Tsunamis and Australia

Earlier today a major earthquake estimated to have a magnitude of 7.3 struck near the Solomon Islands. At this stage reports are that 15 people have died as a result of the quake and resulting tsunami.

With the devastating 2004 Boxing Day tsunami still very much fresh in peoples’ minds, the entire Australian Eastern seaboard was put on alert with the BOM issuing a tsunami warning for Queensland, NSW and Tasmania. There was a rise in the sea level noted in some areas but nothing dangerous. Of course, the tsunami warning was not well handled by the media and the impression was at one stage of imminent waves of destruction. The SMH noted that such a warning is:

..the first stage of a three-step system towards evacuations – should be better explained to the public to prevent panic, a scientist says.

Today’s warning was the first from the Australian Tsunami Warning System, established after the 2004 Boxing Day tsunami, the University of Queensland’s Dr Dion Weatherley says.

Dr Weatherley, a research fellow at the university’s Earth Systems Science Computational Centre, also works with Geoscience Australia, helping them to monitor earthquakes.

He said Australia’s tsunami warning system has three stages, beginning with a “tsunami warning” like that issued this morning, followed by a “tsunami alert”, then a “tsunami alarm”.


Prior to 2004, the last tsunami warning was issued in 2001. Back in early 2005, I put together a history of tsunamis and Australia when I was blogging elsewhere. Forgive me as I plagiarise myself a little.

Tsunamis can and have hit Australia. In 1868 an earthquake off the coast of South America triggered a tsunami that was noticed in Sydney and Newcastle Harbours with boats stranded as the waters receded and/or damaged as the waters came. In more recent times, a tsunami was recorded in 1977 on the Western Australian coast and another in 1994. Both tsunamis were the result of earthquakes in the Java trench off Indonesia. Fortunately in both instances the tsunamis were not destructive. If you dig deeper into the past there is evidence of mega-tsunamis on both coasts of Australian (though these may been caused by a meteorite impact in the ocean rather than earthquakes).

The two areas with the highest risk are the North West and East (especially around Sydney) Coasts of Australia (including Tasmania). The NW coast is obviously in a region that can be affected by quakes in Indonesia. The East coast not only has quakes all around the Pacific to watch out for but New Zealand as well. From what I can gather, the southern part of Australia doesn’t seem a high risk area. I’m not sure why as I am no geologist but I suspect the type of earthquakes and ocean topography aren’t conducive to tsunamis. It seems that the majority of earthquake caused tsunamis have historically occurred on the west and east coasts. Although there is evidence that the Gulf St Vincent was the site of a tsunami after a meteorite impact quite a few years ago.

Back then I noted that Geoscience Australia and the BOM were in discussions regarding a tsunami alert system. A framework is in place that does seem to be working.

It was reported that many on the beaches seem unconcerned with the tsunami warning. Given the warning level, it was probably the right thing to do. But people shouldn’t get to complacent regarding the threat of tsunamis to Australia. They may be rare but not unknown.

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Posted in Disasters, environment
8 comments on “Tsunamis and Australia
  1. Graham Bell says:

    Shaun Cronin:
    Can’t understand why [or perhaps that should be “how”?] Seeney got into a tizzy. The tsunami warning system worked – not perfectly but it did work.

    Maybe growing up with cyclones in the days before satellite imagery and other high-rech luxuries made me less fussy than I should be ……

  2. Shaun says:

    Wasn’t just Sydney. People in Cairns and Port Douglas were high tailin’ it to the hills as well.

    A better explanation of the tsunami warning system is obviously needed. And most times an alert is issued it will amount to nothing but one day it will be the real thing. The 1864 tsunami is a good example of what may happen.

    And I bet if the system wasn’t in place, the papers today would be carping about that.

  3. Brian says:

    Two bits of information.

    Beattie wasn’t happy. He said the initial warning system worked OK, he got together a critical group and then he said they didn’t know what to do because there was no further information. He wants a buoy system, which I gather might be planned, so that we have information on the actual size of the wave.

    A bloke from the Sunshine Coast rang in to say that he has set up a subscription service to warn his clients. He gets automatically notified of the warning and then sends out an SMS conveying the warning and telling them to turn on their radios and/or TVs. He charges $1 per week for the service. I’m not sure what he has to do to initiate the SMS, as that would seem to be the weakest link.

  4. Shaun says:

    Brian,

    I understand that a buoy system is part of the early warning system but not fully implemented yet. It does seem that an education program is needed at all levels.

  5. Enemy Combatant says:

    From Sean’s mega-tsunami link:

    “I hope you enjoy what you see and that the photographs will excite you as much as it did us when we visited these sites and realised what was happening.”

    This little pearler gave me pause:

    “This event produced one wave that overran the 130 m high headland flanking the south of Jervis Bay.”
    Often cliff-walked for fun as a kid and was exhilarated when the big ones came pounding in after the storms. That wall of water sure must have been something to behold. Most surfers start grunting expletives like “Filthy!” when the waves get past 2m.

    Took me back to Peter Weir’s first film, “The Last Wave” and the stories of this great southern land’s original people. Also life’s transience. How many of them were destroyed in The Big One of 1500? Astronomers inform us that we need expect no furthur such cannons in the game of cosmic billiards till circa 3000. Let’s hope our progeny are not extinct by then, and that they inhabit a minimally poisoned biosphere.

    Harnessing 130m waves might even be beyond the next millenium’s scientists but right now we sit on the dock of the bay watchin’ the tide rollin’ by, it’s energy dissipated, and not a water-wheel in sight.

  6. Enemy Combatant says:

    Sorry…. Shaun.

  7. Brian says:

    I heard a news item today saying that a better warning system was about two years away. Then they should be able to tell what size waves are going to hit where.

    I heard that 13 villages were wiped out. The initial death count was 20 but there were estimates that it could go as high as 200.

  8. Barry says:

    Im trying to find as much information on the actual recorded effects of past Tsunamis on the east coast of Tasmnania. Its apart of a wild card hypothesis for my PHd on changes in Little Swanport estuary.
    Ive gathered some info only on 1960 cilean small effect in Hobart and an analogious possible effects on Liitleswanport by looking at the simulated deepwater wave off Eden cf to east coast of Tassy. IN Eden there result was a 1.7m Bay wave.
    However, the 1868 md 1877 Chilean info I cant get at . There has been some intriging power points indicating that the effect on Hobart was greater than in 1960. But there no data to support this

    Has your searching brought anything up

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