Shifting Storms To Bring Extreme Waves, Seaside Damage To Once Placid Areas

2017-07-24T17:18:31+00:00 July 24, 2017|
The June 2016 ‘superstorm’ that battered eastern Australia caused widespread damage to homes and infrastructure, including these homes in Sydney's Collaroy Beach. (Credit: University of New South Wales)

(Click to enlarge) The June 2016 ‘superstorm’ that battered eastern Australia caused widespread damage to homes and infrastructure, including these homes in Sydney’s Collaroy Beach. (Credit: University of New South Wales)

The world’s most extensive study of a major storm front striking the coast has revealed a previously unrecognised danger from climate change: as storm patterns fluctuate, waterfront areas once thought safe are likely to be hammered and damaged as never before.

(From / by Wilson Da Silva) — The study, led by engineers at University of New South Wales (UNSW) in Sydney, was published in the latest issue of Scientific Reports.

“If you have waterfront property or infrastructure that has previously been sheltered from the impacts of extreme waves, this is worrying news” said Mitchell Harley, lead author and a senior research associate at UNSW’s Water Research Laboratory (WRL). “What this study confirms, is that simply by changing direction, storms can be many times more devastating. And that’s what we’re facing in many locations as the climate continues to change.”

Ian Turner, director of WRL and a co-author, said  rise was no longer the only factor at play when preparing for the impact of climate change on waterfront areas. “Shifts in storm patterns and wave direction will also have major consequences because they distort and amplify the natural variability of coastal patterns.”

The study relied on data collected during the June 2016 ‘superstorm’ that battered eastern Australia. One of the fiercest in decades, it inundated towns, smashed buildings, swept away cars and infrastructure and triggered hundreds of evacuations across a 3,000 km swath from Queensland in the north all the way to Tasmania in the south. Three people died and there were more than 80 rescues from stranded cars.

A week before the storm hit, and for many weeks afterwards, the researchers used a fleet of drones, floating sensor buoys, aircraft fitted with LiDAR laser ranging sensors, fixed cameras on buildings and quad bikes and jet skis fitted with real-time satellite positioning across a 200 km swathe of the eastern seaboard. This produced the largest and most detailed pre- and post-storm coastline analysis ever done.

They found that 11.5 million cubic metres of sand were eroded from beaches across a 200 km stretch of Australia’s eastern seaboard in just the three days of the storm – the equivalent of filling the Melbourne Cricket Ground (capacity 100,000 people) to the brim with sand more than seven times.

This was similar to the amount of sand shifted on the US east coast by Hurricane Sandy in 2012, the largest Atlantic hurricane on record, which killed 233 people and caused US$75 billion in damage.

It is the damaging power of wave energy – and the disruption of long-established storm patterns due to climate change – that present a new danger. The June 2016 ‘superstorm’ that devastated Australia’s east coast was only moderately intense, equivalent to a 1-in-5 year event: however, it did hit from the highly unusual easterly direction.

“And that’s what’s really worrying,” said Turner. “The damage we saw from a moderately intense storm last year is a harbinger of what’s to come,” said Turner. “Climate change is not only raising the oceans and threatening foreshores but making our coastlines much more vulnerable as the direction of incoming storms change.

“We need to be prepared,” he added. “Not just for the fact that what we consider as ‘king tides’ will be the norm within decades, but that the storms that strike the coast will come from unexpected directions, damaging coastal areas and infrastructure once thought safe from storm damage.”

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