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Atmospheric Water Vapor duri
| Title |
Atmospheric Water Vapor during the 1998 La Niña (WMS) |
| Abstract |
Water vapor is a small but significant constituent of the atmosphere, warming the planet due to the greenhouse effect and condensing to form clouds which both warm and cool the Earth in different circumstances. A key feature of global atmospheric water vapor convection is the Intertropical Convergence Zone, the low pressure region within five degrees of the equator where the trade winds converge and solar heating of the atmosphere forces the water-laden air to rise in altitude, form clouds, and then precipitate as rain in the afternoon. This visualization shows the global water vapor distribution in gray and white and the global precipitation in yellow every hour from August 30, 1998 to September 20, 1998. The afternoon thunderstorms in the tropics are seen as a flashing yellow region that moves from east to west, following the sun. This is a La Niña period, when the water to the west of South America is cooler than normal, forcing the atmosphere there to cool down and hold less water. Strong east-to-west winds can be seen in this region, contributing to the high water vapor region that forms further to the west over southeast Asia, the Philippines, and Indonesia, causing increased humidity and rainfall in that region. This data is from the Goddard Earth Modeling System, a coupled land-ocean-atmosphere model which uses earth and satellite-based observations to simulate the Earth's physical system during events such as La Niña. |
| Completed |
2004-07-06 |
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Indonesia?s Ruang Volcano Er
| Title |
Indonesia?s Ruang Volcano Erupts |
| Description |
*Full-resolution Images:* ÿÿÿTerra MODIS at 1:55 UTC (1.1 MB) ÿÿÿAqua MODIS at 4:50 UTC (748 KB) Mount Ruang, a stratovolcano in the Indonesian Sulawesi Islands, erupted on September 25, 2002, sending a large plume of ash (gray pixels) streaming westward toward Borneo and Sumatra. The eruption was preceded by earthquakes on the day before, followed by a thick, black column of volcanic ash ejected as high as 5,000 m into the sky on the 25th. While no fatalities were reported, more than 1,000 residents on Ruang Island were forced to evacuate to a nearby island. This comparison pair of true-color images was acquired by the Moderate Resolution Imaging Spectroradiometer, flying aboard NASA's Terra and Aqua satellites, on September 25. The top image was acquired by Terra MODIS at 1:55 UTC, while the bottom image was acquired by Aqua MODIS at 4:50 UTC. Notice how much the plume grew in that 3-hour span of time. (Note: the Aqua image appears noticeably different because the relative sun angle makes both the plume and the ocean surface appear much brighter.) Images courtesy Jacques Descloitres, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov/ ] at NASA GSFC |
|
Indonesia?s Ruang Volcano Er
| Title |
Indonesia?s Ruang Volcano Erupts |
| Description |
*Full-resolution Images:* ÿÿÿTerra MODIS at 1:55 UTC (1.1 MB) ÿÿÿAqua MODIS at 4:50 UTC (748 KB) Mount Ruang, a stratovolcano in the Indonesian Sulawesi Islands, erupted on September 25, 2002, sending a large plume of ash (gray pixels) streaming westward toward Borneo and Sumatra. The eruption was preceded by earthquakes on the day before, followed by a thick, black column of volcanic ash ejected as high as 5,000 m into the sky on the 25th. While no fatalities were reported, more than 1,000 residents on Ruang Island were forced to evacuate to a nearby island. This comparison pair of true-color images was acquired by the Moderate Resolution Imaging Spectroradiometer, flying aboard NASA's Terra and Aqua satellites, on September 25. The top image was acquired by Terra MODIS at 1:55 UTC, while the bottom image was acquired by Aqua MODIS at 4:50 UTC. Notice how much the plume grew in that 3-hour span of time. (Note: the Aqua image appears noticeably different because the relative sun angle makes both the plume and the ocean surface appear much brighter.) Images courtesy Jacques Descloitres, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov/ ] at NASA GSFC |
|
Indonesia?s Ruang Volcano Er
| Title |
Indonesia?s Ruang Volcano Erupts |
| Description |
