摘要:

Worldwide future problems involving coal may become as acute as those now involving oil, say geologists at the ninth International Congress of Carboniferous Stratigraphy and Geology, held at the University of Illinois, Urbana‐Champaign. At the opening session, Gordon H. Wood, Jr., of the U.S. Geological Survey, and Jack A. Simon of the Illinois State Geological Survey discussed the world coal situation to the end of this century. They said that energy problems will increase in the next 20 years and into the next century unless there is ‘vigorous planning and action’ by political, industrial, social, scientific, environmental, and financial leaders.A few countries have sufficient coal for currently projected needs, but most countries have little or no coal, they said. Problems of world dependence on countries with large coal resources may become similar to those now prevailing with oil. The Soviet Union, United States, People's Republic of China, United Kingdom, Australia, West Germany, Canada, and Union of South Africa contain 97% of the world's coal reso

ISSN:0002-8606    

DOI:10.1029/EO060i024p00489-01

年代:1979

数据来源: WILEY

摘要:

In the recent discussion and comments on this topic among colleagues from the U.S. and U.S.S.R. which were published in EOS (April 24,1979), several points centered on the purported equality of heat flow between ocean basins and continents and the heat flow variation with age in the oceans. Although the equality has been a major tenet since the first marine heat flow data were obtained and was supported with a statistical analysis of over 2,500 measurements only a decade ago [Von Herzen and Lee, 1969], recent field evidence and model development have substantially changed this conclusion.The hypothesis that a substantial fraction of heat is lost by hydrothermal circulation in oceanic crustal rocks, particularly on young sea floor, first put forward by Lister [1972], has received increased support in detailed studies of marine heat flow [Williams et al., 1974; Davis and Lister, 1977; Anderson etal, 1977]. Combined with quantitative estimates of heat loss based on plate tectonics models [McKenzie, 1967; Sclater andFrancheteau, 1970; Parsons and Sclater, 1977], it has been shown that hydrothermal effects account for a large fraction of the total sea floor heat loss up to several tens m.y. in age. Taking account of this hydrothermal loss,Williams and Von Herzen[1974] calculated that the mean heat loss per unit area of oceans is about 2.2 H FU (heat flow units; 1HFU = 10−6/μcal cm−2sec−1), about 50% greater than that for continents. This difference has been recently corroborated using a somewhat different approach by Langseth and Anderson

ISSN:0002-8606    

DOI:10.1029/EO060i024p00490-01

年代:1979

数据来源: WILEY

摘要:

Studies of the rotation of the earth and of polar motion have both interdisciplinary and global aspects, involving astronomy, geodesy and geophysics, and even cosmology, in regard to the definition of the inertial reference system. Of concern to us is the establishment of the reference system on a plastic earth, the reference in space, theoretical understanding or at least mathematical modeling of earth rotation and polar motion, the various techniques (optical versus radio; satellites versus distant references), data collection and measurement services and user requirements, and maybe most important, the introduction of new techniques with preservation of continuity in the existing services.The navigation of space probes requires accuracies of 1 to 2 ms in Universal Time and 0.02″ in polar motion, while other users have needs for time and polar motion data with the best available accuracy. Future investigations involving more and increasingly precise data will be used to establish the time span over which the data may be reliably average

ISSN:0002-8606    

DOI:10.1029/EO060i024p00491

年代:1979

数据来源: WILEY

摘要:

The Council met at AGU headquarters on May 27, 1979. Twenty of the twenty‐six Council members were present. As usual, the meeting was open to general members, and about twenty attended. This report gives highlights of the most important actions of the Council; a copy of the minutes of the meeting is available to any interested member on request.The Council urged the United States National Committee for the International Union of Geodesy and Geophysics (IUGG) to invite IUGG to hold its 1983 or 1987 assembly in the U.S. and offered to organize the meeting on their behalf. The last IUGG General Assembly in North America was held in Berkeley, California in 1963. This action involves a substantial staff commitment but the Council contemplates covering these and all other costs through grants and registration fee

ISSN:0002-8606    

DOI:10.1029/EO060i024p00492

年代:1979

数据来源: WILEY