David A Lockner
David Lockner is a geophysicist in the Earthquake Science Center.
Science and Products
Filter Total Items: 14
Compositional and Hydrothermal Frictional Strength Data for Five Chlorite Gouges Compositional and Hydrothermal Frictional Strength Data for Five Chlorite Gouges
A series of hydrothermal frictional strength experiments was conducted on synthetic gouges prepared from five chlorite-rich samples of varying composition. We present chlorite mineral compositions obtained by electron microprobe techniques, and X-ray diffraction and bulk chemical analyses of the gouges that were prepared by hand-grinding each sample to less than 90-µm grain diameter...
Slide-hold-slide experiments on Westerly Granite at temperatures up to 250 °C Slide-hold-slide experiments on Westerly Granite at temperatures up to 250 °C
Laboratory slide-hold-slide tests were conducted in a conventional triaxial deformation configuration on 1-inch diameter cylindrical cores of Westerly granite bisected by a sawcut oriented at 30 degrees from vertical. Tests were conducted at a constant confining pressure of 30 MPa with a 10 MPa pore fluid pressure. The pore fluid was deionized water. Experiments were conducted at...
Whole-rock chemistry of core from serpentinite mud volcanoes, Northern Mariana subduction zone Whole-rock chemistry of core from serpentinite mud volcanoes, Northern Mariana subduction zone
We present whole-rock geochemical analyses of 12 core samples obtained from three serpentinite mud volcanoes (Yinazao, Asut Tesoru, and Fantangisna) located on the forearc of the Mariana subduction system, where the Pacific Plate descends beneath the Philippine Sea Plate. The core was collected during International Ocean Discovery Program Expedition 366 of 2016-2017. The materials...
Data from the manuscript: Direct evidence for fluid pressure, dilatancy, and compaction affecting slip in isolated faults Data from the manuscript: Direct evidence for fluid pressure, dilatancy, and compaction affecting slip in isolated faults
Earthquake instability occurs as a result of strength loss during sliding on a fault. It has been known for over 50 years that fault compaction or dilatancy may cause significant weakening or strengthening by dramatically changing the fluid pressure trapped in faults. Despite this fundamental importance, we have no real understanding of the exact conditions that lead to compaction or...
Data from the manuscript: Electrical properties and anisotropy of schists and fault rocks from New Zealand’s Southern Alps under confining pressure Data from the manuscript: Electrical properties and anisotropy of schists and fault rocks from New Zealand’s Southern Alps under confining pressure
Electrical resistivity measurements of Alpine Fault, NZ outcrop samples saturated with 0.1 M KCl brine and tested at confining pressure of 5 to 200 MP at room temperature.
Data release for effect of cationic species on the friction of clay-bearing faults Data release for effect of cationic species on the friction of clay-bearing faults
Data are time series of clay shearing tests presented in 'Friction in clay-bearing faults increases with the ionic radius of interlayer cations' by Sakuma et al. in Communications Earth & Environment, 2022. Data were used for Figure 1 and Supplementary Figure 8 in that paper. Files contain shear strength as a function of fault slip in laboratory tests for brine-saturated montmorillonite...
Filter Total Items: 115
Comparative properties of saponitic fault gouge and serpentinite muds cored from mud volcanoes of the Mariana subduction zone Comparative properties of saponitic fault gouge and serpentinite muds cored from mud volcanoes of the Mariana subduction zone
We obtained 12 core samples for physical and chemical characterization from three serpentinite mud volcanoes (Yinazao, Asùt Tesoru, and Fantangisña) located on the forearc of the Mariana subduction system, that were drilled during International Ocean Discovery Program Expedition 366. Two samples from the Fantangisña mud volcano are interpreted to be clay-rich fault gouges derived from...
Authors
Diane E. Moore, C.A. Morrow, David A. Lockner, Barbara A. Bekins
Time-dependent weakening of granite at hydrothermal conditions Time-dependent weakening of granite at hydrothermal conditions
The evolution of a fault's frictional strength during the interseismic period is a critical component of the earthquake cycle, yet there have been relatively few studies that examine the time-dependent evolution of strength at conditions representative of seismogenic depths. Using a simulated fault in Westerly granite, we examined how frictional strength evolves under hydrothermal...
