David A Lockner
David Lockner is a geophysicist in the Earthquake Science Center.
Science and Products
Filter Total Items: 115
Electrical properties and anisotropy of schists and fault rocks from New Zealand’s Southern Alps under confining pressure Electrical properties and anisotropy of schists and fault rocks from New Zealand’s Southern Alps under confining pressure
Magnetotelluric models spanning the Pacific–Australian Plate boundary in New Zealand’s South Island indicate a localized zone of low electrical resistivity that is spatially coincident with theductile mid-crustal part of the Alpine Fault Zone (AFZ). We explored the source of this anomaly bymeasuring the electrical properties of samples collected from surface outcrops approaching the...
Authors
Katherine E Kluge, Virginia G. Toy, David A. Lockner
Impact of fluid-rock interaction on strength and hydraulic transmissivity rvolution in shear fractures under hydrothermal conditions Impact of fluid-rock interaction on strength and hydraulic transmissivity rvolution in shear fractures under hydrothermal conditions
Reactivated shear fractures contribute to the creation of pervasive fracture networks in geothermal systems. The creation, reactivation, and sustainability of fracture networks depend on complex coupling among thermal, hydraulic, mechanical, and chemical (THMC) processes. However, most laboratory experiments focus either solely on how fluid transport properties evolve in stationary...
Authors
Tamara Nicole Jeppson, David A. Lockner
Weakening of peridotite sheared at hydrothermal conditions Weakening of peridotite sheared at hydrothermal conditions
We conducted triaxial friction tests at hydrothermal conditions (25°C–350°C) on gouges of peridotite and its principal mineral constituents olivine and orthopyroxene. Pore-fluid chemistry was varied by the use of peridotite, granite, or quartzite driving blocks (representing wall rock) housing the gouge layer. Samples sheared at slow rates initially strengthen to a peak value, and then...
Authors
Diane E. Moore, David A. Lockner
Strength recovery and sealing under hydrothermal conditions Strength recovery and sealing under hydrothermal conditions
While there is significant evidence for healing in natural faults, geothermal reservoirs, and lab experiments, the thermal, hydraulic, mechanical, and chemical interactions that influence healing are poorly understood. We present preliminary results of triaxial slide-hold-slide experiments to constrain rates and mechanisms of healing. Experiments were conducted on gouge composed of...
Authors
Tamara Nicole Jeppson, David A. Lockner, Brian D. Kilgore, Nicholas M. Beeler, Joshua M. Taron
Evolution of fluid transmissivity and strength recovery of shear fractures under hydrothermal conditions Evolution of fluid transmissivity and strength recovery of shear fractures under hydrothermal conditions
Geothermal systems rely on the presence of long-lived and high-volume, permeable fracture systems. The creation, reactivation, and sustainability of these systems depend on complex coupling among thermal, hydraulic, mechanical, and chemical (THMC) processes occurring in geothermal reservoirs. In part due to a paucity of experimental data, the evolution of fractures at geothermal...
Authors
Tamara Nicole Jeppson, David A. Lockner, Brian D. Kilgore, Nicholas M. Beeler, Joshua M. Taron
A geology and geodesy based model of dynamic earthquake rupture on the Rodgers Creek‐Hayward‐Calaveras Fault System, California A geology and geodesy based model of dynamic earthquake rupture on the Rodgers Creek‐Hayward‐Calaveras Fault System, California
The Hayward fault in California's San Francisco Bay area produces large earthquakes, with the last occurring in 1868. We examine how physics‐based dynamic rupture modeling can be used to numerically simulate large earthquakes on not only the Hayward fault, but also its connected companions to the north and south, the Rodgers Creek and Calaveras faults. Equipped with a wealth of images of...
Authors
Ruth A. Harris, Michael Barall, David A. Lockner, Diane E. Moore, David A. Ponce, Russell Graymer, Gareth J. Funning, Carolyn A. Morrow, Christodoulos Kyriakopoulos, Donna Eberhart-Phillips
Filter Total Items: 14
Geothermal slide-hold-slide experiments on bare surface Westerly granite Geothermal slide-hold-slide experiments on bare surface Westerly granite
Laboratory slide-hold-slide tests, combined with flow through tests, conducted on Westerly granite with 30 degree sawcut. Tests were conducted with a constant confining pressure of 30 MPa with an average pore pressure of 10 MPa at temperatures of 23 and 200 degC. Three fluid flow conditions were examined (1) no flow, (2) cycled flow, and (3) continuous flow.
Data for "Weakening of Peridotite Sheared at Hydrothermal Conditions" Data for "Weakening of Peridotite Sheared at Hydrothermal Conditions"
This data release comprises three separate datasets and their accompanying metadata, in zip files. The data were acquired as part of a laboratory study of the response of ultramafic materials to shear at hydrothermal conditions. The principal dataset consists of the strength-displacement data from 28 friction experiments acquired on gouges prepared from peridotite rock samples and from...