*Full-resolution Images:* ÿÿÿTerra MODIS at 1:55 UTC (1.1 MB) ÿÿÿAqua MODIS at 4:50 UTC (748 KB) Mount Ruang, a stratovolcano in the Indonesian Sulawesi Islands, erupted on September 25, 2002, sending a large plume of ash (gray pixels) streaming westward toward Borneo and Sumatra. The eruption was preceded by earthquakes on the day before, followed by a thick, black column of volcanic ash ejected as high as 5,000 m into the sky on the 25th. While no fatalities were reported, more than 1,000 residents on Ruang Island were forced to evacuate to a nearby island. This comparison pair of true-color images was acquired by the Moderate Resolution Imaging Spectroradiometer, flying aboard NASA's Terra and Aqua satellites, on September 25. The top image was acquired by Terra MODIS at 1:55 UTC, while the bottom image was acquired by Aqua MODIS at 4:50 UTC. Notice how much the plume grew in that 3-hour span of time. (Note: the Aqua image appears noticeably different because the relative sun angle makes both the plume and the ocean surface appear much brighter.) Images courtesy Jacques Descloitres, MODIS Land Rapid Response Team [ http://rapidfire.sci.gsfc.nasa.gov/ ] at NASA GSFC |
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Deep Ocean Tsunami Waves off
nasa, nasaimageofthedaygalle
The initial tsunami waves re
PIA04373
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2004-12-26 |
| creator |
NASA -- Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. Text by Clare Averill (Raytheon ITSS/JPL), Michael Garay and David J. Diner (JPL, California Institute of Technology), and Vasily Titov (NOAA/Pacific Marine Environmental Laboratory and University of Washington/Joint Institute for the Study of the Atmosphere and Oceans). |
| identifier |
PIA04373 |
|
La Nina Greenup Patterns: Im
nasa, nasaimageofthedaygalle
La Nina's fingerprint is all
ge_08575_02
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2008 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
ge_08575_02 |
|
La Nina Greenup Patterns: Im
nasa, nasaimageofthedaygalle
La Nina's fingerprint is all
ge_08575_02
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2008 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
ge_08575_02 |
|
La Nina Greenup Patterns: Im
nasa, nasaimageofthedaygalle
La Nina's fingerprint is all
ge_08575_02
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2008 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
ge_08575_02 |
|
La Nina Greenup Patterns: Im
nasa, nasaimageofthedaygalle
La Nina's fingerprint is all
ge_08575_02
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2008 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
ge_08575_02 |
|
La Nina Greenup Patterns: Im
nasa, nasaimageofthedaygalle
La Nina's fingerprint is all
ge_08575_02
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2008 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
ge_08575_02 |
|
La Nina Greenup Patterns: Im
nasa, nasaimageofthedaygalle
La Nina's fingerprint is all
ge_08575_02
| mediatype |
IMAGE |
| mediatype |
image |
| date |
2008 |
| creator |
NASA -- NASA Image Of The Day |
| identifier |
ge_08575_02 |
|
Uplift and Subsidence Associ
PIA02435
Sol (our sun)
ASTER
| Title |
Uplift and Subsidence Associated with the Great Aceh-Andaman Earthquake of 2004 |
| Original Caption Released with Image |
The magnitude 9.2 Indian Ocean earthquake of December 26, 2004, produced broad regions of uplift and subsidence. In order to define the lateral extent and the downdip limit of rupture, scientists from Caltech, Pasadena, Calif., NASA's Jet Propulsion Laboratory, Pasadena, Calif., Scripps Institution of Oceanography, La Jolla, Calif., the U.S. Geological Survey, Pasadena, Calif., and the Research Center for Geotechnology, Indonesian Institute of Sciences, Bandung, Indonesia, first needed to define the pivot line separating those regions. Interpretation of satellite imagery and a tidal model were one of the key tools used to do this. These pre-Sumatra earthquake (a) and post-Sumatra earthquake (b) images of North Sentinel Island in the Indian Ocean, acquired from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft, show emergence of the coral reef surrounding the island following the earthquake. The tide was 30 plus or minus 14 centimeters lower in the pre-earthquake image (acquired November 21, 2000) than in the post-earthquake image (acquired February 20, 2005), requiring a minimum of 30 centimeters of uplift at this locality. Observations from an Indian Coast Guard helicopter on the northwest coast of the island suggest that the actual uplift is on the order of 1 to 2 meters at this site. In figures (c) and (d), pre-earthquake and post-earthquake ASTER images of a small island off the northwest coast of Rutland Island, 38 kilometers east of North Sentinel Island, show submergence of the coral reef surrounding the island. The tide was higher in the pre-earthquake image (acquired January 1, 2004) than in the post-earthquake image (acquired February 4, 2005), requiring subsidence at this locality. The pivot line must run between North Sentinel and Rutland islands. Note that the scale for the North Sentinel Island images differs from that for the Rutland Island images. The tidal model used for this study was based on data from JPL's Topex/Poseidon satellite. The model was used to determine the relative sea surface height at each location at the time each image was acquired, a critical component used to quantify the deformation. The scientists' method of using satellite imagery to recognize changes in elevation relative to sea surface height and of using a tidal model to place quantitative bounds on coseismic uplift or subsidence is a novel approach that can be adapted to other forms of remote sensing and can be applied to other subduction zones in tropical regions. