|
|
Hurricane Dennis
| Title |
Hurricane Dennis |
| Abstract |
The formation of Hurricane Dennis on July 5 made that the earliest date on record that four named storms formed in the Atlantic basin. Dennis proved to be a powerful and destructive storm in the Caribbean Sea and the Gulf of Mexico. It crossed over Cuba on July 8 and 9, leaving at least 10 dead, and caused additional deaths in Haiti. After re-emerging over open water, Dennis re-strengthened into a dangerous Category 4 hurricane with top wind speeds of 233 kilometers per hour (145 mph). The storm passed within 90 kilometers (55 miles) of Pensacola, Florida, and hit land about 80 kilometers (50 miles) east of where Hurricane Ivan struck in September, 2004. A large storm surge of more than 10 feet was created in certain areas, and many homes and businesses in low-lying areas were flooded. |
| Completed |
2005-07-11 |
|
Progression of Hurricane Den
…
| Title |
Progression of Hurricane Dennis, 2005 (WMS) |
| Abstract |
The formation of Hurricane Dennis on July 5 made that the earliest date on record that four named storms formed in the Atlantic basin. Dennis proved to be a powerful and destructive storm in the Caribbean Sea and the Gulf of Mexico. It crossed over Cuba on July 8 and 9, leaving at least 10 dead, and caused additional deaths in Haiti. After re-emerging over open water, Dennis re-strengthened into a dangerous Category 4 hurricane with top wind speeds of 233 kilometers per hour (145 mph). The storm passed within 90 kilometers (55 miles) of Pensacola, Florida, and hit land about 80 kilometers (50 miles) east of where Hurricane Ivan struck in September, 2004. A large storm surge of more than 10 feet was created in certain areas, and many homes and businesses in low-lying areas were flooded. |
| Completed |
2005-07-18 |
|
Hurricane Dennis
| Title |
Hurricane Dennis |
| Description |
The swirling clouds of Tropical Storm Dennis span from the northern tip of Venezuela to the southern half of the island of Hispaniola in this Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) image. NASA's Terra [ http://terra.nasa.gov/ ] satellite captured this image on July 6, 2005, at 10:05 a.m. local time (15:05 UTC) when Dennis was building to winds of 110 kilometers per hour (70 mph). The storm was moving northwest across the Caribbean and should pass between the eastern arm of Haiti and Jamaica, hammering both with four to eight inches of rain. The National Hurricane Center [ http://www.nhc.noaa.gov/ ] predicts that Dennis may become a major hurricaneCategory 3 or higherby July 8. This image is available in additional resolutions from the MODIS Rapid Response System. NASA image courtesy Jeff Schmaltz, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov ] at NASA GSFC |
|
Fires Across Northern South
…
| Title |
Fires Across Northern South America |
| Description |
In eastern Columbia (left) and northern Venezuela (right), a vast stretch of plains called the Llanos rests at the eastern foothills of the Andes Mountains. The Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite detected numerous fires (red dots) scattered across the region, even in wetland areas between two of the Llanos? majors rivers: the Apure (running from center toward the right of the image) and the Meta (flowing northeast from bottom left). Where the Meta leaves the Columbia-Venezuela border, it is joined by the Atabapo River and becomes the Orinoco, which flows out to meet the Atlantic. In the high-resolution imagery, dark purplish-brown burn scars are apparent against the green vegetation of the prairies. At bottom right, the grasses of the llanos give way to the upper reaches of the Amazon Rainforest. This image was captured December 12, 2002. Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC |
|
Fires Across Northern South
…
| Title |
Fires Across Northern South America |
| Description |
Widespread biomass burning in northern South America that began in late 2002 has continued into the new year. This true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from the Terra satellite on January 4, 2003, shows active fire detections (red dots) in Columbia (left) and Venezuela (right). Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC |
|
Fires Across Northern South
…
| Title |
Fires Across Northern South America |
| Description |
Fires were still burning across the Llanos on January 13, 2003. This Moderate Resolution Imaging Spectroradiometer (MODIS) image shows Columbia (left) and Venezuela (right) and numerous fires (red dots) scattered across the region. Image courtesy Jeff Schmaltz, MODIS Rapid Response Team, NASA GSFC |
