Continental Drift Calculator

It folds together two unit conversions at once: converting velocity from centimeters per year to kilometers per year (divide by 100,000) and converting elapsed time from millions of years to years (multiply by 1,000,000). Multiplying those two conversion factors together collapses to a net multiplier of 10, so velocity (cm/yr) times time (million years) times 10 gives drift distance directly in kilometers without needing separate conversion steps.

Both are recorded as reference points in this calculator (about 15 cm/yr versus about 2.5 cm/yr) because different mid-ocean ridges spread at genuinely different rates depending on the tectonic forces driving them and the underlying mantle dynamics at that boundary. The calculator doesn't model why the rates differ — it just lets you plug in either figure (or your own GPS-measured value) to see how a six-fold difference in velocity compounds over tens of millions of years of elapsed time.

Yes, in the model's framing — an initial separation of zero means the calculator's total separation is purely the computed drift distance, useful for modeling two landmasses that were joined together at the starting point in time you're measuring from (such as during a supercontinent breakup). Setting a nonzero initial separation instead lets you model plates that were already a known distance apart before the elapsed-time window begins.

The calculator applies a constant-velocity assumption throughout — the same plateVelocity input is used both to compute historical drift over the elapsed time and to project future drift over the projection years, added on top of the total separation already reached. This is explicitly a simplification: real plate velocities change as boundaries evolve, so the further out you project, the less reliable the constant-rate assumption becomes, even though it's a reasonable approximation over shorter geologic timescales.