Speaker 1: Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff,
Speaker 1: Lauren bobobum here. If you've been around beach is enough,
Speaker 1: you've probably run across the sign at some point with
Speaker 1: a warning to avoid a particular area because of a
Speaker 1: rip current. Rip currents are responsible for about one hundred
Speaker 1: and fifty deaths every year in the United States. In Florida,
Speaker 1: they kill more people on average than thunderstorms, hurricanes, and
Speaker 1: tornadoes combined, and they're the number one concern for beach lifeguards.
Speaker 1: About eighty percent of all beach rescues are related to
Speaker 1: rip currents. These scary statistics exist partially because lots of
Speaker 1: swimmers aren't familiar with how rip currents work and how
Speaker 1: to survive if you happen to get caught in one.
Speaker 1: So today let's talk about all that and how to
Speaker 1: hopefully avoid them in the first place. A rip current
Speaker 1: is a narrow but powerful current of water running erpendicular
Speaker 1: to a beach out into the ocean or lake. These
Speaker 1: currents may extend hundreds of feet or meters outward, but
Speaker 1: they're typically less than thirty feet or nine meters wide,
Speaker 1: and they can move it a pretty good clip, often
Speaker 1: five miles or eight kilometers an hour or faster, which
Speaker 1: doesn't sound that fast until you consider that it's like
Speaker 1: being dragged at a brisk jog by something that doesn't
Speaker 1: tire out. A rip currents form when water gets blocked
Speaker 1: in near a beach and then suddenly finds a way
Speaker 1: back out to the open water and rushes out. They're
Speaker 1: dangerous because they're unpredictable. This is different from ripped tides,
Speaker 1: which happen like liquid clockwork, when the tide pulls water
Speaker 1: out through an inlet or similar into the sea. They're
Speaker 1: still dangerous and can be more powerful than rip currents,
Speaker 1: but at least they're predictable. Always heed any warning signage
Speaker 1: you see at a waterfront. Rip currents are also different
Speaker 1: from undertoe. Undertow describe the water that washes back from
Speaker 1: the shore where the waves break up on the land.
Speaker 1: It flows underneath the next wave and may continue out
Speaker 1: along the seafloor into the open water. Undertow is a normal,
Speaker 1: continual feature of any body of water big enough to
Speaker 1: have waves. It's what you feel when the receding water
Speaker 1: pulls at your feet for a moment before the next
Speaker 1: wave hits, but it's only strong right at the shoreline
Speaker 1: and usually not dangerous to anyone but small kids who
Speaker 1: might get knocked over. They can wind up below the
Speaker 1: water line and struggle to get back up. Always keep
Speaker 1: an eye on kids in the water. Rip currents, by contrast,
Speaker 1: move along the surface of the water. They're so hazardous
Speaker 1: because they catch you off guard. One minute you're bobbing
Speaker 1: along peacefully in the surf, and the next you're being
Speaker 1: dragged out to sea at top speed. They occur in
Speaker 1: all kinds of weather and on a wide range of beaches.
Speaker 1: Unlike a violent, choppy water, rip currents can look calm,
Speaker 1: so you might not noticeable until you're right in the
Speaker 1: middle of it. Rip currents are anomalous occurrences, but they're
Speaker 1: borne out of ordinary, everyday waves. On a basic level,
Speaker 1: you can think of waves as traveling fluctuations in water level.
Speaker 1: Some external force off in the wind pushes on the water,
Speaker 1: creating a swell, which is passed along the surface. The
Speaker 1: energy of the wave, which may be built up by
Speaker 1: more pressure from the wind, is passed from water molecule
Speaker 1: to water molecule. The water itself doesn't actually travel much.
Speaker 1: It mostly just bobs up and down, only the energy
Speaker 1: keeps going until the swells reach the shore. In areas
Speaker 1: with a rocky shore, the wave breaks as it's deflected.
Speaker 1: On a sandy beach with a gently sloping shore, the
Speaker 1: swell pushes up hill. The climb up the beach drains
Speaker 1: the energy from the breaking waves, and the water eventually
Speaker 1: flows downhill back to the sea as undertow. Normally, undertow
Speaker 1: move with minimal force. The slight slope of the beach
Speaker 1: effectively spreads out the force over a great distance, so
Speaker 1: it's not particularly strong at any one point, and since
Speaker 1: it's weaker than the opposing force of incoming waves, the
Speaker 1: receding flow usually won't carry you out into deeper water.
Speaker 1: A rip current occurs when the receding flow becomes concentrated
Speaker 1: in a particular area. There are a number of things
Speaker 1: that can cause this, but the most common is a
Speaker 1: break in a sand bar. Sandbars are long, narrow hills
Speaker 1: of accumulated sand along the outer part of a shore.
Speaker 1: They are formed by the motion of the waves and tides.
Speaker 1: Some sandbars stay short, but some can build up pretty
Speaker 1: tall and may even peak above the water's surface. When
Speaker 1: a large sand bar forms, it can produce a sort
Speaker 1: of basin along the shoreline. Incoming waves can rise up
Speaker 1: over or move up against the sand bar with enough
Speaker 1: force to push water into the basin, but the receding water,
Speaker 1: moving the long the seafloor, has a hard time making
Speaker 1: it back over the sandbar to return to the open water.
