Relational Database for California Strong Ground Motions

We present a relational database of earthquake ground motion intensity measures and associated metadata for the state of California. NGA-West2 project spreadsheets have been adapted into a relational database format, and the data set has been expanded to include contributions from earthquakes, generally with magnitudes greater than M3.9, that have occurred since the conclusion of the data synthesis component of the NGA-West2 project in 2011. Aside from the newly added information, some site metadata fields have been updated for some ground motion stations. The relational-database is composed of multiple tables connected through a series of primary and foreign keys. We use various data types (beyond integers and floats) to increase the storage efficiency for several types of data. Currently the database includes 33,422 ground motions recorded at 2,739 stations for 478 events within or close to California. The database was designed to also accommodate the various fields included in other NGA databases, including NGA-East and NGA-Sub. This will eventually allow for certain database tables to be merged for all event types (e.g., a single site table could be created) in one central location.