摘要:

There is much evidence of the existence of a system of shear planes in the greatest part of the Earth's crust, and it seems likely that some planetary cause must have brought it about. Two possible causes are investigated here, (1) the decrease of the Earth's flattening because of the slowing down of its rotation by tidal friction and (2) a change of the axis of the flattening because of a movement of the Earth's rotation axis with regard to the crust. Only the latter phenomenon gives a good explanation of the existing system of shear planes. A good correlation is obtained with the Earth's topography, with the distribution of volcanoes, with the gravity fields in several areas, and with most of the evidence about shear planes brought out by the “lineament” tectonicians Hobbs, Sederholm, Daubrée, Sonder, and others.The hypothesis is not in harmony with the continental drift theory of Wegener. At the end of the paper some tentative conclusions are drawn about the origin of the contin

ISSN:0002-8606    

DOI:10.1029/TR028i001p00001

年代:1947

数据来源: WILEY

摘要:

A proposed plan for the readjustment of the European network of triangulation is presented. A discussion of the Central European triangulation readjustment which is in progress is followed by a general outline for an expansion of this project to Include all of Europe west of 32° east longitude. The outline includes suggestions for the adoption of a preliminary datum followed by the determination of the final datum using the Bowie method of adjustment with whatever modifications are necessary

ISSN:0002-8606    

DOI:10.1029/TR028i001p00062

年代:1947

数据来源: WILEY

摘要:

Equipment and methods for automatically changing the wind‐speed range of the Grinnell condenser‐discharge wind‐speed recorder to accord with the prevailing average wind speed are here outlined, with salient empirical theory. One automatic range switch is described in working detail, and two others are briefly outlined. Other applications of the general principles employed are ment

ISSN:0002-8606    

DOI:10.1029/TR028i001p00067

年代:1947

数据来源: WILEY

摘要:

Radar photographs of thunderstorms and the Florida hurricane of September 1945 were shown to illustrate structure of those storms (see Fig. 1). The relation between radar echoes and the reflecting material in the storms was discussed. Previous research has shown the intensity of the return radiation, among other things, to be proportional to the number and sixth power of the diameter of the intercepted water droplets. For radar frequencies now in usage, this means that only water drops large enough to fall out as precipitation reflect a detectable echo. The possibility of determining distribution and intensity of precipitation during a given storm by radar was discussed, but it was concluded that this cannot be done on an absolute basis at present, but that the relative intensities can be determined by suitably modified radar. However, if observed rainfall intensities are available at a small number of stations in the area swept by the radar, then it is possible to “calibrate” the radar intensities in terms of rainfall intensit

ISSN:0002-8606    

DOI:10.1029/TR028i001p00070

年代:1947

数据来源: WILEY

摘要:

Variations of sporadic‐E ionization observed at Washington, D.C., were investigated with respect to diurnal, seasonal, and both long‐period and short‐period solar‐activity variations, as well as variation of fEs above a given frequency with the fr

ISSN:0002-8606    

DOI:10.1029/TR028i001p00071

年代:1947

数据来源: WILEY

摘要:

Several sets of temperature measurements both from surface ships and submarines show that internal waves exist in the ocean with periods shorter than those heretofore observed. The waves with a period of one to two hours have heights up to 100 feet, and those with periods of the order of ten minutes have heights up to 20 feet.

ISSN:0002-8606    

DOI:10.1029/TR028i001p00079

年代:1947

数据来源: WILEY

摘要:

Series of measurements of the depth of an isothermal layer made with bathythermographs or thermocouples simultaneously at three stations indicate strongly the existence of internal waves in the ocean. The properties of the internal waves found in this way are: (1) The wave length is of the order of a few hundred yards; (2) the shorter periods are of the order of a few minutes up to a few hours; and (3) the speed in all cases observed thus far is less than one knot.

ISSN:0002-8606    

DOI:10.1029/TR028i001p00087

年代:1947

数据来源: WILEY

摘要:

The theory of motion of a horizontally stratified fluid under gravity is extended to include three linear gradients from the surface to the bottom. Tho resulting equation is then simplified to give tho special cases In which first the upper layer and then tho upper and lower layers aro of constant density. The latter case is then shown by further simplification to load to Stokes's theory of two layers of constant density separated by a sharp discontinuity. The wave lengths, as calculated by Stokes's theory and its extension to linear gradients, agree with previously measured values as well as is to be expected.

ISSN:0002-8606    

DOI:10.1029/TR028i001p00096

年代:1947

数据来源: WILEY

摘要:

It has been known for a long time that in potash feldspar the optical properties are functions of both the chemical composition and the thermal history of the feldspar. As a first approximation we may speak of low‐temperature optics in adularia and common orthoclase characterized by a large axial angle, and high‐temperature optics in sanidine characterized by a small axial angle. By heating orthoclase it is usually feasible to convert it into sanidine, optically. On cooling the sanidine type is preserved; indeed, no conversion of sanidine into tho low‐temperature type has been reported. One may conclude, therefore, that once the high‐temperature type has been formed its reversal to the low‐temperature type is very slow; observations on natural feldspars indicate that sanidines are (meta) stable at ordinary temperatures for geological tim

ISSN:0002-8606    

DOI:10.1029/TR028i001p00102

年代:1947

数据来源: WILEY

摘要:

This is a preliminary report of results of a study wherein vegetation has been cut along the stream bank of a 22‐acre watershed on the Coweeta Experimental Forest. Previous measurements on this forest have shown that complete removal of vegetation results in notable gains in water yield because of a reduction in transpiration. The cutting of riparian growth has also resulted in an increase in yield of sufficient magnitude to be significant in water‐resource management.Preliminary examination of the data immediately following cutting shows a virtual elimination of the diurnal fluctuation during the growing season. This indicates that the vegetation immediately adjacent to the stream is making appreciable demands upon groundwater supplies contributing directly to streamflow.It can be concluded, therefore, that important gains in water yield during the growing season in the southern Appalachian region may be realized with relatively little effort by eliminating the transpiration draft of riparian vegetation. This procedure can be of much practical value during drought years for municipal and industrial watersheds, when even small increases in yield are of unusual importa

ISSN:0002-8606    

DOI:10.1029/TR028i001p00105

年代:1947

数据来源: WILEY