Exciting news! We're transitioning to the Statewide California Earthquake Center. Our new website is under construction, but we'll continue using this website for SCEC business in the meantime. We're also archiving the Southern Center site to preserve its rich history. A new and improved platform is coming soon!

SCEC Glossary

The SCEC community uses many terms to describe their research, technologies, projects, activities and work groups. The table below is a list of commonly used terms by the SCEC collaboration. For a general glossary of earthquake related terms, see the USGS Earthquake Glossary and other resources.
Have a SCEC term you think belongs in this glossary? Email web@scec.org to share your term.


Term Definition
AC Advisory Council; an appointed external body to SCEC that provides advice on the Center’s activities with an emphasis on their broader impacts and sustainability. The AC is composed of academics, practicing professionals, and other stakeholders from academia, government, and the private sector. The AC is charged with developing an overview of SCEC operations and advising the SCEC Directors and Board of Directors on major issues that confront the Center.
ACI Advanced Cyberinfrastructure; a division at the National Science Foundation reorganized as the Office of Advanced Cyberinfrastructure (OAC; www.nsf.gov/div/index.jsp?div=OAC)
AD Associate Director (for Administration; for Communication, Education, and Outreach; for Information Technology; for Science Operations); SCEC senior staff positions at headquarters located at the University of Southern California
AEG Association of Environmental and Engineering Geologists (www.aegweb.org)
AGU American Geophysical Union; an international scientific society of over 60,000 engaged in gaining understanding about the Earth, oceans, atmosphere, space, and planets for the benefit of humanity (www.agu.org
ALCF Argonne Leadership Computing Facility, a U.S. Department of Energy (DOE) Office of Science User Facility located at Argonne National Laboratory, enables breakthroughs in science and engineering by providing supercomputing resources and expertise to the research community (www.alcf.anl.gov)
ALLCAL An earthquake simulator, developed by SCEC researcher Steven N. Ward; participating in the Earthquake Simulators Comparison Project, a SCEC Technical Activity Group activity (www.scec.org/research/eqsims)
ALOS Advanced Land Observing Satellite (www.eorc.jaxa.jp/ALOS/en/about/about_index.htm)
AMR Adaptive Mesh Refinement; method of adapting the accuracy of a solution within certain sensitive or turbulent regions of simulation, dynamically and during the time the solution is being calculated
ANL Argonne National Laboratory; a multidisciplinary science and engineering research center (www.anl.gov); home to the Argonne Leadership Computing Facility (ALCF)
ANSS Advanced National Seismic System; provides real-time data and information products for seismic events; includes a national Backbone network, the National Earthquake Information Center (NEIC), the National Strong Motion Project, and 15 regional seismic networks operated by USGS and its partners (www.usgs.gov/natural-hazards/earthquake-hazards/anss-advanced-national-s... )
AOI Area of Interest
API Application Program Interface; a set of routines, protocols, and tools for building software applications
ASCE 7-10, ASCE 7-16 Standards for minimum design loads for buildings and other structures, established and published by the American Society of Civil Engineers in 2010 and 2016 respectively
ASCE 41-17 Standards for seismic evaluation and retrofit of existing buildings, established and published by the American Society of Civil Engineers in 2017
AWP-ODC Anelastic Wave Propagation code developed SCEC researchers Kim B. Olsen, Steven M. Day, and Yifeng Cui (ODC); a highly scalable, parallel earthquake wave propagation code that generates realistic dynamic earthquake source description and detailed physics-based anelastic ground motions at frequencies pertinent to safe building design and enables petascale 3D earthquake calculations
BBP Broadband Platform; SCEC software system that can generate 0-20+ Hz seismograms for historical and scenario earthquakes in California, Eastern North America, and Japan using several alternative computational methods (www.scec.org/research/bbp)
CalOES California Governor’s Office of Emergency Services; sponsor of SCEC projects (www.caloes.ca.gov)
CCSP Central California Seismic Project; a partnership between SCEC and Pacific Gas & Electric Company to use the central coast region of California as a testbed for developing and validating new physics-based ground-motion forecasting models; with goal to assess the effectiveness of seismic wavefield modeling in reducing the epistemic uncertainties in path effects that control hazard estimates at low exceedance probabilities
CDM Crustal Deformation Modeling; an interdisciplinary focus group of the SCEC Science Planning Committee
CEA California Earthquake Authority; privately funded, publicly managed organization that sells California earthquake insurance policies through participating insurance companies (www.earthquakeauthority.com)
CEETEP Cascadia EarthScope Earthquake and Tsunami Education Program; and EarthScope program funded by the National Science Foundation (NSF) that fosters community engagement of earthquake science and preparedness, and encourages collaboration and exchange between formal and informal coastal educators (ceetep.oregonstate.edu)
CEO Communication Education and Outreach; SCEC program focused on communicating understanding to end-users and society at large as useful knowledge for reducing earthquake risk and improving community resilience (www.scec.org/ceo)
CEO PC Communication, Education, and Outreach Planning Committee
CERT Community Emergency Response Team; an organization of volunteer emergency workers who have received specific training in basic disaster response skills, and who agree to supplement existing emergency responders in the event of a major disaster
CESA California Emergency Services Association; a non-profit professional organization dedicated to the promotion of mutual support and cooperation across disciplines in preparing for natural and human caused disasters and public emergencies (cesa.net).