|
Fires Across Northern South
…
| Title |
Fires Across Northern South America |
| Description |
The fires currently burning across northern South America are producing a significant amount of pollution, as indicated by enhanced levels of carbon monoxide in the region. This false-color image shows the concentrations of carbon monoxide (CO) at an altitude of roughly 3 km (700 millibars) in the atmosphere. The data were taken by the Measurements Of Pollution In The Troposphere (MOPITT) instrument aboard NASA's Terra satellite for the period February 24-March 4, 2003. The colors represent the mixing ratios of carbon monoxide in the air, given in parts per billion by volume. The large grey areas in the center of the image show where no data were collected, either due to persistent cloud cover or gaps between satellite viewing swaths. The regions of high carbon monoxide correlate well with observations of the source fires [ http://earthobservatory.nasa.gov/NaturalHazards/shownh.php3?img_id=5633 ] by the Moderate Resolution Imaging Spectroradiometer (MODIS). Carbon monoxide is produced as a result of incomplete combustion during burning processes, and is important due to its impact on chemistry in the lower atmosphere. It is a good indicator of atmospheric pollution, and its presence adversely affects the atmosphere's ability to cleanse itself. Because carbon monoxide is persistent for several weeks, it clearly shows the propagation of pollution plumes from the region of the fires over Columbia and Venezuela westward out into the atmosphere over the Pacific Ocean. The high levels of carbon monoxide in the right of the image over the Atlantic Ocean result from pollution plumes that have traversed the Atlantic from the fires that are currently burning in western Africa [ http://earthobservatory.nasa.gov/NaturalHazards/shownh.php3?img_id=5400 ]. Image courtesy the NCAR and University of Toronto MOPITT Teams |
|
Fires Across Northern South
…
| Title |
Fires Across Northern South America |
| Description |
The fires currently burning across northern South America are producing a significant amount of pollution, as indicated by enhanced levels of carbon monoxide in the region. This false-color image shows the concentrations of carbon monoxide (CO) at an altitude of roughly 3 km (700 millibars) in the atmosphere. The data were taken by the Measurements Of Pollution In The Troposphere (MOPITT) instrument aboard NASA's Terra satellite for the period February 24-March 4, 2003. The colors represent the mixing ratios of carbon monoxide in the air, given in parts per billion by volume. The large grey areas in the center of the image show where no data were collected, either due to persistent cloud cover or gaps between satellite viewing swaths. The regions of high carbon monoxide correlate well with observations of the source fires [ http://earthobservatory.nasa.gov/NaturalHazards/shownh.php3?img_id=5633 ] by the Moderate Resolution Imaging Spectroradiometer (MODIS). Carbon monoxide is produced as a result of incomplete combustion during burning processes, and is important due to its impact on chemistry in the lower atmosphere. It is a good indicator of atmospheric pollution, and its presence adversely affects the atmosphere's ability to cleanse itself. Because carbon monoxide is persistent for several weeks, it clearly shows the propagation of pollution plumes from the region of the fires over Columbia and Venezuela westward out into the atmosphere over the Pacific Ocean. The high levels of carbon monoxide in the right of the image over the Atlantic Ocean result from pollution plumes that have traversed the Atlantic from the fires that are currently burning in western Africa [ http://earthobservatory.nasa.gov/NaturalHazards/shownh.php3?img_id=5400 ]. Image courtesy the NCAR and University of Toronto MOPITT Teams |
|
Fires Across Northern South
…
| Title |
Fires Across Northern South America |
| Description |
Fires continue to burn across northern South America over large regions of Colombia and Venezuela. Measurements of carbon monoxide (CO) from the Measurements of Pollution in The Troposphere (MOPITT) instrument on NASA's Terra satellite show very high concentrations over the region of the fires. This false-color image shows the mixing ratios of CO at an altitude of about 3 km (700 hPa) averaged from March 13-18, 2003. Gray areas indicate where no data are available, either due to cloud cover or gaps between satellite views. The concentrations observed during this period are higher than those measured a couple weeks earlier [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=5640 ]. The highest concentrations correlate well with the recent images of the fires [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=6116 ] observed by MODIS. Relatively high mixing ratios also are seen being transported to the west over the Pacific Ocean, and to the north into the Caribbean Sea. Image courtesy NCAR and University of Toronto MOPITT Teams |
