California Reference Geologic Fault Parameter Database

This database is the result of much planning and coordination between SCEC, CGS, and the USGS offices in Golden and Menlo Park. It is designed not as a complete archive of fault information, but rather as a set of reference parameters for use by modelers (supporting first and foremost this WGCEP, but other modelers will likely find the data useful as well). This database, which is based on the data model available at CA_RefFaultParams_v4.6.pdf, has two primary components: a Fault Section Database and a PaleoSites Database (each discussed below).

This database has been implemented in Oracle and supports electronic access (e.g., for on-the-fly access). A GUI-based application has also been developed (see Fault Database Tools) to aid in populating the database. Both the continually updated "living" version of this database, as well as any locked-down official releases (e.g., used in a published UCERF) are intended to be part of the USGS Quaternary Fault and Fold Database.

Fault-Section Database:

This is composed of the following information for each fault section:

  • section name
  • fault trace (list of lats and lons)
  • average dip estimate
  • average upper seismogenic depth estimate
  • average lower seismogenic depth estimate
  • average long-term slip-rate estimate
  • average aseismic-slip-factor estimate
  • average rake estimate

(note that "estimate" includes formal uncertainties, with virtually all conceivable types being supported)

Neighboring sections are defined to the extent that any of the parameters (except fault trace) are significantly different. Note that this sectioning is for descriptive purposes only, and does not necessarily imply rupture segmentation. Note also that this Fault-Section Database is nearly (and deliberately) identical to the information used in the NSHMP 2002 hazard model.

Versions of this are:

Fault Section Database 1

Fault Section Database 2

(see these links for addition information including related tasks)

Paleo Sites Database:

The primary purpose of this database is to provide the following at specific fault location.

Slip-Rate Estimate

Event Sequence Lists

Note that these are actually derived from more elemental information stored in the database (e.g., slip-rate might come from a fault-offset inferred for a particular time interval). Please see the data model CA_RefFaultParams_v4.6.pdf for more details

Each slip-rate estimate is associated with a specified time span, allowing more than one value to distinguish between shorter-term and longer-term estimates. No "preferred" values are specified because there is no objective way of making such designations (we can add different types of "preferred" or "best" estimates if users can define exactly what they mean). This is also not necessarily a complete archive of all previously inferred values. This slip-rate information will be useful for both deformation modeling and in assigning averages for fault sections in the Fault Section Databases. 

An event-sequence list is someone's interpretation of the previous events at the site (including date of and/or amount of slip). The database supports more than one event sequence (thus, the event-sequence list) because there may be differing opinions (an epistemic uncertainty in that there is, at most, only one correct sequence). This database is designed explicitly to support the type of analyses being conducted by Ray Weldon and Glenn Biasi. It will also, of course, support probability calculations that depend on the date or amount of slip in the last event.