As I write this column the number of people estimated to have died from the Boxing Day Tsunami that devastated Indian Ocean communities is 150,000.
The earth quake that generated the tsunami occurred on the anniversary of that which killed approximately 41,000 Iranians when the city of Bam was flattened in 2003.
Earthquakes have the potential to cause great destruction.
When the island volcano of Krakatoa erupted in August, 1883, giant waves hurled ashore coral blocks weighing as much as 600 tonnes.
A year ago nobody was discussing the possibility of another Krakatoa.
During 2004 the world's media were preoccupied with "human-induced climate change" the "war on terror" and "the war on Iraq" as potential sources of devastation.
The Global Coral Reef Monitoring Network identified the 1997-98 coral bleaching event as severely impacting on reefs in South Asia including Sri Lanka and the Maldives with concern that climate change and/ or another El Nino event could slow recovery.
The human death toll from the Boxing Day tsunami tragedy would have been much greater had the giant waves not first struck the coral reefs that protect beaches on these Indian Ocean Island, in this way dissipating a lot of energy.
Yet earthquakes and tsunamis are not listed by the large global environmental organisations as environmental threats.
These organisations focus exclusively on human impacts on the environment.
There are four potential sources of tsunami: earthquakes, undersea volcanoes, submarine landslides and asteroids.
NASA estimates that asteroids with a diameter of 90 metres or more can be expected to hit one of Earth's oceans once every 2,000 years.
Eastern Australia is more likely to be hit from a tsunami resulting from an earthquake along the Alpine fault which runs through New Zealand. There would be a maximum of three hours before such a tsunami hit Australia's east coast.
Unlike coral reefs that have the effect of reducing the land impact of tsunamis, bays and inlets -- for example, Sydney Harbour -- create opportunity for wave reflection and refraction potentially magnifying and focusing impacts.
Professor Ted Bryant, of the University of Wollongong and author or Tsunami: The Underrated Hazard, suggests the Australian Government should plan for tsunamis including through a public awareness campaign.
In contrast, Dr Anne Felton, an Australian and a tsunami expert based at the University of Hawaii, suggests that because of the difficulty of calculating the likelihood of a tsunami hitting the east coast of Australia it is not worth establishing an early warning system.
While the experts don't agree on whether we should plan for a tsunami, they do agree that the Australian coastline is always at risk.
ADVERTISEMENT
No comments:
Post a Comment