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Abrams, M.

Publications and source records attributed to Abrams, M..

At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Lahar Risk on the NE Flank of Popocatepetl Volcano

Popocatepetl volcano has an altitude of 5452 meters and is capped by glaciers which represent a volume of less than 0.017 km(sup 3) of ice. These glaciers are distributed on the northwest-north face of the cone, starting at 4900 m.a.s.l. The ablation runoff of the glaciers is channelized to the north through the Barranca Central and Barranca Ventorillo which at the lower altitude join together to form a larger canyon bent to the northeast following a spur made of volcanic rock from the extinct Iztacchuatl volcano. At 3200 m.a.s.l. a sudden change in morphology marks the starting point of lahar deposits. Several of these mudflows have been mapped. The San Nicolas Lahar covers a poorly developed soil where pottery and other cultural remains have been found. There are now several towns in the area.

volcanos Popocatepetl Mexico lahar mudflows glacie↗
NASA NTRS1994

Lessons from Popocatepetl Volcano (Mexico): Ancient Settlement Buried by Lavas, Mudflows, and Air-Fall Deposits

Popocatepetl volcano is 5452 m in altitude and capped by glaciers with a long Late Pleistocene-Holocene history. Volcanic activity has been intense during the last 10 000 years. Therefore, the valleys at the NE foothills of the volcano, covered by air-fall ejecta and drained by the runoff of the glaciers, became very attractive to ancient inhabitants of the Xalizintla Valley (XV) west of Puebla City, because of fertility of soils. The XV was occupied by humans about 2000 years ago who witnessed five events related to volcanic activity related to Popo. These events, described in this paper, are being taken into account for volcanic risk evaluation since several towns with a population of more than 23 000 people reoccupied again the Xalizintla Valley.

volcano Popocatepetl Mexico glacier mud flows huma↗
NASA NTRS1994

Pressure Sounding of the Middle Atmosphere from ATMOS Solar Occultation Measurements of Atmospheric CO(sub 2) Absorption Lines

A method for retrieving the atmospheric pressure corresponding to the tangent point of an infrared spectrum recorded in the solar occultation mode is described and applied to measurements made by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform spectrometer. Tangent pressure values are inferred from measurements of isolated CO(sub 2) lines with temperature-insensitive intensities. Tangent pressures are determined with a spectroscopic precision of 1-3%, corresponding to a tangent point height precision, depending on the scale height, of 70-210 meters.

Atmospheric Trace Molecule Spectroscopy ATMOS atmo↗
NASA NTRS1994

Simulated ASTER data for Geologic Studies

The Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) is a high spatial resolution imaging instrument, due to be launched on NASA's Earth Observing System AM-1 satellite platform in 1998. ASTER acquires data in 14 bands, spanning the wavelength region from the visible, near infrared, short wavelength infrared, and thermal infrared, with spatial resolution varying from 15 m to 90 m, depending on wavelength region. In order to evaluate our ability to use ASTER data for geological mapping, we used aircraft data over Cuprite, Nevada to create a simulated 14-band ASTER data set. The study site has sparse vegetation, and exposes a wide range of unaltered and hydrothermally altered volcanic rocks. The wide range of wavelengths covered by ASTER allowed us to recognize or separate iron oxide minerals, clay-bearing minerals, sulfate minerals, ammonia minerals, siliceous rocks, and carbonates. Combined with laboratory spectral measurements, we were able to identify these constituents. Based on both sets of information, we produced an alteration map showing the distribution of argillized rocks, opalized rocks with alunite, silicified rocks, and areas dominated by kaolinite and buddingtonite. The map was as accurate as published maps made by traditional field methods. ASTER promises to be a major improvement over existing satellite systems for geologic mapping.

Advanced↗
NASA NTRS1985

Geologic Utility of LANSDAT-4 TM Data

The performance of the TM vis-a-vis various geological applications was quantified by analyzing: (1) the geological utility of the data with respect to the increased spatial resolution and number of bands (compared to the MSS); (2) the geometric accuracy; (3) the radiometric performance of the TM scanner. Preliminary analyses were performed on TM scenes: over Death Valley, California, and over southern Arizona. Both scenes were acquired in CCT-PT format, where the data were geometrically and radiometrically corrected. Overall, the TM data appears to contain a marked increase in geologically useful information; however, a number of instrumental or processing artifacts may well limit the ability of the geologist to fully extract this information.

Abrams, M.↗
NASA NTRS1984

Recent developments in lithologic mapping using remote sensing data

Major development trends noted in remote sensing scanners are toward greater spatial and spectral resolution, as well as the acquisition of data over a broader portion of the electromagnetic spectrum. Attention is presently given to representative samples of the product of two new-generation satellite sensors, the Landsat-4 Thematic Mapper and SPOT, as well as the status of airborne scanner research aimed at the exploration of multispectral data in the thermal IR wavelength region (which encompasses the diagnostic spectral features of silicates and carbonates). Testing is underway for scanners having spectral bands as narrow as 0.01 micron in the visible and near-IR, which will be capable of identifying specific minerals.

Abrams, M.↗