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with, critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats, monitoring potentially active volcanoes, identifying crop stress, determining cloud morphology and physical properties, wetlands evaluation, thermal pollution monitoring, coral reef degradation, surface temperature mapping of soils and geology, and measuring surface heat balance. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate. |
|
QuikScat Shows Rough Seas/At
PIA09110
Sol (our sun)
SeaWinds Scatterometer
| Title |
QuikScat Shows Rough Seas/Atmospheric Conditions at Time of Two Java Sea Disasters |
| Original Caption Released with Image |
. QuikScat is managed for NASA's Science Mission Directorate, Washington, DC, by NASA's Jet Propulsion Laboratory, Pasadena, CA. JPL also built the SeaWinds radar instrument and is providing ground science processing systems. NASA's Goddard Space Flight Center, Greenbelt, MD, managed development of the satellite, designed and built by Ball Aerospace & Technologies Corp., Boulder, CO. The National Oceanic and Atmospheric Administration has contributed support to ground systems processing and related activities., A ferry carrying more than 600 passengers sank in the Java Sea between the island of Java and Borneo just before midnight on December 29, 2006, during high winds and rough seas. On January 1, 2007, a plane carrying more than 100 people crashed on its flight over the Java Sea, high winds and turbulent weather are being investigated as possible causes. The origin of surges of deadly winds in this usually relatively calm region is poorly monitored and understood. However, ocean winds data from NASA's QuikScat satellite show potential for helping alleviate such deficiencies. Data obtained from QuikScat on December 30 and January 1 shed new insights into the atmospheric conditions at the time of these incidents. QuikScat data are available in near real time to operational weather forecasting agencies around the world. The data from December 30 and January 1 observed that the strong winds in the Java Sea originated from the surge of a strong winter monsoon from the Asian continent. The monsoon winds blew south across the South China Sea and deflected eastward after they crossed the equator due to the rotation of Earth. The winds strengthened as they were channeled through the land masses of Indonesia. The winds in the Java Sea remained strong through January 1, 2007. Associated with the eastward winds, twin cyclones (a counter-clockwise circulation in the Northern Hemisphere and a clockwise circulation in the Southern Hemisphere) were also observed by QuikScat, the stronger one was south of the equator (summer hemisphere) between Java and Australia, and a weaker one was north of the equator (winter hemisphere) west of Borneo. In this image from January 1, the different colors denote different wind speeds. White arrows are wind vectors showing both direction and speed. The large-scale, broad and simultaneous observations by QuikScat make it possible to put the local weather into the context of the large-scale circulation, and confirm one of the assumptions that links the cold surge of the Asian monsoon with tropical cyclones in the western Pacific. QuikScat, managed by JPL, measures ocean surface wind/stress by sending radar pulses to the surface and measuring the strength of the signals returned. "QuikScat Background" NASA's Quick Scatterometer (QuikScat) spacecraft was launched from Vandenberg Air Force Base, California on June 19, 1999. QuikScat carries the SeaWinds scatterometer, a specialized microwave radar that measures near-surface wind speed and direction under all weather and cloud conditions over the Earth's oceans. More information about the QuikScat mission and observations is available at http://winds.jpl.nasa.gov [ http://photojournal.jpl.nasa.gov/catalog/PIA09110 http://winds.jpl.nasa.gov ] |
|
Breaking Tsunami Waves along
PIA04372
Sol (our sun)
Multi-angle Imaging SpectroR
| Title |
