The ocean has an expansion problem.

Welcome to the slightly suspicious water laboratory. Three puzzles. One tank.

One freshwater tank, a tap that is off, some ice and a heater. Three puzzles ask you to move the waterline using only what warming water, floating ice and ice from land actually do.

Waterline changes are deliberately exaggerated and do not express real-world quantities or a forecast. Floating sea ice has small additional salinity effects, noted in the activity.

1. Raise the line. Add no water. The tap is off. Find another way to make the water take up more room.
2. Melt the ice. Keep the line. This time, ice must melt. Can you leave the waterline where it started?
3. Two reasons to rise. Build a setup where new water enters AND the water already here expands.

Check the evidence · NOAA · Why sea level rises ↗

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Independent project by Ambar, not affiliated with NUS or NEA. Experiments are illustrations; measured numbers carry their dates and sources.