CESMD Center for Engineering Strong Motion Data (www.strongmotion.org/Projects/CESMD)
CFM Community Fault Model; an object-oriented, three-dimensional representation of active faults in southern California and adjacent offshore basins (www.scec.org/research/cfm)
CGM Community Geodetic Model; integrates current GPS data and spatially dense InSAR data into a comprehensive understanding of the interseismic, coseismic, postseismic, and hydrologic processes associated with the earthquake cycle along the complex fault network of the southern San Andreas system (www.scec.org/research/cgm)
cGPS continuous Global Positioning System (GPS)
CIG Computational Infrastructure for Geodynamics; community-driven organization that advances Earth science by developing and disseminating software for geophysics and related fields (geodynamics.org)
CIRES Cooperative Institute for Research in Environmental Sciences; conducts innovative research that advances our understanding of the global, regional, and local environments and the human relationship with those environments, for the benefit of society (cires.colorado.edu)
CISE Computer and Information for Science and Engineering; Directorate of the National Science Foundation
CISM Collaboratory for Interseismic Simulation and Modeling (www.scec.org/research/cism); a SCEC project to provide an environment for developing large-scale numerical models that can simulate sequences of fault ruptures and the seismic shaking they produce, and potentially be calibrated against existing data and tested against observations within the Collaboratory for the Study of Earthquake Predictability (CSEP)
CISN California Integrated Seismic Network; seeks to mitigate the impact of future earthquakes by collecting, processing, and disseminating critical earthquake information in a timely way (www.cisn.org)
CME Community Modeling Environment; a SCEC project initiated in 2001 as an NSF Information Technology Research (ITR) award to apply advanced computer science technology to develop improved seismic hazard analysis (www.scec.org/research/cme)
CRM Community Rheology Model; a rheological description of the southern California lithosphere, based on an ongoing synthesis of geophysical and geological data.  It comprises three main ingredients: a community thermal model (CTM), a 3D geologic framework (GF), and constitutive relationships applicable to low- and high-strain (shear zone) settings (www.scec.org/research/crm)
CSEP Collaboratory for the Study of Earthquake Predictability; SCEC project that supports an international effort to conduct and rigorously evaluate earthquake forecasting experiments. This unique facility accelerates progress in prediction research by functioning as a new type of environment for earthquake prediction experiments: a virtual, distributed laboratory (collaboratory) with a cyberinfrastructure adequate to support a global program of research on earthquake predictability. CSEP testing centers are now operational in California, New Zealand, Japan, China, and Europe (www.scec.org/research/csep)
CSM Community Stress Model; provides the SCEC community with a suite of models and constraints on the stress and stressing rate in the southern California lithosphere (www.scec.org/research/csm)
CSTA California Science Teachers Association; a non-profit membership organization that represents science educators throughout the state of California—in every science discipline at every grade level, Kindergarten through University (cascience.org)
CTM Community Thermal Model; provides average 1D steady-state geotherms from the surface to 100 km for 13 distinct heat flow regions (www.scec.org/research/ctm)
CUSEC Central U.S. Earthquake Consortium; partnership of the federal government and the eight states most affected by earthquakes in the central United States that serves as a coordinating hub for the region, performing the critical role of coordinating the multi-state efforts of the central region (cusec.org)
CVM Community Velocity Model; detailed basin velocity descriptions based on tens of thousands of direct velocity measurements that incorporate the locations and displacements of major fault zones that influence basin structure. These basin descriptions are used to develop tomographic models of crust and upper mantle velocity structure, which are subsequently iterated and improved using 3D waveform adjoint tomography (www.scec.org/research/cvm)
CVM-H Community Velocity Model-Harvard
CVM-S Community Velocity Model-SCEC
CXM SCEC Community Models (CXM) working group develops, refines and integrates community models describing a wide range of features of the southern California lithosphere and asthenosphere. The ultimate long-term goal of the CXM working group is to provide an internally consistent suite of models that can be used together to simulate seismic phenomena in southern California. (www.scec.org/research/cxm)
