El Nina threatens local beaches
THE oceans are rising and the storms are coming, a coastal scientist has warned as the severe erosion at Kingscliff Beach worsened yesterday.
High tides, rough seas and northerly wind has combined over the past two days to scour up to six metres of sand from the already critically-eroded section of beach stretching north 500 metres from Cudgen Creek.
Workers were racing to complete a breakwall at the Cudgen Headland Surf Life Saving Club as the sea encroached to within metres of the construction site.
Tweed Shire Council will also remove Norfolk pines which are now leaning on a dangerous angle with much of their soil washed away.
The problem has gradually worsened since first observed in November last year, and occurred without the help of a significant storm event. The council is blaming it on an ‘erosion cell'.
Dr Peter Helman, a senior research fellow at Griffith University's Centre for Coastal Management, said sea levels were rising and, at the same time, both the Inter Decadal Pacific Oscillation (DPO) and the Southern Oscillation Index (SOI) were high.
The DPO and SOI are both indicators of sea-level fluctuation and other weather patterns.
It is causing erosion not only at Kingscliff, but on all exposed areas of coast.
“What is happening at the moment is the sea level is particularly high,” Dr Helman said. “The sea level is rising on a long-term trend and it oscillates around that trend.
“The SOI has been increasing for the past six months or so, so the sea is expected to rise higher than it normally would.
“Sometimes it is higher, and it is now.”
When the SOI is in negative figures, it indicates dry, El Nino weather. But when it is positive, an El Nina usually brings storms and wet weather.
The SOI has been in positive figures since April this year and reached 20.3 in July, the highest it has been in about a decade. The Bureau of Meteorology has officially declared an El Nina event is developing.
“Unfortunately, the seas are rising and the storms are coming,” Dr Helman, of Broken Head, said.
He compared the immense energy of a major storm to that of a nuclear weapon.
“Storms provide the energy for marine erosion. If storms come during a period of higher sea levels that is when the erosion comes.”
While the problem is highly visible at Kingscliff, Dr Helman said it was by no means alone in experiencing erosion.
Areas along the coast, especially around Byron Bay, have experienced significant problems.
Dr Helman said that in the Byron Bay area there were old sand dunes well inland from the coast, formed when the ocean reached much further inland about 120,000 years ago.
“That is where the coast can go to if the sea continues to rise,” he said'