• Accurate tremor locations from coherent S and P waves

    J. G. Armbruster; W.-Y. Kim; A. M. Rubin
    Journal Article

    Nonvolcanic tremor is an important component of the slow slip processes which load faults from below, but accurately locating tremor has proven difficult because tremor rarely contains clear P or S wave arrivals. Here we report the observation of coherence in the shear and compressional waves of tremor at widely separated stations which allows...

  • Aftershock asymmetry on a bimaterial surface

    A. M. Rubin; J. P. Ampuero
    Journal Article
  • Aftershock asymmetry/rupture directivity among central San Andreas fault microearthquakes

    A. M. Rubin; D. Gillard
    Journal Article

    Using a waveform cross-correlation technique, we have obtained precise relative locations for nearly 75% of the Northern California Seismic Network catalog (4300 earthquakes) occurring between 1984 and 1997 along 50 km of the San Andreas fault. Errors in relative location are meters to tens of meters for events separated by tens to hundreds of...

  • Aftershocks of microearthquakes as probes of the mechanics of rupture

    A. M. Rubin
    Journal Article

    Using a waveform cross-correlation technique, Rubin and Gillard [2000] obtained precise relative locations for 4300 0.5 < M < 3.5 earthquakes occurring along 50 km of the San Andreas fault. This study adds to that another 5000 earthquakes distributed along 10 km of the San Andreas fault and 20 km of the Calaveras fault. Errors in relative...

  • A comparison of rift-zone tectonics in Iceland and Hawaii

    A. M. Rubin
    Journal Article

    Observations of eroded volcanic rift zones indicate that dikes in Iceland are typically several times thicker than those in Hawaii. Geodetic and seismic observations of active rifts, however, suggest that dike heights in the two regions are similar. Provided the elastic properties of the rift zones are the same, this implies that dikes are...

  • Complex characteristics of slow slip events in subduction zones reproduced in multi-cycle simulations

    H. V. Colella; J. H. Dieterich; K. Richards-Dinger; A. M. Rubin
    Journal Article

    Since the discovery of slow slip events along subduction zone interfaces worldwide, dense geodetic and seismic networks have illuminated detailed characteristics of these events and associated tremor. High-resolution observations of tremor, where the spatial-temporal evolution is presumed to reflect that of the underlying slow slip events, show...

  • Compound earthquakes on a bimaterial interface and implications for rupture mechanics

    E. Wang; A. M. Rubin; J-P. Ampuero
    Journal Article

    Earthquake ruptures on the San Andreas Fault are affected by the material contrast across the fault. Previous observations of microearthquakes at the northern end of the creeping section have found strong signals of asymmetry in both rupture directivity (preferential propagation to the SE), and aftershock asymmetry (many more to the NW, on...

  • On corner frequencies, attenuation, and low-frequency earthquakes

    M. G. Bostock; A. M. Thomas; A. M. Rubin; N. I. Christensen
    Journal Article

    Abstract We have recently suggested that the nearly constant duration of low-frequency earthquakes (LFEs) (and, equivalently, the band limitation of tectonic tremor) manifests a moment-duration scaling that is fundamentally different from regular earthquakes and is most easily explained as rupture on asperities of roughly constant dimension. In...

  • Critical evaluation of state evolution laws in rate and state friction: Fitting large velocity steps in simulated fault gouge with time-, slip-, and stress-dependent constitutive laws

    Pathikrit Bhattacharya; Allan M. Rubin; Elsa Bayart; Heather M. Savage; Chris Marone
    Journal Article

    Abstract The variations in the response of different state evolution laws to large velocity increases can dramatically alter the style of earthquake nucleation in numerical simulations. But most velocity step friction experiments do not drive the sliding surface far enough above steady state to probe this relevant portion of the parameter space...

  • Designer friction laws for bimodal slow slip propagation speeds

    A. M. Rubin
    Journal Article

    A striking observation from both Cascadia and Japan is that the tremor associated with slow slip often migrates along strike at speeds close to 10 km/d but updip and downdip at speeds approaching 100 km/h. In this paper I adopt the view that the friction law appropriate for these regions is unknown, and I ask what constraints the observed...