Breaking Tsunami Waves along India's Eastern Coast |
| Original Caption Released with Image |
(3.8 MB) shows a region further south, at the northern end of India's Coromandel Coast, and covers an area of 43 kilometers x 58 kilometers. Cloud "motion" in these animations results from apparent displacements due to parallax associated with their height above the surface. The tsunami waves, on the other hand, are at sea level and show actual motion. When the waves arrive in the shallower water near the shore, they grow and, if they become large enough, they will break in a manner similar to typical oceanic waves, but on a much larger scale. The leading edge of the breaking waves is likely what is visible in the imagery. Additionally, if the tsunami waves impact the coast at an angle, they can produce what are known as "edge waves" which propagate parallel to the coast. There is clear evidence of edge wave generation in these images. Upon discovering the unique content of this imagery, MISR scientists contacted Dr. Vasily Titov at the National Oceanic and Atmospheric Administration's Pacific Marine Environmental Laboratory in Seattle, WA. Dr. Titov is an expert in the propagation of tsunamis, and has generated a model animation of the tsunami's progression from its origin near Sumatra (see http://www.pmel.noaa.gov/tsunami/indo_1204.html [ http://www.pmel.noaa.gov/tsunami/indo_1204.html ]). The MISR imagery provides measurements of the location and timing of the breaking waves, their angle relative to the shoreline, and their speed of propagation, which is estimated from these data to be around 30 kilometers/hour. In conjunction with bathymetric measurements of ocean depth, this information can be used to refine and calibrate tsunami propagation models. According to Dr. Titov, improving these models has two primary benefits. First, a detailed understanding of wave interactions with coastal areas is necessary for developing damage mitigation approaches. Second, a better predictive capability of the models will make possible more accurate near-real-time forecasts of tsunami arrival times and effects. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82° north and 82° south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 26720 and utilize data from within blocks 77 and 78 within World Reference System-2 path 142. 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., At 00:58:53 UTC (Coordinated Universal Time) on 26 December 2004, a magnitude 9.0 earthquake occurred off the west coast of Sumatra, Indonesia. This was the fourth largest earthquake in the world since 1900 and the largest in over 40 years. It was caused by the release of stresses in the Earth that are built up as the Indian tectonic plate descends into the mantle beneath the Burma plate. It is estimated that the sea floor was displaced several meters due to the quake, resulting in large ocean waves, called "tsunamis" from the Japanese for "harbor waves." The tsunami moved rapidly across the deep ocean, with speeds estimated around 640 km/hr. When the waves reach shallow water near land, they slow considerably, but their size increases dramatically and they strike with catastrophic force. With human casualities exceeding 150,000, this event is one of the deadliest natural disasters in modern history, causing devastation along the shores of Indonesia, Sri Lanka, India, Thailand, and other countries. The initial tsunami waves reached the eastern Indian coast around 3:35 UTC, based on tide gauge measurements made at the port city of Vishakapatnam. The Multi-angle Imaging SpectroRadiometer (MISR) aboard NASA's Terra satellite passed over the eastern Indian coast between 5:10 to 5:20 UTC, when the tide gauge indicated the arrival of another series of waves. Because MISR's nine cameras imaged the coast over a time span of about 7 minutes, and because the the waves are unusually large, MISR was able to capture unique time-lapse imagery of the breaking waves. The still image shows four frames from the instrument's backward-viewing cameras spanning a period of about 2.5 minutes. This scene is located along the shores of Andhra Pradesh, near the mouth of the Godavari River, and covers an area of 42 kilometers x 37 kilometers. The arrows show the progression of the southwestern edges of the breakers. A series of frames spanning nearly 6 minutes has been made into a small animated GIF (below). An animated GIF (5.8 MB) covering a somewhat larger area of 86 kilometers x 49 kilometers is also available. A second animated GIF |
|
Breaking Tsunami Waves along
PIA04372
Sol (our sun)
Multi-angle Imaging SpectroR
| Title |
Breaking Tsunami Waves along India's Eastern Coast |
| Original Caption Released with Image |
