Mount St. Helens' 1980 debris avalanche was about one million Olympic-pool reference volumes.

USGS gives the debris avalanche as approximately 2.5 km³ — an estimate, not a surveyed exact figure. To make that liveable we divide it by Scaleidoscope's conventional Olympic-pool reference of 2,500 m³ (a 50 × 25 × 2 m rectangular pool). That reference is our convention for comparison, not a universal exact volume for every Olympic-size pool.

Debris avalanche volume

≈2.5 km³Source value (USGS, approximate)

In cubic metres

2,500,000,000 m³Scaleidoscope calculation

Olympic-pool reference volume

2,500 m³Scaleidoscope reference

Division

2,500,000,000 ÷ 2,500 = 1,000,000Scaleidoscope calculation

Result

about one million pool reference volumes

Approximate calculated comparison — derived from an approximate source volume and our pool reference.

USGS gives the debris avalanche as approximately 2.5 km³; the displayed result is rounded.

• Mount St. Helens debris-avalanche volume — USGS

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• Can a mountain lose height?🌋Mount St. Helens lost about 1,300 feet of height in the 1980 eruption.
• Same amount☕Our Olympic-size pool reference equals about 5.3 million Starbucks Grandes.
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• Measurement trap🏊An “Olympic-size pool” doesn’t have one universal exact volume.
• Things in things🏓About 1.3 million.