  • Dike ascent in partially molten rock

    A. M. Rubin
    Journal Article

    Field observations indicate that dikes form and grow in magma source regions, but the mechanics of this process are poorly understood. I derive time-dependent and self-similar solutions for the growth of buoyant dikes fed by porous flow in partially molten rock. The host rock is treated as poroelastic; for basaltic (but not rhyolitic) dikes,...

  • Dike-induced earthquakes: Theoretical considerations

    A. M. Rubin; D. Gillard
    Journal Article
  • Dike-induced faulting and graben subsidence in volcanic rift zones

    A. M. Rubin
    Journal Article

    Field observations and geodetic data indicate that dike intrusion in volcanic rift zones typically generates normal faulting and graben subsidence at the Earth's surface. Elastic models indicate that two-dimensional (infinite strike length) dikes do not lower the ground surface above the dike and that normal faults do not lower the surface...

  • Dike-induced faulting in rift zones of Iceland and Afar

    A. M. Rubin; D. D. Pollard
    Journal Article

    Geodetic data and field observations demonstrate that the emplacement of dikes in volcanic rift zones frequently generates normal faulting and graben subsidence at the Earth's surface. Elastic modeling of the vertical ground-surface displacements above dikes and faults indicates that the extent of graben subsidence can be achieved only if fault...

  • Dikes vs. diapirs in viscoelastic rock

    A. M. Rubin
    Journal Article

    Geophysical models have traditionally treated diapiric ascent as occurring in purely viscous host rock, and dike intrusion as occurring in purely elastic host rock. Such models are incapable of determining (1) what governs the transition between the two transport mechanisms, (2) the properties of diapirs that ascend via a combination of...

  • Dikes vs. diapirs in viscoelastic rock

    A. M. Rubin
    Journal Article
  • Dilatant strengthening as a mechanism for slow slip events

    P. Segall; A. M. Rubin; A. M. Bradley; J. R. Rice
    Journal Article

    The mechanics of slow slip events (SSE) in subduction zones remain unresolved. We suggest that SSE nucleate in areas of unstable friction under drained conditions, but as slip accelerates dilatancy reduces pore pressure p quenching instability. Competition between dilatant strengthening and thermal pressurization may control whether slip is...

  • Do flexural stresses explain the mantle fault zone beneath Kilauea volcano?

    M. E. Pritchard; A. M. Rubin; C. J. Wolfe
    Journal Article

    Recent relocation and focal mechanism analyses of deep earthquakes beneath Kilauea volcano, Hawaii indicate that seismicity is concentrated on a horizontal fault zone at a depth of 30 km, with seaward slip of the upper block on a low-angle plane. We discuss whether the observed localization of the earthquakes can be explained primarily by...

  • Does fault strengthening in laboratory rock friction experiments really depend primarily upon time and not slip?

    P. Bhattacharya; A. M. Rubin; N. M. Beeler
    Journal Article

    The popular constitutive formulations of rate-and-state friction offer two end-member views on whether friction evolves only with slip (Slip law) or with time even without slip (Aging law). While rate stepping experiments show support for the Slip law, laboratory-observed frictional behavior near zero slip rates has traditionally been inferred...

  • Duration of deep earthquakes determined by stacking of Global Seismograph Network seismograms

    A. G. Bos; G. Nolet; A. Rubin; H. Houston; J. E. Vidale
    Journal Article

    The duration of each subevent of 48 earthquakes with magnitude larger than 5.5 and depth greater than 100 km was determined from stacked traces of broadband records of Global Seismograph Network stations. We fitted the source time function by one or more triangles convolved with attenuation. We found that global stacks of displacement...

  • Dynamic tensile-failure-induced velocity deficits in rock

    A. M. Rubin; T. J. Ahrens
    Journal Article

    Planar impact experiments were employed to induce dynamic tensile failure in Bedford limestone. Rock discs were impacted with aluminum and polymethyl methacralate (PMMA) flyer plates at velocities of 10 to 25 m/s. Tensile stress magnitudes and duration were chosen so as to induce a range of microcrack growth insufficient to cause complete...