|
Oil Slicks on Lake Maracaibo
…
| Title |
Oil Slicks on Lake Maracaibo, Venezuela |
| Description |
browse image of orbit 16081 (310 KB JPEG) Several oil slicks occurred on Lake Maracaibo in northwestern Venezuela between December 2002 and January 2003, and were observed by various satellite instruments. These images from the Multi-angle Imaging SpectroRadiometer (MISR) provide new information relating to one such event near the center of Lake Maracaibo on December 26, 2002. In unpolluted areas, the water surface is "ruffled" by wind and the resulting wave facets divert reflected rays into many directions. An oil film dampens the presence of small wind-driven "capillary" waves, resulting a smoother, more mirror-like surface. Also, oil is more strongly absorbing than the surrounding water. Therefore, at most viewing angles, a surface slick will appear darker than the surrounding unpolluted areas, whereas near the specular angle (the angle at which a perfect mirror reflects light) it will appear brighter. Simultaneous observation at multiple view angles therefore enhances the reliability of oil-slick detection using optical imaging. An example of how the optical contrast of an oil film on a water surface changes as a function of viewing angle is illustrated by these false-color MISR images, comprised of near-infrared, red and blue spectral data at three different angles, using the vertical-viewing camera (left), the 26ø-forward-viewing camera (center) and the 46ø-forward-viewing camera (right). A swirly area in the middle of the lake appears darker than the surrounding waters at both the nadir and 46° views, but brighter than the surrounding waters at the 26° view. Of the three images, only the 26° camera observes close to specular reflection angle. Lake Maracaibo is the largest lake in South America. The lake is somewhat saline, since it is connected to the Gulf of Venezuela by a narrow strait in the north. Venezuela is the largest oil producing nation in the Western Hemisphere, and the Lake Maracaibo basin includes the largest oil fields and almost a quarter of this nation's population. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. The MISR Browse Image Viewer [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://eosweb.larc.nasa.gov/MISRBR/ ] provides access to low-resolution true-color versions of these images. These data products were generated from a portion of the imagery acquired during Terra orbit 16081. The panels cover an area of 72 kilometers x 225 kilometers. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://www-misr.jpl.nasa.gov/ ] Text by Clare Averill (Acro Service Corporation/JPL) |
|
Oil Slicks on Lake Maracaibo
…
| Title |
Oil Slicks on Lake Maracaibo, Venezuela |
| Description |
browse image of orbit 16081 (310 KB JPEG) Several oil slicks occurred on Lake Maracaibo in northwestern Venezuela between December 2002 and January 2003, and were observed by various satellite instruments. These images from the Multi-angle Imaging SpectroRadiometer (MISR) provide new information relating to one such event near the center of Lake Maracaibo on December 26, 2002. In unpolluted areas, the water surface is "ruffled" by wind and the resulting wave facets divert reflected rays into many directions. An oil film dampens the presence of small wind-driven "capillary" waves, resulting a smoother, more mirror-like surface. Also, oil is more strongly absorbing than the surrounding water. Therefore, at most viewing angles, a surface slick will appear darker than the surrounding unpolluted areas, whereas near the specular angle (the angle at which a perfect mirror reflects light) it will appear brighter. Simultaneous observation at multiple view angles therefore enhances the reliability of oil-slick detection using optical imaging. An example of how the optical contrast of an oil film on a water surface changes as a function of viewing angle is illustrated by these false-color MISR images, comprised of near-infrared, red and blue spectral data at three different angles, using the vertical-viewing camera (left), the 26ø-forward-viewing camera (center) and the 46ø-forward-viewing camera (right). A swirly area in the middle of the lake appears darker than the surrounding waters at both the nadir and 46° views, but brighter than the surrounding waters at the 26° view. Of the three images, only the 26° camera observes close to specular reflection angle. Lake Maracaibo is the largest lake in South America. The lake is somewhat saline, since it is connected to the Gulf of Venezuela by a narrow strait in the north. Venezuela is the largest oil producing nation in the Western Hemisphere, and the Lake Maracaibo basin includes the largest oil fields and almost a quarter of this nation's population. