144 research outputs found

    Engineering the Ocean

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    Developments in microprocessors, artificial intelligence, and new forms of power and communications for autonomous systems are already bringing about a revolution in our ability to explore, experiment within, and ultimately understand Earth\u27s last frontier: the ocean. It is inevitable, with this growing capability, that there will be pressure to use the same and similar technology to manipulate and enhance the ocean environment, just as we have our terrestrial environment. We will be able to fertilize the ocean to increase its productivity, adjust its climate in an attempt to halt natural and human-induced global change, harvest its internal energy to power our society, mine its raw materials, manage its inhabitants to maximize fish harvest, and exploit its overpowering beauty for human recreation. In this lecture, I present a series of fictional, but not entirely fanciful, future scenarios for man\u27s intervention in the ocean. Such manipulations might end up helping or hurting mankind. Will we have the intelligence to understand the implications of our actions? The humility to admit what we do not know? The unselfishness to take the long-term view on what is the best policy for the planet? We are the first species on Earth to have ever possessed the ability to purposefully change the conditions on our planet. The question is whether we will use this power wisely

    Analysis of gravity, magnetic, and seismic reflection data from Tibet and neighboring regions of China

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    Our principal effort was devoted to completing the analysis of the new gravity data over the Tibet plateau and its margins. A paper was completed discussing the statistical relationship between gravity and topography over the plateau. A paper on the structure of the Tarim Basin as constrained by Love wave dispersion is also under completion. This research project has also supported research on the newly-released gravity data from the former Soviet Union

    Results of the Basin and Range Geoscientific Experiment (BARGE): A marine-style seismic reflection survey across the eastern boundary of the central Basin and Range Province

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    Approximately 120 km of marine-style deep seismic reflection data were shot during a survey on the waters of Lake Mead in southeastern Nevada. The survey extends from near the abrupt eastern edge of the Basin and Range Province (BRP) to a point ~80 km into the extended domain. Data quality throughout the survey ranged from fair to poor; the recorded data include significant towing noise and occasionally problematic diffractions and sideswipe from canyon walls. The upper 2–4 s of the data shows well-defined reflections from sedimentary fill, but below that point, reflectivity is weak. Lower crustal reflectivity is generally absent under the eastern part of the survey, with a slight increase in reflectivity to the west. The reflection Moho appears as a series of weakly defined, discontinuous reflections, most of which occur at 10–11 s. A particularly interesting feature of the data set is the relative lack of reflectivity from the lower crust, which is a region of strong reflectivity on other seismic reflection data sets from the BRP

    Report of the panel on lithospheric structure and evolution, section 3

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    The panel concluded that NASA can contribute to developing a refined understanding of the compositional, structural, and thermal differences between continental and oceanic lithosphere through a vigorous program in solid Earth science with the following objectives: determine the most fundamental geophysical property of the planet; determine the global gravity field to an accuracy of a few milliGals at wavelengths of 100 km or less; determine the global lithospheric magnetic field to a few nanoTeslas at a wavelength of 100 km; determine how the lithosphere has evolved to its present state via acquiring geologic remote sensing data over all the continents

    Report of the panel on plate motion and deformation, section 2

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    Given here is a panel report on the goals and objectives, requirements and recommendations for the investigation of plate motion and deformation. The goals are to refine our knowledge of plate motions, study regional and local deformation, and contribute to the solution of important societal problems. The requirements include basic space-positioning measurements, the use of global and regional data sets obtained with space-based techniques, topographic and geoid data to help characterize the internal processes that shape the planet, gravity data to study the density structure at depth and help determine the driving mechanisms for plate tectonics, and satellite images to map lithology, structure and morphology. The most important recommendation of the panel is for the implementation of a world-wide space-geodetic fiducial network to provide a systematic and uniform measure of global strain

    A simple proposal for the publication of journal citation distributions

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    Although the Journal Impact Factor (JIF) is widely acknowledged to be a poor indicator of the quality of individual papers, it is used routinely to evaluate research and researchers. Here, we present a simple method for generating the citation distributions that underlie JIFs. Application of this straightforward protocol reveals the full extent of the skew of these distributions and the variation in citations received by published papers that is characteristic of all scientific journals. Although there are differences among journals across the spectrum of JIFs, the citation distributions overlap extensively, demonstrating that the citation performance of individual papers cannot be inferred from the JIF. We propose that this methodology be adopted by all journals as a move to greater transparency, one that should help to refocus attention on individual pieces of work and counter the inappropriate usage of JIFs during the process of research assessment

    Mantle plume-midocean ridge interaction : geophysical observations and mantle dynamics

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1996.Includes bibliographical references.by Garrett Tetsuo Ito.Ph.D
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