Technical Information
Methods, data sources, and technical specifications used by Intensity Lab, organized by topic. Each page below is a standalone reference — start with whichever one answers your question.
Intensity Information & Examples
How instrumental intensity (MMI) is calculated from ShakeMap grids and station recordings, and the GMICE conversion from PGA/PGV to MMI.
USGS Earthquake Data & ShakeMap
Where event data comes from, the magnitude floor and coverage region, ShakeMap grid interpolation, and how notifications are triggered.
Place & Population Data
The gazetteer of 2,002 cities and communities used for automated intensity reports — source, population threshold, and coverage.
Observed Seismic Station Data
How ShakeMap's station list is used to identify instruments that recorded an event, and how real waveforms are retrieved via ObsPy.
ShakeMap vs. GMPE Comparison
The four NGA-West2 ground motion prediction equations, their required inputs, and how they're compared against observed ShakeMap intensity.
Physics Animation (Blender)
Same rigid-body scene, same earthquake, rendered at different sites — object properties, how displacement drives the scene, and GPU rendering.
Text-to-Speech Narration
How each animation's spoken narration is written, normalized for speech, and synthesized locally with Kokoro TTS.
Local Language Model
The Ollama-hosted model behind narration city enrichment and the Seismic Chat interface, plus a standardized question/answer baseline.
APIs Used & Offered
The outside services Intensity Lab depends on, and the API Intensity Lab itself offers — public, no-key endpoints and registered, API-key endpoints.
Related: the Instrumental Intensity and MMI Scale pages explain what the intensity numbers and colors mean for a general audience. Questions or feedback? Submit feedback.