摘要:

Wherever oceanic information is exhibited in graphic form one thing is notable, and that is the great distortions of relative area and linear representation, due to the use of Mercator's Nautical Projection as a base. Instruments and methods have been devised for securing and recording data and a number of nautical organizations are co‐operating in collecting it. Thus, many data are being assembled, but an adequate instrument for the proper exhibition of these data has been lacking. To supply this deficiency an equal‐area map of the oceans was devised. It represents an effort on the part of the cartographer to serve the oceanograp

ISSN:0002-8606    

DOI:10.1029/TR007i001p00116

年代:1926

数据来源: WILEY

摘要:

The topic for the symposium was suggested by the immediate prospect of the founding of a volcano observatory in the Aleutian Range under the United States Geological Survey. The Aleutians are difficult of access and remain but little more explored than when Alaska was first acquired. The region of greatest interest is the Andreanof group about Atka, between the Islands of the Four Mountains and Tanaga. This region has hitherto defied all attempts at mapping, collections, soundings, and geophysical measurements, beyond the barest reconnaissance. There are here thirty unknown volcanic islands, in the latitude of southern British Columbia (52°), in the middle belt of the Aleutian arc, in a length of 350 nautical miles. The climate is mild, but windy and foggy

ISSN:0002-8606    

DOI:10.1029/TR007i001p00120

年代:1926

数据来源: WILEY

摘要:

No matter what the study of a large area of the earth's surface may be, an essential factor in the successful working out of the problems and their solution is the knowledge of the geographic positions, elevations and configuration of the ground. Without such data, one works largely in the dark.As far as the Aleutian Islands are concerned and the regions of Bering Sea and the Pacific Ocean nearby, which would be involved in any investigation covering the islands, we have scant data. It is true that the islands are shown on charts, but are they in their correct positions? The chances are that they are not. A glance at the charts covering the islands will show that beyond Unalaska Island there are exceedingly few soundings, certainly not enough to afford any idea of a detailed nature as to the configuration of the bottom of the Pacific Ocean and Bering Sea near the islands and the degree of slope out to deep water.

ISSN:0002-8606    

DOI:10.1029/TR007i001p00121

年代:1926

数据来源: WILEY

摘要:

So little is actually known about the igneous rocks of the Aleutian Islands that it might seem as if there were little more to say on the subject of magmatic problems than that the whole field lies before the investigator.That can indeed be said, and it can be said further that the region is especially favorable for investigation because of the great number of active and extinct volcanoes situated along this chain of islands; but it is possible to suggest two or three more specific problems.

ISSN:0002-8606    

DOI:10.1029/TR007i001p00124-2

年代:1926

数据来源: WILEY

摘要:

To the seismologist the idea of establishing a geophysical observatory in the Aleutian Islands immediately brings to mind two outstanding facts. First, it is the most neglected of any major seismic region of the world so far as securing local instrumental data is concerned; secondly, establishment of such an observatory would eliminate duplication of effort in the fields of instrumental seismology and volcanology. Just what the exact relation is between volcanoes and earthquakes, is immaterial at this time. It is sufficient to know that students in all branches of geophysics are unanimous in their support of observational projects which aim to explain this relation on a quantitative or correlative basis rather than on any other.

ISSN:0002-8606    

DOI:10.1029/TR007i001p00127

年代:1926

数据来源: WILEY

摘要:

Prior to 1915, magnetic observations in the Aleutian Islands were limited to 30 values at eight localities on land and 14 values at 10 localities at sea, the first observations having been made at Dutch Harbor in 1867. In 1915, theCarnegiemade observations in the vicinity of the Aleutian Islands during her cruise up into the Bering Sea, calling at Dutch Harbor on the way north, and returning south near Attu, the westernmost island of the group. During the following year, on the same cruise, she passed near the group on her voyage across the north Pacific from Guam to San Francisco. In 1925 Lieut. G. C. Jones of the Coast and Geodetic Survey made observations at four islands of the group, establishing 12 stations, his results indicating very large local disturbances, especially on Atka Island. Three of these islands had been occupied in 1873, and the results of Lieut. Jones' observations give valuable information concerning the annual variation at the repeat stations.

ISSN:0002-8606    

DOI:10.1029/TR007i001p00131

年代:1926

数据来源: WILEY

摘要:

The maintenance of regular observing stations in the Aleutian Islands and of uninterrupted communication between them and the Pacific coast of the United States is of very great importance to the Weather Bureau. The U.S. Navy maintains radio stations at Dutch Harbor, Kodiak, and St. Paul, and twice‐daily observations are sent from each of these station

ISSN:0002-8606    

DOI:10.1029/TR007i001p00134

年代:1926

数据来源: WILEY