Robert W Graves
Rob Graves is a geophysicist in the Earthquake Hazards Program.
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Filter Total Items: 43
Refinements to the Graves and Pitarka (2010) Broadband Ground Motion Simulation Method
This brief article describes refinements to the Graves and Pitarka (2010) broadband ground motion simulation methodology (GP2010 hereafter) that have been implemented in version 14.3 of the SCEC Broadband Platform (BBP). The updated version of our method on the current SCEC BBP is referred to as GP14.3. Our simulation technique is a hybrid approach that combines low-‐frequency and high-‐frequenc
Authors
Robert Graves, Arben Pitarka
Ground motion-simulations of 1811-1812 New Madrid earthquakes, central United States
We performed a suite of numerical simulations based on the 1811–1812 New Madrid seismic zone (NMSZ) earthquakes, which demonstrate the importance of 3D geologic structure and rupture directivity on the ground‐motion response throughout a broad region of the central United States (CUS) for these events. Our simulation set consists of 20 hypothetical earthquakes located along two faults associated w
Authors
L. Ramirez-Guzman, Robert Graves, Kim Olsen, Oliver S. Boyd, Chris H. Cramer, Stephen H. Hartzell, Sidao Ni, Paul G. Somerville, Robert Williams, Jinquan Zhong
The 2014 Mw6.1 South Napa Earthquake: A unilateral rupture with shallow asperity and rapid afterslip
The Mw6.1 South Napa earthquake occurred near Napa, California on August 24, 2014 (UTC), and was the largest inland earthquake in Northern California since the 1989 Mw6.9 Loma Prieta earthquake. The first report of the earthquake from the Northern California Earthquake Data Center (NCEDC) indicates a hypocentral depth of 11.0km with longitude and latitude of (122.3105°W, 38.217°N). Surface rupture
Authors
Shengji Wei, Sylvain Barbot, Robert Graves, James J. Lienkaemper, Teng Wang, Kenneth W. Hudnut, Yuning Fu, Don Helmberger
Adding fling effects to processed ground‐motion time histories
Fling is the engineering term for the effects of the permanent tectonic offset, caused by a rupturing fault in the recorded ground motions near the fault. It is expressed by a one‐sided pulse in ground velocity and a nonzero final displacement at the end of shaking. Standard processing of earthquake time histories removes some of the fling effects that may be required for engineering applications.
Authors
Ronnie Kamai, Norman A. Abrahamson, Robert Graves
CyberShake-derived ground-motion prediction models for the Los Angeles region with application to earthquake early warning
Real-time applications such as earthquake early warning (EEW) typically use empirical ground-motion prediction equations (GMPEs) along with event magnitude and source-to-site distances to estimate expected shaking levels. In this simplified approach, effects due to finite-fault geometry, directivity and site and basin response are often generalized, which may lead to a significant under- or overes
Authors
Maren Bose, Robert Graves, David Gill, Scott Callaghan, Phillip J. Maechling
Calibration of semi-stochastic procedure for simulating high-frequency ground motions
Broadband ground motion simulation procedures typically utilize physics-based modeling at low frequencies, coupled with semi-stochastic procedures at high frequencies. The high-frequency procedure considered here combines deterministic Fourier amplitude spectra (dependent on source, path, and site models) with random phase. Previous work showed that high-frequency intensity measures from this simu
Authors
Emel Seyhan, Jonathan P. Stewart, Robert Graves
Rupture complexity of the Mw 8.3 sea of okhotsk earthquake: Rapid triggering of complementary earthquakes?