(3.8 MB) shows a region further south, at the northern end of India's Coromandel Coast, and covers an area of 43 kilometers x 58 kilometers. Cloud "motion" in these animations results from apparent displacements due to parallax associated with their height above the surface. The tsunami waves, on the other hand, are at sea level and show actual motion. When the waves arrive in the shallower water near the shore, they grow and, if they become large enough, they will break in a manner similar to typical oceanic waves, but on a much larger scale. The leading edge of the breaking waves is likely what is visible in the imagery. Additionally, if the tsunami waves impact the coast at an angle, they can produce what are known as "edge waves" which propagate parallel to the coast. There is clear evidence of edge wave generation in these images. Upon discovering the unique content of this imagery, MISR scientists contacted Dr. Vasily Titov at the National Oceanic and Atmospheric Administration's Pacific Marine Environmental Laboratory in Seattle, WA. Dr. Titov is an expert in the propagation of tsunamis, and has generated a model animation of the tsunami's progression from its origin near Sumatra (see http://www.pmel.noaa.gov/tsunami/indo_1204.html [ http://www.pmel.noaa.gov/tsunami/indo_1204.html ]). The MISR imagery provides measurements of the location and timing of the breaking waves, their angle relative to the shoreline, and their speed of propagation, which is estimated from these data to be around 30 kilometers/hour. In conjunction with bathymetric measurements of ocean depth, this information can be used to refine and calibrate tsunami propagation models. According to Dr. Titov, improving these models has two primary benefits. First, a detailed understanding of wave interactions with coastal areas is necessary for developing damage mitigation approaches. Second, a better predictive capability of the models will make possible more accurate near-real-time forecasts of tsunami arrival times and effects. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82° north and 82° south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 26720 and utilize data from within blocks 77 and 78 within World Reference System-2 path 142. 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., At 00:58:53 UTC (Coordinated Universal Time) on 26 December 2004, a magnitude 9.0 earthquake occurred off the west coast of Sumatra, Indonesia. This was the fourth largest earthquake in the world since 1900 and the largest in over 40 years. It was caused by the release of stresses in the Earth that are built up as the Indian tectonic plate descends into the mantle beneath the Burma plate. It is estimated that the sea floor was displaced several meters due to the quake, resulting in large ocean waves, called "tsunamis" from the Japanese for "harbor waves." The tsunami moved rapidly across the deep ocean, with speeds estimated around 640 km/hr. When the waves reach shallow water near land, they slow considerably, but their size increases dramatically and they strike with catastrophic force. With human casualities exceeding 150,000, this event is one of the deadliest natural disasters in modern history, causing devastation along the shores of Indonesia, Sri Lanka, India, Thailand, and other countries. The initial tsunami waves reached the eastern Indian coast around 3:35 UTC, based on tide gauge measurements made at the port city of Vishakapatnam. The Multi-angle Imaging SpectroRadiometer (MISR) aboard NASA's Terra satellite passed over the eastern Indian coast between 5:10 to 5:20 UTC, when the tide gauge indicated the arrival of another series of waves. Because MISR's nine cameras imaged the coast over a time span of about 7 minutes, and because the the waves are unusually large, MISR was able to capture unique time-lapse imagery of the breaking waves. The still image shows four frames from the instrument's backward-viewing cameras spanning a period of about 2.5 minutes. This scene is located along the shores of Andhra Pradesh, near the mouth of the Godavari River, and covers an area of 42 kilometers x 37 kilometers. The arrows show the progression of the southwestern edges of the breakers. A series of frames spanning nearly 6 minutes has been made into a small animated GIF (below). An animated GIF (5.8 MB) covering a somewhat larger area of 86 kilometers x 49 kilometers is also available. A second animated GIF |
|
Breaking Tsunami Waves along
PIA04372
Sol (our sun)
Multi-angle Imaging SpectroR
| Title |
Breaking Tsunami Waves along India's Eastern Coast |
| Original Caption Released with Image |
