by dams in southern Egypt so that only its upper reaches and its tributaries, the White and Blue Nile Rivers, still rise and fall with the annual rainy season in the Ethiopian highlands. Most of the flood water on the Nile typically comes from the Blue Nile River, the tributary that flows out of Ethiopia, but in this image, it is the White Nile River that appears most flooded. The floods on the White Nile most often arise when high water on the Blue Nile blocks the flow of water from the White Nile into the Nile River. Unable to continue flowing freely downstream, the White Nile pools behind the convergence point, as shown here. Another sign of flooding in the image is the addition of green to the land. Even beyond the irrigated land between the two rivers, the arid orange landscape is brushed with green where seasonal rivers have nourished new plants. NASA image courtesy the MODIS Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC. |
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Dust Plume off the Coast of
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| Title |
Dust Plume off the Coast of Egypt |
| Description |
Dwarfing the Nile, a river of dust flowed out of the deserts of northern Egypt on May 19, 2007. As the Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite passed overhead at 12:05 p.m. local time in Cairo, the sensor captured this image of the dust spreading northward over the Mediterranean Sea from the sandy deserts that span the country. At the margins of the plume, ribbons and ripples of dust are translucent, allowing a glimpse of the desert and water beneath, but in the center, the cloud is opaque, revealing nothing of the surface below. The part of north-central Egypt hidden by the dust plume is the Qattara Depression, the country's lowest point. Dipping down to 133 meters below sea level (436 feet), the depression is home to sandy deserts and dry lake beds that occasionally flood. The sand and fine, lake bed sediments are easily lofted into the air by strong winds that scour the area in late winter and early spring. In the eastern (right-hand) part of the image, the Nile River is lined by narrow ribbons of dull green vegetation. The fan-shaped delta is dotted with tan-colored spots, marking the location of cities and towns. The Nile Valley and Delta make up only a small fraction of the country's total land area, yet they support almost the entire population. The large image provided above has a spatial resolution (level of detail) of 250 meters per pixel. The MODIS Rapid Response Team provides this image in additional resolutions. [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2007139-0519/Egypt.A2007139.0905 ] The Earth Observatory also provides a 250-meter-resolution KMZ file [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/May2007/Egypt.A2007139.0905.250m.kmz ] of this image for use with Google Earth. NASA image by Jeff Schmaltz, MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center. |
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Dust Plume off the Coast of
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| Title |
Dust Plume off the Coast of Northern Africa |
| Description |
Dust blew off the African coast and over the Mediterranean Sea on June 9, 2007. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Terra [ http://terra.nasa.gov ] satellite captured this image the same day. In this image, the opaque tan dust plume billows off the coast, along the Libya-Egypt border, in a shape vaguely resembling a giant inverted teardrop. Directly north of the dust plume lies the island of Kriti (Crete). North of that, much smaller islands dot the Aegean Sea. Pale streamers sweep southward from these islands, from a cause that appears unrelated to the dust plume. The streamers may be "wind shadows" on the ocean surface highlighted by sunglint that results from the Sun's light bouncing off the water's surface and into the satellite sensor. You can download a 250-meter-resolution KMZ file [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Jun2007/nafrica_tmo_2007160.kmz ] of the dust storm for use with Google Earth. [ http://earth.google.com/download-earth.html ] NASA image created by Jesse Allen, using data provided courtesy of the MODIS Rapid Response [ http://rapidfire.sci.gsfc.nasa.gov/ ] team. |
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Dust Storm over Libya
| Title |
Dust Storm over Libya |
| Description |
Saharan dust swept northward across Libya and northwestern Egypt toward the Mediterranean on February 23, 2007. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Aqua [ http://aqua.nasa.gov ] satellite took this picture the same day. In this image, the semitransparent plume of dust covers most of Libya and part of Egypt. The dust also appears over Chad, with part of the plume covering a dark, rocky area near the lower left corner of the image. The dust storm did not likely originate in this region, but farther south. NASA image by Jeff Schmaltz, MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center. |
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Dust Storm over the Mediterr
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| Title |
Dust Storm over the Mediterranean Sea |
| Description |
A dust storm, likely originating in the Sahara Desert, swept across the Mediterranean Sea on February 24, 2007. The Moderate Resolution Imaging Spectroradiometer (MODIS) [ http://modis.gsfc.nasa.gov ] on NASA's Aqua [ http://aqua.nasa.gov ] satellite took this picture the same day. In this image, the dust appears as an undulating swath of tan over the dark ocean water. The storm also clouds skies over Lebanon, Israel, the West Bank, Gaza, and Egypt. Even through a layer of dust, however, the Nile Delta still sports a lush green hue, in contrast to its largely arid surroundings. NASA image by Jeff Schmaltz, MODIS Rapid Response Team, [ http://rapidfire.sci.gsfc.nasa.gov ] Goddard Space Flight Center. |
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Smoke from Fires in Greece
| Title |
Smoke from Fires in Greece |
| Description |