  • Earthquake nucleation on (aging) rate and state faults

    A. M. Rubin; J-P. Ampuero
    Journal Article

    We obtain quasi-static, two-dimensional solutions for earthquake nucleation on faults obeying Dieterich's ?aging? version of the rate and state friction equations. Two distinct nucleation regimes are found, separated by roughly a/b ? 0.5, where a and b are the constitutive parameters relating changes in slip rate V and state ? to frictional...

  • Earthquake nucleation on rate and state faults – Aging and slip laws

    J-P. Ampuero; A. M. Rubin
    Journal Article

    We compare 2-D, quasi-static earthquake nucleation on rate-and-state faults under both "aging" and "slip" versions of the state evolution law. For both versions mature nucleation zones exhibit 2 primary regimes of growth: Well above and slightly above steady state, corresponding respectively to larger and smaller fault weakening rates. Well...

  • Episodic slow slip events and rate-and-state friction

    A. M. Rubin
    Journal Article

    There are several ways of generating episodic slow slip events in models of rate-and-state friction. Here I explore the possibility that they arise on velocity-weakening faults whose length is "tuned" in some sense. Unlike spring-block sliders, which have a unique critical stiffness for instability, elastically deformable faults have multiple...

  • Erratum: Aftershock asymmetry on a bimaterial surface

    A. M. Rubin; J. P. Ampuero
    Journal Article
  • Evidence for prehistoric coseismic folding along the Tsaotun segment of the Chelungpu fault near Nan-Tou, Taiwan

    A. R. Streig; C. M. Rubin; W-S. Chen; Y-G. Chen; L-S. Lee; S. C. Thompson; C. Madden; S-T. Lu
    Journal Article

    Taiwan's 1999 Mw 7.6 earthquake generated over 85 km surface rupture along the Chelungpu thrust fault. Paleoseismic studies at the Shi-Jia site near Nantou city, reveal folding as the predominant form of deformation. Stratigraphic relations across the 1999 fold scarp show the style and degree of deformation caused by the penultimate event is...

  • Frictional response to velocity steps and 1-D fault nucleation under a state evolution law with stressing-rate dependence

    P. Bhattacharya; A. M. Rubin
    Journal Article

    A new state evolution law has recently been proposed by Nagata et al. (2012) that includes a dependence upon stressing rate through a laboratory derived proportionality constant c. It has been claimed that this law, while retaining the time-dependent healing of the Dieterich (or Aging) law, can also match the symmetric response of the Ruina (or...

  • Getting granite dikes out of the source region

    Allan M. Rubin
    Journal Article

    Whether a dike can propagate far from a magma reservoir depends upon the competition between the rate at which propagation widens the dike and the rate at which freezing constricts the aperture available for magma flow. Various formulations are developed for a viscous fluid at temperature Tm intruding a growing crack in an elastic solid. The...

  • A Granular Physics-Based View of Fault Friction Experiments

    B. Ferdowsi; A. M. Rubin
    Journal Article

    Rate‐ and state‐dependent friction (RSF) equations are commonly used to describe the time‐dependent frictional response of fault gouge to perturbations in sliding velocity. Among the better‐known versions are the Aging and Slip laws for the evolution of state. Although the Slip law is more successful, neither can predict all the robust features...

  • Ground ruptures of the 1974 and 1983 Kaoiki Earthquakes, Mauna Loa Volcano, Hawaii

    M. D. Jackson; E. T. Endo; P. T. Delaney; T. Arnadottir; A. M. Rubin
    Journal Article

    The November 30, 1974, ML = 5.5 and November 16, 1983, ML = 6.6 earthquakes generated left-stepping, en echelon ground cracks within the Kaoiki seismic zone, on the southeast flank of Mauna Loa volcano, Hawaii. The general trend of the ruptures, N48°-55°E, parallels a nodal plane of the main shocks' focal mechanisms. The ruptures themselves...

