THE DELINEATION OF THE BEDROCK CONFIGURATION OF PART OF PORT JACKSON,NEW SOUTH WALES,WITH A BOOMER SYSTEM*     

D. W. EMERSON  C. V. G. PHIPPS 《Geophysical Prospecting》1969,17(3):219-230

A high resolution Boomer system was used to investigate the bedrock configuration of part of Port Jackson, New South Wales. The continuous reflection profiling technique was successful in delineating a channel incised in bedrock under a thickness of up to 60 m. of unconsolidated sediment covered by up to 20 m. of water.  相似文献   

THE ELECTRICAL CURRENT PATTERN INDUCED BY AN OSCILLATING MAGNETIC DIPOLE IN A SEMI INFINITE CONDUCTIVE THIN PLATE*     

O. KOEFOED  A. P. STRUYK 《Geophysical Prospecting》1969,17(2):182-195

In a paper by Koefoed and Kegge (1968), which was based on previous work of Wesley (1958), the electrical current pattern has been derived that is induced by an oscillating magnetic dipole in a semi-infinite thin plate of infinitesimal resistivity. In the present paper, the range of validity of the assumptions, on which the work of Wesley is based, is subjected to a theoretical analysis. It is found that the decisive factor for the validity of Wesley's derivation is the quotient of the square of the penetration depth of the electrical current over the product of the thickness of the plate and a distance that is indicative of the size of the current loops in the plate. Wesley's derivation is shown to be valid only when this factor is negligible. It is also shown that in this condition the imaginary component of the anomaly must be negligible. Model experiments are described in which the electrical current pattern is studied also in the range in which the derivation of Wesley is not valid. The procedure used in these model experiments was to measure the tangential component of the magnetic field strength very close to the metal plate that simulated the conductive dyke. In order to express the results of the measurements in terms of the imaginary to real ratio, these results are compared with an interpretation graph for field measurements that was published by Hedström and Parasnis (1958). It is found that the current pattern in the plate is essentially the same as that which follows from Wesley's derivation, provided that the imaginary to real ratio is less than one third. The measurements do not permit to draw conclusions regarding the current pattern in the plate in conditions that correspond to larger values of the imaginary to real ratio.  相似文献   

AERIAL SURVEY: COLONY OF HONG KONG     

H. G. Dawe 《The Photogrammetric Record》1969,6(34):335-347

This paper describes the planning and implementation of a very extensive aerial survey contract undertaken by Hunting Surveys on behalf of the Hong Kong Government. From photography carried out during January and February 1963, photogrammetric plotting at 1 : 600 and 1 : 1200 proceeded steadily over a period of 5 years to the point where all but the highest land in the Colony had been surveyed at one or other of these two large scales. The problems arising from the rather unique terrain conditions and the urban and industrial development of Hong Kong are dealt with mainly from the photographic and photogrammetric aspect but reference is made to the contribution of the Crown Lands and Survey Office of the Public Works Department of Hong Kong, who provided all ground control and undertook field verification.  相似文献   

Mapping from Colour Aerial Photography     

W. G. Sims  M. L. Benson. 《The Photogrammetric Record》1969,6(33):321-324

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THE LAUSANNE CONGRESS     

G. R. Cooper  G. Petrie  A. D. N. Smith  M. Sowton  K. B. Atkinson 《The Photogrammetric Record》1969,6(33):239-258

The International Society for Photogrammetry held the Xlth International Congress at Lausanne during July 1968. The authors review the activities of five of the seven I.S.P. Commissions.  相似文献   

Pole-to-pole moisture conditions for the IGY   总被引：1，自引：0，他引：1  

Victor P. Starr  José P. Peixoto  Robert G. McKean 《Pure and Applied Geophysics》1969,75(1):300-331

Summary A study of the mean atmospheric humidity conditions on a planetary scale during the IGY covering the calendar year 1958 is presented. The fields of mean precipitable water content and of the zonal and meridional transports of water vapor are analyzed for the entire globe. Zonally averaged values of the various quantities at several levels are presented in tabular form and compared whenever possible with previous results or indirectly are analyzed on the basis of information obtained from different sources. The structure of these fields is studied and the corresponding implications for the general circulations of the atmosphere are discussed. Finally the zonal water balance for all the globe is discussed and its implications analyzed.  相似文献   

THOUGHTS ON MAPPING BY PHOTOGRAMMETRY     

V. A. Williams 《The Photogrammetric Record》1968,6(31):18-23

Topics of immediate practical interest formed the basis of the Address. Particular emphasis was placed upon problems of point transfer, pre-marking of ground control points, aerial triangulation by observation of independent models, and the status of photogrammetric operators.  相似文献   

ROTATIONAL SLUMPS AND SLUMP SCARS IN SILURIAN ROCKS, WESTERN IRELAND     

M. G. LAIRD 《Sedimentology》1968,10(2):111-120

Curved or planar discordant surfaces occurring within a limited stratigraphic range immediately beneath shallow marine deposits represent penecontemporaneous shear surfaces along which slumps have moved. Rotated packets of strata frequently retained within the curved discordant surfaces show both internal and external evidence of having moved laterally. Movement is considered to have been triggered off by a sudden shock or shocks which may have been either of sedimentary or tectonic origin. The slumping occurred at the change in gradient between slope and shallow marine shelf deposits.  相似文献   

AN OPTICAL METHOD OF MEASURING GRAIN ORIENTATION IN SEDIMENTS     

A. M. WINKELMOLEN  W. VAN DER  KNAAP R. EIJPE 《Sedimentology》1968,11(3-4):183-196

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MYTHICAL TOPOGRAPHIC FEATURES IN THE EARLY MAPPING OF OTAGO AND SOUTHLAND, 1823-1851     

Murray A. Bathgate 《New Zealand geographer》1968,24(2):206-213

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