CyberShake Simulation-based probabilistic seismic hazard model by the Southern California Earthquake Center (www.scec.org/research/cybershake)
DAS Distributed Acoustic Sensing; technique which utilizes coherent optical time-domain reflectometry to measure the phase and amplitude of vibrations along an optical fiber. DAS enables seismic measurements at a combination of high frequency (kHz range), large distances (tens of km), and fine spatial sampling (as small as 1 m), a combination unavailable with conventional sensors at moderate costs.
DMP Data Management Plan; a written document that describes the data expected to be acquired or generated during the course of a research project, how that data will be managed, described, analyzed, and stored, and what mechanisms will be used at the end of the project to share and preserve the data
DOE Department of Energy; U.S. federal agency and sponsor of SCEC projects
DOI Digital Object Identifier; a serial code used to uniquely identify content of various types on electronic networks
EAR Division of Earth Science, National Science Foundation; primary sponsor for the SCEC base program since 1991
EarthScope Program of the National Science Foundation (NSF) from 2003-2018 that deployed thousands of seismic, GPS, and other geophysical instruments to study the structure and evolution of the North American continent and the processes that cause earthquakes and volcanic eruptions (www.earthscope.org)
ECA Earthquake Country Alliance; public-private-grassroots partnership of people, organizations, and regional alliances that work together to improve earthquake and tsunami preparedness, mitigation and resiliency (www.earthquakecountry.org)
ECR Early Career Researcher; SCEC defines early career researcher as students and scholars who are within 10 years of their most recent academic degree
ECSZ Eastern California Shear Zone; an important component of the Pacific-North America plate boundary, active region of deformation that is predominantly strike-slip, and includes area east of the San Andreas fault that extends from the southern Mojave Desert, along the east side of the Sierra Nevada, and into western Nevada
ED-SP Executive Science Director for Special Projects; SCEC senior staff person responsible for managing science activities of the externally funded SCEC projects and coordinating these activities with the SCEC Science Planning Committee; in 2019 the position was restructured to focus on applied science projects only and the title changed to Executive Director for Applied Science
EDGE Extreme Scale Discontinuous Galerkin Environment; used to solve hyperbolic partial differential equations for seismic wave propagation
EEII Earthquake Engineering Implementation Interface; an interdisciplinary focus group of the SCEC Science Planning Committee
EERI Earthquake Engineering Research Institute; leading non-profit membership organization that connects those dedicated to reducing earthquake risk, including engineers, geoscientists, social scientists, architects, planners, emergency managers, academics, students, and other like-minded professionals (www.eeri.org)
EEW Earthquake Early Warning; rapid detection of earthquakes, real-time assessment of the shaking hazard, and notification of people prior to shaking; the U.S. Geological Survey and State of California have developed and implemented earthquake early warning systems, such as ShakeAlert
EFP Earthquake Forecasting and Predictability; an interdisciplinary focus group of the SCEC Science Planning Committee
EGA Earthquake Gates Area; a SCEC5 (2017-2022) initiative that evolved from the SCEC4 (2012-2016) Special Fault Study Areas (SFSAs) that were established to focus interdisciplinary research on geographically-targeted problems of fault system behavior. An “earthquake gate” describes a region of fault complexity that can halt earthquake ruptures conditional on proximal fault geometry, rupture direction, and prior earthquake history. (www.scec.org/research/ega)
ELCA Experiential Learning and Career Advancement; SCEC program that supports students and early career researchers by providing research opportunities, networking, and resources to the SCEC community in order to encourage and sustain careers in STEM fields (www.scec.org/elca)
ELM Equivalent Linear Model; approach used in earthquake engineering to estimate amplification due to seismic motion
Envisat Environmental Satellite; a large inactive Earth-observing satellite that was operated by the European Space Agency (ESA); active from 2002-2012 with 10 instruments aboard and at eight tons, was at the time the largest civilian Earth observation mission.