(3.8 MB) shows a region further south, at the northern end of India's Coromandel Coast, and covers an area of 43 kilometers x 58 kilometers. Cloud "motion" in these animations results from apparent displacements due to parallax associated with their height above the surface. The tsunami waves, on the other hand, are at sea level and show actual motion. When the waves arrive in the shallower water near the shore, they grow and, if they become large enough, they will break in a manner similar to typical oceanic waves, but on a much larger scale. The leading edge of the breaking waves is likely what is visible in the imagery. Additionally, if the tsunami waves impact the coast at an angle, they can produce what are known as "edge waves" which propagate parallel to the coast. There is clear evidence of edge wave generation in these images. Upon discovering the unique content of this imagery, MISR scientists contacted Dr. Vasily Titov at the National Oceanic and Atmospheric Administration's Pacific Marine Environmental Laboratory in Seattle, WA. Dr. Titov is an expert in the propagation of tsunamis, and has generated a model animation of the tsunami's progression from its origin near Sumatra (see http://www.pmel.noaa.gov/tsunami/indo_1204.html [ http://www.pmel.noaa.gov/tsunami/indo_1204.html ]). The MISR imagery provides measurements of the location and timing of the breaking waves, their angle relative to the shoreline, and their speed of propagation, which is estimated from these data to be around 30 kilometers/hour. In conjunction with bathymetric measurements of ocean depth, this information can be used to refine and calibrate tsunami propagation models. According to Dr. Titov, improving these models has two primary benefits. First, a detailed understanding of wave interactions with coastal areas is necessary for developing damage mitigation approaches. Second, a better predictive capability of the models will make possible more accurate near-real-time forecasts of tsunami arrival times and effects. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82° north and 82° south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 26720 and utilize data from within blocks 77 and 78 within World Reference System-2 path 142. 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., At 00:58:53 UTC (Coordinated Universal Time) on 26 December 2004, a magnitude 9.0 earthquake occurred off the west coast of Sumatra, Indonesia. This was the fourth largest earthquake in the world since 1900 and the largest in over 40 years. It was caused by the release of stresses in the Earth that are built up as the Indian tectonic plate descends into the mantle beneath the Burma plate. It is estimated that the sea floor was displaced several meters due to the quake, resulting in large ocean waves, called "tsunamis" from the Japanese for "harbor waves." The tsunami moved rapidly across the deep ocean, with speeds estimated around 640 km/hr. When the waves reach shallow water near land, they slow considerably, but their size increases dramatically and they strike with catastrophic force. With human casualities exceeding 150,000, this event is one of the deadliest natural disasters in modern history, causing devastation along the shores of Indonesia, Sri Lanka, India, Thailand, and other countries. The initial tsunami waves reached the eastern Indian coast around 3:35 UTC, based on tide gauge measurements made at the port city of Vishakapatnam. The Multi-angle Imaging SpectroRadiometer (MISR) aboard NASA's Terra satellite passed over the eastern Indian coast between 5:10 to 5:20 UTC, when the tide gauge indicated the arrival of another series of waves. Because MISR's nine cameras imaged the coast over a time span of about 7 minutes, and because the the waves are unusually large, MISR was able to capture unique time-lapse imagery of the breaking waves. The still image shows four frames from the instrument's backward-viewing cameras spanning a period of about 2.5 minutes. This scene is located along the shores of Andhra Pradesh, near the mouth of the Godavari River, and covers an area of 42 kilometers x 37 kilometers. The arrows show the progression of the southwestern edges of the breakers. A series of frames spanning nearly 6 minutes has been made into a small animated GIF (below). An animated GIF (5.8 MB) covering a somewhat larger area of 86 kilometers x 49 kilometers is also available. A second animated GIF |
|
Breaking Tsunami Waves along
PIA04372
Sol (our sun)
Multi-angle Imaging SpectroR
| Title |
Breaking Tsunami Waves along India's Eastern Coast |
| Original Caption Released with Image |