Data Release for the Susceptibility of Oklahoma's Basement to Seismic Reactivation Published in NGEO 2019 Data Release for the Susceptibility of Oklahoma's Basement to Seismic Reactivation Published in NGEO 2019
Recent widespread seismicity in Oklahoma is attributed to the reactivation of pre existing, critically-stressed, and seismically unstable faults due to decades of wastewater injection. However, the structure and properties of the reactivated faults remain concealed by the sedimentary cover. Here, we explore the major ingredients needed to induce earthquakes in Oklahoma by characterizing...
Data Release for Shear Failure of a Granite Pin Traversing a Sawcut Fault published in IJRMMS Data Release for Shear Failure of a Granite Pin Traversing a Sawcut Fault published in IJRMMS
Fault heterogeneities such as bumps, bends, and stepovers are commonly observed on natural faults but challenging to recreate under controlled laboratory conditions. We study deformation and microseismicity of a 76 mm-diameter Westerly granite cylinder with a sawcut fault with known frictional properties. An idealized asperity is added by emplacing a precision-ground 21 mm-diameter solid...
Data Release for Data Report: Permeability, porosity, and frictional strength of core samples from IODP Expedition 366 in the Mariana forearc Data Release for Data Report: Permeability, porosity, and frictional strength of core samples from IODP Expedition 366 in the Mariana forearc
Core samples from the International Ocean Discovery Program (IODP) Expedition 366 were tested in the laboratory to determine permeability, porosity, density, and frictional strength and their relation to mineralogy as part of an effort to understand hydro-mechanical processes at convergent plate margins. Seven samples were tested from a depth range of 19.6 to 197.9 m below the sea floor...
Data for Frictional Properties and 3-D Stress Analysis of the Southern Alpine Fault, New Zealand (2013) Data for Frictional Properties and 3-D Stress Analysis of the Southern Alpine Fault, New Zealand (2013)
New Zealand's Alpine Fault (AF) ruptures quasi-periodically in large-magnitude earthquakes. Paleoseismological evidence suggests that about half of all recognized AF earthquakes terminated at the boundary between the Central and South Westland sections of the fault. There, fault geometry and the polarity of uplift change. The South Westland AF exhibits oblique-normal fault motion on a...
Science and Products
Filter Total Items: 115
Electrical properties and anisotropy of schists and fault rocks from New Zealand’s Southern Alps under confining pressure Electrical properties and anisotropy of schists and fault rocks from New Zealand’s Southern Alps under confining pressure
Magnetotelluric models spanning the Pacific–Australian Plate boundary in New Zealand’s South Island indicate a localized zone of low electrical resistivity that is spatially coincident with theductile mid-crustal part of the Alpine Fault Zone (AFZ). We explored the source of this anomaly bymeasuring the electrical properties of samples collected from surface outcrops approaching the...
Authors
Katherine E Kluge, Virginia G. Toy, David A. Lockner
Impact of fluid-rock interaction on strength and hydraulic transmissivity rvolution in shear fractures under hydrothermal conditions Impact of fluid-rock interaction on strength and hydraulic transmissivity rvolution in shear fractures under hydrothermal conditions
Reactivated shear fractures contribute to the creation of pervasive fracture networks in geothermal systems. The creation, reactivation, and sustainability of fracture networks depend on complex coupling among thermal, hydraulic, mechanical, and chemical (THMC) processes. However, most laboratory experiments focus either solely on how fluid transport properties evolve in stationary...
Authors
Tamara Nicole Jeppson, David A. Lockner
Weakening of peridotite sheared at hydrothermal conditions Weakening of peridotite sheared at hydrothermal conditions
We conducted triaxial friction tests at hydrothermal conditions (25°C–350°C) on gouges of peridotite and its principal mineral constituents olivine and orthopyroxene. Pore-fluid chemistry was varied by the use of peridotite, granite, or quartzite driving blocks (representing wall rock) housing the gouge layer. Samples sheared at slow rates initially strengthen to a peak value, and then...
Authors
Diane E. Moore, David A. Lockner
Strength recovery and sealing under hydrothermal conditions Strength recovery and sealing under hydrothermal conditions
While there is significant evidence for healing in natural faults, geothermal reservoirs, and lab experiments, the thermal, hydraulic, mechanical, and chemical interactions that influence healing are poorly understood. We present preliminary results of triaxial slide-hold-slide experiments to constrain rates and mechanisms of healing. Experiments were conducted on gouge composed of...
