Iceberg Life Cycle Risk Barometer
From Greenland to Twillingate
An iceberg’s risk of collapse increases as it nears the end of its life.97–100% | Final Weeks of Life
The Twillingate Stage
Many icebergs viewed around Twillingate and the Isles of Notre Dame are nearing the end of a journey that began years earlier in Greenland.
- 21 days left: 97.1% complete
- 14 days left: 98.1% complete
- 7 days left: 99.0% complete
- Final day: 99.86% complete
This is often the highest-risk period.
90–97% | Late-Stage Iceberg
- Significant loss of mass
- Undercutting below the waterline
- Centre of gravity becoming less predictable
- Increased potential for rolling and collapse
50–90% | Mature Iceberg
- Continuous melting above and below water
- Shape begins changing
- Internal weaknesses slowly develop
0–50% | Young Iceberg
- Recently calved from a Greenland glacier
- Large mass and relatively stable structure
- Beginning a journey that may last years
The Math of Risk
A two-year-old iceberg with only three weeks remaining in its life cycle is already more than 97% through its entire journey.
3 weeks = ~2.9% of a two-year journey.
Even under a straight-line model, an iceberg in its final three weeks is in the last ~3% of its life. Real-world instability may increase faster than shown in this simplified model.
Icebergs are classified by shape, including tabular, dome, pinnacle, blocky, wedge, and dry dock formations. Around Twillingate, pinnacle and blocky bergs are common.
As icebergs melt, wave action, cracking, hidden cavities, grounding, refloating, and changes in buoyancy can make them unstable. They may roll, split, collapse, or founder without warning.
Most of an iceberg is underwater. The visible portion may look stable while hidden melting and structural weakening continue below the surface.
Yes. Icebergs are dynamic natural structures. Conditions can change in seconds, especially during the final weeks of their life cycle.
Observe from a safe distance, never climb on icebergs, stay away from unstable shoreline edges, and follow local closures, posted warnings, and marine safety guidance.