摘要:

The American Geophysical Union is the American National Committee of the International Geodetic and. Geophysical Union, and the Executive Committee of the American Geophysical Union is the Committee on Geophysics of the National Research Council. The object of the Union is 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 this object, the Union is divided into six sections in accordance with the organization of the International Geodetic and Geophysical Union as follows: (a) Geodesy; (b) Seismology; (c) Meteorology; (d) Terrestrial Magnetism and Electricity; (e) Oceanography; (f) Volcanology.

ISSN:0002-8606    

DOI:10.1029/TR008i001p00007

年代:1927

数据来源: WILEY

摘要:

The interest of the American Geophysical Union in the Third Pan‐Pacific Science Congress held at Tokyo, Japan, in October, 1926, lies in the fact that the Division of Physical Sciences of the National Research Council included in its scope all the subjects of geophysics into which the work of the American Geophysical Union is divided. Furthermore, in establishing the Pacific Science Association as a permanent organization, the plan was adopted of having each country represented by a National Committee, in the case of the United States, the National Research Council. Inasmuch as the function of the American Geophysical Union is to keep the National Research Council informed of the activities coming within its field, there is an opportunity for service in this connectio

ISSN:0002-8606    

DOI:10.1029/TR008i001p00013

年代:1927

数据来源: WILEY

摘要:

Numerous factors enter into the problem of the control of climate, and climate is subject to change. The geologists tells us that we have had many variations of climate in the past, and we know that we have many varieties, sometimes even in the same locality, in New England, for instance. What are the things that determine the climate for a particular place? The radiation from the Sun, the composition of the atmosphere that permits certain radiations to get through and shuts others out, the way the wind blows, the way the water flows, the heights of mountains and their locations in respect to the oceans and directions of prevailing winds, and a host of other influences.

ISSN:0002-8606    

DOI:10.1029/TR008i001p00018

年代:1927

数据来源: WILEY

摘要:

Climate is largely determined by the prevailing range of temperature. The temperature is maintained first, by the solar radiation which continuously fails upon our atmosphere at the mean rate of 1.93 calories per square centimeter per minute; and secondly, by the exceedingly complicated series of absorptions, scatterings, reflections, endless re‐radiations, and convection‐ and conduction‐effects which result from the passage of the solar beam through the atmosphere. Langley, and more recently Dietzius and others, have shown that the Moon, receiving solar radiation per unit area identical with the Earth, experiences within the brief interval of a lunar eclipse a change of temperature ranging from about that of boiling water to far below freezing. On the Earth the average daily range is less than 10° C and seldom exceeds 20° C. The difference is due to this: the Earth has an atmosphere; the Moon has not. Oxygen and nitrogen, which comprise the bulk of the atmosphere, have relatively little effect on temperature. From other constituents, however, comprising less than three per cent of the weight of the atmosphere are highly important as affecting temperatures. These constituents are water (both as water vapor and in the form of clouds), dust, ozone, and carbon

ISSN:0002-8606    

DOI:10.1029/TR008i001p00019

年代:1927

数据来源: WILEY

摘要:

Meteorologists of the first half of the nineteenth century thought of the general atmospheric circulation as consisting essentially of a rising current of warm air in the tropics with an overflow poleward in the higher levels, a descent at the poles, and a return current on the surface of the Earth.The modern notion, although it holds to the connective interchange between the equator and the poles, discards the idea of warm air rising in the tropics and flowing poleward and substitutes therefor a poleward flow of disconnected masses of warm air side by side with similar masses of cold polar air flowing equatorward. This interchange takes place for the most part through the action of traveling cyclones and anticyclones of the temperate latitudes.

