摘要:

The American Geophysical Union was established In 1919 as the American Committee of the International Union of Geodesy and Geophysics, and its Executive Committee is the Committee on Geophysics of the National Research Council. The objects of the Union are to promote the study of problems concerned with the figure and physics of the Earth, to initiate and coordinate researches which depend upon international and national cooperation, and to provide for their scientific discussion and publication. In the accomplishment of these objects, the Union is divided into Sections following the plan of organization of the International Union of Geodesy and Geophysics. There are now eight Sections, namely, (a) Geodesy, (b) Seismology, (c) Meteorology, (d) Terrestrial Magnetism and Electricity, (e) Oceanography, (f) Volcanology, (g) Hydrology, and (n) Tectonophysics. A Section of Geophysical Chemistry was discontinued May 31, 1924, as the international Union had failed to provide such a Section. The Section of Hydrology was established November 15, 1930—matters pertaining to scientific hydrology referred to the American Geophysical Union had been previously looked after by special committees on Hydrology. The Section of Tectonophysics was established April 9, 1940, for the purpose of promoting and encouraging research of fundamental importance to our knowledge of Earth‐structure not covered in any one of the other Sections of the Un

ISSN:0002-8606    

DOI:10.1029/TR022i002p00219

年代:1941

数据来源: WILEY

摘要:

The International Union of Geodesy and Geophysics was founded in the hopeful year of 1919, when the scientists of the world, largely under Anglo‐French leadership, had ceased their highly regimented and destructive efforts in the art of war, and had naturally returned to their constructive efforts in the art of peace, that is, so far as peace and justice may be acquired through the invention and production of new gadgets, the alleviation of physical disease, and the further elaboration of a highly mathematical and a mechanistic but none too natural philosophy. The American Geophysical Union was organized in 1919 to serve as the American Committee of the International Union, and also, through its Executive Committee, to serve as the Committee on Geophysics of the National Research Council. It is important, especially at this time, that we should appreciate both the national and international responsibilities of our Executive Committee; the difficulty and delicacy of these responsibilities being even more complicated in time of war by the fact that several of our officers are also employed by the Government of the United States. In 1920 membership in the American Geophysical Union numbered 56, five of whom were ex‐officio, and it has steadily increased to 1327. Thus the American Geophysical Union is today primarily an American Society of Geophysicists whose Executive Committee officially represents American geophysics, both in this country and abroad. Like its international parent, the American Geophysical Union is made up of Sections or Associations representing Geodesy, Seismology, Meteorology, Terrestrial Magnetism and Electricity, Oceanography, and Volcanology, and the Section of Hydrology was added in 1930. In 1940, after much careful deliberation, a new Section of Tectonophysics was added, in spite of the fact that this Section does not exist in the International Union. This necessity for the eighth branch to the candlestick came through the increasing interest and accomplishments of those students of earth‐science who were coordinating the experimental and observational data derived from the study of the deformation of the crust of the Earth, both as to cause and effect. Tectonophysics is of particular interest to the structural and economic geologist, and our new Section will serve a unique and useful purpose in encouraging and supporting experimental and theoretical investigations of the deformation of rocks and all closely related phenomena. This statement is well supported by the excellent program which the new Section has submitted for this me

ISSN:0002-8606    

DOI:10.1029/TR022i002p00225

年代:1941

数据来源: WILEY

摘要:

Just preceding the President's address the third award of the William Bowie Medal of the American Geophysical Union honoring unselfish cooperation in geophysical research was made to John A. Fleming.

ISSN:0002-8606    

DOI:10.1029/TR022i002p00234

年代:1941

数据来源: WILEY

摘要:

The twin concepts “normal erosion” and “accelerated erosion” commonly considered to include all erosion past and present, are disarmingly simple, if interpreted literally, they suggest that accelerated erosion was unknown before the coming of man, and, conversely, that the changes brought about by man merely quickened the pace of certain normal processes. Both of these interpretations are misleading.Realizing that normal erosion was a flexible quantity varying widely with meteorological, tectonic, and other influences, Lowdermllk, in 1929, set up an idealized standard of natural erosion, aptly named the “geologic norm of erosion” [see 6 and 7 of “References” at end of paper]. Erosion was considered in the broadest possible sense and was made to include the mass‐movement processes, many of which are highly effective in the natural denuda

ISSN:0002-8606    

DOI:10.1029/TR022i002p00236

年代:1941

数据来源: WILEY

摘要:

Successful control of erosion and floods requires an accurate problem analysis. It is essential, first, to know the relation of the current flood‐ and erosion‐phenomena to the geologic norm and, secondly, to determine the relative importance of each of the many factors that contribute to the problem.These considerations are especially important in the semiarid West where conditions of climate, topography, and the plant‐and‐soi1 mantle are highly varied and significantly influential in determining the character of erosion and runoff. Here, the norm in one drainage may mean imperceptible erosion and relatively uniform stream‐flow. In an adjacent area the normal may be characterized by unstable slopes and channels and greatly fluctuating streams, frequently in flood‐stage. Here, also, it is not uncommon for the degree of soil‐stability and the regimen of stream‐flow in one watershed to be due primarily to some dominant factor such as climate, topography, or condition of the plant‐and‐soil mantle, while in another the forces of several factors may compensate to establish a delicately b

ISSN:0002-8606    

DOI:10.1029/TR022i002p00240

年代:1941

数据来源: WILEY

摘要:

Those particles of the Earth's land‐surface that are in contact with the atmosphere are at the mercy of two powerful natural forces, resulting from water‐ and air‐flow. The story a single soil‐grain could tell of its travels would surpass that of Marco Polo. It is unfortunate that one cannot “get the story” and thus answer many questions that are in the minds of those who wish to explain and control its behavior.The transport of granular material by fluids has been a subject of intense interest, especially in connection with flowing water. A great number of investigations have been made, both in the laboratory and in streams, on the effects of water‐erosion and the underlying mechanisms of the movement of debris. As a result, at least for some phases of the process, explanations and empirical rules have b

ISSN:0002-8606    

DOI:10.1029/TR022i002p00262

年代:1941

数据来源: WILEY

摘要:

Soil‐erosion caused by rainfall and runoff and the transportation of sediment by surface‐runoff, of necessity, have been studied in an empirical manner because of the complexity and extent of the problems and the need for the development of useful working formulas from a limited, supply of data. Empirical formulas are generally restricted in their application, even within the range of the experimental data upon which they are based. Yet such formulae often are extrapolated beyond the limits of their validity.Solution of soil‐erosion problems, based on purely rational methods, would require many simplifications for a rigorous mathematical treatment. For the present, a combination of empirical and rational methods seems desirable. Correlation of the process of rational analysis with experimental observation permits evaluation of the factors in more or less the order of their importance and reduces the number of data necessary to the purely empirical app

ISSN:0002-8606    

DOI:10.1029/TR022i002p00287

年代:1941

数据来源: WILEY

摘要:

Study of the problem of modern sedimentation is, in essence, an analysis of the corpus delicti—the waste products—of soil‐erosion. The objectives of such a study are to locate and appraise the effects of erosional waste, to establish the laws that govern the transportation of sediment from its places of origin to its places of deposition, to determine quantitatively the sources of each type of erosional waste causing each type of sedimentation‐damage, and lastly, to develop measures designed to minimize the damages, and, where possible, to create benefits from the stream‐borne sediment. A few of the recent findings will perhaps best illustrate the relation of sedimentation to the dynamics of erosion in this new lan

ISSN:0002-8606    

DOI:10.1029/TR022i002p00305

年代:1941

数据来源: WILEY

摘要:

Peoples and civilizations write their records in the land. The scale of this writing is small in comparison with that of geophysical forces which have written a marvelous record in the Earth; nevertheless, its effects may mean life or death of peoples and rise or decline of civilizations. Land‐erosion in Northern Syria proved to be in the end more devastating than war. Land‐erosion has become a menace to national welfare and a vital problem of national economy of the United States. Only a beginning has been made in the present movement for land‐conservation.To establish an enduring and adequate agriculture in this new land of America confronts us with complex problems of which basic ones are geophysical. A guiding principle in applying findings of geophysical science is to set the stage in the use of land so that natural forces work for us rather than again

ISSN:0002-8606    

DOI:10.1029/TR022i002p00316

年代:1941

数据来源: WILEY

摘要:

The war has brought international geodetic activities almost to a standstill.The composition of the Executive Committee of the International Association of Geodesy at the time of the Washington Assembly was as follows:Office Name Country Expiration of termPresident F. A. Vening Meinesz Holland 1939Vice‐President E. Soler Italy 1942Vice‐President W. D. Lambert United States 1939Secretary G. Perrier France 1942Member‐at‐large K. S. Klingenberg Norway 1942Member‐at‐large J. Maury Belgium 1942Member‐at‐large N. MacLeod Great Britain 1939Member‐at‐large K. Weigel Poland 1939In accordance with the agreement at Washington no elections were held; the incumbent officers all hold over until their successors can be elected.

ISSN:0002-8606    

DOI:10.1029/TR022i002p00323

年代:1941

数据来源: WILEY