Speaker 1: This is something like a bathtub with the drain plugged up.
Speaker 1: Just as the water in a bathtub is being pulled
Speaker 1: downward by gravity but is blocked by the drain plug,
Speaker 1: the receding wave is being coaxed to flow back off
Speaker 1: shore by the undertow and gravity, but is kept in
Speaker 1: by the sand bar. In some cases, the pressure of
Speaker 1: the water trying to recede may be strong enough to
Speaker 1: break through part of the sand bar. Other times, water
Speaker 1: will flow along parallel to the beach until it reaches
Speaker 1: a low point of the sandbar. In either case, once
Speaker 1: it finds an opening, the water that's piled up inside
Speaker 1: the basin rushes out to sea, just as the water
Speaker 1: in your bathtub rushes out when you unplug the drain.
Speaker 1: The resulting rip current pushes water from the basin through
Speaker 1: the narrow opening and spits it out on the other
Speaker 1: side of the sandbar. Because waves keep pushing more water
Speaker 1: into the basin between the sand bar and the beach,
Speaker 1: the rip current may continue for several minutes or even
Speaker 1: several hours. Some rip currents are brief occurrences, but others
Speaker 1: are long term fixtures of an area. Typically, the strongest
Speaker 1: part of a rip current is the direct line between
Speaker 1: the sand bars opening to the water's edge, but the
Speaker 1: current will also pull in surrounding water from each side
Speaker 1: of the basin. In this way, a rip current might
Speaker 1: pull you sideways parallel to the beach before it pulls
Speaker 1: you outward away from the beach. Once the receding water
Speaker 1: makes its way through the opening in the sand bar,
Speaker 1: the pressure equalizes and the current will dissipate. You can
Speaker 1: sometimes see rip currents from the beach. They disrupt incoming
Speaker 1: waves and can stir up sand or sediment from the seafloor,
Speaker 1: So keep an eye out for a narrow break in
Speaker 1: the waves or for a column of froth or differently
Speaker 1: colored water pushing off shore. If you get caught in
Speaker 1: a rip current, it's crucial that you keep your wits
Speaker 1: about you. A rip currents may knock you off your
Speaker 1: feet in shallow water, and if you thrash or get disoriented,
Speaker 1: you might end up being pulled along under the surface,
Speaker 1: but if you relax your body and float, the current
Speaker 1: should keep you near the surface. Your first instinct might
Speaker 1: be too swim against the current back to shallow water.
Speaker 1: In most cases, even if you're a strong swimmer, this
Speaker 1: will only wear you out. Rip currents can be way
Speaker 1: too strong to fight head on. Instead, swim sideways parallel
Speaker 1: to the beach and out of the current. Think of
Speaker 1: it like your wiley coyote. You want to run sideways
Speaker 1: out of the way of the boulder and not try
Speaker 1: to outrun it. If you can break sideways out of
Speaker 1: the current, you can swim back to shore more easily
Speaker 1: with help from the waves. But if it's too hard
Speaker 1: to swim parallel while you're being dragged outward by the current,
Speaker 1: just wait until it carries you past the sandbar. The
Speaker 1: water will be much calmer there and you can get
Speaker 1: clear of the rip current before heading back in. If
Speaker 1: you don't think you can swim all the way back
Speaker 1: to the beach, get past the rip current and just
Speaker 1: tread water. Call for help, signal the people on the beach,
Speaker 1: and if all us fails, concentrate on floating and let
Speaker 1: the waves help carry you in. People drown when they
Speaker 1: expend all their energy brashing or struggling to swim. To
Speaker 1: survive a rip current or any crisis in the water,
Speaker 1: you have to keep calm and conserve your energy. If
Speaker 1: you're on the beach and see someone else caught in
Speaker 1: a rip current, call for help from a lifeguard or
Speaker 1: emergency services. Don't dive in and try to swim out
Speaker 1: to the person unless you are both very sure of
Speaker 1: yourself and the situation, and you have a raft, buggy board,
Speaker 1: or life preserver with you to give to the person
Speaker 1: who's struggling. The most effective way to fight rip currents
Speaker 1: is to follow basic swimming safety. Never go in deep
Speaker 1: water alone, and if you aren't a strong swimmer, stick
Speaker 1: to the shallows. Ideally, you should only swim in areas
Speaker 1: where there's a lifeguard or other strong swimmer on the
Speaker 1: beach who can keep an eye on things. Today's episode
Speaker 1: based on the article what is a ripcurrent? On HowStuffWorks
Speaker 1: dot Com written by Tom Harris. Brain Stuff is production
Speaker 1: of iHeartRadio in partnership with how stuffworks dot Com and
Speaker 1: is produced by Tyler Klaange. For more podcasts from my
Speaker 1: heart Radio, visit the iHeartRadio app, Apple podcasts, or wherever
Speaker 1: you listen to your favorite shows.