EPIcenter Earthquake and tsunami education and Public Information Center; network of museums, science centers, and libraries organized by SCEC and ECA to provide reliable earthquake information and programs for the public
EQ Earthquake
ERF Earthquake Rupture Forecast
ETAS Epidemic Type Aftershock Sequence
ExCom Executive Committee of the Center; began as a subcommittee of the SCEC Board of Directors and restructured during SCEC5 (2017-2022) to be the committee responsible for conducting the day-to-day business of the Center; comprised of the Center Director and Co-Director, SCEC Board of Directors Chair and Vice-Chair, SCEC Science Planning Committee Chair and Vice-Chair, and the SCEC senior staff at the University of Southern California headquarters
ExGM Extreme Ground Motion; very large amplitudes of earthquake ground motions that can arise at very low probabilities of exceedance; a SCEC project funded by the U.S. Department of Energy to seek the physical limits on the amplitude of strong ground motion in rock, specifically at the Yucca Mountain Nuclear Waste Repository
F3DT Full 3-Dimensional waveform Tomography; a computationally intensive methodology for imaging 3D Earth structure through the iterated assimilation of waveform data into 3D models of seismic wave propagation; SCEC relies on F3DT as the means to develop the 3D models of crustal structure needed for ground-motion prediction and seismic source recovery
FARM Fault and Rupture Mechanics; an interdisciplinary focus group of the SCEC Science Planning Committee
FEMA Federal Emergency Management Agency; U.S. federal agency and sponsor of SCEC projects
FGF Fragile Geologic Features; naturally occurring geological features that could be easily toppled by strong earthquake shaking that provide several forms of information valuable for understanding seismic hazard; see precariously balanced rock (PBR) for a specific subset of fragile geologic features
FLASH Federal Alliance for Safe Homes; non-profit consumer advocate for strengthening homes and safeguarding families from natural and manmade disasters (www.flash.org)
GEER Geotechnical Extreme Events Reconnaissance; association that coordinates National Science Foundation (NSF) sponsored reconnaissance efforts of geotechnically important extreme events (www.geerassociation.org)
GEM Global Earthquake Model; a non-profit, public-private partnership that focuses on developing scientific and high-quality resources for transparent assessment of earthquake risk and to facilitate their application for risk management around the globe (www.globalquakemodel.org)
GeoPRISMS Geodynamic Processes at Rifting and Subducting Margins (formerly MARGINS program); decadal program funded by the National Science Foundation (NSF) that studies the origin and evolution of continental margins (geoprisms.org)
GF Geologic Framework; a model that describes the lithologic variation across southern California at a scale appropriate for physics-based simulation of the fault system, used to inform the physical conditions for earthquake rupture, increase understanding of the depth extent of shear zones, and constrain post-seismic deformation and stress transfer; integrating the Geologic Framework with the SCEC’s Unified Structural Representation (USR) is an important step toward model delivery, refinement and testing with seismic velocity information, and integration with other components to complete the Community Rheology Model (CRM).
GM Ground Motions; also an interdisciplinary focus group of the SCEC Science Planning Committee
GMC GeoHazards Messaging Collaboratory; working group of communications professionals from the U.S. Geological Survey (USGS), National Oceanic and Atmospheric Administration (NOAA), Incorporated Research Institutions for Seismology (IRIS), University NAVSTAR Consortium (UNAVCO), and Southern California Earthquake Center (SCEC)
GMP Ground Motion Prediction; an interdisciplinary focus group of the SCEC Science Planning Committee
GMPE Ground Motion Prediction Equation; or “attenuation” relationships used to estimate ground motions for use in both deterministic and probabilistic seismic hazard analyses; provides a means of predicting the level of ground shaking and its associated uncertainty at any given site or location, based on an earthquake magnitude, source-to-site distance, local soil conditions, fault mechanism, etc.
