摘要:

The U.S. Navy satellite, GEOSAT (Figure 1) is third in the series of microwave altimeter satellites which make, or made, precise, direct observations of the marine geoid. GEOSAT, launched March 1985, is active today. Its two predecessors are NASA's Geos‐3 mission which operated from 1975 through 1978 and NASA's SEASAT mission which functioned only during the summer of 1978. Each of the three has provided highly significant, abundant, new information about the gravity field of the oceans. As such, these missions have begun a revolution in marine geodesy and geophysics. One exemplary result of this ongoing revolution is the global map of marine gravity constructed from SEASAT altimeter data by Haxby [1987]. In fact, members of the marine geophysical community were, and, in some cases, still are, largely unaware of the spate of gravity field information coming from these satellites. Our purpose here is to help assure that this same community is aware of the very major increase in our knowledge of the marine gravity field which will come from GEOSAT, and that this increase will come on top of the gains made from SEASAT and Geos

ISSN:0002-8606    

DOI:10.1029/88EO01183

年代:1988

数据来源: WILEY

摘要:

Nearly 400 oral and poster papers have been selected and programs are fully developed for all eight symposia of the International Association of Hydrological Sciences Third Scientific Assembly. The proceeding volumes are being typed in preparation for printing prior to the Assembly. A wide variety of organizational details are being handled by AGU staff, serving as the adminstrative group for the Assembly.The Second Circular was printed in its entirety in the July 19 issue ofEosand thus distributed to all AGU members. In addition, separate copies of Circular 2 were printed and distributed widely. Anyone not having this Circular (containing registration and hotel reservation forms) or the Eos article (also with forms) may request copies from the office of the Meetings manager, at AGU headquarters; tel. 202‐462‐6

ISSN:0002-8606    

DOI:10.1029/88EO01186

年代:1988

数据来源: WILEY

摘要:

New travel time tables to locate earthquakes are being developed under the Subcommission on Earthquake Algorithms of the International Association of Seismology and the Physics of the Earth's Interior (IASPEI).The standard travel time tables used by seismological agencies such as the National Earthquake Information Center in Golden, Colo., and the International Seismological Centre (ISC) in Newbury, U.K., are the Jeffreys and Bullen tables published in 1940. These tables were developed 1930–1939 based on available observations, when station time keeping was frequently not reliable. Although the limitations of these tables have been recognized, no other tables provide such a complete representation of P, S and core phase

ISSN:0002-8606    

DOI:10.1029/88EO01191

年代:1988

数据来源: WILEY

摘要:

Scientists often say that only a practicing scientist can understand certain things vital to the workings of science, things that often escape historians. Scientists, more often than not, believe that the sense required to understand how science is done can be gained only by doing it. They suggest that history written by historians, especially internal history, which is based on critical examination of the scientific ideas themselves, will be wanting.The historian, on the other hand, through the methods and techniques of history, social studies and philosophy— tools not often possessed by scientists—can show scientists how their discipline has come to be, how it is bedded in society, and how it derives its esteem and support for be

ISSN:0002-8606    

DOI:10.1029/88EO01194

年代:1988

数据来源: WILEY

摘要:

The National Science Foundation has set key deadline dates for grants and proposals due for the next several months. Dates given below are subject to change; more information may be obtained by contacting the NSF staff member listed.The program deadline date means that proposals received after this cutoff date generally will be returned to the proposer. The target date means that proposals received after this cutoff date will be reviewed, although they may miss a particular panel meeting.

ISSN:0002-8606    

DOI:10.1029/EO069i046p01573-02

年代:1988

数据来源: WILEY

摘要:

This book is a well‐written English translation of the original 1981 Russian edition,Strukturnoye issledovaniye mineralov metodami mikrodifraktsii i elechtronnoi mikroskopii vysokogo razresheniya. The 1987 English version has been extensively updated and includes references up to 1986. The book is essentially a text on the theoretical and experimental aspects of transmission electron microscopy and has chapters on the reciprocal lattice, electron diffraction (both kinematic and dynamic), and high‐resolution electron microscopy.Electron diffraction is emphasized, especially its use for structure analysis of poorly crystalline and fine‐grained phases not readily determined by the more exact X ray diffraction method. Two methods of electron diffraction are discussed: selected area electron diffraction (SAED) and oblique‐texture electron diffraction (OTED); the latter technique is rarely used in the west and is never discussed in western electron microscopy texts. A SAED pattern is formed by isolating a small micrometer‐size area with an aperture and obtaining single‐crystal patterns from the diffracted beams. By tilting the sample and obtaining many patterns, a complete picture of the reciprocal lattice can be taken. An OTED pattern is formed when the incident electron beam passes through an inclined preparation consisting of a great number of thin platy crystals lying normal to the texture axis (axis normal to the support grid). To form an OTED pattern, the plates must all lie on a common face, such as a basal plane in phyllosilicates. Upon tilting the plates, an elliptical powder diffraction pattern is formed. Intensities measured from these patterns are used for a structural analysis of the pla

ISSN:0002-8606    

DOI:10.1029/88EO01195

年代:1988

数据来源: WILEY

摘要:

During the week of June 13–17, 1988, 72 sediment transport researchers “aggregated” at the Universidad Nacional del Sur in Bahfa Blanca, Argentina, to participate in an AGU Chapman Conference on Sediment Transport Processes in Estuaries. The main goals of the meeting were to discuss recent advances in estuarine science, to appraise promising future research directions, and to develop contacts and establish working relationships between Latin American and non‐Latin‐ American estuarine researchers. The meeting drew participants from Argentina, Brazil, Chile, Uruguay, Venezuela, the U.S., Canada, Britain, France, the Federal Republic of Germany, The Netherlands, and South Africa. Meeting cosponsors were UNESCO, Secretaria de Ciencía y Técnica, Consejo Nacional de Investigaciones Cientificas y Técnicas, Comision de Investigaciones Cientificas de la Provincia de Buenos Aires, Universidad del Sur, Municipalidad de Bahia Blanca, Asociaciôn Argentina de Geofisicos y Geodestas (AGU sister organization), and the Instituto Argentino de Oceano

ISSN:0002-8606    

DOI:10.1029/88EO01196

年代:1988

数据来源: WILEY