This week we commemorate the 50th anniversary of Cyclone Tracy and the 20th anniversary of the Indian Ocean Tsunami. These catastrophes resulted in death and destruction of unimaginable scales. The trauma for both has been long-lasting and the process of recovery has changed people, the places they live and the environment forever. But both tragedies have left a positive legacy too – without them, we would not have the buildings and the early warning systems that we have now.
Cyclone Tracy was a defining moment in Australian history, destroying Darwin when it struck in the early morning of Christmas Day in 1974. For many hours communication was impossible, with national authorities having little understanding of the extent of response that was required.
The toll on people was enormous – 66 people were killed and 640 were injured. Almost all homes were flattened or severely damaged, ripped apart by winds reaching over 200 kilometres per hour. Only ten percent of homes remained habitable and Darwin’s other infrastructure was severely damaged. In today’s terms, Tracy caused over seven billion dollars in insurance losses, making it one of Australia’s most costly disasters. Of the 45,000 people residing in Darwin at the time, 35,000 were evacuated to other places around the country – this sheer volume of people movement changed the very fabric of the city.
The 2004 Indian Ocean tsunami was triggered by a very large earthquake off northern Indonesia that uplifted the sea floor, causing destructive waves that raced across the ocean, taking lives as far away as Africa. At their worst, waves tens of metres high struck the shorelines of Indonesia without warning, flooding low-lying communities for kilometres inland. Australia escaped the worst of the impacts but did record strong currents along beaches and harbours. Two people had to be rescued after a strong rip current swept them out to sea at Busselton, Western Australia. Without an early warning system to alert people, it is estimated that some 275,000 people lost their lives, including 26 Australians whilst overseas.
Following both catastrophes there was a realisation that more could and must be done to prevent similar destruction in the future.
The key learning from Tracy was that historical methods of building construction had exacerbated destruction. The cyclone was the impetus for a complete overhaul of the national building codes, improved building standards were designed with the aid of scientific research and enacted to increase the resilience of homes in cyclone-prone regions across Australia. These changes have likely contributed to improved safety as research has shown a decrease in Australian cyclone deaths since 1974.
We had not been prepared for tsunami in Australia. The lack of early warning to reduce loss of life initiated international collaboration to establish a warning system across the Indian Ocean. In Australia, the Australian Government invested in the creation of the Australian Tsunami Warning System, greatly enhancing the ability of Australians to receive tsunami warnings with time to evacuate to higher ground. Scientists also generated an improved understanding of tsunami risk and emergency services developed detailed plans to evacuate communities in case communities were ever threatened.
These catastrophes illustrate that despite such enormous loss, we can recover, prosper and adapt to reduce the impacts of future disasters. This is critical as our natural hazard risks are worsening – climate change is here. Sea levels are rising and warmer ocean temperatures will lead to more destructive cyclones. We don’t have to look too far back to see the challenges that intense and compounding cyclones can cause, with the devastation wrought by Hurricane’s Helene and Milton only weeks apart in the United States in September and October this year. By continuing to build in low-lying areas, we are increasing the risks associated with flooding, cyclones and tsunami. Ultimately, our decisions about where we build and how we live only place greater demands on government to support the recovery of communities, which means everyone pays.
There is more to do. We must stop building in high-risk areas. We must invest more in disaster mitigation to reduce risk. We must consider moving communities that suffer intolerable risks to safer places, however hard these decisions are. Of course, it is impossible to move everything that currently exists, but a national retrofitting strategy would improve the strength and resistance of homes in high-risk areas, reducing effects on people and reducing costs. Our national building codes can be expanded, as they were after Cyclone Tracy, to take into account climate change. Technology provides opportunities to improve decision making and emergency response through the use of advanced sensing, robotics and artificial intelligence.
We must not wait for future catastrophes to strike. Let us heed the learnings from Tracy 50 years ago, and the Indian Ocean tsunami 20 years ago, and act on what we know now. Research gives us many of the answers and the time for action is now. Our future safety depends on it.