Summary
In a series of triaxial experiments we have measured V p , V s and volumetric strain simultaneously in dilating dry and saturated rocks. For the first time these data permit quantitative comparison of seismic velocities or their ratio and dilatant volumetric strain. In air-dry samples V p /V s decreases by a few per cent at strains of 10−3; in saturated materials with high pore pressure, V p /V s increases by a comparable amount. Decreases in seismic velocity ratio are difficult to generate in initially saturated rocks even with low pore pressures and at strain rates of 10−4/sec. A liquid-vapor transition will not produce a significant drop in V p /V s . If dilatancy and fluid flow are responsible for seismic travel time anomalies prior to earthquakes, our results suggest that such anomalies will occur only in regions where pore fluid source to sink dimensions are of the order of 10 km or more, or in regions where the rocks are not saturated to begin with.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
A.N. Semenov, Variations in the travel time of transverse and longitudinal waves before violent earthquakes, Izv. Phys. Solid Earth 3 (1969), 245.
I.L. Nersesov, A.N. Semenov and I.G. Simbireva, Space-time distribution of the travel time ratios of transverse and longitudinal waves in the Garm area, in The Physical Basis of Foreshocks (Nauka Publ., Moscow 1969).
D.L. Anderson and J.H. Whitcomb. The dilatancy-diffusion model of earthquake prediction, in Proc. of Conf. on Tectonic Problems of the San Andreas Fault System, edited by R.L. Kovach and A. Nur (Stanford University Press, California 1973), p. 417.
Y.P. Aggarwal, L. Sykes, D.W. Simpson and P.G. Richards, Spatial and temporal variations in t s/t p and in P-wave residuals at Blue Mountain Lake, New York: Application to earthquake prediction (Preprint, 1974).
A. Nur, Dilatancy, pore fluids, and premonitory variations of t s/t p travel times, Bull. Seismol. Soc. Amer. 62 (1912), 1217.
C.H. Scholz, L.R. Sykes and Y.P. Aggarwal, Earthquake prediction: A physical basis, Science 181 (1973), 803.
B. Bonner, Shear wave birefringence in dilating granite, Geophys. Res. Lett. 1 (1974), 217. and pers. comms.
D. Tocher, Anisotropy in rocks under simple compression, AGU Trans. 38 (1957), 89.
S. Matsushima, Variation of the elastic wave velocities of rocks in the process of deformation and fracture under high pressure, Dis. Prev. Res. Inst. Bull 32 (1960), 2.
R.E. Thill, Acoustic methods for monitoring failure in rock, in Proc. of the 14th Sympos. on Rock Mech. edited by H.R. Hardy, Jr. and R. Stefanko (Am. Soc. Civil. Eng., N.Y., 1973).
I.N. Gupta, Seismic velocities in rock subjected to axial loading up to shear fracture, J. Geophys. Res. 78 (1973), 6936.
F. Birch, The velocity of compressional waves in rocks to 10 kilobars, J. Geophys. Res. 66 (1961), 2199.
W.F. Brace, J.B. Walsh and W.T. Frangos, Permeability of granite under high pressure, J. Geophys. Res. 73 (1968), 2225.
H.S. Carslaw and J.C. Jaeger, Conduction of Heat in Solids, 2nd ed. (Oxford Univ. Press 1959), 510 pp.
W.F. Brace, A.S. Orange and T.R. Madden, The effect of pressure on the electrical resistivity of water-saturated crystalline rocks, J. Geophys. Res. 70 (1965), 5669.
W.F. Brace and A.S. Orange, Further studies of the effects of pressure on electrical resistivity of rocks, J. Geophys. Res. 73 (1968), 5407.
K. Hadley, Laboratory investigation of dilatancy and motion on fault surfaces at low confining pressures, in Proc. of Conf. on Tectonic Problems of the San Andreas Fault System, edited by R.L. Kovach and A. Nur (Stanford University Press, California 1973), p. 427.
W.F. Brace, B.W. Paulding, Jr., and C. Scholz, Dilatancy in the fracture of crystalline rocks, J. Geophys. Res. 71 (1966), 3939.
W.F. Brace and R.J. Martin III, A test of the law of effective stress for crystalline rocks of low porosity, Int. J. Rock Mech. Min. Sci. 5 (1968), 415.
C.H. Scholz and R. Kranz, Notes on dilatancy recovery, J. Geophys. Res. 79 (1974), 2132.
B.T. Brady, Theory of earthquakes, Part I: A scale independent theory of rock failure, Pure and Appl. Geophys., in press.
R.J. O’Connell and B. Budiansky, Seismic velocities in dry and saturated cracked solids, Preprint, 1974.
D.L. Anderson and J.H. Whitcomb, Time dependent seismology, Preprint, 1974.
E.W. Washburn (editor), International Critical Tables: Vol. V (McGraw-Hill, N.Y. 1929, for the National Research Council).
G.C. Kennedy and W.T. Holster, Pressure-volume-temperature and phase relations of water and carbon dioxide, in Handbook of Physical Constants, Geol. Soc. Amer. Mem. 97 (1966).
T.L. de Fazio, K. Aki and J. Alba, Solid earth tide and observed change in the in situ seismic velocity, J. Geophys. Res. 78 (1973), 1319.
P. Reasenberg and K. Aki, A precise, continuous measurement of seismic velocity for monitoring in situ stress, J. Geophys. Res. 79 (1974), 399.
J.B. Walsh, The effect of cracks on the compressibility of rock, J. Geophys. Res. 70 (1965), 381.
J.B. Walsh, The effect of cracks on the uniaxial elastic compression of rocks, J. Geophys. Res. 70 (1965), 399.
J.B. Walsh, The effect of cracks on Poisson’s ratio, J. Geophys. Res. 70 (1965), 5249.
T.C. Hanks, Constraints on the dilatancy-diffusion model of the earthquake mechanism, J. Geophys Res. 79 (1974), 3023.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1975 Springer Basel AG
About this chapter
Cite this chapter
Hadley, K. (1975). V p /V s Anomalies in Dilatant Rock Samples. In: Wyss, M. (eds) Earthquake Prediction and Rock Mechanics. Contributions to Current Research in Geophysics (CCRG). Birkhäuser, Basel. https://doi.org/10.1007/978-3-0348-5534-1_1
Download citation
DOI: https://doi.org/10.1007/978-3-0348-5534-1_1
Publisher Name: Birkhäuser, Basel
Print ISBN: 978-3-0348-5536-5
Online ISBN: 978-3-0348-5534-1
eBook Packages: Springer Book Archive