Infrasound Monitoring for Atmospheric Studies


Book Description

The use of infrasound to monitor the atmosphere has, like infrasound itself, gone largely unheard of through the years. But it has many applications, and it is about time that a book is being devoted to this fascinating subject. Our own involvement with infrasound occurred as graduate students of Prof. William Donn, who had established an infrasound array at the Lamont-Doherty Geological Observatory (now the Lamont-Doherty Earth Observatory) of Columbia University. It was a natural outgrowth of another major activity at Lamont, using seismic waves to explore the Earth’s interior. Both the atmosphere and the solid Earth feature velocity (seismic or acoustic) gradients in the vertical which act to refract the respective waves. The refraction in turn allows one to calculate the respective background structure in these mediums, indirectly exploring locations that are hard to observe otherwise. Monitoring these signals also allows one to discover various phenomena, both natural and man-made (some of which have military applications).




Monitoring the Comprehensive Nuclear-Test-Ban Treaty: Data Processing and Infrasound


Book Description

On September 10, 1996, The United Nations General Assembly adopted the Copmprehensive Nuclear-Test-Ban Treaty (CTBT), prohibiting nuclear explosions worldwide, in all environments. The treaty calls for a global verification system, including a network of 321 monitoring stations distributed around the globe, a data communications network, an international data center (IDC), and on-site inspections, to verify compliance. This volume presents certain recent research results pertaining on methods used to process data recorded by instruments of the International Monitoring System (IMS) and addressing recording infrasound signals generated by atmospheric explosions. Six papers treating data processing provide an important selection of topics expected to contribute to improving our ability to successfully monitor a CTBT. Five papers concerning infrasound include descriptions of ways in which that important research area can contribute to CTBT monitoring, the automatic processing of infrasound data, and site conditions that serve to improve the quality of infrasound data.




United States Nuclear Tests


Book Description

This document lists chronologically and alphabetically by name all nuclear tests and simultaneous detonations conducted by the United States from July 1945 through September 1992. Two nuclear weapons that the United States exploded over Japan ending World War II are not listed. These detonations were not "tests" in the sense that they were conducted to prove that the weapon would work as designed (as was the first test near Alamogordo, New Mexico on July 16, 1945), or to advance nuclear weapon design, or to determine weapons effects, or to verify weapon safety as were the more than one thousand tests that have taken place since June 30,1946. The nuclear weapon (nicknamed "Little Boy") dropped August 6,1945 from a United States Army Air Force B-29 bomber (the Enola Gay) and detonated over Hiroshima, Japan had an energy yield equivalent to that of 15,000 tons of TNT. The nuclear weapon (virtually identical to "Fat Man") exploded in a similar fashion August 9, 1945 over Nagaski, Japan had a yield of 21,000 tons of TNT. Both detonations were intended to end World War II as quickly as possible. Data on United States tests were obtained from, and verified by, the U.S. Department of Energy's three weapons laboratories -- Los Alamos National Laboratory, Los Alamos, New Mexico; Lawrence Livermore National Laboratory, Livermore, California; and Sandia National Laboratories, Albuquerque, New Mexico; and the Defense Threat Reduction Agency. Additionally, data were obtained from public announcements issued by the U.S. Atomic Energy Commission and its successors, the U.S. Energy Research and Development Administration, and the U.S. Department of Energy, respectively.




Research Required to Support Comprehensive Nuclear Test Ban Treaty Monitoring


Book Description

On September 24, 1996, President Clinton signed the Comprehensive Nuclear Test Ban Treaty at the United Nations Headquarters. Over the next five months, 141 nations, including the four other nuclear weapon statesâ€"Russia, China, France, and the United Kingdomâ€"added their signatures to this total ban on nuclear explosions. To help achieve verification of compliance with its provisions, the treaty specifies an extensive International Monitoring System of seismic, hydroacoustic, infrasonic, and radionuclide sensors. This volume identifies specific research activities that will be needed if the United States is to effectively monitor compliance with the treaty provisions.




