Where did the change begin?
Labs / Geography
Subduction Zone Machine
A cold oceanic plate dives beneath a continent, bending down into the mantle along an inclined slab. Change how fast the plates converge and how old & dense the slab is, then hover over the slab to read the earthquake depth. Watch the trench deepen, the quakes trace the slab, and water rising off it melt the mantle to build a chain of volcanoes.
Labs / Geography / Subduction Zone Machine
Subduction Zone Machine
A cold oceanic plate dives beneath a continent, bending down into the mantle along an inclined slab. Change how fast the plates converge and how old & dense the slab is, then hover over the slab to read the earthquake depth. Watch the trench deepen, the quakes trace the slab, and water rising off it melt the mantle to build a chain of volcanoes.
Why it matters
Why explore this?
Geography explains how places, people, and Earth systems affect one another. This model lets you change one factor and watch its effects spread across space.
Explore
Try the model
Dip 26°Trench 6.0 kmArc 222 kmQuake @cursor —
Investigate
Questions to test
Predict first, try it in the model, then use what you observe to answer.
What to try
- Make the slab old and dense (slide toward 180 Myr). Why does the dip get steeper, and what happens to the distance between the trench and the volcanoes?
- Compare the Cascadia and Marianas presets. Which one puts its volcanic arc far inland, and which crowds it near the coast?
- Hover down the line of earthquakes. How deep do they reach, and why do quakes stop happening below the bottom of the slab?
- Turn off Melt & water. If the slab released no water, would you still expect a volcanic arc to exist here?
- Crank up the convergence speed. Do earthquakes happen more often, and does a faster plate dive at a shallower or steeper angle?
Explain
Make sense of what happened
Connect the pattern to place: identify where the change begins, where its effects appear, and which process links those locations.
Check
Before you leave
What spatial pattern appeared?
Which process connects the cause and effect?
If you can answer all three using evidence from the model, you understand the main idea. If not, return to Explore and change one setting at a time.