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ANOMALE ULTRASCHALL‐GESCHWINDIGKEITEN IN GESTEINSBOHRKERNEN *
Author(s) -
BAULE H.
Publication year - 1960
Publication title -
geophysical prospecting
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.735
H-Index - 79
eISSN - 1365-2478
pISSN - 0016-8025
DOI - 10.1111/j.1365-2478.1960.tb01494.x
Subject(s) - supersonic speed , drill , core (optical fiber) , range (aeronautics) , geology , longitudinal wave , mineralogy , optics , physics , materials science , mechanics , wave propagation , composite material , metallurgy
A bstract The velocity of supersonic pulses in cylindrical drill cores and rock samples is measured as a function of the frequency or wave length λ of the pulses. If λ is very much lower than the diameter D of the drill core –λ < D – the higher velocity of the longitudinal waves v l appears; on the other side we get the lower velocity of the rod waves v d (Stabdehnungswellen) if λ > D . Some drill cores from the carbon were found the velocities of which for sonic and supersonic pulses do not follow the above rule. It is shown that these cores have a constant velocity both for short and for long wave lengths in a frequency range between 5 kHz and 2 MHz.