diff --git a/ACCESSIBILITY.md b/ACCESSIBILITY.md
index 8d3028c..6d3f1d9 100644
--- a/ACCESSIBILITY.md
+++ b/ACCESSIBILITY.md
@@ -11,7 +11,7 @@ default.
 
 > **Scope:** every active SceneryStack TypeScript simulation in
 > [`structure/repos.json`](structure/repos.json) (`isSimulation` + `framework: SceneryStack`)
-> plus `SceneryStackTemplate`. As of 2026-07-31 that is 29 sims including ACPhasor,
+> plus `SceneryStackTemplate`. As of 2026-08-05 that is 31 sims including ACPhasor,
 > BasicCoordinatesAndSeasons, CarnotHeatEngine, HabitableZones, LightPropagation, MotionsOfTheSun,
 > Oscilloscope, Precession, SpecialRelativity, SternGerlach, and Zenith. The hardware
 > web UI `tscd48` and the Python apps are out of scope and keep their own a11y docs.
diff --git a/CONVENTIONS.md b/CONVENTIONS.md
index 0075b86..337a7c1 100644
--- a/CONVENTIONS.md
+++ b/CONVENTIONS.md
@@ -12,7 +12,7 @@ conformant by default.
 
 > **Scope:** every active SceneryStack TypeScript simulation in
 > [`structure/repos.json`](structure/repos.json) (`isSimulation` + `framework: SceneryStack`)
-> plus `SceneryStackTemplate`. As of 2026-07-31 that is 29 sims including ACPhasor,
+> plus `SceneryStackTemplate`. As of 2026-08-05 that is 31 sims including ACPhasor,
 > BasicCoordinatesAndSeasons, CarnotHeatEngine, HabitableZones, LightPropagation, MotionsOfTheSun,
 > Oscilloscope, Precession, SpecialRelativity, SternGerlach, and Zenith. The hardware
 > web UI `tscd48` and the Python apps (`pyro`, `pycd48`) are out of scope. Orchestration (`Baton`)
diff --git a/docs/assets/PlateTectonics.webp b/docs/assets/PlateTectonics.webp
new file mode 100644
index 0000000..603f080
Binary files /dev/null and b/docs/assets/PlateTectonics.webp differ
diff --git a/docs/index.html b/docs/index.html
index 58b79c1..477dd04 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -283,7 +283,7 @@ <h1>OpenPhysics</h1>
     <section>
       <div class="section-head">
         <h2>Core Simulations</h2>
-        <span class="count">16</span>
+        <span class="count">17</span>
       </div>
       <div class="grid">
         <a class="card" href="https://openphysics.github.io/ACPhasor/" style="--hue: 33;">
@@ -363,6 +363,17 @@ <h3>Oscilloscope</h3>
             <div class="tags"><span class="tag">oscilloscope</span><span class="tag">waveforms</span><span class="tag">signals</span></div>
           </div>
         </a>
+        <a class="card" href="https://openphysics.github.io/PlateTectonics/" style="--hue: 2;">
+          <div class="thumb"><img src="assets/PlateTectonics.webp" alt="Plate Tectonics simulation screenshot" loading="lazy" decoding="async" width="1154" height="753"><span class="badge">PT</span></div>
+          <div class="card-body">
+            <div class="card-head">
+              <h3>Plate Tectonics</h3>
+              <span class="card-arrow" aria-hidden="true">&rarr;</span>
+            </div>
+            <p>Interactive map of the Earth's tectonic plates drawn entirely from real data — PB2002 plate boundaries, USGS earthquakes, Holocene volcanoes and NOAA relief — plus cross-sections through a subduction zone, a spreading ridge and a transform fault, and a reconstruction clock running 50 Myr either side of the present.</p>
+            <div class="tags"><span class="tag">plate tectonics</span><span class="tag">seismology</span><span class="tag">volcanism</span></div>
+          </div>
+        </a>
         <a class="card" href="https://openphysics.github.io/Precession/" style="--hue: 331;">
           <div class="thumb"><img src="assets/Precession.webp" alt="Precession simulation screenshot" loading="lazy" decoding="async" width="1154" height="753"><span class="badge">P</span></div>
           <div class="card-body">
@@ -639,7 +650,7 @@ <h3>Variable Star Photometry</h3>
     </main>
 
     <footer>
-      <p>30 live simulations &middot; Built with <a href="https://scenerystack.org/">SceneryStack</a> &middot; GNU Affero GPL v3 &middot;
+      <p>31 live simulations &middot; Built with <a href="https://scenerystack.org/">SceneryStack</a> &middot; GNU Affero GPL v3 &middot;
       <a href="https://github.com/OpenPhysics/Baton">OpenPhysics/Baton</a></p>
     </footer>
   </div>
diff --git a/screenshots/PlateTectonics.png b/screenshots/PlateTectonics.png
new file mode 100644
index 0000000..bc4cd17
Binary files /dev/null and b/screenshots/PlateTectonics.png differ
diff --git a/structure/repos.json b/structure/repos.json
index 0c348ee..ef8fd23 100644
--- a/structure/repos.json
+++ b/structure/repos.json
@@ -551,6 +551,31 @@
       ],
       "status": "active"
     },
+    {
+      "name": "PlateTectonics",
+      "displayName": "Plate Tectonics",
+      "type": "simulation",
+      "isSimulation": true,
+      "lineage": "original",
+      "upstream": null,
+      "language": [
+        "TypeScript"
+      ],
+      "framework": "SceneryStack",
+      "description": "Interactive map of the Earth's tectonic plates drawn entirely from real data — PB2002 plate boundaries, USGS earthquakes, Holocene volcanoes and NOAA relief — plus cross-sections through a subduction zone, a spreading ridge and a transform fault, and a reconstruction clock running 50 Myr either side of the present.",
+      "deployedUrl": "https://openphysics.github.io/PlateTectonics",
+      "physicsTopics": [
+        "plate tectonics",
+        "seismology",
+        "volcanism",
+        "geophysics",
+        "plate reconstruction"
+      ],
+      "screens": [
+        "Plate Tectonics"
+      ],
+      "status": "active"
+    },
     {
       "name": "Precession",
       "displayName": "Precession",