We derive a finite slip model for the 2013 Mw 8.3 Sea of Okhotsk Earthquake (Z = 610 km) by inverting calibrated teleseismic P waveforms. The inversion shows that the earthquake ruptured on a 10° dipping rectangular fault zone (140 km × 50 km) and evolved into a sequence of four large sub-events (E1–E4) with an average rupture speed of 4.0 km/s. The rupture process can be divided into two main sta
Authors
Shengji Wei, Don Helmberger, Zhongwen Zhan, Robert Graves
Validation of ground-motion simulations for historical events using SDoF systems
The study presented in this paper is among the first in a series of studies toward the engineering validation of the hybrid broadband ground‐motion simulation methodology by Graves and Pitarka (2010). This paper provides a statistical comparison between seismic demands of single degree of freedom (SDoF) systems subjected to past events using simulations and actual recordings. A number of SDoF syst
Authors
C. Galasso, F. Zareian, I. Iervolino, R.W. Graves
Comparison of ground motions from hybrid simulations to nga prediction equations
We compare simulated motions for a Mw 7.8 rupture scenario on the San Andreas Fault known as the ShakeOut event, two permutations with different hypocenter locations, and a Mw 7.15 Puente Hills blind thrust scenario, to median and dispersion predictions from empirical NGA ground motion prediction equations. We find the simulated motions attenuate faster with distance than is predicted by the NGA m
Authors
L.M. Star, J.P. Stewart, R.W. Graves
The ShakeOut earthquake source and ground motion simulations
The ShakeOut Scenario is premised upon the detailed description of a hypothetical Mw 7.8 earthquake on the southern San Andreas Fault and the associated simulated ground motions. The main features of the scenario, such as its endpoints, magnitude, and gross slip distribution, were defined through expert opinion and incorporated information from many previous studies. Slip at smaller length scales,
Authors
R.W. Graves, Douglas B. Houston, K.W. Hudnut
Broadband ground-motion simulation using a hybrid approach
This paper describes refinements to the hybrid broadband ground-motion simulation methodology of Graves and Pitarka (2004), which combines a deterministic approach at low frequencies (f< 1 Hz) with a semistochastic approach at high frequencies (f> 1 Hz). In our approach, fault rupture is represented kinematically and incorporates spatial heterogeneity in slip, rupture speed, and rise time. The pre
Authors
R.W. Graves, A. Pitarka
The ShakeOut earthquake scenario: Verification of three simulation sets
This paper presents a verification of three simulations of the ShakeOut scenario, an Mw 7.8 earthquake on a portion of the San Andreas fault in southern California, conducted by three different groups at the Southern California Earthquake Center using the SCEC Community Velocity Model for this region. We conducted two simulations using the finite difference method, and one by the finite element me
Authors
J. Bielak, R.W. Graves, K.B. Olsen, R. Taborda, L. Ramirez-Guzman, S.M. Day, G.P. Ely, D. Roten, T.H. Jordan, P.J. Maechling, J. Urbanic, Y. Cui, G. Juve
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Filter Total Items: 43
Refinements to the Graves and Pitarka (2010) Broadband Ground Motion Simulation Method
This brief article describes refinements to the Graves and Pitarka (2010) broadband ground motion simulation methodology (GP2010 hereafter) that have been implemented in version 14.3 of the SCEC Broadband Platform (BBP). The updated version of our method on the current SCEC BBP is referred to as GP14.3. Our simulation technique is a hybrid approach that combines low-‐frequency and high-‐frequencAuthorsRobert Graves, Arben PitarkaGround motion-simulations of 1811-1812 New Madrid earthquakes, central United States
We performed a suite of numerical simulations based on the 1811–1812 New Madrid seismic zone (NMSZ) earthquakes, which demonstrate the importance of 3D geologic structure and rupture directivity on the ground‐motion response throughout a broad region of the central United States (CUS) for these events. Our simulation set consists of 20 hypothetical earthquakes located along two faults associated wAuthorsL. Ramirez-Guzman, Robert Graves, Kim Olsen, Oliver S. Boyd, Chris H. Cramer, Stephen H. Hartzell, Sidao Ni, Paul G. Somerville, Robert Williams, Jinquan ZhongThe 2014 Mw6.1 South Napa Earthquake: A unilateral rupture with shallow asperity and rapid afterslip
The Mw6.1 South Napa earthquake occurred near Napa, California on August 24, 2014 (UTC), and was the largest inland earthquake in Northern California since the 1989 Mw6.9 Loma Prieta earthquake. The first report of the earthquake from the Northern California Earthquake Data Center (NCEDC) indicates a hypocentral depth of 11.0km with longitude and latitude of (122.3105°W, 38.217°N). Surface ruptureAuthorsShengji Wei, Sylvain Barbot, Robert Graves, James J. Lienkaemper, Teng Wang, Kenneth W. Hudnut, Yuning Fu, Don HelmbergerAdding fling effects to processed ground‐motion time histories