GMSV Ground Motion Simulation Validation; a SCEC Technical Activity Group
GPS Global Positioning System; space-based navigation system that provides location and time information in all weather conditions, anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites
GPU Graphics Processing Unit, used together with CPU to accelerate scientific, analytics, engineering, consumer, and enterprise applications that are floating point compute-intensive applications
GTL GeoTechnical Layer, representing the near-surface (~300 m thick) low-velocity zone of unlithified sediments and weathered crystalline rocks, geologically mapped and calibrated by local measurements
Hercules Deterministic wave propagation computational codes developed by SCEC researchers; a finite-element parallel code that relies on an octree-based mesher and solves the anelastic wave equations by approximating the spatial variability of the displacements and the time evolution with piecewise polynomial elements and central differences, respectively. Learn more at the Hercules GitHub repository.
High-F SCEC simulation activity that supports dynamic-rupture and ground-motion studies working to push earthquake simulations to higher frequencies (>1 Hz) by modeling the effects of fault roughness, near-fault plasticity, frequency-dependent attenuation, topography, small-scale near-surface heterogeneities, and near-surface nonlinearities. Learn more at the High-F GitHub repository.
HPC High-Performance Computing
HVSR Horizontal-to-Vertical Spectral Ratio
ICP-MS Inductively Coupled Plasma Mass Spectrometry
IM Intensity Measure (ground motions)
IME Improvement Method Enabler
INCITE Innovative and Novel Computational Impact on Theory and Experiment; program that awards time on Oak Ridge and Argonne Leadership Computing Facility high performance computer systems for researchers to pursue transformational advances in science and technology (https://www.doeleadershipcomputing.org/)
InSAR Interferometric Synthetic Aperture Radar; a remote sensing technique for mapping ground deformation using radar images from Earth-orbiting satellites
IRIS Incorporated Research Institutions for Seismology; a consortium of universities dedicated to the operation of science facilities for the acquisition, management, and distribution of seismological data (https://www.iris.edu/hq/)
IRIS DMC IRIS Data Management Center archives and distributes data to support seismological research community (https://ds.iris.edu/ds/nodes/dmc/)
IT Information Technology
JPC Joint Planning Committee, comprised of USGS and SCEC members who participate in the construction of the annual science collaboration plan, to ensure SCEC maintains close alignment with the USGS Earthquake Hazards Program
K14 Term used to describe sum of primary, secondary, and community (first two years of) college education
LAD Lithospheric Architecture and Dynamics; an interdisciplinary focus group of the SCEC Science Planning Committee
LASSIE Los Angeles Seismic Syncline Interferometry Experiment; cooperative experiment between industry and academia to image the deeper structure of the Los Angeles Basin with broadband seismology
LiDAR Light Detection And Ranging; remote sensing method that uses light in the form of a pulsed laser to measure ranges (variable distances) to the Earth
LOS Line of Sight
MARGINS National Science Foundation Continental Margins Program; now known as GeoPRISMS
MCE Maximum Considered Earthquake
MCER Maximum Considered Earthquake Response
MOU Memorandum of Understanding
NASA JPL National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory; federally funded research and development center managed by Caltech for robotic exploration of the solar system (www.jpl.nasa.gov)
NCSA National Center for Supercomputing Applications (www.ncsa.illinois.edu)
NEHRP National Earthquake Hazards Reduction Program; the federal government's coordinated long-term nationwide program to reduce risks to life and property in the United States that result from earthquakes (www.nehrp.gov)
NGA Next Generation Attenuation model
NHERI Natural Hazards Engineering Research Infrastructure
NHR3 Natural Hazards Risk and Resiliency Research Center; a multidisciplinary and multi-university research center with the goal of reducing the risk of natural hazards from becoming natural disasters. Research at NHR3 focuses on improving resiliency of communities and reduction of risks to infrastructures against natural hazards (www.risksciences.ucla.edu/nhr3)
NRC National Research Council or Nuclear Regulatory Commission
NSF National Science Foundation (www.nsf.gov)
NSF RAPID NSF Rapid Response Research funding mechanism, which allows NSF to receive and review proposals having a severe urgency
OEF Operational Earthquake Forecasting
OLCF Oak Ridge Leadership Computing Facility; designated user facility operated by Oak Ridge National Laboratory and the Department of Energy, operating several supercomputers, including Summit, ranked 1st on the TOP500 list of world's fastest supercomputers as of November 2019