  • Highly concentrated seismicity caused by deformation of Kilauea's deep magma system

    D. Gillard; A. M. Rubin; P. Okubo
    Journal Article

    FREQUENT shallow earthquakes within the rift zones of the Hawaiian volcano Kilauea have been interpreted as resulting from stress changes associated with a shallow magma conduit system1,2. Here, by using a precise earthquake relocation technique3, we show that what had been imaged as a diffuse cloud of seismicity in the Upper East Rift in 1991...

  • High-resolution images of tremor migrations beneath the Olympic Peninsula from stacked array of arrays seismic data

    Y. Peng; A. M. Rubin
    Journal Article

    Abstract Episodic tremor and slip (ETS) in subduction zones is generally interpreted as the manifestation of shear slip near the base of earthquake-generating portion of the plate interface. Here we devise a new method of cross-correlating stacked Array of Arrays seismic data that provides greatly improved tremor locations, a proxy for the...

  • High-resolutions images of tremor migrations beneath the Olympic Peninsula from stacked array of arrays seismic data

  • Imaging slow slip fronts in Cascadia with high precision cross-station tremor locations

    A. M. Rubin; J. G. Armbruster
    Journal Article

    We apply a new method to obtain accurate locations of tremor sources beneath southern Vancouver Island. Unlike more standard "cross-time" methods, which compare waveforms from different time windows at the same station, this "cross-station" method compares waveforms from the same time window at widely separated stations. It performs well,...

  • Impact-induced tensional failure in rock

    T. J. Ahrens; A. M. Rubin
    Journal Article

    Planar impact experiments were employed to induce dynamic tensile failure in Bedford limestone. Rock discs were impacted with aluminum and polymethyl methacralate flyer plates at velocities of 10 to 25 m/s. This resulted in tensile stresses in the range of ~11 to 160 MPa. Tensile stress durations of 0.5 and 1.3 μs induced microcrack growth...

  • Implications of diverse fault orientations imaged in relocated aftershocks of the Mount Lewis, ML 5.7, California, earthquake

    D. Kilb; A. M. Rubin
    Journal Article

    We use seismic waveform cross correlation to determine the relative positions of 2747 microearthquakes near Mount Lewis, California, that have waveforms recorded from 1984 to 1999. These earthquakes include the aftershock sequence of the 1986 ML5.7 Mount Lewis earthquake. Approximately 90% of these aftershocks are located beyond the tips of the...

  • Implications of rate-and-state friction for properties of aftershock sequence: Quasi-static inherently discrete simulations

    A. Ziv; A. M. Rubin
    Journal Article

    Dieterich [1994] modeled the response to a stress step of a population of faults governed by rate- and state-dependent friction. This model assumes that aftershocks nucleate over areas on the fault that at the time of the main shock are already accelerating toward failure and disregards the effect of interactions among aftershocks. The main...

  • Intermittent tremor migrations beneath Guerrero, Mexico, and implications for fault healing within the slow slip zone

    Y. Peng; A. M. Rubin
    Journal Article

    Abstract Slow slip events exhibit significant complexity in slip evolution and variations in recurrence intervals. Behavior that varies systematically with recurrence interval is likely to reflect different extents of fault healing between these events. Here we use high-resolution tremor catalogs beneath Guerrero, Mexico, to investigate the...

  • Intersecting Faults Simulation for Three-Dimensional Reservoir-Geomechanical Models

    J. H. Prevost; A. M. Rubin; N. Sukumar
    Conference Proceedings
  • Laterally propagating slow slip events in a rate and state friction model with a velocity-weakening to velocity-strengthening transition

    J. C. Hawthorne; A. M. Rubin
    Journal Article

    We investigate the behavior of simulated slow slip events using a rate and state friction model that is steady state velocity weakening at low slip speeds but velocity strengthening at high slip speeds. Our simulations are on a one-dimensional (line) fault, but we modify the elastic interactions to mimic the elongate geometry frequently...

  • Magnitudes and moment-duration scaling of low-frequency earthquakes beneath southern Vancouver Island

    M. G. Bostock; A. M. Thomas; G. Savard; L. Chuang; A. M. Rubin
    Journal Article

    Abstract We employ 130 low-frequency earthquake (LFE) templates representing tremor sources on the plate boundary below southern Vancouver Island to examine LFE magnitudes. Each template is assembled from hundreds to thousands of individual LFEs, representing over 269,000 independent detections from major episodic-tremor-and-slip (ETS) events...

