Academic cracks riddle of sands

Portstewart Strand has held firm against the tide

An academic light has been shone on the mystery surrounding the shifting sands of Northern Ireland's north coast.

For years Portrush's popular West Strand has been gradually disappearing into the sea as the nearby Portstewart Strand has held firm against the tide.

Now a University of Ulster academic has said he has found the answer.

Dr Joni Backstrom, from Finland, said the seabed off Portrush is less stable and acts differently than the ocean floor a few miles away off Portstewart.

Using echo sounding technology Dr Backstrom was able to analyse the sedimentary movements on the respective 'shorefaces'.

Dr Derek Jackson, who supervised the PhD research project at UU's Centre for Coastal and Marine Research, explained the significance of the research.

Dr Joni Backstorm has been surveying the seabed

"The work showed for the first time that almost the entire Portrush seabed - the shoreface - was set in motion during high energy storms, whereas at Portstewart only the upper part near the beach showed significant changes," he said.

"A beach's ability to retain its position is usually reflected in what happens on the seabed area out to a depth of 35 metres, and this is seen at Portrush West Strand where the beach has shown instability over the years.

"Portstewart's beach on the other hand has been relatively stable and this corresponds with its less dynamic, gently sloping seabed."

He said the steeper angle of the Portrush West Strand shoreface also leads to offshore transport of sediment, especially during storms.

"Dunes which can act as a sand reservoir to feed the beach when required, have long since been removed through human destruction at West Strand, so this makes Portrush's beach more vulnerable to storms in the future," he added.

Dr Backstrom's research paper has now been published in a number of international marine science journals.