- Coastal Risk -

At some time over the next 400 years a tsunami is likely to overwhelm Sydney - approaching the coastline at 85 m/s it will release enough energy as it slows to 5m/s over land to force a 20m wave crest over obstacles higher than 100m. There is evidence of the effect of such large waves previously all around the Australian coastline ('Sydney: the coming Tsunami', Financial Review, 11-12/8/01) (see also Climatic change)