OpenSHA Open Seismic Hazard Analysis; an object-oriented Java-based framework that can accomodate arbitrarily complex (e.g., physics based) earthquake rupture forecasts (ERFs), ground-motion models, and engineering-response models, which narrows the gap between cutting-edge geophysics and state-of-the-art hazard and risk evaluations
ORNL Oak Ridge National Laboratory; the largest U.S. Department of Energy science and energy laboratory, conducting basic and applied research to deliver transformative solutions to compelling problems in energy and security; its OLCF program provides computing and data management resources to supercomputing systems, including Titan, capable of 27 petaflops. (www.ornl.gov/)
OSL Dating of Feldspar
PBIC SCEC Portable Broadband Instrument Center; established to provide researchers in Southern California with year-round access to a "pool" of portable seismic recording equipment; also serves as a Rapid Array Mobilization Procedure (RAMP) facility in the event of significant earthquakes
PBO Plate Boundary Observatory; the geodetic component of the EarthScope project, designed to study the 3D strain field across the active boundary zone between the Pacific and North American tectonic plates in the western United States; data from PBO's integrated network of GPS stations, strainmeters and seismometers, coupled with aerial and satellite imagery, are providing important temporal constraints on plate boundary deformation and are improving our knowledge of the fundamental physics that govern deformation, faulting, and fluid transport in earth’s lithosphere (www.unavco.org/projects/past-projects/pbo/pbo.html)
PBR Precariously Balanced Rock; naturally occurring geological features that could be easily toppled by strong earthquake shaking that provide several forms of information valuable for understanding seismic hazard (www.scec.org/research/pbr)
PC SCEC Planning Committee; responsible for developing the Annual Science Plan, which describes the SCEC’s research interests and priorities, and the Annual Collaboration Plan, which details how resources will be allocated to projects; chaired by the SCEC Co-Director, assisted by a PC Vice-Chair, and comprises representatives from each of the working groups (www.scec.org/leadership)
PC-VC Planning Committee Vice-Chair
PEER Pacific Earthquake Engineering Research Center (https://peer.berkeley.edu)
PEP Public Education and Preparedness
PFDHA Probabilistic Fault Displacement Hazard Analysis
PFO Piñon Flat Observatory; operated by UCSD with partial funding from the SCEC to measure, as accurately as possible, crustal deformation in a tectonically active area and serves as a testing ground for new geophysical instrumentation; the PFO data—which provide the longest ultra-broadband records of crustal motion (from minutes to years) from any plate boundary—are used for studies of the seismic cycle in southern California and for comparison with other measurements in the immediate area, with the surrounding array of deformation measurements made with continuous GPS and borehole strainmeters by the PBO, and more broadly, with other long-base and borehole strainmeter measurements made throughout the PBO
PG&E Pacific Gas & Electric Company (pge.com)
PGA Peak Ground Acceleration
PGV Peak Ground Velocity
PI Principal Investigator
PO Program Officer of sponsoring agency
PRAC Petascale Computing Resource Allocations; NSF program that invites research groups to submit requests for allocations of resources on the Blue Waters system, deployed at the University of Illinois
PSA Pseudo-Spectral Acceleration
PSHA Probabilistic Seismic Hazard Analysis
QCN Quake Catcher Network (quakecatcher.net)
QTM Quake Template Matching, a seismicity catalog; https://scedc.caltech.edu/research-tools/QTMcatalog.html
QuakeSmart Program developed by SCEC CEO in partnership with FLASH, Safe-T-Proof, Simpson Strong-Tie, and several other partners that recognizes businesses that have demonstrated earthquake preparedness and hazard mitigation (https://www.fema.gov/quakesmart)
RAMP Rapid Array Mobilization Procedure; plan to ensure the most rapid and effective post-earthquake scientific investigations
REAKT Strategies and tools for “Real-time EArthquake risK reducTion”
RELM Regional Earthquake Likelihood Model
REU Research Experiences for Undergraduates; NSF program that supports active research participation by undergraduate students in any of the areas of research funded by the National Science Foundation
RISE Real-time Earthquake Risk Reduction for a Resilient Europe (www.rise-eu.org)
RotD50 Median rotated component, a type of ground motion response spectra
RSQSim An earthquake simulator developed by SCEC researcher James Dieterich and Keith Richards-Dinger; participating in the Earthquake Simulators Comparison Project, a SCEC Technical Activity Group activity, and the Collaboratory for Interseismic Simulation and Modeling
RCTWG Redwood Coast Tsunami Work Group https://rctwg.humboldt.edu/ Three leaders from RCTWG serve as part of the ECA Statewide Steering Committee.