(3.8 MB) shows a region further south, at the northern end of India's Coromandel Coast, and covers an area of 43 kilometers x 58 kilometers. Cloud "motion" in these animations results from apparent displacements due to parallax associated with their height above the surface. The tsunami waves, on the other hand, are at sea level and show actual motion. When the waves arrive in the shallower water near the shore, they grow and, if they become large enough, they will break in a manner similar to typical oceanic waves, but on a much larger scale. The leading edge of the breaking waves is likely what is visible in the imagery. Additionally, if the tsunami waves impact the coast at an angle, they can produce what are known as "edge waves" which propagate parallel to the coast. There is clear evidence of edge wave generation in these images. Upon discovering the unique content of this imagery, MISR scientists contacted Dr. Vasily Titov at the National Oceanic and Atmospheric Administration's Pacific Marine Environmental Laboratory in Seattle, WA. Dr. Titov is an expert in the propagation of tsunamis, and has generated a model animation of the tsunami's progression from its origin near Sumatra (see http://www.pmel.noaa.gov/tsunami/indo_1204.html [ http://www.pmel.noaa.gov/tsunami/indo_1204.html ]). The MISR imagery provides measurements of the location and timing of the breaking waves, their angle relative to the shoreline, and their speed of propagation, which is estimated from these data to be around 30 kilometers/hour. In conjunction with bathymetric measurements of ocean depth, this information can be used to refine and calibrate tsunami propagation models. According to Dr. Titov, improving these models has two primary benefits. First, a detailed understanding of wave interactions with coastal areas is necessary for developing damage mitigation approaches. Second, a better predictive capability of the models will make possible more accurate near-real-time forecasts of tsunami arrival times and effects. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82° north and 82° south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 26720 and utilize data from within blocks 77 and 78 within World Reference System-2 path 142. 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., At 00:58:53 UTC (Coordinated Universal Time) on 26 December 2004, a magnitude 9.0 earthquake occurred off the west coast of Sumatra, Indonesia. This was the fourth largest earthquake in the world since 1900 and the largest in over 40 years. It was caused by the release of stresses in the Earth that are built up as the Indian tectonic plate descends into the mantle beneath the Burma plate. It is estimated that the sea floor was displaced several meters due to the quake, resulting in large ocean waves, called "tsunamis" from the Japanese for "harbor waves." The tsunami moved rapidly across the deep ocean, with speeds estimated around 640 km/hr. When the waves reach shallow water near land, they slow considerably, but their size increases dramatically and they strike with catastrophic force. With human casualities exceeding 150,000, this event is one of the deadliest natural disasters in modern history, causing devastation along the shores of Indonesia, Sri Lanka, India, Thailand, and other countries. The initial tsunami waves reached the eastern Indian coast around 3:35 UTC, based on tide gauge measurements made at the port city of Vishakapatnam. The Multi-angle Imaging SpectroRadiometer (MISR) aboard NASA's Terra satellite passed over the eastern Indian coast between 5:10 to 5:20 UTC, when the tide gauge indicated the arrival of another series of waves. Because MISR's nine cameras imaged the coast over a time span of about 7 minutes, and because the the waves are unusually large, MISR was able to capture unique time-lapse imagery of the breaking waves. The still image shows four frames from the instrument's backward-viewing cameras spanning a period of about 2.5 minutes. This scene is located along the shores of Andhra Pradesh, near the mouth of the Godavari River, and covers an area of 42 kilometers x 37 kilometers. The arrows show the progression of the southwestern edges of the breakers. A series of frames spanning nearly 6 minutes has been made into a small animated GIF (below). An animated GIF (5.8 MB) covering a somewhat larger area of 86 kilometers x 49 kilometers is also available. A second animated GIF |
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Deep Ocean Tsunami Waves off
PIA04373
Sol (our sun)
Multi-angle Imaging SpectroR
| Title |
Deep Ocean Tsunami Waves off the Sri Lankan Coast |
| Original Caption Released with Image |
