wave height · International waters
Southern Ocean, south of Tasmania
Annual peak significant wave height
Modelled demonstration series · not observed data
This is the roughest water on the planet and the hardest to measure, which is why the record is short and patchy in reality. The swell generated here does not stay here: it propagates thousands of kilometres north and arrives on Pacific island coastlines as the long-period surge that overtops them on a calm, sunny day.
75 years, modelled
Same reading, two normals
| Normal | Mean | σ | Pct | Return |
|---|---|---|---|---|
| 1951–1980 | 14.20 m | +1.70σ | 96th | 1 in 22 years |
| 1991–2020 | 14.65 m | +1.90σ | 97th | 1 in 35 years |
Today would rank 3 of 76 for highest value in the modelled series. Nothing about the reading changes between rows — only the yardstick.
The season here
The Southern Ocean is the only place on Earth where wind and swell can circle the globe without ever meeting land.
Where this series comes from
MODELLED SERIES — not observed. Parameters set from published Southern Ocean buoy and altimeter wave climatology. The 75 annual values are synthesised by the seeded generator. Real observational coverage in this region is sparse and short.
Every number on this page comes from a modelled series: 75 annual values synthesised by a seeded generator from published climatological parameters for Southern Ocean, south of Tasmania. It shows how anomaly reasoning works. It is not a measurement and must not be cited as one.
How to read σ
σ counts standard deviations from this place's own normal. The sigma guide · return periods.
More wave height stations
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