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. The MISR Browse Image Viewer [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://eosweb.larc.nasa.gov/MISRBR/ ] provides access to low-resolution true-color versions of these images. These data products were generated from a portion of the imagery acquired during Terra orbit 16081. The panels cover an area of 72 kilometers x 225 kilometers. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://www-misr.jpl.nasa.gov/ ] Text by Clare Averill (Acro Service Corporation/JPL) |
|
Fires in Northern South Amer
…
| Title |
Fires in Northern South America |
| Description |
Across the grassy plains, known as the "Llanos," that stretch across Venezuela and Columbia in northern South America, numerous fires (yellow) were detected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite on February 1, 2004. The area supports ranching and other agriculture, and many of these fires are probably intentional fires set by people for land management purposes. Though not necessarily hazardous, such large-scale burning can have a strong impact on weather, climate, human health, and natural resources. At bottom left, a pall of smoke hangs over the area, and a few scattered fires in the heart of the forests (deep green areas at right) could be related to deforestation. Image courtesy Jesse Allen, based on data from the MODIS Rapid Response Team at NASA GSFC |
|
Fires in Venezuela
| Title |
Fires in Venezuela |
| Description |
As can be seen in this true-color scene acquired on April 9, 2002, many fires dotted the landscape across Venezuela. This image was acquired by the Moderate-resolution Imaging Spectroradiometer [ http://modarch.gsfc.nasa.gov/ ] (MODIS), flying aboard NASA?s Terra [ http://terra.nasa.gov/ ] satellite. Please note that the high-resolution scene provided here is 500 meters per pixel. For a copy of this scene at the sensor?s fullest resolution, visit the MODIS Rapidfire [ http://rapidfire.sci.gsfc.nasa.gov/gallery/?2002092-0402 ] site. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov/ ] at NASA GSFC |
|
Flooding in Columbia and Ven
…
| Title |
Flooding in Columbia and Venezeula |
| Description |
February is typically the dry season in northern Venezuela, but not in 2005. Torrential rains brought deadly floods to the country's coastal provinces, including the capital, Caracas. In this Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) image, blue smudges along the coast show flooding in the Falcon Province. In these false-color images, clear water is black, while muddy water is blue. Clouds are white and pale blue, and vegetation is green. When this image was acquired by NASA's Terra [ http://terra.nasa.gov/ ] satellite on February 14, up to 25,000 people had been affected by floods throughout the country. NASA image credited by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team. |
|
Flooding in Columbia and Ven
…
| Title |
Flooding in Columbia and Venezeula |
| Description |
February is typically the dry season in northern Venezuela, but not in 2005. Torrential rains brought deadly floods to the country's coastal provinces, including the capital, Caracas. In this Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) image, blue smudges along the coast show flooding in the Falcon Province. In these false-color images, clear water is black, while muddy water is blue. Clouds are white and pale blue, and vegetation is green. When this image was acquired by NASA's Terra [ http://terra.nasa.gov/ ] satellite on February 14, up to 25,000 people had been affected by floods throughout the country. NASA image credited by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team. |
|
Flooding in Columbia and Ven
…
| Title |
Flooding in Columbia and Venezeula |
| Description |
