November 27, 2013
Rip Currents Are Australia’s Deadliest Natural Hazard
Lee Rannals for redOrbit.com - Your Universe Online
Researchers from the University of New South Wales found that rip currents actually claim more lives in Australia than any other natural hazards.
The team wrote in the journal Natural Hazards and Earth Science Systems how rip currents cause more deaths than bushfires, floods, cyclones and sharks combined. They found rip currents cause an average of 21 confirmed human fatalities per year, compared with 5.9 for bushfires, 4.3 for floods, 7.5 for cyclones and 1 for sharks.
"Rips account for greater overall loss of human life than other high profile natural hazards. Yet they do not get anywhere near as much attention and dedicated funding," said Dr Rob Brander, a coastal geomorphologist at UNSW and lead author of the study.
Australia has about 11,000 mainland beaches and about 17,500 rip currents operating at any given time. These currents are strong, narrow seaward-flowing currents that can carry unsuspecting swimmers significant distances offshore, which can lead to exhaustion, panic and drowning.
Data from Australia's National Coronial Information System shows there were an average of 21 confirmed deaths involving rips per year during the period 2004 to 2011.
"And this is likely to be an underestimate because there has to be a witness to an event who saw the person was caught in a rip, and then this information has to be included in the coronial report," said Dr Brander, a co-author on the study which was led by researchers from Surf Life Saving Australia.
Brander and colleagues used information from the Australian Emergency Management Institute National Disaster Database to help identify the average number of deaths per year caused by tropical cyclones, bushfires and floods since the mid-to-late 1800s.
They also analyzed data from the Australia Shark Attack File administered by Taronga Zoo in Sydney, which showed there has been an average of one death by shark per year since 1962.
"Other types of hazards, like bushfires, have the capacity to claim large numbers of lives in a single event. On the other hand, rip currents are almost always present and rarely result in more than one death at a time. But in the end, more people die as a result of them," said Brander. "As rip current are a global problem, it is hoped that this study can be applied in other countries to more appropriately place the rip current hazard in perspective with and context of other natural hazard types."