Authors
Tamara Nicole Jeppson, David A. Lockner, Nicholas M. Beeler, Diane E. Moore
Interlaboratory comparison of testing hydraulic, elastic, and failure properties in compression: Lessons learned Interlaboratory comparison of testing hydraulic, elastic, and failure properties in compression: Lessons learned
Many geoscientific problems require us to exploit synergies of experimental and numerical approaches, which in turn lead to questions regarding the significance of experimental details for validation of numerical codes. We report results of an interlaboratory comparison regarding experimental determination of mechanical and hydraulic properties of samples from five rock types, three...
Authors
Yang Cheng, David A. Lockner, Mandy Duda, Carolyn A. Morrow, Demian Saffer, Insun Song, Joerg Renner
Strength recovery in quartzite is controlled by changes in friction in experiments at hydrothermal conditions up to 200°C Strength recovery in quartzite is controlled by changes in friction in experiments at hydrothermal conditions up to 200°C
The rate of fault zone restrengthening between earthquakes can be influenced by both frictional and cohesive healing processes. Friction is dependent on effective normal stress while cohesion is independent of normal stress, potentially explaining—in part—the lack of depth dependence of earthquake stress drops. Although amenable to laboratory testing, few studies have systematically...
Authors
Tamara Nicole Jeppson, David A. Lockner, Nicholas M. Beeler, Stephen H. Hickman
Effect of thermal and mechanical processes on hydraulic transmissivity evolution Effect of thermal and mechanical processes on hydraulic transmissivity evolution
Fracture healing is a critical component of enhanced geothermal systems, the earthquake cycle, and induced seismicity. Accordingly, there is significant interest in understanding the process of healing and its effects on fluid transport. The creation, reactivation, and sustainability of fracture networks depend on complex coupling among thermal, hydraulic, mechanical, and chemical...
Authors
Tamara Nicole Jeppson, David A. Lockner, Joshua M. Taron, Diane E. Moore, Brian D. Kilgore, Nicholas M. Beeler, Stephen H. Hickman
Friction in clay-bearing faults increases with the ionic radius of interlayer cations Friction in clay-bearing faults increases with the ionic radius of interlayer cations
Smectite can dramatically reduce the strength of crustal faults and may cause creep on natural faults without great earthquakes; however, the frictional mechanism remains unexplained. Here, our shear experiments reveal systematic increase in shear strength with the increase of the ionic radius of interlayer cations among lithium-, sodium-, potassium-, rubidium-, and cesium...
Authors
Hiroshi Sakuma, David A. Lockner, John Solum, Nick Davatzes
Science and Products
Filter Total Items: 14
Compositional and Hydrothermal Frictional Strength Data for Five Chlorite Gouges Compositional and Hydrothermal Frictional Strength Data for Five Chlorite Gouges
A series of hydrothermal frictional strength experiments was conducted on synthetic gouges prepared from five chlorite-rich samples of varying composition. We present chlorite mineral compositions obtained by electron microprobe techniques, and X-ray diffraction and bulk chemical analyses of the gouges that were prepared by hand-grinding each sample to less than 90-µm grain diameter...
Slide-hold-slide experiments on Westerly Granite at temperatures up to 250 °C Slide-hold-slide experiments on Westerly Granite at temperatures up to 250 °C
Laboratory slide-hold-slide tests were conducted in a conventional triaxial deformation configuration on 1-inch diameter cylindrical cores of Westerly granite bisected by a sawcut oriented at 30 degrees from vertical. Tests were conducted at a constant confining pressure of 30 MPa with a 10 MPa pore fluid pressure. The pore fluid was deionized water. Experiments were conducted at...
Whole-rock chemistry of core from serpentinite mud volcanoes, Northern Mariana subduction zone Whole-rock chemistry of core from serpentinite mud volcanoes, Northern Mariana subduction zone
We present whole-rock geochemical analyses of 12 core samples obtained from three serpentinite mud volcanoes (Yinazao, Asut Tesoru, and Fantangisna) located on the forearc of the Mariana subduction system, where the Pacific Plate descends beneath the Philippine Sea Plate. The core was collected during International Ocean Discovery Program Expedition 366 of 2016-2017. The materials...
Data from the manuscript: Direct evidence for fluid pressure, dilatancy, and compaction affecting slip in isolated faults Data from the manuscript: Direct evidence for fluid pressure, dilatancy, and compaction affecting slip in isolated faults
Earthquake instability occurs as a result of strength loss during sliding on a fault. It has been known for over 50 years that fault compaction or dilatancy may cause significant weakening or strengthening by dramatically changing the fluid pressure trapped in faults. Despite this fundamental importance, we have no real understanding of the exact conditions that lead to compaction or...
