Terry Tullis

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An important unsolved problem in earthquake mechanics is to determine the resistance to slip on faults in the Earth's crust during earthquakes. Knowledge of coseismic slip resistance is critical for understanding the magnitude of shear-stress reduction and hence the near-fault acceleration that can occur during earthquakes, which affects the amount of(More)
The sliding resistance of faults during earthquakes is a critical unknown in earthquake physics. The friction coefficient of rocks at slow slip rates in the laboratory ranges from 0.6 to 0.85, consistent with measurements of high stresses in Earth's crust. Here, we demonstrate that at fast, seismic slip rates, an extraordinary reduction in the friction(More)
  • Terry Tullis
  • Proceedings of the National Academy of Sciences…
  • 1996
The friction of rocks in the laboratory is a function of time, velocity of sliding, and displacement. Although the processes responsible for these dependencies are unknown, constitutive equations have been developed that do a reasonable job of describing the laboratory behavior. These constitutive laws have been used to create a model of earthquakes at(More)
We describe the goals and initial implementation of the International Solid Earth Virtual Observatory (iSERVO). This system is built using a Web Services approach to Grid computing infrastructure and is accessed via a component-based Web portal user interface. We describe our implementations of services used by this system, including Geographical(More)
Andrea Donnellan, Geoffrey Fox, John Rundle, Dennis McLeod, Terry Tullis, Lisa Grant 1) Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 2) Indiana University, 501 N. Morton, Ste. 224, Bloomington, IN 47404 3) University of California, One Shields Ave., Davis, CA 95616 4) University of Southern California, 3651 Trousdale Pkwy, Los(More)
Earthquakes have long been recognized as being the result of stick-slip frictional instabilities. Over the past few decades, laboratory studies of rock friction have elucidated many aspects of tectonic fault zone processes and earthquake phenomena. Typically, the static friction of rocks grows logarithmically with time when they are held in stationary(More)
We are developing simulation and analysis tools in order to develop a solid Earth Science framework for understanding and studying active tectonic and earthquake processes. The goal of QuakeSim and its extension, the Solid Earth Research Virtual Observatory (SERVO), is to study the physics of earthquakes using state-of-the-art modeling, data manipulation,(More)
The QuakeSim Problem Solving Environment uses a web-services approach to unify and deploy diverse remote data sources and processing services within a browser environment. Here we focus on the high-performance crustal modelling applications that will be included in this set of remote but interoperable applications. PARK is a model for unstable slip on a(More)
In order to develop a solid earth science framework for understanding and studying of active tectonic and earthquake processes, this task develops simulation and analysis tools to study the physics of earthquakes using state-of-the-art modeling, data manipulation, and pattern recognition technologies. We develop clearly defined accessible data formats and(More)
QuakeSim is problem-solving environment for understanding earthquake processes through the integration of multiscale models and data. The goal of QuakeSim is to substantially improve earthquake forecasts, which will ultimately lead to mitigation of damage from this natural hazard. Improved earthquake forecasting is dependent on measurement of surface(More)