shadow-zone / commit
Add README
README.md | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/README.md b/README.md new file mode 100644 index 0000000..6b6257b --- /dev/null +++ b/README.md @@ -0,0 +1,46 @@ +# Seismic Shadow Zone + +An interactive browser simulation of seismic wave propagation through +Earth's interior, showing how the liquid outer core creates regions — +*shadow zones* — where earthquake waves cannot be directly detected. + +**Live demo: https://pavelsafronov.gitlab.io/shadow-zone** + +--- + +## What it shows + +When an earthquake occurs, P-waves and S-waves spread outward through +the planet. The liquid outer core refracts P-waves sharply, leaving a +~91°–110° band around the globe with no direct arrivals. S-waves cannot +travel through liquid at all, so they are absent beyond ~105°. + +The simulation lets you adjust core size and seismic velocities to see +how internal structure shapes the shadow zone. Try the presets — *Water +Core*, *Giant Core*, *Solid Earth* — to explore non-Earth-like scenarios. + +## Features + +- P/S-wave ray tracing using Bouguer's law on a parameterised Earth model +- Shadow zone detection: finds angular gaps in ray coverage, merges + nearby zones to reduce visual noise +- Velocity-based layer colouring — equal speed → equal colour +- Hover over any red arc on the surface to see the exact shadow zone range +- Collapsible description and Wikipedia reference in the sidebar + +## Tech stack + +TypeScript · Vite · Canvas 2D API — no runtime dependencies. + +## Running locally + +```bash +npm install +npm run dev +``` + +Then open http://localhost:5173/shadow-zone/ + +## Credits + +Earth icon by [Icongeek26](https://www.flaticon.com/authors/icongeek26) on Flaticon.