Influence of Frictional Melt on the Seismic Cycle: Insights From Experiments on Rock Analog Material

Conrad, Ethan; Tisato, Nicola; Carpenter, B. M.; Toro, Giulio Di

doi:10.1029/2022jb025695

“…The frictional properties of rocks play a crucial role in fault behavior and control a wide range of phenomena, from slow‐slip events and tremors to the nucleation and propagation of earthquakes (e.g., Cebry et al., 2022; Conrad et al., 2023; Leeman et al., 2016; Tal et al., 2020). The rupture propagation style, source properties, and recurrence patterns of earthquakes are determined predominantly by the rheological properties of faults (Kaneko et al., 2010; Liang et al., 2022; Liu et al., 2012; Michel et al., 2017; Qiu et al., 2016; Veedu & Barbot, 2016).…”

Section: Introductionmentioning

confidence: 99%

Constitutive Behavior of Rocks During the Seismic Cycle

Barbot

2023

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Establishing a constitutive law for fault friction is a crucial objective of earthquake science. However, the complex frictional behavior of natural and synthetic gouges in laboratory experiments eludes explanations. Here, we present a constitutive framework that elucidates the rate, state, and temperature dependence of fault friction under the relevant sliding velocities and temperatures of the brittle lithosphere during seismic cycles. The competition between healing mechanisms, such as viscoelastic collapse, pressure‐solution creep, and crack sealing, explains the low‐temperature stability transition from steady‐state velocity‐strengthening to velocity‐weakening as a function of slip‐rate and temperature. In addition, capturing the transition from cataclastic flow to semi‐brittle creep accounts for the stabilization of fault slip at elevated temperatures. We calibrate the model using extensive laboratory data on synthetic albite and granite gouge, and on natural samples from the Alpine Fault and the Mugi Mélange in the Shimanto accretionary complex in Japan. The constitutive model consistently explains the evolving frictional response of fault gouge from room temperature to 600°C for sliding velocities ranging from nanometers to millimeters per second. The frictional response of faults can be uniquely determined by the in situ lithology and the prevailing hydrothermal conditions.

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“…% H2O) of CM2, we conduct rotary shear tests to characterize its dry frictional behavior. These tests were conducted using an energy controlled rotary shear apparatus (see Conrad et al, 2023) fitted with a granular sample holder (Conrad et al, 2020).…”

Section: Experimental Materialsmentioning

confidence: 99%

Morpho-tectonics of transpressional systems: insights from analog modeling

Conrad

¹

,

Reitano

²

,

Faccenna

³

et al. 2023

Preprint

0

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Transpressional margins are widespread, and their dynamics are relevant for plate boundary evolution globally. Though transpressional orogen evolution involves a topographic response to deformation, many studies focus only on the structural development of the system ignoring surface processes. Here, we present a new set of analog models constructed to investigate how tectonic and surface processes interact at transpressive plate boundaries and shape topography. Experiments are conducted by deforming a previously benchmarked crustal analog material in a meter-scale plexiglass box while controlling erosion through misting nozzles mounted along the transpressional wedge. We used a laser scanner to generate digital elevation models throughout the model evolution and photos for particle image velocimetry analysis. We focus on three experiments that cover a range of rainfall and convergence settings, with two end-member erosion settings and a dry reference. In all experiments, a bivergent wedge forms, and strain partitioning broadly evolves according to previously established models. Regarding drainage networks, we find that the streams in our models develop differently through feedback between fault development and drainage rearrangement processes. Differences between end-member erosional models can be explained by the varying response of streams to structure modulated by rainfall. Additionally, erosion may influence the structural evolution of transpressional topography, leading to accelerated strike-slip partitioning. From these results, we create a model for developing structures, streams, and topography where incision and valley formation along main structures localize exhumation. We apply insights from the models to natural transpressional systems, including the Transverse Ranges, CA., and the Venezuelan Andes.

show abstract

Morpho-tectonics of transpressional systems: insights from analog modeling

Conrad

¹

,

Reitano

²

,

Faccenna

³

et al. 2023

Preprint

View full text Add to dashboard Cite

Transpressional margins are widespread, and their dynamics are relevant for plate boundary evolution globally. Though transpressional orogen evolution involves a topographic response to deformation, many studies focus only on the structural development of the system ignoring surface processes. Here, we present a new set of analog models constructed to investigate how tectonic and surface processes interact at transpressive plate boundaries and shape topography. Experiments are conducted by deforming a previously benchmarked crustal analog material in a meter-scale plexiglass box while controlling erosion through misting nozzles mounted along the transpressional wedge. We used a laser scanner to generate digital elevation models throughout the model evolution and photos for particle image velocimetry analysis. We focus on three experiments that cover a range of rainfall and convergence settings, with two end-member erosion settings and a dry reference. In all experiments, a bivergent wedge forms, and strain partitioning broadly evolves according to previously established models. Regarding drainage networks, we find that the streams in our models develop differently through feedback between fault development and drainage rearrangement processes. Differences between end-member erosional models can be explained by the varying response of streams to structure modulated by rainfall. Additionally, erosion may influence the structural evolution of transpressional topography, leading to accelerated strike-slip partitioning. From these results, we create a model for developing structures, streams, and topography where incision and valley formation along main structures localize exhumation. We apply insights from the models to natural transpressional systems, including the Transverse Ranges, CA., and the Venezuelan Andes.

show abstract

Influence of Frictional Melt on the Seismic Cycle: Insights From Experiments on Rock Analog Material

Abstract: High velocity laboratory rock friction experiments show that thermally controlled mechanisms may play a role in modulating the strength of crustal faults (

Cited by 3 publications

References 88 publications

Constitutive Behavior of Rocks During the Seismic Cycle

Constitutive Behavior of Rocks During the Seismic Cycle

Morpho-tectonics of transpressional systems: insights from analog modeling

Morpho-tectonics of transpressional systems: insights from analog modeling

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