Tsunami too small to be noticed

Surf Lifesavers placed warning sings on every beach up and down the NSW coast yesterday, similar to those here at Woolgoolga.

Trevor Veale

The NSW coast has been affected by more than 30 tsunamis over the past 200 years, but like yesterday’s incident they are generally too small to be noticed.

The largest tsunami to have affected the NSW coast in recent times occurred in May 1960 after a 9.5 magnitude earthquake in Chile resulted in a one metre tidal fluctuation at Fort Denison in Sydney Harbour. This caused some damage to boats and coastal infrastructure.

The following quote provides some indication of the damage caused by the 1960 tsunami in Sydney.

“Freak currents tore away moored boats and upset shipping. The huge tide tore from their moorings about 30 launches and small craft and two barges at the spit: swirled the barges in among drifting launches, overturning several of them and damaging others: smashed one of the barges into the spit bridge. Set adrift 800 logs from moorings at Balmain shipping yard, which were then swept down the Parramatta River. Swept away a strip 100 yards by 60 yards from Clontarf Reserve Point Park exposing a high tension submarine cable: in one tense moment a 30ft. fishing trawler sank in Throsby Creek near Newcastle. Eight launches were ripped from their moorings in Throsby Creek and swept half a mile into Newcastle Harbour.”

Recently the State Emergency Service has worked closely with other State and Federal Government agencies in the development of a tsunami plan for NSW. This sets out the responsibilities of the SES and other agencies in warning of and managing the effects of a tsunami.

The SES is ideally placed to provide assistance along with other emergency services.

Should a tsunami occur the SES would co-ordinate the warning and evacuation of at-risk areas prior to the tsunami’s arrival.

Once a tsunami impacted the coast they would be active in such tasks as reconnaissance of areas likely to have been impacted, making temporary repairs to damaged buildings, rescuing people trapped by flooding caused by the tsunami and providing isolated communities with supplies.