Besides laying waste to huge areas of forest, fires [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14474 ] burning in Greece in August 2007 released pollutants that traveled across the Mediterranean Sea and into Africa. This image shows aerosols—tiny solid or liquid particles suspended in air—observed by the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite layered on the photo-like Blue Marble [ http://earthobservatory.nasa.gov/Newsroom/BlueMarble/ ] composite image. Relatively clear air is transparent. Highest aerosol concentrations are pink. On August 26, 2007, aerosols from the fires on the southwestern coast of Greece took a fairly direct route across the Mediterranean Sea to the western part of the Libyan coast. A large pool of smoke collected over the Gulf of Sirte, off the Libyan coast. Another pocket of thick aerosols appears over Algeria. These particles are probably smoke emitted from fires burning in Algeria [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14478 ] over a long stretch of the coastal Atlas Mountains. Farther south over the deserts of northern Africa, the light green areas of moderate aerosol amounts could be smoke or dust. On August 27, 2007, aerosols still crossed the Mediterranean Sea, but they took a more circular route. They spread southward in a clockwise direction from Greece, across the island of Crete, and concentrated thickly over eastern Libya. The other large pocket of aerosols—the pink patch hovering over the border of Libya and Algeria—may include smoke from Algeria and Greece. As on the previous day, some aerosols collected over Egypt and eastern Libya. OMI detects the amount of light of different wavelengths that the atmosphere scatters back to space, the amount of backscattered sunlight is affected by what is in the atmosphere. To make an aerosol index with OMI data, scientists compare the amount of ultraviolet (UV) light the atmosphere scatters back at given place and time to the amount of UV light that the atmosphere would scatter back if it were totally clear. You can download a KMZ file KMZ file of the smoke from Greece suitable for use with Google Earth [ http://earth.google.com/ ] for both August 26 [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Aug2007/greece_omi_2007238.kmz ] and August 27. [ http://earthobservatory.nasa.gov/NaturalHazards/Archive/Aug2007/greece_omi_2007239.kmz ] Image courtesy Omar Torres, OMI Science Team, and Colin Seftor, NASA NPP Science Team. |
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Floods in Sudan: Natural Haz
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nasa, nasanaturalhazards
Though flooding occurs every
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Khartoum_TMO_2007241
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-08-28 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
Khartoum_TMO_2007241 |
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Dust Storm over the Mediterr
…
nasa, nasanaturalhazards
A dust storm, likely origina
…
med_amo_2007055
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-02-24 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
med_amo_2007055 |
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Dust Storm over Libya: Natur
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nasa, nasanaturalhazards
Saharan dust swept northward
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nafrica_amo_2007054
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-02-23 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
nafrica_amo_2007054 |
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Dust Plume off the Coast of
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nasa, nasanaturalhazards
Dwarfing the Nile, a river o
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egypt_tmo_2007139
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-05-19 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
egypt_tmo_2007139 |
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Dust Storm in Egypt: Natural
…
nasa, nasanaturalhazards
A dust storm blew off the co
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nafrica_amo_2007293
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-10-20 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
nafrica_amo_2007293 |
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Port of Suez, Egypt: Image o
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nasa, nasaimageofthedaygalle
…
The Port of Suez is located
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ISS016-E-019375
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-12-30 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
ISS016-E-019375 |
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Smoke Spreading from Greece
…
nasa, nasaimageofthedaygalle
…
Besides laying waste to huge
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greece_omi_2007239_lrg
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-08-26 |
| creator |
NASA -- Image courtesy Omar Torres, OMI Science Team, and Colin Seftor, NASA NPP Science Team. |
| identifier |
greece_omi_2007239_lrg |
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Smoke Spreading from Greece
…
nasa, nasaimageofthedaygalle
…
Besides laying waste to huge
…
greece_omi_2007239_lrg
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-08-26 |
| creator |
NASA -- Image courtesy Omar Torres, OMI Science Team, and Colin Seftor, NASA NPP Science Team. |
| identifier |
greece_omi_2007239_lrg |
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Dust Plume off the Coast of
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nasa, nasaimageofthedaygalle
…
Dwarfing the Nile, a river o
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ge_07701
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-05-19 |
| creator |
NASA -- NASA image by Jeff Schmaltz, rapidfire.sci.gsfc.nasa.gov MODIS Rapid Response Team, Goddard Space Flight Center. |
| identifier |
ge_07701 |
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Dust Plume off the Coast of
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nasa, nasanaturalhazards
Dust blew off the African co
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nafrica_tmo_2007160
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2007-06-09 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
nafrica_tmo_2007160 |
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