Publication:20121010091231

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Title Environmental mapping of the World Trade Center area with imaging spectroscopy after the September 11, 2001 attack
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Publication Date 2006/01/01
Exact Publication Date Unknown
Publication Number
Publication Version
Authors R.N. Clark, G.A. Swayze, T.M. Hoefen, R.O. Green, K.E. Livo, G., Meeker, S. Sutley, G. Plumlee, B. Pavri, C. Sarture, J. Boardman, I., Brownfield, L.C. Morath
Number of Pages 18
Original URL

http://www.us.oup.com/us/catalog/general/subject/Chemistry/EnvironmentalChemistry/?view=usa&ci=9780841239166

Working URL

http://911datasets.org/images/ACS_919_Urban_Aerosols_and_Their_Impacts_2006.torrent

Abstract URL

http://pubs.acs.org/doi/abs/10.1021/bk-2006-0919.ch004

Preprint URL


Company or Agency U.S. Geological Survey
Journal
Journal Issue
Book Urban Aerosols and Their Impact: Lessons Learned from the World Trade Center Tradgedy
Book Chapter 4
Book Start Page 66
Book End Page 83
doi
isbn 0-8412-3916-9
Cite as Clark, R.N., G.A. Swayze, T.M. Hoefen, R.O. Green, K.E. Livo, G., Meeker, S. Sutley, G. Plumlee, B. Pavri, C. Sarture, J. Boardman, I., Brownfield, L.C. Morath, 2006, Chapter 4: Environmental mapping of the World Trade Center area with imaging spectroscopy after the September 11, 2001 attack: in Urban Aerosols and Their Impacts: Lessons Learned from the World Trade Center Tragedy, Jeff Gaffney and N. A. Marley (eds), American Chemical Society, Symposium Series 919, Oxford University Press, p. 66-83, plates 4.1-4.6.
Abstract The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) was flown over the World Trade Center area on September 16, 18, 22, and 23, 2001. The data were used to map the WTC debris plume and its contents, including the spectral signatures of asbestiform minerals. Samples were collected and used as ground truth for the AVARIS mapping. A number of thermal hot spots were observed with temperatures greater than 700 °C. The extent and temperatures of the fires were mapped as a function of time. By September 23, most of the fires observed by AVIRIS had been eliminated or reduced in intensity. The mineral absorption features mapped by AVARIS only indicated the presence of serpentine mineralogy and not if the serpentine has asbestiform.
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Starts on page 66:

http://911datasets.org/index.php/SFile:2AHXP3LFIPR4GCCLI3SJNALHIU675N2Y


Figure 1. False color images showing the core affected area around the World Trade Center extending from 5 to 12 days after the collapse. Hot spots appear orange and yellow. Dozens of hot spots are seen on September 16th and 18th, but most had cooled or the fires had been put out by September 23. The image on the 18th is dark because of clouds which blocked sunlight but not light emitted by the fires. The key shows hot spot locations in Table I. Analysis of the data indicates temperatures greater than 700o C. Over 3 dozen hot spots are identified in the core zone. By September 23, only 4, or possibly 5, hot spots are apparent in the image, with temperatures cooler than those on September 16. Figure 1 also shows vegetated areas as green. Water appears blue, and the smoke from the fires appears as a light blue haze. White and lighter blue areas are rooftops, roads, and concrete as well as dust and debris from the collapsed buildings. Dust, probably more than a few millimeters thick (the optical depth), appears in shades of brown around the core WTC area on the 16th.


Figure 2. AVIRIS spectra for thermal hot spot C (black lines) are shown with the fitted thermal response for September 16 (orange) and 18 (red). The spectral shape is used to constrain temperature and the intensity constrains area. The small rise near 2.5 fm in the spectrum from September 18 indicates another thermal component at a temperature lower than 330o C.


Figure 3. Spectra of the field samples show a general range of spectral characteristics. Samples WTC01-37B and WTC01-37Am are concrete that display ferrous iron absorptions (most likely due to the minerals in the aggregate). The spectrum of concrete minus the aggregate is shown in sample WTC01-37A(c): the cement shows less ferrous iron absorption. Pervasive in the spectra of the debris is gypsum, with variations in abundance of other components. These spectra were used to map the WTC plume.


