System Update Log
A plain-language summary of significant changes as we improve Intensity Lab. Minor fixes and behind-the-scenes work aren't listed here.
- There is now a page explaining how Intensity Lab uses the BBP simulation service, at Technical Information → How We Use the BBP Simulation API. It follows one earthquake through the whole exchange: what USGS supplies about the fault, how the cities and distance points are chosen, how the simulation method and crustal model are picked, what the request actually contains, how site stiffness (Vs30) is resolved, and what comes back — acceleration seismograms that are integrated twice to drive the animations. Two diagrams and no equations.
- Intensity Lab and BBP Services are now operating together. Intensity Lab reports what the shaking was at populated places and turns it into media people can watch; BBP Services runs the physics-based ground motion simulations behind those animations. Splitting them means each does one job properly: the consumer site is not carrying a simulation platform, and the simulation platform publishes its own verification evidence rather than asking you to take the animations on trust.
- Everything the site produces after an earthquake is now described in one place, with a live example of each: the population and seismic station intensity lists, the nearest site report, and the three kinds of animation.
- The site now states plainly who builds it, where every number comes from, and what it should not be relied on for, across a rewritten About page and a disclaimer covering data sources, editorial standards and corrections.
- Shaking animations can now be driven by physics-based simulated ground motion rather than motion synthesized from a peak value. This is what lets us show the shaking at a town with no seismometer in it, which is most towns.