Waves patterns and rip currents in four different months during 2010, at Tairau Beach (images: NIWA)
Rip currents are a common cause of drownings at beaches, but what causes them to form and are they predictable? Karin Bryan at the University of Waikato and NIWA’s Giovanni Coco talk to Alison Ballance about findings from a ten year analysis of images taken by a remote camera overlooking Tairua Beach in the Coromandel. Among their key findings are that rips are very persistent near headlands, but are very difficult to predict in the middle of beaches, as they result from a complex interaction between waves and the underlying seafloor, which is also constantly changing shape. El Nino and La Nina weather conditions also create very different patterns of rips.