HR: 1340h
AN: IN43A-0325    [Abstracts]
TI: An Earthquake Source Ontology for Seismic Hazard Analysis and Ground Motion Simulation
AU: * Zechar, J D
EM: zechar@usc.edu
AF: University of Southern California, Department of Earth Sciences 3651 Trousdale Pkwy, Los Angeles, CA 90089 United States
AU: Jordan, T H
EM: tjordan@usc.edu
AF: University of Southern California, Department of Earth Sciences 3651 Trousdale Pkwy, Los Angeles, CA 90089 United States
AU: Gil, Y
EM: gil@isi.edu
AF: University of Southern California, Information Sciences Institute 4676 Admiralty Way Suite 1001, Marina del Rey, CA 90292 United States
AU: Ratnakar, V
EM: varunr@isi.edu
AF: University of Southern California, Information Sciences Institute 4676 Admiralty Way Suite 1001, Marina del Rey, CA 90292 United States
AB: Representation of the earthquake source is an important element in seismic hazard analysis and earthquake simulations. Source models span a range of conceptual complexity - from simple time-independent point sources to extended fault slip distributions. Further computational complexity arises because the seismological community has established so many source description formats and variations thereof; what this means is that conceptually equivalent source models are often expressed in different ways. Despite the resultant practical difficulties, there exists a rich semantic vocabulary for working with earthquake sources. For these reasons, we feel it is appropriate to create a semantic model of earthquake sources using an ontology, a computer science tool from the field of knowledge representation. Unlike the domain of most ontology work to date, earthquake sources can be described by a very precise mathematical framework. Another uniqueness associated with developing such an ontology is that earthquake sources are often used as computational objects. A seismologist generally wants more than to simply construct a source and have it be well-formed and properly described; additionally, the source will be used for performing calculations. Representation and manipulation of complex mathematical objects presents a challenge to the ontology development community. In order to enable simulations involving many different types of source models, we have completed preliminary development of a seismic point source ontology. The use of an ontology to represent knowledge provides machine interpretability and the ability to validate logical consistency and completeness. Our ontology, encoded using the OWL Web Ontology Language - a standard from the World Wide Web Consortium, contains the conceptual definitions and relationships necessary for source translation services. For example, specification of strike, dip, rake, and seismic moment will automatically translate into a double couple seismic moment tensor. The seismic point source ontology captures a set of domain-specific knowledge and thus it can serve as the foundation for software tools designed to manipulate seismic sources. We demonstrate this usage through software called Seismic Source Translator (SST), a Java Application Programming Interface (API) accessed via an interactive Graphical User Interface (GUI). This application provides means for constructing a point source representation and translating this source into a number of formats compatible with wave propagation modeling codes.
DE: 7212 Earthquake ground motions and engineering seismology
DE: 7223 Earthquake interaction, forecasting, and prediction (1217, 1242)
DE: 7290 Computational seismology
SC: Earth and Space Science Informatics [IN]
MN: Fall Meeting 2005