摘要:

Many attempts have been made to arrive at a better understanding of atmospheric processes by a study of the movement of the migratory high‐ and low‐pressure centers which follow more or less regular paths over the Earth's surface.As early as 1884 charts were published by FINLEY [see 1 of “References” at end of paper], showing relative storm‐frequency for quite a large portion of the Northern H

ISSN:0002-8606    

DOI:10.1029/TR026i001p00049

年代:1945

数据来源: WILEY

摘要:

This paper presents a new method of analysis of rainfall‐ and runoff‐data which permits surface‐runoff and ground‐water flow to be segregated and infiltration‐capacity determined during stream‐rises. The method is equally applicable to areas with and without snowcover. The determination of infiltration‐capacity during the snow‐melting periods is, however, the most difficult problem and the method is here applied to this case, using data for areas in the Allegheny Experimental Forest, with varying degrees of forest‐cover density. For these areas the rate of snow‐melting per degree‐day of temperature excess above 32° decreased as the c

ISSN:0002-8606    

DOI:10.1029/TR026i001p00059

年代:1945

数据来源: WILEY

摘要:

We consider the largest observation in a sample of size n and ask: What is the mean number of observations such that this value, or a larger one, happens once again? This question is important for statistical variates as earthquake magnitudes, precipitations, floods, temperatures, and pressures, where the largest value involves specific dangers. Similar problems arise in quality‐control and in gunnery.It will be shown that the mean number depends, in general, upon the nature of the variate. However, for a wide class of statistical distributions, it converges toward the sample‐size. The general solution given in the first section will be applied, in the second section, to some interesting distributions; in the last section it will be used to simplify the plotting procedure advocated in a previous article [see 6 of “References” at end of

ISSN:0002-8606    

DOI:10.1029/TR026i001p00069

年代:1945

数据来源: WILEY

摘要:

Any solution of the snow‐melt problem which will improve the forecasting of floods as well as forecasting of agricultural and industrial water‐supplies is dependent upon a knowledge of the hydromechanic and dynamic potentials which influence the retention and discharge of water by the snow‐mantle.A deep snow‐pack is relatively permeable. During the spring melting‐season, water from the melting‐snow surface percolates through the pack and is discharged to streams and reservoirs by overland paths or flow in the soil beneath the snow. Under some conditions, heavy rain upon the snow‐blanket may not be reflected by appreciable changes in river‐stages. Under other conditions rain upon the snow‐pack may produ

ISSN:0002-8606    

DOI:10.1029/TR026i001p00083

年代:1945

数据来源: WILEY

摘要:

Data are presented for five western soils showing their permeability to Riverside tap‐water after preliminary leaching with waters of various percentages of sodium. Although the tendency for high‐sodium water to reduce soil‐permeability has been known qualitatively for many years, few data are available to indicate the magnitude of the change that occurs.The data indicate: (1) There is no sharp break in the permeability‐curves as the percentage of sodium in the waters is increased. (2) Permeability decreases greatly when the salt‐concentration is reduced following percolation with high‐sodium water. (3) Other factors also greatly modify permeabilities, that is, all soils do not act alike. (4) Under field‐conditions it is the absolute permeability which governs soil use and productivity. Since soils react differently to the same water, it is incorrect to give a precise percentage of sodium above which irrigation‐waters will cause trouble in this respect. Indicating a range of percentages would seem to be preferable practice. (5) Soils high in organic matter have higher permeabilities than normal soils when irrigated with waters of low‐sodium percentage, and vice, versa with waters of high

ISSN:0002-8606    

DOI:10.1029/TR026i001p00091

年代:1945

数据来源: WILEY

摘要:

Deformation lamellae in quartz are described in detail. Statistical studies confirm previously described relationships. Detailed measurements in separate zones of the petrofabric diagrams yield new data on the nature of the lamellae and their control. The uses of the lamellae in geologic interpretation are outlined.

ISSN:0002-8606    

DOI:10.1029/TR026i001p00095

年代:1945

数据来源: WILEY

摘要:

Published data imply that normal faults in general are steeply inclined, and it is commonly assumed that faults of this class have developed habitually with dips of 45° or more. The writer has not seen in the literature many descriptions of large normal faults that have conspicuously low dips. Those that dip 25° or less usually are assumed to have been rotated from initially steep inclinations. Moreover, few published descriptions of large normal faults known to the writer cite evidence of decreasing dip with increasing depth, to indicate concavity of fault‐surfaces toward the hanging wall. Indeed, some structural geologists have argued that evidence favors steepening of ordinary normal faults downward, with resulting concavity toward the footwall‐block [see 12 of “References” at end of paper]. Pronounced concavity of a fault‐surface toward the hanging wall has been interpreted as a characteristic of superficial “lands

ISSN:0002-8606    

DOI:10.1029/TR026i001p00107

年代:1945

数据来源: WILEY

摘要:

The National Geographic Society has made it possible to continue the study of aurora at Cornell and we have been able to speed up some of our work.The recording of all auroral occurrences was of sufficient importance that the observer‐group has been enlarged so now there are 25 stations ranging from Oregon to Prince Edward Island and north of Lake Superior to Ithaca. Five stations of the United States Weather Bureau and several in Canada give reports based on hourly observation each nigh

ISSN:0002-8606    

DOI:10.1029/TR026i001p00119

年代:1945

数据来源: WILEY

摘要:

The long‐sustained effort required for waging a war of world‐wide extent has continued unabated through the period under report and rendered impossible the execution of anything like the normal program of the Department of Terrestrial Magnetism. Military and naval operations, so inimical to geophysical investigations requiring international cooperation, of which terrestrial magnetism and electricity are good examples, have greatly interfered with work in this field of research. It has not been possible to equip expeditions for field‐work in foreign lands and on the oceans for providing the much needed data for secular‐variation studies. Although practically all of the Department's staff have turned attention to the solution of problems connected with the war, considerable progress along certain lines has been made. Moreover, much important work, the results of which may not be published until the war is over, has been brought to a successful con

ISSN:0002-8606    

DOI:10.1029/TR026i001p00123

年代:1945

数据来源: WILEY

摘要:

Participation of members of the staff in war work has continued and has been further expanded. The nature of the work is such that as yet no report can be given to the American Geophysical Union.G. F. McEWEN has completed the revision of certain preliminary basic mathematical tables required for further researches on evaporation and mixing, and a limited number of photostatic copies are on file.

ISSN:0002-8606    

DOI:10.1029/TR026i001p00127

年代:1945

数据来源: WILEY