February is typically the dry season in northern Venezuela, but not in 2005. Torrential rains brought deadly floods to the country's coastal provinces, including the capital, Caracas. In this Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) image, blue smudges along the coast show flooding in the Falcon Province. In these false-color images, clear water is black, while muddy water is blue. Clouds are white and pale blue, and vegetation is green. When this image was acquired by NASA's Terra [ http://terra.nasa.gov/ ] satellite on February 14, up to 25,000 people had been affected by floods throughout the country. NASA image credited by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team. |
|
Flooding in Columbia and Ven
…
| Title |
Flooding in Columbia and Venezeula |
| Description |
Though water levels have subsided since mid-February, the Escalante River of southwestern Venezuela and northeastern Colombia was still flooded on February 26, 2005. The floods along this river and others were triggered by days of heavy rain early in February, and resulted in nearly 100 deaths and left thousands homeless throughout both countries. In this image, taken by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite, the muddy flood water is light blue. The river covers a broader area than it did on January 27, 2005. In both images, clouds are white and turquoise, plant-covered land is bright green, and deep, clear water is black. Further evidence of flooding can be seen in Lake Maracaibo in the center of the image. Flood water carries dirt into the rivers that empty into the lake. The sediment entering the lake reflects light, which makes the water appear a lighter shade of blue in satellite imagery. While sediment is present in the southwest corner of the lake on January 27, the sediment plume is much brighter and larger on February 26. On both dates, green swirls of duck weed [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=12404 ] float on the surface of the lake. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team and the Goddard Land Processes DAAC. |
|
Flooding in Columbia and Ven
…
| Title |
Flooding in Columbia and Venezeula |
| Description |
Though water levels have subsided since mid-February, the Escalante River of southwestern Venezuela and northeastern Colombia was still flooded on February 26, 2005. The floods along this river and others were triggered by days of heavy rain early in February, and resulted in nearly 100 deaths and left thousands homeless throughout both countries. In this image, taken by the Moderate Resolution Imaging Spectroradiometer (MODIS [ http://modis.gsfc.nasa.gov ]) on NASA's Terra [ http://terra.nasa.gov/ ] satellite, the muddy flood water is light blue. The river covers a broader area than it did on January 27, 2005. In both images, clouds are white and turquoise, plant-covered land is bright green, and deep, clear water is black. Further evidence of flooding can be seen in Lake Maracaibo in the center of the image. Flood water carries dirt into the rivers that empty into the lake. The sediment entering the lake reflects light, which makes the water appear a lighter shade of blue in satellite imagery. While sediment is present in the southwest corner of the lake on January 27, the sediment plume is much brighter and larger on February 26. On both dates, green swirls of duck weed [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=12404 ] float on the surface of the lake. NASA image created by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team and the Goddard Land Processes DAAC. |
|
Fires Across Northern South
…
nasa, nasanaturalhazards
Widespread biomass burning i
…
Venezuela.TMOA2003004
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2003-01-04 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
Venezuela.TMOA2003004 |
|
Fires Across Northern South
…
nasa, nasanaturalhazards
In eastern Columbia (left) a
…
NSAmerica.TMOA2002346
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2002-12-12 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
NSAmerica.TMOA2002346 |
|
Fires Across Northern South
…
nasa, nasanaturalhazards
The fires currently burning
…
Llanos_TMP2003063
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2003-03-04 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
Llanos_TMP2003063 |
|
Fires Across Northern South
…
nasa, nasanaturalhazards
The fires currently burning
…
Llanos_TMP2003063
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2003-03-04 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
Llanos_TMP2003063 |
|
Close-up of Lake Maracaibo,
…
nasa, nasaimageofthedaygalle
…
This false-color (near-infra
…
maracaibo_aster
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2003-01-20 |
| creator |
NASA -- Image courtesy NASA Earth Observatory |
| identifier |
maracaibo_aster |
|
Fires in Northern South Amer
…
nasa, nasanaturalhazards