  • A microscopic model of rate and state friction evolution

    T. Li; A. M. Rubin
    Journal Article

    Abstract Whether rate- and state-dependent friction evolution is primarily slip dependent or time dependent is not well resolved. Although slide-hold-slide experiments are traditionally interpreted as supporting the aging law, implying time-dependent evolution, recent studies show that this evidence is equivocal. In contrast, the slip law...

  • Numerical simulation of high-pressure rock tensile fracture experiments: Evidence of an increase in fracture energy with pressure?

    Y. A. Fialko; A. M. Rubin
    Journal Article

    High confining pressure fracture tests of Indiana limestone [Abou-Sayed, 1977] and Iidate granite [Hashida et al., 1993] were simulated using boundary element techniques and a Dugdale-Barenblatt (tension-softening) model of the fracture process zone. Our results suggest a substantial (more than a factor of 2) increase in the fracture energy of...

  • Origin and lateral migration of linear dunes in the Qaidam Basin of NW China revealed by dune sediments, internal structures, and optically stimulated luminescence ages, with implications for linear dunes on Titan: Discussion

    D.M. Rubin; A.M. Rubin
    Journal Article

    Zhou et al. (2012) proposed that longitudinal dunes in the Qaidam Basin, China, formed like yardangs: by erosion into sediment that was not deposited by those dunes. Because erosion occurs on the upwind fl anks of most migrating dunes (Rubin and Hunter, 1982, 1985), the key to demonstrating a yardang-like origin is to show that the dunes did...

  • Origins of blade-like dikes in volcanic rift zones

    A. M. Rubin; D. D. Polland
    Government Report

    Seismic and geodetic data have demonstrated that dikes in the rift zones of Kilauea Volcano in Hawaii and Krafla Volcano in Iceland are typically intruded laterally from a central magma reservoir and acquire a blade-like form. A remarkable feature of many such dikes is that they propagate at shallow depths for 10s of km without erupting. Using...

  • Propagation of Magma-Filled Cracks

    Allan M. Rubin
    Journal Article

    The mechanism of magma transport at depth influences direction magma moves, the distance it travels before freezing, the degree to which it communicates chemically with the host rock, the form of surficial volcanism, and ultimately the growth of oceanic and continental crust. Commonly envisioned transport processes include porous flow in...

  • A reinterpretation of seismicity associated with the January 1983 dike intrusion at Kilauea Volcano, Hawaii

  • Role of fault gouge dilatancy on aseismic deformation transients

    Y. Liu; A. M. Rubin
    Journal Article

    In the vicinity of episodic aseismic transients in several subduction zones, the presence of interstitial fluids and near-lithostatic pore pressure has been proposed to interpret seismic observations of high P to S wave speed ratio and high Poisson's ratio. Under such conditions, fault stabilization by dilatancy-induced suction during increased...

  • Rupture directivity of microearthquakes on the San Andreas Fault from spectral ratio inversion

    E. Wang; A. M. Rubin
    Journal Article

    Earthquakes often occur on faults separating materials with different elastic properties. On theoretical grounds, it is expected that earthquakes on such bimaterial interfaces might have a preferred rupture propagation direction, that being the direction of motion of the more compliant material. The goal of this paper is to determine whether a...

  • Self-similar slip pulses during rate-and-state earthquake nucleation

    A. M. Rubin; J-P. Ampuero
    Journal Article

    For a wide range of conditions, earthquake nucleation zones on rate- and state-dependent faults that obey either of the popular state evolution laws expand as they accelerate. Under the "slip" evolution law, which experiments show to be the more relevant law for nucleation, this expansion takes the form of a unidirectional slip pulse. In...

