David A Lockner
David Lockner is a geophysicist in the Earthquake Science Center.
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Microcrack interaction leading to shear fracture
In this paper we draw upon recent laboratory results concerning the nucleation and growth of shear fractures in brittle rock. In homogeneous, crystalline rock such as granite, fault nucleation occurs rapidly and with only subtle changes in precursory microcrack patterns. Once nucleated, the fault grows rapidly, restricting microcrack damage to a small region near the advancing fracture front. Obse
Authors
David A. Lockner, Diane E. Moore, Ze'ev Reches
Observations of quasistatic fault growth from acoustic emissions
The location of acoustic emission (AE) sources during deformation of rock has proven to be a useful non-destructive analytic technique. We present experimental results,based on AE observations, that show the nucleation and growth of macroscopic fault planes in granite and sandstone samples. By controlling axial stress to maintain constant AE rate rather than more conventional loading conditions su
Authors
David A. Lockner, J.D. Byerlee, V. Kuksenko, A. Ponomarev, A. Sidorin
Fault growth and acoustic emissions in confined granite
The failure process in a brittle granite was studied by using acoustic emission techniques to obtain three dimensional locations of the microfracturing events. During a creep experiment the nucleation of faulting coincided with the onset of tertiary creep, but the development of the fault could not be followed because the failure occurred catastrophically. A technique has been developed that enabl
Authors
David A. Lockner, James D. Byerlee
An earthquake mechanism based on rapid sealing of faults
RECENT seismological, heat flow and stress measurements in active fault zones such as the San Andreas have led to the suggestion1,2 that such zones can be relatively weak. One explanation for this may be the presence of overpressured fluids along the fault3-5, which would reduce the shear stress required for sliding by partially 'floating' the rock. Although several mechanisms have been proposed f
Authors
M.L. Blanpied, D.A. Lockner, J.D. Byerlee
Fault stability inferred from granite sliding experiments at hydrothermal conditions
Seismicity on crustal faults is concentrated in the depth interval 1–3 to 12–15km. Tse and Rice (1986) suggested that the lower bound on seismicity is due to a switch with increasing temperature from velocity weakening (destabilizing) to velocity strengthening (stabilizing) friction. They inferred this transition from friction data for dry granite; however, pore fluids exist at elevated temperatur
Authors
M.L. Blanpied, D.A. Lockner, J.D. Byerlee
Quasi-static fault growth and shear fracture energy in granite
The failure process in a brittle granite sample can be stabilized by controlling axial stress to maintain a constant rate of acoustic emission. As a result, the post-failure stress curve can be followed quasistatically, extending to hours the fault growth process which normally would occur violently in a fraction of a second. Using a procedure originally developed to locate earthquakes, acoustic e
Authors
D.A. Lockner, J.D. Byerlee, V. Kuksenko, A. Ponomarev, A. Sidorin
Effects of temperature and sliding rate on frictional strength of granite
Layers of artificial granite gouge have been deformed on saw-cut granite surfaces inclined 30?? to the sample axes. Samples were deformed at a constant confining pressure of 250 MPa and temperatures of 22 to 845??C. The velocity dependence of the steady-state coefficient of friction (??ss) was determined by comparing sliding strengths at different sliding rates. The results of these measurements a
Authors
D.A. Lockner, R. Summers, J.D. Byerlee
Stick slip, charge separation and decay
Measurements of charge separation in rock during stable and unstable deformation give unexpectedly large decay times of 50 sec. Time-domain induced polarization experiments on wet and dry rocks give similar decay times and suggest that the same decay mechanisms operate in the induced polarization response as in the relaxation of charge generated by mechanical deformation. These large decay times a
Authors
D.A. Lockner, J.D. Byerlee, V.S. Kuksenko, A.V. Ponomarev
Changes in complex resistivity during creep in granite
A sample of Westerly granite was deformed under constant stress conditions: a pore pressure of 5 MPa, a confining pressure of 10 MPa, and an axial load of 170 MPa. Pore volume changes were determined by measuring the volume of pore fluid (0.01 M KClaq) injected into the sample. After 6 days of creep, characterized by accelerating volumetric stain, the sample failed along a macroscopic fault. Measu
Authors
D.A. Lockner, J.D. Byerlee
Laboratory measurements of velocity-dependent frictional strength
Water levels, location, depths, and aquifers tapped are given for 113 observation wells in Michigan. Tabulated data include extremes of water levels for 1985 and for the period of record, pumpage of most major groundwater users in the state, and water quality data from selected wells. (USGS)
Authors
D.A. Lockner, J.D. Byerlee
Complex resistivity of fault gouge and its significance for earthquake lights and induced polarization
We have measured complex resistivity of 2 water-saturated San Andreas fault gouges from 10−3 to 106 Hz and confining pressures of 0.2 to 200 MPa. Consistent with earlier observations of clays and common rocks, large low-frequency permittivities were observed in all cases. Comparisons were made to induced polarization (IP) measurements by inversion of the data into the time domain, where we found t
Authors
David A. Lockner, James D. Byerlee
Pressure solution and hydrothermal recrystallization of carbonate sediments — an experimental study — reply
No abstract available.