Across the grassy plains, kn
…
terra_venezuela_01feb04
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2004-02-01 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
terra_venezuela_01feb04 |
|
Deforestation Patterns in th
…
nasa, nasaimageofthedaygalle
…
Deforestation in the Amazon
…
tree_herb_bare
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2003 |
| creator |
NASA -- Image by Robert Simmon, based on data provided by the University of Maryland's glcf.umiacs.umd.edu/'' target=''_blank Global Land Cover Facility |
| identifier |
tree_herb_bare |
|
Fires Across Northern South
…
nasa, nasanaturalhazards
Fires continue to burn acros
…
SAmerica_TMP2003077
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2003-03-18 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
SAmerica_TMP2003077 |
|
Oil Slicks on Lake Maracaibo
…
nasa, nasaimageofthedaygalle
…
Several oil slicks occurred
…
PIA04331
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2002-12-26 |
| creator |
NASA -- Image courtesy NASA/GSFC/LaRC/JPL, www-misr.jpl.nasa.gov/ MISR Team. Text by Clare Averill (Acro Service Corporation/JPL) |
| identifier |
PIA04331 |
|
Hurricane Dennis: Natural Ha
…
nasa, nasanaturalhazards
The swirling clouds of Tropi
…
Dennis_TMO_2005187
| mediatype |
IMAGE |
| mediatype |
image |
| date |
July 6, 2005 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
Dennis_TMO_2005187 |
|
Flooding in Columbia and Ven
…
nasa, nasanaturalhazards
* eoimages.gsfc.nasa.gov/ima
…
venezeula_tmo_01_14feb05
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2005-02-14 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
venezeula_tmo_01_14feb05 |
|
Flooding in Columbia and Ven
…
nasa, nasanaturalhazards
* eoimages.gsfc.nasa.gov/ima
…
venezeula_tmo_01_14feb05
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2005-02-14 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
venezeula_tmo_01_14feb05 |
|
Flooding in Columbia and Ven
…
nasa, nasanaturalhazards
* eoimages.gsfc.nasa.gov/ima
…
venezula_tmo_26feb05
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2005-02-26 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
venezula_tmo_26feb05 |
|
Oil Slicks on Lake Maracaibo
…
PIA04331
Sol (our sun)
Multi-angle Imaging SpectroR
…
| Title |
Oil Slicks on Lake Maracaibo, Venezuela |
| Original Caption Released with Image |
Several oil slicks occurred on Lake Maracaibo in northwestern Venezuela between December 2002 and January 2003, and were observed by various satellite instruments. These images from the Multi-angle Imaging SpectroRadiometer (MISR) provide new information relating to one such event near the center of Lake Maracaibo on December 26, 2002. In unpolluted areas, the water surface is "ruffled" by wind and the resulting wave facets divert reflected rays into many directions. An oil film dampens the presence of small wind-driven "capillary" waves, resulting a smoother, more mirror-like surface. Also, oil is more strongly absorbing than the surrounding water. Therefore, at most viewing angles, a surface slick will appear darker than the surrounding unpolluted areas, whereas near the specular angle (the angle at which a perfect mirror reflects light) it will appear brighter. Simultaneous observation at multiple view angles therefore enhances the reliability of oil-slick detection using optical imaging. An example of how the optical contrast of an oil film on a water surface changes as a function of viewing angle is illustrated by these false-color MISR images, comprised of near-infrared, red and blue spectral data at three different angles, using the vertical-viewing camera (left), the 26°-forward-viewing camera (center) and the 46°-forward-viewing camera (right). A swirly area in the middle of the lake appears darker than the surrounding waters at both the nadir and 46° views, but brighter than the surrounding waters at the 26° view. Of the three images, only the 26° camera observes close to specular reflection angle. Lake Maracaibo is the largest lake in South America. The lake is somewhat saline, since it is connected to the Gulf of Venezuela by a narrow strait in the north. Venezuela is the largest oil producing nation in the Western Hemisphere, and the Lake Maracaibo basin includes the largest oil fields and almost a quarter of this nation's population. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 16081. The panels cover an area of 72 kilometers x 225 kilometers, and utilize data from blocks 81 to 83 within World Reference System-2 path 8. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology. |
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