Fling is the engineering term for the effects of the permanent tectonic offset, caused by a rupturing fault in the recorded ground motions near the fault. It is expressed by a one‐sided pulse in ground velocity and a nonzero final displacement at the end of shaking. Standard processing of earthquake time histories removes some of the fling effects that may be required for engineering applications.AuthorsRonnie Kamai, Norman A. Abrahamson, Robert GravesCyberShake-derived ground-motion prediction models for the Los Angeles region with application to earthquake early warning
Real-time applications such as earthquake early warning (EEW) typically use empirical ground-motion prediction equations (GMPEs) along with event magnitude and source-to-site distances to estimate expected shaking levels. In this simplified approach, effects due to finite-fault geometry, directivity and site and basin response are often generalized, which may lead to a significant under- or overesAuthorsMaren Bose, Robert Graves, David Gill, Scott Callaghan, Phillip J. MaechlingCalibration of semi-stochastic procedure for simulating high-frequency ground motions
Broadband ground motion simulation procedures typically utilize physics-based modeling at low frequencies, coupled with semi-stochastic procedures at high frequencies. The high-frequency procedure considered here combines deterministic Fourier amplitude spectra (dependent on source, path, and site models) with random phase. Previous work showed that high-frequency intensity measures from this simuAuthorsEmel Seyhan, Jonathan P. Stewart, Robert GravesRupture complexity of the Mw 8.3 sea of okhotsk earthquake: Rapid triggering of complementary earthquakes?
We derive a finite slip model for the 2013 Mw 8.3 Sea of Okhotsk Earthquake (Z = 610 km) by inverting calibrated teleseismic P waveforms. The inversion shows that the earthquake ruptured on a 10° dipping rectangular fault zone (140 km × 50 km) and evolved into a sequence of four large sub-events (E1–E4) with an average rupture speed of 4.0 km/s. The rupture process can be divided into two main staAuthorsShengji Wei, Don Helmberger, Zhongwen Zhan, Robert GravesValidation of ground-motion simulations for historical events using SDoF systems
The study presented in this paper is among the first in a series of studies toward the engineering validation of the hybrid broadband ground‐motion simulation methodology by Graves and Pitarka (2010). This paper provides a statistical comparison between seismic demands of single degree of freedom (SDoF) systems subjected to past events using simulations and actual recordings. A number of SDoF systAuthorsC. Galasso, F. Zareian, I. Iervolino, R.W. GravesComparison of ground motions from hybrid simulations to nga prediction equations
We compare simulated motions for a Mw 7.8 rupture scenario on the San Andreas Fault known as the ShakeOut event, two permutations with different hypocenter locations, and a Mw 7.15 Puente Hills blind thrust scenario, to median and dispersion predictions from empirical NGA ground motion prediction equations. We find the simulated motions attenuate faster with distance than is predicted by the NGA mAuthorsL.M. Star, J.P. Stewart, R.W. GravesThe ShakeOut earthquake source and ground motion simulations
The ShakeOut Scenario is premised upon the detailed description of a hypothetical Mw 7.8 earthquake on the southern San Andreas Fault and the associated simulated ground motions. The main features of the scenario, such as its endpoints, magnitude, and gross slip distribution, were defined through expert opinion and incorporated information from many previous studies. Slip at smaller length scales,AuthorsR.W. Graves, Douglas B. Houston, K.W. HudnutBroadband ground-motion simulation using a hybrid approach
This paper describes refinements to the hybrid broadband ground-motion simulation methodology of Graves and Pitarka (2004), which combines a deterministic approach at low frequencies (f< 1 Hz) with a semistochastic approach at high frequencies (f> 1 Hz). In our approach, fault rupture is represented kinematically and incorporates spatial heterogeneity in slip, rupture speed, and rise time. The preAuthorsR.W. Graves, A. PitarkaThe ShakeOut earthquake scenario: Verification of three simulation sets
This paper presents a verification of three simulations of the ShakeOut scenario, an Mw 7.8 earthquake on a portion of the San Andreas fault in southern California, conducted by three different groups at the Southern California Earthquake Center using the SCEC Community Velocity Model for this region. We conducted two simulations using the finite difference method, and one by the finite element meAuthorsJ. Bielak, R.W. Graves, K.B. Olsen, R. Taborda, L. Ramirez-Guzman, S.M. Day, G.P. Ely, D. Roten, T.H. Jordan, P.J. Maechling, J. Urbanic, Y. Cui, G. Juve