Figure 4. WTC AVIRIS dust/debris plume map. The plume map indicates an asymmetry in the dust/debris distribution, with more iron bearing materials to the south by southeast. The colors match the colors of the spectra in Figure 3.


Figure 5. Spectral reflectance mapping keyed to minerals that can have asbestiform morphology shows only scattered possible occurrences at the surface around the WTC area. Spectroscopy identifies mineralogy by detecting absorptions, due to molecular bonds, at a characteristic wavelength and with a diagnostic band shape. The grain size of a mineral affects the intensity and, to some extent, the shape of its spectral absorptions, but spectroscopy may not be sensitive to whether or not a mineral has an asbestiform shape (long needle-like shapes with diameters less than a micrometer), especially at the relatively low spectral resolution of AVIRIS. Therefore this map indicates possible areas of asbestiform mineralogy. The colored pixels show only small scattered locations. Locations are enhanced on Figure 6.


Figure 6 The AVIRIS dust plume data, field sample data and field observations were combined to show the extend of the WTC dust plume on September 16, 2001 (green to yellow). Locations of asbestiform mineral spectral signatures from Figure 5 are shown as small orange spots. Note the asbestiform mineral signatures may indicate non-asbestiform amphibole and serpentine group minerals that are part of building materials. The locations of AVIRIS derived amphibole and serpentine group minerals is representative, and not exact because viewing angles of the sensor displaces positions of the tops of tall buildings relative to the ground (buildings appear to tilt at the edge of the scan lines compared to the center). For more accurate position of any one spot, use the data in Figure 5.

Listed at: http://speclab.cr.usgs.gov/wtc/

Facts about "20121010091231"RDF feed
AbstractThe Airborne Visible/Infrared Imaging SpecThe Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) was flown over the World Trade Center area on September 16, 18, 22, and 23, 2001. The data were used to map the WTC debris plume and its contents, including the spectral signatures of asbestiform minerals. Samples were collected and used as ground truth for the AVARIS mapping. A number of thermal hot spots were observed with temperatures greater than 700 °C. The extent and temperatures of the fires were mapped as a function of time. By September 23, most of the fires observed by AVIRIS had been eliminated or reduced in intensity. The mineral absorption features mapped by AVARIS only indicated the presence of serpentine mineralogy and not if the serpentine has asbestiform.and not if the serpentine has asbestiform. +
Abstract URLhttp://pubs.acs.org/doi/abs/10.1021/bk-2006-0919.ch004 +
AuthorsR.N. Clark +, G.A. Swayze +, T.M. Hoefen +, R.O. Green +, K.E. Livo +, G. +, Meeker +, S. Sutley +, G. Plumlee +, B. Pavri +, C. Sarture +, J. Boardman +, I. +, Brownfield + and L.C. Morath +
BookUrban Aerosols and Their Impact: Lessons Learned from the World Trade Center Tradgedy +
Book Chapter4 +
Book End Page83 +
Book Start Page66 +
Cite asClark, R.N., G.A. Swayze, T.M. Hoefen, R.OClark, R.N., G.A. Swayze, T.M. Hoefen, R.O. Green, K.E. Livo, G., Meeker, S. Sutley, G. Plumlee, B. Pavri, C. Sarture, J. Boardman, I., Brownfield, L.C. Morath, 2006, Chapter 4: Environmental mapping of the World Trade Center area with imaging spectroscopy after the September 11, 2001 attack: in Urban Aerosols and Their Impacts: Lessons Learned from the World Trade Center Tragedy, Jeff Gaffney and N. A. Marley (eds), American Chemical Society, Symposium Series 919, Oxford University Press, p. 66-83, plates 4.1-4.6.niversity Press, p. 66-83, plates 4.1-4.6. +
Company or AgencyU.S. Geological Survey +
Isbn0-8412-3916-9 +
Number of Pages18 +
Original URLhttp://www.us.oup.com/us/catalog/general/subject/Chemistry/EnvironmentalChemistry/?view=usa&ci=9780841239166 +
Publication Date1 January 2006 +
TitleEnvironmental mapping of the World Trade Center area with imaging spectroscopy after the September 11, 2001 attack +
Working URL

http://911datasets.org/images/ACS_919_Urban_Aerosols_and_Their_Impacts_2006.torrent

+
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