ISSN:0002-8606    

DOI:10.1029/TR008i001p00024

年代:1927

数据来源: WILEY

摘要:

Overspreading more than two‐thirds of the surface of the globe, throughout all longitudes and nearly from pole to pole, in basins whose cubical content is fourteen‐fold greater than the bulk of all the land of the world above sea‐level, is a medium whose capacity for heat far outruns the like property in any other abundant substance in Nature. The place of water in the economy of Nature is most remarkable. Everywhere natural conditions are seen to be molded and influenced by its wonderful properties. Although it is nowhere told how much water there is in the world, there is no doubt that the presence in the oceanic basins of 324,000,000 cubic miles of this substance must constitute the ocean a dominant factor in geophysics, exercising through its circulation a governing influence upon heat transference and upon climate. Throughout the ocean's vast expanse of one hundred and forty million square miles, exceeding, by eighty million square miles, the total area of the land surface of the Earth, it is never in equilibrium, and, consequently, forever in reaction under stresses both external and internal, resulting in movement to bring about a redistribution of

ISSN:0002-8606    

DOI:10.1029/TR008i001p00026

年代:1927

数据来源: WILEY

摘要:

This is a brief review of our present knowledge concerning one aspect of climatic control. The subject is of importance in connection with certain phases of geology such as glaciation and the Wegener hypothesis. According to this hypothesis the continents at various times have drifted apart in an east‐west direction and have also experienced large movements from south to north and from north to south again. This latter feature of Wegener's theory is supported by climatological evidence, and loses its only support if other means of securing large variations in climate are foun

ISSN:0002-8606    

DOI:10.1029/TR008i001p00031

年代:1927

数据来源: WILEY

摘要:

It is well known that the Sierra Nevada and Cascade ranges intercept, moisture from the Pacific, causing it to be precipitated on their western slopes with resulting arid or semi‐arid conditions east of them. In a less degree the Rocky Mountains effect a similar result, particularly north of the latitude of Yellowstone Park. Precipitation on their western sides or westernmost ranges, such as the Clearwater Mountains, Cœr d'Alene, Cabinet, and Purcell ranges is much greater than on the ranges farther east or the plains beyond. It follows that if the intercepting ranges were removed or even lowered considerably, the interior plateaus and the great plains in northern United States and Canada would receive an increased precipitation which, of course, would be one of the factors necessary to renewed glaciation. In this connection, it is noteworthy, perhaps, that in the Olympic Mountains, which receive a heavy precipitation, permanent snow and ice‐fields are rather general above an altitude of five thousand feet. Farther east in the same latitude, the present lower ice‐limit rises as the precipitation decreases. In Glacier Park it is at least seven thousan

ISSN:0002-8606    

DOI:10.1029/TR008i001p00033

年代:1927

数据来源: WILEY

摘要:

Discussion of relatively late changes in Alaska that may have had climatic significance is much hampered by the lack of specific information relating to many of the pertinent factors, but even then it is too large a topic to touch more than the fringes of in the short time allotted.One of the speculations that crops up periodically both in its relation to climate and to migrations of animals and plants, is the inquiry into what would be the result if the region near Bering Strait had been at one time more depressed or more elevated than at present. The details of the situation that would have been produced can not be stated with finality, but it seems doubtful whether possible changes of this sort would have effected as radical physical differences as might be conjectured from the casual inspection of an ordinary map. The reason for this conclusion is, that unless depression exceeded 2,300 feet the Strait would maintain practically its present width as the portals at Cape Prince of Wales and at East Cape rise abruptly to elevations of 2,300 and 2,521 feet, respectively, and in the midst of the Strait are three islands, the largest of which is from three to four miles in diameter and has a height of 1,759 feet above the sea. In Seward Peninsula there are no deposits or other evidence that even remotely suggest that the region has been submerged two thousand feet below its present stand during Tertiary time or later.

ISSN:0002-8606    

DOI:10.1029/TR008i001p00035

年代:1927

数据来源: WILEY

摘要:

In comparison with the eastern half of North America, great topographic changes have occurred, in the Pacific Coast States during the last three periods of geological time—the Pliocene, Pleistocene, and Recent. During these later periods of geological history the eastern mountains and plains have apparently suffered only relatively gentle upbowing or downwarping, but since the beginning of the Pliocene the western mountains and plateaus have not merely been uplifted thousands of feet but have been strongly folded and broken by faults. In the West, neighboring areas have moved in opposite directions. Some have gone up great distances and now form the high ranges; others have sunk and now either form the valleys into which the erosional detritus from the ranges is being in part deposited or they form estuaries or sounds if, lying near the Coast, they sank below sea‐le

ISSN:0002-8606    

DOI:10.1029/TR008i001p00039

年代:1927

数据来源: WILEY