Authors
P.A. Baker, M. Kastner, J.D. Byerlee, D.A. Lockner
Science and Products
Filter Total Items: 13
No Result Found
Filter Total Items: 112
Microcrack interaction leading to shear fracture
In this paper we draw upon recent laboratory results concerning the nucleation and growth of shear fractures in brittle rock. In homogeneous, crystalline rock such as granite, fault nucleation occurs rapidly and with only subtle changes in precursory microcrack patterns. Once nucleated, the fault grows rapidly, restricting microcrack damage to a small region near the advancing fracture front. Obse
Authors
David A. Lockner, Diane E. Moore, Ze'ev Reches
Observations of quasistatic fault growth from acoustic emissions
The location of acoustic emission (AE) sources during deformation of rock has proven to be a useful non-destructive analytic technique. We present experimental results,based on AE observations, that show the nucleation and growth of macroscopic fault planes in granite and sandstone samples. By controlling axial stress to maintain constant AE rate rather than more conventional loading conditions su
Authors
David A. Lockner, J.D. Byerlee, V. Kuksenko, A. Ponomarev, A. Sidorin
Fault growth and acoustic emissions in confined granite
The failure process in a brittle granite was studied by using acoustic emission techniques to obtain three dimensional locations of the microfracturing events. During a creep experiment the nucleation of faulting coincided with the onset of tertiary creep, but the development of the fault could not be followed because the failure occurred catastrophically. A technique has been developed that enabl
Authors
David A. Lockner, James D. Byerlee
An earthquake mechanism based on rapid sealing of faults
RECENT seismological, heat flow and stress measurements in active fault zones such as the San Andreas have led to the suggestion1,2 that such zones can be relatively weak. One explanation for this may be the presence of overpressured fluids along the fault3-5, which would reduce the shear stress required for sliding by partially 'floating' the rock. Although several mechanisms have been proposed f
Authors
M.L. Blanpied, D.A. Lockner, J.D. Byerlee
Fault stability inferred from granite sliding experiments at hydrothermal conditions
Seismicity on crustal faults is concentrated in the depth interval 1–3 to 12–15km. Tse and Rice (1986) suggested that the lower bound on seismicity is due to a switch with increasing temperature from velocity weakening (destabilizing) to velocity strengthening (stabilizing) friction. They inferred this transition from friction data for dry granite; however, pore fluids exist at elevated temperatur
Authors
M.L. Blanpied, D.A. Lockner, J.D. Byerlee
Quasi-static fault growth and shear fracture energy in granite
The failure process in a brittle granite sample can be stabilized by controlling axial stress to maintain a constant rate of acoustic emission. As a result, the post-failure stress curve can be followed quasistatically, extending to hours the fault growth process which normally would occur violently in a fraction of a second. Using a procedure originally developed to locate earthquakes, acoustic e
Authors
D.A. Lockner, J.D. Byerlee, V. Kuksenko, A. Ponomarev, A. Sidorin
Effects of temperature and sliding rate on frictional strength of granite
Layers of artificial granite gouge have been deformed on saw-cut granite surfaces inclined 30?? to the sample axes. Samples were deformed at a constant confining pressure of 250 MPa and temperatures of 22 to 845??C. The velocity dependence of the steady-state coefficient of friction (??ss) was determined by comparing sliding strengths at different sliding rates. The results of these measurements a
Authors
D.A. Lockner, R. Summers, J.D. Byerlee
Stick slip, charge separation and decay
Measurements of charge separation in rock during stable and unstable deformation give unexpectedly large decay times of 50 sec. Time-domain induced polarization experiments on wet and dry rocks give similar decay times and suggest that the same decay mechanisms operate in the induced polarization response as in the relaxation of charge generated by mechanical deformation. These large decay times a
Authors
D.A. Lockner, J.D. Byerlee, V.S. Kuksenko, A.V. Ponomarev
Changes in complex resistivity during creep in granite
A sample of Westerly granite was deformed under constant stress conditions: a pore pressure of 5 MPa, a confining pressure of 10 MPa, and an axial load of 170 MPa. Pore volume changes were determined by measuring the volume of pore fluid (0.01 M KClaq) injected into the sample. After 6 days of creep, characterized by accelerating volumetric stain, the sample failed along a macroscopic fault. Measu
Authors
D.A. Lockner, J.D. Byerlee
Laboratory measurements of velocity-dependent frictional strength
Water levels, location, depths, and aquifers tapped are given for 113 observation wells in Michigan. Tabulated data include extremes of water levels for 1985 and for the period of record, pumpage of most major groundwater users in the state, and water quality data from selected wells. (USGS)
Authors
D.A. Lockner, J.D. Byerlee
Complex resistivity of fault gouge and its significance for earthquake lights and induced polarization
We have measured complex resistivity of 2 water-saturated San Andreas fault gouges from 10−3 to 106 Hz and confining pressures of 0.2 to 200 MPa. Consistent with earlier observations of clays and common rocks, large low-frequency permittivities were observed in all cases. Comparisons were made to induced polarization (IP) measurements by inversion of the data into the time domain, where we found t
Authors
David A. Lockner, James D. Byerlee
Pressure solution and hydrothermal recrystallization of carbonate sediments — an experimental study — reply
No abstract available.
Authors
P.A. Baker, M. Kastner, J.D. Byerlee, D.A. Lockner