  • Shock compression and isentropic release of granite

    T. Sekine; T. S. Duffy; A. M. Rubin; W. W. Anderson; T. J. Ahrens
    Journal Article

    New equation of state data for a weathered granite shocked to about 125 GPa are reported and combined with the Westerly granite data of McQueen, Marsh & Fritz (1967). The shock velocity (Us)-particle velocity (Up) relations can be fitted with two linear regressions: Us = 4.40 + 0.6Up for a range of Up up to about 2 km s−1 and Us = 2.66 + 1....

  • Shock wave equation of state of muscovite

    T. Sekine; A. M. Rubin; T. J. Ahrens
    Journal Article

    Shock wave data to provide an equation of state of muscovite (initial density: 2.835 g/cm3) were determined up to a pressure of 141 GPa. The shock velocity (Us) versus particle velocity (Up) data are fit with a single linear relationship: Us=4.62(±0.12) +1.27(±0.04)Up (km/s). Third-order Birch-Murnaghan equation of state parameters (isentropic...

  • Short-time scale correlation between slow slip and tremor in Cascadia

    J. C. Hawthorne; A. M. Rubin
    Journal Article

    We use borehole strain and seismic data to show that slow slip and tremor in central Cascadia are correlated on a range of time scales shorter than 1 day. The recorded strain rate is our proxy for the slow slip moment rate, and the seismic amplitude is our proxy for the tremor amplitude. We find that, on average, the strain rate is higher when...

  • Simulating Short-Term Evolution of Slow Slip Influenced by Fault Heterogeneities and Tides

    Y. Peng; A. M. Rubin
    Journal Article

    Abstract In this study, we analyze high-resolution tremor catalogs from northern Cascadia, Guerrero, and northern Kii Peninsula. We find that tremor often occurs in short bursts that repeatedly occupy the same source area within a slow slip event. We hypothesize that these bursts are driven by loading from slow slip in areas surrounding the...

  • Spatiotemporal Analyses of Earthquake Productivity and Size Distribution: Observations and Simulations

    A. Ziv; A. M. Rubin; D. Kilb
    Journal Article

    We use relocated catalogs of microearthquakes to investigate earthquake interaction along sections of the Sargent, Calaveras, and San Andreas faults in California. We examine the stress dependence of seismicity rate change along the three fault segments and find that the seismicity rate following a mainshock decays approximately as 1/time, the...

  • Stability of dike intrusion along preexisting fractures

    A. Ziv; A. M. Rubin; A. Agnon
    Journal Article

    We investigate the ability of magma to propagate along preexisting fractures oblique to the least compressive stress. Relaxation of the preexisting shear stress to zero over the portion of the fracture dilated by magma (the dike) results in slip for some distance along the closed portion of the fracture ahead of the dike tip and a stress...

  • Static stress transfer and earthquake triggering: No lower threshold in sight?

    A. Ziv; A. M. Rubin
    Journal Article

    The main objective of this study is to see if a lower threshold for earthquake triggering exists. Resolving this issue is important for the understanding of earthquake mechanics and for the purpose of hazard analysis. We compute the cumulative static stress changes imposed on 63 M ≥ 4.5 earthquakes in central California between 1969 and 1998,...

  • Streaks of microearthquakes along creeping faults

    A. M. Rubin; D. Gillard; J-L. Got
    Journal Article

    Crustal faults that produce most of their slip aseismically typically generate large numbers of small earthquakes. These events have generally been interpreted as coming from localized patches of the fault that undergo unstable (stick–slip) sliding, surrounded by larger regions of stable sliding (creep). In published catalogues the...

  • Stress inversion methods: are they based on faulty assumptions?

    D.D. Pollard; S.D. Saltzer; A. M. Rubin
    Journal Article

    Stress inversion methods employed by structural geologists for estimating a regional stress tensor from populations of faults containing slickenlines rely on the basic assumption that slip on each fault plane occurs in the direction of maximum resolved regional shear stress. This premise ignores directional differences in fault compliance...

  • Sustained eruptions on Enceladus explained by turbulent dissipation in tiger stripes

    E. S. Kite; A. M. Rubin
    Journal Article

    Eruptions on the ice moon Enceladus provide access to materials from Enceladus’ ocean. The mechanism that drives and sustains the eruptions is unclear, and it is also not known what sets the rate of volcanism. We found that a simple model in which the erupting fissures are underlain by slots that connect the surface to the ocean can explain the...

