NGA-Subduction Database
Date: 4/24/2019
Time: 11:00 AM
Room: Pine
The NGA-Subduction database is a collection of data from magnitude 4 to 9 earthquakes from global subduction zones including Japan, Taiwan, Mexico, Central and South America, Cascadia, and Alaska. The database includes information from more than 71,000 three-component recordings, many of which are from digital accelerograms. Maximum PGA and PGV are > 2.0 g and 90 cm/sec, respectively.
NGA-Subduction uses a relational database structure, consisting of a series of metadata and data tables that communicate via primary and foreign keys. The most critical tables are those related to source, site, and recordings. Advantages of relational databases include efficiency in data entry and access, and expandability.
The source table contains moment tensor information, classifications of events as interface, intraslab, or outer rise, and finite fault parameters describing planar representations of the ruptured fault surface. Finite-fault models are adapted from literature via trimming protocols for about 80 events. Simulation procedures, enhanced from prior work, were implemented to develop rupture distances for the remaining events. Rupture distances in the database range from 14 km to > 1000 km.
The site table contains average velocity VS30 for all sites, and basin depth parameters where available (Japan, Taiwan, Pacific Northwest). A significant effort was undertaken to compile seismic velocity profiles for use in defining VS30 at station locations and elsewhere in the study regions. This data was also used to derive a series of regional models for prediction of VS30 given local geology and other morphological parameters. VS30 was assigned from data where available, and from such models otherwise. Both aleatory uncertainty in VS30 and epistemic uncertainty in the natural log mean of VS30 are provided.
The relational database outputs flatfiles used in model development. Flatfiles are specific to different intensity measures, including pseudo-spectral acceleration for alternate damping values, Fourier amplitude spectra, and significant durations.
Presenting Author: Jonathan P. Stewart
Authors
Sean K Ahdi seanahdi@gmail.com University of California, Los Angeles, Los Angeles, California, United States |
Timothy D Ancheta timothydancheta@gmail.com Risk Management Solutions, Portland, Oregon, United States |
Yousef Bozorgnia yousef.bozorgnia@ucla.edu University of California, Los Angeles, Los Angeles, California, United States |
Brian S J Chiou brian_chiou@comcast.net Caltrans, Sacramento, California, United States |
Victor Contreras vcontreras@ucla.edu University of California, Los Angeles, Los Angeles, California, United States |
Robert B Darragh bbalindavis@gmail.com Pacific Engineering and Analysis, El Cerrito, California, United States |
Tadahiro Kishida kishidapple@gmail.com Khalifa University, Abu Dabi, , United Arab Emirates |
Nicolas M Kuehn kuehn@ucla.edu University of California, Los Angeles, Los Angeles, California, United States |
Annie O Kwok annieolkwok@engineering.ucla.edu National Taiwan University, Taipei, , Taiwan (Greater China) |
Po-Shen Lin person@sinotech.org.tw Sinotech Engineering Consultants, Inc, Taipei, , Taiwan (Greater China) |
Robert R Youngs bob.youngs@amec.com AMEC E&I, Oakland, California, United States |
Jonathan P Stewart jstewart@seas.ucla.edu University of California, Los Angeles, Los Angeles, California, United States Presenting Author
Corresponding Author
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NGA-Subduction Database
Category
Earthquake Ground Motions and Structural Response in Subduction Zones: A Focus on Cascadia