Research Required to Support Comprehensive Nuclear Test Ban Treaty Monitoring


Book Description

On September 24, 1996, President Clinton signed the Comprehensive Nuclear Test Ban Treaty at the United Nations Headquarters. Over the next five months, 141 nations, including the four other nuclear weapon statesâ€"Russia, China, France, and the United Kingdomâ€"added their signatures to this total ban on nuclear explosions. To help achieve verification of compliance with its provisions, the treaty specifies an extensive International Monitoring System of seismic, hydroacoustic, infrasonic, and radionuclide sensors. This volume identifies specific research activities that will be needed if the United States is to effectively monitor compliance with the treaty provisions.




Antarctica


Book Description

Sixty articles arranged in eight thematic sections refer to most recent geological and geophysical results of Antarctic research. The Precambrian of the East Antarctic shield and its geological history is considered as well as sub-ice topography, geophysics and stratigraphy, sedimentology and geophysics of the surrounding Southern Ocean. Particular emphasis is given to the connection of the Antarctic and the surrounding continents when forming part of Gondwana.




Monitoring the Comprehensive Nuclear-Test-Ban-Treaty: Hydroacoustics


Book Description

In September 1996, the United Nations General Assembly adopted the Comprehensive Nuclear-Test-Ban Treaty (CTBT), prohibiting nuclear explosions worldwide, in all environments. The treaty calls for a global verification system, including a network of 321 monitoring stations distributed around the globe, a data communications network, an international data centre (IDC), and on-site inspections, to verify compliance. A global hydroacoustic monitoring system is being planned and implemented for verification of the CTBT. Much of the research conducted over the past several decades on acoustic surveillance of the oceans, formerly driven by the need to detect and track submarines, is now being applied to the development of effective monitoring methods to verify compliance with the CTBT. The aim of this volume on Hydroacoustic Monitoring of the CTBT is to summarize the research being conducted in this field and to provide basic references for future research. Much of the new research emphasizes major advances in understanding the coupling of ocean acoustic waves with elastic waves in the solid Earth. Topics covered include source excitation, detection and classification of events generating hydroacoustic signals, discrimination between underwater explosions and naturally occurring events, as well as topics in coupling of acoustic to seismic wavefields.




Volcanic Plumes


Book Description

Volcanoes release plumes of gas and ash to the atmosphere during episodes of passive and explosive behavior. These ejecta have important implications for the chemistry and composition of the troposphere and stratosphere, with the capacity to alter Earth's radiation budget and climate system over a range of temporal and spatial scales. Volcanogenic sulphur dioxide reacts to form sulphate aerosols, which increase global albedo, e.g., by reducing surface temperatures, in addition to perturbing the formation processes and optical properties of clouds. Released halogen species can also deplete stratospheric and tropospheric ozone. Volcanic degassing, furthermore, played a key role in the formation of Earth’s atmosphere, and volcanic plumes can affect air quality, pose hazards to aviation and human health, as well as damage ecosystems. The chemical compositions and emission rates of volcanic plumes are also monitored via a range of direct-sampling and remote-sensing instrumentation, in order to gain insights into subterranean processes, in the respect of the magmatic bodies these volatiles exsolve from. Given the significant role these gases play in driving volcanic activity, e.g., via pressurisation, the study of volcanic plumes is proving to be an increasingly fruitful means of improving our understanding of volcanic systems, potentially in concert with observations from geophysics and contributions from fluid dynamical modelling of conduit dynamics. This Special Issue is aimed at presenting the state of the art of the multidisciplinary science concerning all aspects of volcanic plumes, of relevance to the volcanology, climatology, atmospheric science, and remote sensing communities.




Meteor Showers and their Parent Comets


Book Description

Meteor Showers and their Parent Comets is a unique handbook for astronomers interested in observing meteor storms and outbursts. Spectacular displays of 'shooting stars' are created when the Earth's orbit crosses a meteoroid stream, as each meteoroid causes a bright light when it enters our atmosphere at high speed. Jenniskens, an active meteor storm chaser, explains how meteoroid streams originate from the decay of meteoroids, comets and asteroids, and how they cause meteor showers on Earth. He includes the findings of recent space missions to comets and asteroids, the risk of meteor impacts on Earth, and how meteor showers may have seeded the Earth with ingredients that made life possible. All known meteor showers are identified, accompanied by fascinating details on the most important showers and their parent comets. The book predicts when exceptional meteor showers will occur over the next fifty years, making it a valuable resource for both amateur and professional astronomers.




Fish Passage Technologies


Book Description