SAC Seismic Analysis Code; general-purpose interactive program designed for the study of sequential signals, especially time-series data, with an emphasis placed on analysis tools used by research seismologists in the detailed study of seismic events; developed at Lawrence Livermore National Laboratory, copyrighted by the University of California, and currently developed and maintained by IRIS
SACNAS Society for Advancing Chicanos/Hispanics & Native Americans in Science (www.sacnas.org)
SAF San Andreas Fault
SAFS San Andreas Fault System; also an interdisciplinary focus group of the SCEC Science Planning Committee that evolved from the Southern San Andreas Fault Evaluation (SoSAFE) project
SAGE/GAGE Seismological Facilities for the Advancement of Geosciences and EarthScope (SAGE) and Geodesy Advancing Geosciences and EarthScope (GAGE); NSF-supported large multi-user facilities that provide geodetic, seismic, and related geophysical instrumentation, data, and educational capabilities to a wide range of EAR-supported communities
SAVI Science Across Virtual Institutes; NSF program to facilitate collaboration among teams of NSF-supported U.S. scientists and engineers and their international partners who have complementary strengths and common interests and who wish to form virtual institutes to foster enhanced research collaboration; data sharing; networking; and technical exchanges of students, post docs, and junior faculty across borders
SCEC Southern California Earthquake Center
SCEC AM SCEC Annual Meeting (www.scec.org/meetings)
SCEC-VDO SCEC Virtual Display of Objects, developed by interns of the UseIT program (http://scecvdo.usc.edu)
SCEC2 Southern California Earthquake Center, 2nd phase (1 Feb 2002 to 31 Jan 2007)
SCEC3 Southern California Earthquake Center, 3rd phase (1 Feb 2007 to 31 Jan 2012)
SCEC4 Southern California Earthquake Center, 4th phase (1 Feb 2012 to 31 Jan 2017)
SCEC5 Southern California Earthquake Center, 5th phase (1 Feb 2017 to 31 Jan 2022)
SCEDC Southern California Earthquake Data Center (https://scedc.caltech.edu)
SCI Site-City Interaction; describes the soil-structure interaction effects that come from the dynamic interaction of multiple structures
SCIGN Southern California Integrated GPS Network
SCSN Southern California Seismic Network; the modern digital ground motion seismic network monitoring seismicity in southern California and providing real-time earthquake information products, including rapid notifications, hypocenters, magnitudes, moment tensors, and ShakeMap (www.scsn.org)
SDLM Science Data Lifecycle Model; data management model developed by the USGS as a high-level view of data—from conception through preservation and sharing—to illustrate how data management activities relate to project workflows, and to assist with understanding the expectations of proper data management; application of the model can help ensure that data products will be well-described, preserved, accessible, and fit for re-use
SDOT Stress and Deformation Over Time; an interdisciplinary focus group of the SCEC Science Planning Committee; also a science theme topic for SCEC5 (www.scec.org/research/sdot)
SDSC San Diego Supercomputer Center (https://www.sdsc.edu)
SEAOC Structural Engineers Association of California (www.seaoc.org)
SEAONC Structural Engineers Association of Northern California (www.seaonc.org)
SEAOSC Structural Engineers Association of Southern California (www.seaosc.org)
SEAS Sequence of Earthquakes and Aseismic Slip
SEED Standard for the Exchange of Earthquake Data; data format intended primarily for the archival and exchange of seismological time series data and related metadata, maintained by the International Federation of Digital Seismograph Networks
SEISM Software Environment for Integrated Seismic Modeling
SfM Structure-from-Motion; range imaging technique that estimates three-dimensional structures from two-dimensional image sequences which may be coupled with local motion signals; for example, SfM photogrammetry can be used for rapid construction of high-resolution 3D surface models for paleoseismic and structural geology studies
SFSA Special Fault Study Area
SGP San Gorgonio Pass
SGS A method of ground motion modeling, developed by researcher Seok Goo Song
SGT Strain Green Tensor, a data product calculated using wave propagation codes.  These are routinely generated in CyberShake.
