🧊 Glacier Calving Dynamics

Warmer air and water soften the ice, lowering its effective tensile yield strength, which lets crevasses penetrate deeper for the same stress and triggers calving more often. Warmer water also melts the ice directly at the terminus and waterline, undercutting the front and further increasing the calving rate — both effects are modelled explicitly in this simulation.

Calved icebergs float away and eventually melt in the ocean, adding their meltwater volume to the sea. Because that ice was previously on land (or grounded), its loss contributes to global sea-level rise, unlike sea ice which is already floating and does not raise sea level when it melts. This simulation's sea-level-equivalent tally is a small illustrative number, not a literal global measurement.

Each time a wedge of ice calves away, the glacier's leading edge is physically shorter than it was, so the terminus position steps back. If the ice flowing in from upstream cannot keep pace with calving and melt losses, the average terminus position retreats over time — exactly the pattern observed at many real tidewater glaciers in a warming climate.

In this model, iceberg size scales with the ice thickness at the terminus and with how deep the triggering crevasse had grown. Thicker glaciers tend to calve larger icebergs, which is consistent with real observations that deep tidewater termini can produce spectacularly large calving events.

It captures the real mechanism — stress-driven crevasse propagation via a Nye-style criterion, temperature-dependent ice weakening and melt, and iceberg calving with terminus retreat — but with simplified, illustrative constants rather than full continuum ice-mechanics modelling. It is designed to demonstrate the correct cause-and-effect relationships, not to reproduce a specific real glacier's numbers.