4/17/2023 0 Comments Ripping o0ut of you smedium teeLearning how to spot a rip current can help you avoid getting caught, Carey added. "It's also really important to know how to swim and how to float before you venture ankle-deep into the ocean." Swim at a lifeguard-protected beach and talk to the lifeguard on duty about ocean conditions for the day," she said. Surviving a rip current starts before you even enter the water, Carey said. ![]() "There is a new understanding of rip current flow and behavior," Carey said. Highly detailed laser measurements of the beach environment shows how water and topography combine to trigger rips. The instrument measures the frequency of this returning signal - If the particle (and surrounding water) is moving away from the instrument, the signal will have a lower frequency and if it's moving toward the instrument, the return signal will have a higher frequency, according to NOAA. This acoustic Doppler current profiler sends out high-frequency pulses of sound that hit and bounce off particles in the water. Acoustic Doppler current profiling (similar to sonar) has revealed the inner workings of rip currents. Researchers now toss GPS-equipped drifters into the surf to precisely track rip current movements and speed. In the past decade, advances in measurement techniques have provided many new insights into how these complicated currents work. Scientists have been studying rip currents for more than 100 years. "Tides are really slow changes in water level and by themselves do not induce a rip current," she said. In the past, rip currents were sometimes called rip tides, which was a mistake, Carey said. Heavy breaking waves can trigger a sudden rip current, but rip currents are most hazardous around low tide, when water is already pulling away from the beach. "An adult standing in waist-deep water in a rip current would find it hard to stay in the same place," she said. The strong flow can sweep you off your feet, Carey said. The unsteady flow of a rip current is similar to standing in a river on land. Rip currents can speed up dramatically in a short time. (Olympic gold medalist Michael Phelps can swim the butterfly stroke at about 6.5 feet/second.) "Even an Olympic swimmer would find themselves going backward in a rip current pulse," she said. That's the same pace as a world-record Olympic freestyler, Carey said. The currents usually move at 1 to 2 feet per second (0.3 to 0.6 meters per second), but stronger ones can pull at 8 feet per second (1.6 meters/second). These strong and often very localized currents can carry unsuspecting swimmers out to sea. ![]() Some beaches may have rip currents nearly all the time, while other beaches almost never see the dangerous flows. The risk of rip currents is determined by many factors, including weather, tides, local variations in beach shape and how waves break offshore. "If there are no breaking waves, there won't be any rip currents," Carey said. Strong rip currents also often appear next to structures such as piers, jetties and groins, Carey said.īreaking waves are the key ingredients for all rip currents. When water returns to the ocean, it follows the path of least resistance, which is typically through these channels. These channels in sandbars lie just off the beach. Rip currents can also occur at spots where there's a break in a sandbar there, water is funneled out to sea. Quickly changing wave heights, which occur when a large set of swells rolls in, can trigger a rip current. There are many different types of rip currents, and they form in several ways.
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