摘要:

AbstractThis paper describes the measurement of the Earth's total magnetic field by a determination of the frequency of free precession around this field of the protons in a sample of water. The angular frequency of precession, ω, is related to the fieldFby the relationship ω=γpFwhereγpis the gyromagnetic ratio of the proton.A bottle of water is magnetised in a direction approximately at right angles to the earth's field, by passing a current through a coil wound around the bottle. The current is switched off rapidly, leaving the magnetic moment vector to precess around the earth's field direction, inducing in the coil a small alternating voltage. This voltage is amplified and its frequency measured by means of a counter. The accuracy of measurement of the total field is estimated at ± 0.5γ.In addition to the total field value, the form of the signal voltage contains information on the field gradient across the sample.Simple theory, experimental details and results are

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1956.tb01392.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe results of an 805‐mile (1300 km) airborne magnetometer profile flown across Tunisia and Algeria, from Tunis to the coast west of Oran, across north‐western Spanish Morocco and Tangier, and across south central Portugal to Lisbon are presented. The general geology of the zone over which the profile was flown is shown with the magnetic variations. Depth, structural and rock type interpretations have been made from the magnetic control. The depth values are believed to be high due to angle of the flight line with respect to the probable maximum gradient of the magnetic anomalies. However, depth values are given in all of the basins of possible inter

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1956.tb01393.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractExamples are given illustrating the application of geo‐electrical methods to engineering problems in Austria and Yugoslavia. A large number of these examples deal with dam problems. In this field, resistivity methods are used for bedrock investigations, to check the efficiency of cement injections into the rock, and to investigate the seepage of water underneath the dam. In the building and maintenance of roads, resistivity methods are used for the detection of cavities underneath the road. On the Vienna air port, a radio method was used for the same purpos

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1956.tb01394.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThis paper is presented to the geophysicist concerned with the interpretation of seismic records. Those instrumental factors which can affect the validity or accuracy of the records are detailed. Inferences are drawn relating to the picking, timing and grading of reflections, and the shooting of records in the field.

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1956.tb01395.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractAn analytical solution of refraction problems in anisotropic media is based on the expression for the refraction angle in an uniaxial anisotropic medium with vertical axis and elliptic anisotropy. The theory is applied to a test on the anisotropic behaviour of the sedimentary section in the vicinity of Betun, South Sumatra, employing the results from a refraction profile, a well velocity survey and a radial well survey. It is concluded that, in the Betun area, the anisotropy factor is variable with depth. Its maximum value may be as high as 1.15 in the middle part of the section.

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1956.tb01396.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractIn seismic underground surveys carried out by Seismos GmbH in siderite mines of Siegerland (Germany) anomalies in velocities have been found which could be explained only by the assumption of slates being aeolotropic. In this paper some of the peculiarities connected with the propagation of elastic waves in aeolotropic media–especially those consisting of thin beds of isotropic material–are discussed. Schlieren‐pictures of wave‐fronts are presented, which show the validity of the

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1956.tb01397.x

出版商:Blackwell Publishing Ltd    

年代:1956

数据来源: WILEY