Data from the manuscript: Electrical properties and anisotropy of schists and fault rocks from New Zealand’s Southern Alps under confining pressure Data from the manuscript: Electrical properties and anisotropy of schists and fault rocks from New Zealand’s Southern Alps under confining pressure
Electrical resistivity measurements of Alpine Fault, NZ outcrop samples saturated with 0.1 M KCl brine and tested at confining pressure of 5 to 200 MP at room temperature.
Data release for effect of cationic species on the friction of clay-bearing faults Data release for effect of cationic species on the friction of clay-bearing faults
Data are time series of clay shearing tests presented in 'Friction in clay-bearing faults increases with the ionic radius of interlayer cations' by Sakuma et al. in Communications Earth & Environment, 2022. Data were used for Figure 1 and Supplementary Figure 8 in that paper. Files contain shear strength as a function of fault slip in laboratory tests for brine-saturated montmorillonite...
Filter Total Items: 115
Comparative properties of saponitic fault gouge and serpentinite muds cored from mud volcanoes of the Mariana subduction zone Comparative properties of saponitic fault gouge and serpentinite muds cored from mud volcanoes of the Mariana subduction zone
We obtained 12 core samples for physical and chemical characterization from three serpentinite mud volcanoes (Yinazao, Asùt Tesoru, and Fantangisña) located on the forearc of the Mariana subduction system, that were drilled during International Ocean Discovery Program Expedition 366. Two samples from the Fantangisña mud volcano are interpreted to be clay-rich fault gouges derived from...
Authors
Diane E. Moore, C.A. Morrow, David A. Lockner, Barbara A. Bekins
Time-dependent weakening of granite at hydrothermal conditions Time-dependent weakening of granite at hydrothermal conditions
The evolution of a fault's frictional strength during the interseismic period is a critical component of the earthquake cycle, yet there have been relatively few studies that examine the time-dependent evolution of strength at conditions representative of seismogenic depths. Using a simulated fault in Westerly granite, we examined how frictional strength evolves under hydrothermal...
Authors
Tamara Nicole Jeppson, David A. Lockner, Nicholas M. Beeler, Diane E. Moore
Interlaboratory comparison of testing hydraulic, elastic, and failure properties in compression: Lessons learned Interlaboratory comparison of testing hydraulic, elastic, and failure properties in compression: Lessons learned
Many geoscientific problems require us to exploit synergies of experimental and numerical approaches, which in turn lead to questions regarding the significance of experimental details for validation of numerical codes. We report results of an interlaboratory comparison regarding experimental determination of mechanical and hydraulic properties of samples from five rock types, three...
Authors
Yang Cheng, David A. Lockner, Mandy Duda, Carolyn A. Morrow, Demian Saffer, Insun Song, Joerg Renner
Strength recovery in quartzite is controlled by changes in friction in experiments at hydrothermal conditions up to 200°C Strength recovery in quartzite is controlled by changes in friction in experiments at hydrothermal conditions up to 200°C
The rate of fault zone restrengthening between earthquakes can be influenced by both frictional and cohesive healing processes. Friction is dependent on effective normal stress while cohesion is independent of normal stress, potentially explaining—in part—the lack of depth dependence of earthquake stress drops. Although amenable to laboratory testing, few studies have systematically...
Authors
Tamara Nicole Jeppson, David A. Lockner, Nicholas M. Beeler, Stephen H. Hickman
Effect of thermal and mechanical processes on hydraulic transmissivity evolution Effect of thermal and mechanical processes on hydraulic transmissivity evolution
Fracture healing is a critical component of enhanced geothermal systems, the earthquake cycle, and induced seismicity. Accordingly, there is significant interest in understanding the process of healing and its effects on fluid transport. The creation, reactivation, and sustainability of fracture networks depend on complex coupling among thermal, hydraulic, mechanical, and chemical...
Authors
Tamara Nicole Jeppson, David A. Lockner, Joshua M. Taron, Diane E. Moore, Brian D. Kilgore, Nicholas M. Beeler, Stephen H. Hickman
Friction in clay-bearing faults increases with the ionic radius of interlayer cations Friction in clay-bearing faults increases with the ionic radius of interlayer cations
Smectite can dramatically reduce the strength of crustal faults and may cause creep on natural faults without great earthquakes; however, the frictional mechanism remains unexplained. Here, our shear experiments reveal systematic increase in shear strength with the increase of the ionic radius of interlayer cations among lithium-, sodium-, potassium-, rubidium-, and cesium...
Authors
Hiroshi Sakuma, David A. Lockner, John Solum, Nick Davatzes