ShakeOut Global earthquake drill to practrice self-protective actions and prepare communities for major earthquakes (www.ShakeOut.org)
SHRA Seismic Hazard and Risk Analysis, an interdisciplinary focus group of the SCEC Science Planning Committee
SJFZ San Jacinto Fault Zone
SoCal Southern California
SOLES Society of Latinxs/Hispanics in Earth and Space Science (https://ciresdiversity.colorado.edu/soless)
SORD Support Operator Rupture Dynamics; SORD code simulates spontaneous rupture within a 3D isotropic viscoelastic solid
SoSAFE Southern San Andreas Fault Evaluation (www.scec.org/research/sosafe)
SOURCES Supported Opportunities for Undergraduates and Researchers to Collaborate on Earthquake Science (www.scec.org/internships/sources
SRL Seismological Research Letters
SSA Seismological Society of America; an international scientific society devoted to the advancement of seismology and the understanding of earthquakes for the benefit of society
SSEs Scientific Software Elements
SSI Soil-Structure Interactions
STC Science & Technology Center
STEM Acronym referring to the academic disciplines of Science, Technology, Engineering, and Mathematics; used when addressing education policy and curriculum choices in schools to improve competitiveness in science and technology development
STP Seismic Transfer Program
SU Service Units; a measure of the amount of processing work a computer can perform in one hour
SURE Summer Undergraduate Research Experience (www.scec.org/internships/sure
SWUS SouthWest U.S. ground motion characterization project, sponsored by the western U.S. electric power companies in response to requirements of the Nuclear Regulatory Commission
TACC Texas Advanced Computing Center (https://www.tacc.utexas.edu)
TAG Technical Activity Group
UAVSAR Uninhabited Aerial Vehicle Synthetic Aperture Radar
UCERF Uniform California Earthquake Rupture Forecast; represents the best available science for authoritative estimates of the magnitude, location, and likelihood of potentially damaging earthquakes in California (www.scec.org/ucerf)
UCERF2 Uniform California Earthquake Rupture Forecast (Version 2)
UCERF3 Uniform California Earthquake Rupture Forecast (Version 3)
UCERF3-ETAS Uniform California Earthquake Rupture Forecast (Version 3) Epidemic Type Aftershock Sequence
UCERF3-TD Uniform California Earthquake Rupture Forecast (Version 3) Time-Dependent Model
UCERF3-TI Uniform California Earthquake Rupture Forecast (Version 3) Time-Independent Model
UCVM Unified Community Velocity Model (www.scec.org/research/ucvm)
UGMS Committee on the Utilization of Ground Motion Simulations (www.scec.org/research/ugms)
UNAVCO A non-profit university-governed consortium that facilitates geoscience research and education using geodesy (www.unavco.org)
USC University of Southern California, home of SCEC headquarters (www.usc.edu)
UseIT Undergraduate Studies in Earthquake Information Technology (www.scec.org/internships/useit
USGS U. S. Geological Survey (www.usgs.gov)
USGS EHP U.S. Geological Survey (USGS) Earthquake Hazards Program responsible for monitoring, reporting, and researching earthquakes and earthquake hazards
USR Unified Structural Representation; an interdisciplinary focus group of the SCEC Science Planning Committee
VSP Vital Signs of the Planet, teacher development program
WGCEP Working Group on California Earthquake Probabilities
WInSAR Western North America InSAR
XSEDE Extreme Science and Engineering Discovery Environment, an NSF-funded virtual organization consisting of cyberinfrastructure providers
ZHS Zumberge Hall of Science; building on the University of Southern California that houses SCEC headquarters