BBP Services

About the BBP API

What the hosted SCEC Broadband Platform gives you, and how the metered API around it works.

What the BBP API Is

Running the SCEC Broadband Platform yourself means installing a Fortran scientific code, downloading tens of gigabytes of Green's functions per region, and finding a machine to run it on. BBP Services hosts the Broadband Platform as a metered REST API so you do not have to. The exact build a job runs — its version, the source commit it was compiled from, and the SCEC data release its Green's functions come from — is shown in the simulation builder and returned by GET /v1/catalog/versions.

Configure a scenario from a real earthquake or design a hypothetical rupture by hand, place your sites, see what the compute will cost before you commit to it, then submit the job and download the resulting simulated seismograms — no cluster, no Fortran, no Green's functions to install. The Simulation Lab follows the same sequence of questions as the Broadband Platform's own command-line program, so a seismologist who already runs BBP from a terminal can express the same run here.

Create an account → API reference →

The hosted service is being prepared for launch; running metered simulations requires an approved account. The API reference documents the interface so you can plan an integration, and the System Update Log carries availability news.

How We Check It

A simulation that looks convincing is not necessarily accurate, so each qualifying event is measured against the real earthquake: recorded accelerations are retrieved from seismic stations around the epicenter and compared with the simulation of the same event. We publish the resulting bias — period by period, not as a single average, because a simulation can pass on the mean while being well off at the period a particular structure cares about — along with the spectra and the caveats. See Verification & Validation.

A worked result: the M7.1 Ridgecrest earthquake (ci38457511), simulated against the Mojave500 velocity model from its USGS moment-tensor source, produced a mean absolute bias of 0.131 — a factor of 1.14× — against a pass band declared in advance at a factor of two (0.69).

What These Results Are Not

  • Not design values. These are research and visualization products illustrating the character of shaking, not site-specific engineering ground motions for design.
  • The rupture is derived, not observed. Fault dimensions come from magnitude scaling, and a moment tensor's two nodal planes are equally consistent with the data. Event-based scenarios use the plane a published USGS finite-fault or ShakeMap rupture model supports; without one, the first plane is an assumption, and the other would produce different waveforms.
  • Calibration range. The Graves & Pitarka method is validated for finite-fault ruptures of roughly M5.5 and above; smaller qualifying events run below that range and carry the caveat on their report.
  • A velocity model is a 1-D crustal profile, not a map. An event outside every installed region's native extent is simulated against the nearest one and the result is labeled an approximation, and nothing in the platform checks that a rupture's tectonic style matches the crustal profile it runs against.

The full list of standing limitations lives on Physics-Based Simulation (BBP).