Authors
Tamara Nicole Jeppson, David A. Lockner, Brian D. Kilgore, Nicholas M. Beeler, Joshua M. Taron
Evolution of fluid transmissivity and strength recovery of shear fractures under hydrothermal conditions Evolution of fluid transmissivity and strength recovery of shear fractures under hydrothermal conditions
Geothermal systems rely on the presence of long-lived and high-volume, permeable fracture systems. The creation, reactivation, and sustainability of these systems depend on complex coupling among thermal, hydraulic, mechanical, and chemical (THMC) processes occurring in geothermal reservoirs. In part due to a paucity of experimental data, the evolution of fractures at geothermal...
Authors
Tamara Nicole Jeppson, David A. Lockner, Brian D. Kilgore, Nicholas M. Beeler, Joshua M. Taron
A geology and geodesy based model of dynamic earthquake rupture on the Rodgers Creek‐Hayward‐Calaveras Fault System, California A geology and geodesy based model of dynamic earthquake rupture on the Rodgers Creek‐Hayward‐Calaveras Fault System, California
The Hayward fault in California's San Francisco Bay area produces large earthquakes, with the last occurring in 1868. We examine how physics‐based dynamic rupture modeling can be used to numerically simulate large earthquakes on not only the Hayward fault, but also its connected companions to the north and south, the Rodgers Creek and Calaveras faults. Equipped with a wealth of images of...
Authors
Ruth A. Harris, Michael Barall, David A. Lockner, Diane E. Moore, David A. Ponce, Russell Graymer, Gareth J. Funning, Carolyn A. Morrow, Christodoulos Kyriakopoulos, Donna Eberhart-Phillips
Filter Total Items: 14
Geothermal slide-hold-slide experiments on bare surface Westerly granite Geothermal slide-hold-slide experiments on bare surface Westerly granite
Laboratory slide-hold-slide tests, combined with flow through tests, conducted on Westerly granite with 30 degree sawcut. Tests were conducted with a constant confining pressure of 30 MPa with an average pore pressure of 10 MPa at temperatures of 23 and 200 degC. Three fluid flow conditions were examined (1) no flow, (2) cycled flow, and (3) continuous flow.
Data for "Weakening of Peridotite Sheared at Hydrothermal Conditions" Data for "Weakening of Peridotite Sheared at Hydrothermal Conditions"
This data release comprises three separate datasets and their accompanying metadata, in zip files. The data were acquired as part of a laboratory study of the response of ultramafic materials to shear at hydrothermal conditions. The principal dataset consists of the strength-displacement data from 28 friction experiments acquired on gouges prepared from peridotite rock samples and from...
Data Release for the Susceptibility of Oklahoma's Basement to Seismic Reactivation Published in NGEO 2019 Data Release for the Susceptibility of Oklahoma's Basement to Seismic Reactivation Published in NGEO 2019
Recent widespread seismicity in Oklahoma is attributed to the reactivation of pre existing, critically-stressed, and seismically unstable faults due to decades of wastewater injection. However, the structure and properties of the reactivated faults remain concealed by the sedimentary cover. Here, we explore the major ingredients needed to induce earthquakes in Oklahoma by characterizing...
Data Release for Shear Failure of a Granite Pin Traversing a Sawcut Fault published in IJRMMS Data Release for Shear Failure of a Granite Pin Traversing a Sawcut Fault published in IJRMMS
Fault heterogeneities such as bumps, bends, and stepovers are commonly observed on natural faults but challenging to recreate under controlled laboratory conditions. We study deformation and microseismicity of a 76 mm-diameter Westerly granite cylinder with a sawcut fault with known frictional properties. An idealized asperity is added by emplacing a precision-ground 21 mm-diameter solid...
Data Release for Data Report: Permeability, porosity, and frictional strength of core samples from IODP Expedition 366 in the Mariana forearc Data Release for Data Report: Permeability, porosity, and frictional strength of core samples from IODP Expedition 366 in the Mariana forearc
Core samples from the International Ocean Discovery Program (IODP) Expedition 366 were tested in the laboratory to determine permeability, porosity, density, and frictional strength and their relation to mineralogy as part of an effort to understand hydro-mechanical processes at convergent plate margins. Seven samples were tested from a depth range of 19.6 to 197.9 m below the sea floor...
Data for Frictional Properties and 3-D Stress Analysis of the Southern Alpine Fault, New Zealand (2013) Data for Frictional Properties and 3-D Stress Analysis of the Southern Alpine Fault, New Zealand (2013)
New Zealand's Alpine Fault (AF) ruptures quasi-periodically in large-magnitude earthquakes. Paleoseismological evidence suggests that about half of all recognized AF earthquakes terminated at the boundary between the Central and South Westland sections of the fault. There, fault geometry and the polarity of uplift change. The South Westland AF exhibits oblique-normal fault motion on a...