Interesting fact: Roughly 90 percent of an iceberg sits below the waterline, which is why the visible part tells only a small part of the story.
The answer: An iceberg can weigh anywhere from thousands of tons to billions of tons depending on size. Since glacier ice weighs about 917 kilograms per cubic meter, even a modest iceberg can contain an enormous mass of frozen water.
Icebergs are hard to weigh because most of their volume is hidden underwater and their shapes are irregular. Scientists estimate mass using above-water measurements, sonar, satellite imagery, and buoyancy physics. That information matters for shipping safety, climate research, freshwater budgets, and understanding how polar ice loss moves through the ocean system.