  • Systematic variations in recurrence interval and moment of repeating aftershocks

    Z. Peng; J. E. Vidale; C. Marone; A. M. Rubin
    Journal Article
  • Tensile fracture of rock at high confining pressure: Implications for dike propagation

    A. M. Rubin
    Journal Article

    Field observations indicate that zones of inelastic deformation produced at the tips of propagating dikes can be much larger than those produced at the tips of tensile cracks in laboratory experiments. This is in direct conflict with the concept that fracture toughness and fracture energy are rock properties, independent of crack size and...

  • Thermal and mechanical aspects of magma emplacement in giant dike swarms

    Y. A. Fialko; A. M. Rubin
    Journal Article

    We consider the thermal history and dynamics of magma emplacement in giant feeder dikes associated with continental flood basalts. For driving pressure gradients inferred for giant dike swarms, thicknesses of <10 m would enable dikes to transport magma laterally over the distances observed in the field (up to thousands of kilometers) without...

  • On the thermal viability of dikes leaving magma chambers

    A. M. Rubin
    Journal Article

    Dikes beginning to propagate away from a magma source are thin and grow slowly, and thus are susceptible to freezing. A self-similar solution is obtained for a dike propagating down a temperature gradient when the wallrock and magma temperatures are equal at the chamber wall. The solution applies only to the special case of a single-component...

  • Thermodynamics of lateral dike propagation: Implications for crustal accretion at slow spreading mid-ocean ridges

    Y. A. Fialko; A. M. Rubin
    Journal Article

    We consider solidification of hot fluid flowing through a rigid-wall channel of infinite extent. The calculated ?thermal arrest? lengths are used to investigate the role of magma freezing in limiting the propagation distance of lateral dike intrusions. Our results demonstrate that for reasonable parameters the propagation distances of meter-...

  • Tidal modulation and back-propagating fronts in slow slip events simulated with a velocity-weakening to velocity-strengthening friction law

    J. C. Hawthorne; A. M. Rubin
    Journal Article

    We examine tidal modulation and back-propagating fronts in simulated slow slip events using a rate and state friction law that is steady state velocity weakening at low slip rates and velocity strengthening at high slip rates. Tidal forcing causes a quasi-sinusoidal modulation of the slip rate during the events, with the maximum moment rate...

  • Tidal modulation of slow slip in Cascadia

    J. C. Hawthorne; A. M. Rubin
    Journal Article

    Several studies have shown that the seismic tremor in episodic tremor and slip is tidally modulated, suggesting a sensitivity to the rather small tidal stresses. We address whether the slip rate in slow slip events is also tidally modulated by examining data from six borehole strainmeters in northwest Washington and southern Vancouver Island....

  • Using Repeating Earthquakes to Correct High-Precision Earthquake Catalogs for Time-Dependent Station Delays

    A. M. Rubin
    Journal Article

    Waveform cross-correlation allows one to measure the relative arrival times of similar microearthquakes with errors of less than 1/10 of 1 sample. Location algorithms based on these measurements have greatly improved images of earthquake distribution. For the Northern California Seismic Network catalog, however, the relative location errors...

  • What controls the along-strike slopes of volcanic rift zones?

    Y. A. Fialko; A. M. Rubin
    Journal Article

    We investigate the dynamics of viscous pressure losses associated with lateral magma transport in volcanic rift zones by performing (1) coupled elastic-hydrodynamic simulations of downrift magma flow in dikes and (2) analog experiments mimicking lateral dike propagation in the presence of an along-rift topographic slope. It is found that near-...

  • Why geologists should avoid using “fracture toughness: (at least for dykes):

    A. M. Rubin
    Book

    G. Baer & A. Heimann (eds).

    This work combines research results with review papers, discussing dykes from different scientific perspectives. Coverage includes: current dyke geometry measurements; field observation of host rock deformation; textural analyses; and geochemical and petrological studies of dyke swarms.