The initial tsunami waves resulting from the undersea earthquake that occurred at 00:58:53 UTC (Coordinated Universal Time) on 26 December 2004 off the island of Sumatra, Indonesia, took a little over 2 hours to reach the teardrop-shaped island of Sri Lanka. Additional waves continued to arrive for many hours afterward. At approximately 05:15 UTC, as NASA's Terra satellite passed overhead, the Multi-angle Imaging SpectroRadiometer (MISR) captured this image of deep ocean tsunami waves about 30-40 kilometers from Sri Lanka's southwestern coast. The waves are made visible due to the effects of changes in sea-surface slope on the reflected sunglint pattern, shown here in MISR's 46° forward-pointing camera. Sunglint occurs when sunlight reflects off a water surface in much the same way light reflects off a mirror, and the position of the Sun, angle of observation, and orientation of the sea surface determines how bright each part of the ocean appears in the image. These large wave features were invisible to MISR's nadir (vertical-viewing) camera. The image covers an area of 208 kilometers x 207 kilometers. Since the greatest impact of the tsunami was generally in an east-west direction, the havoc caused by the tsunami along the southwestern shores of Sri Lanka was not as severe as along the eastern coast, though there was still substantial damage in this region--as evidenced by the brownish debris in the water--because tsunami waves can diffract around land masses. The ripple-like wave pattern evident in this MISR image roughly correlates with the undersea boundary of the continental shelf. This surface manifestation is likely to be caused by interaction of deep waves with the ocean floor, rather than by the more usually-observed surface waves driven by winds. It is possible that this semi-concentric pattern represents wave reflection from the continental land mass, however, a combination of wave modeling and detailed bathymetric data is required to fully understand the dynamics. Examination of other MISR images of this area, taken under similar illumination conditions, has not uncovered any surface patterns resembling those seen here. This image is an example of how MISR's multiangular capability provides unique information for understanding how tsunamis propagate. Another application of MISR data enabled measuring the motion of breaking tsunami waves [ http://www-misr.jpl.nasa.gov/gallery/galhistory/2005_jan_12.html ], along the eastern shores of Andhra Pradesh, India. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82° north and 82° south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 26720 and utilize data from within blocks 85 to 86 within World Reference System-2 path 142. 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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Smoke over Sumatra, Indonesi
PIA03449
Sol (our sun)
Multi-angle Imaging SpectroR
| Title |
Smoke over Sumatra, Indonesia |
| Original Caption Released with Image |
At least once a year for a period lasting from a week to several months, northern Sumatra is obscured by smoke and haze produced by agricultural burning and forest fires. These data products from the Multi-angle Imaging SpectroRadiometer document the presence of airborne particulates on March 13, 2002, during Terra orbit 11880. On the left is an image acquired by MISR's 70-degree backward-viewing camera. On the right is a map of aerosol optical depth, a measure of the abundance of atmospheric particulates. This product utilized a test version of the MISR retrieval that incorporates an experimental set of aerosol mixtures. The haze has completely obscured northeastern Sumatra and part of the Strait of Malacca, which separates Sumatra and the Malaysian Peninsula. A northward gradient is apparent as the haze dissipates in the direction of the Malaysian landmass. Each panel covers an area of about 760 kilometers x 400 kilometers. Haze conditions had posed a health concern during late February (when schools in some parts of North Sumatra were closed), and worsened considerably in the first two weeks of March. By mid-March, local meteorology officials asked residents of North Sumatra's provincial capital, Medan, to minimize their outdoor activities and wear protective masks. Poor visibility at Medan airport forced a passenger plane to divert to Malaysia on March 14, and visibility reportedly ranged between 100 and 600 meters in some coastal towns southeast of Medan. The number and severity of this year's fires was exacerbated by dry weather conditions associated with the onset of a weak to moderate El Niño. The governments of Indonesia, Malaysia, and Brunei have agreed to ban open burning in plantation and forest areas. The enforcement of such fire bans, however, has proven to be an extremely challenging task. 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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