A rip current is one specific kind of water current that can be found near beaches. It is a strong, localized, and rather narrow current of water. It is strongest near the surface of the water, and it moves directly away from the shore, cutting through the lines of breaking waves. Rip currents can occur at any beach where there are breaking waves: on oceans, seas, and large lakes. Lake Michigan is no exception. The location of rip currents can be unpredictable: while some tend to reoccur always in the same place, others can appear and disappear suddenly at various locations near the beach. A rip current forms because breaking waves push water towards the land. Water that has been pushed up near the beach flows together and this water finds a place where it can flow back out to sea. The water then flows out at a right angle to the beach in a tight current called the "neck" of the rip, where the flow is most rapid. When the water in the rip current reaches outside of the lines of breaking waves, the flow loses power, and dissipates in what is known as the "head" of the rip. Sometimes tendrils of left-over current then actually curve back towards the shore. Rip currents can be hazardous to people who are in the water. Swimmers or floaters who are caught in a rip and who do not understand what is going on, may not have the necessary water skills, may panic, or may exhaust themselves by trying to swim directly against the flow of water. Because of these factors, rips are the leading cause of rescues by lifeguards at beaches, and in the US rips are responsible for an average of 46 deaths from drowning each year.
Rip currents have a characteristic appearance, and this means that with practice, and using careful observation, lifeguards, beach goers, and water users can learn to notice and identify rips, thus generally being able to avoid them. Rip currents often look almost like a road or a river running out to sea, away from the shore. Rip currents are easiest to notice and identify when the zone of breaking waves is viewed from a high vantage point. Beachgoers can also talk to lifeguards, who are always watching for rip currents, and who will move their safety flags so that swimmers can avoid rips.
Coastal Erosion is the wearing away of land and the removal of beach or dune sediments by wave action, tidal currents, wave currents, drainage or high winds. Waves, generated by storms, wind, or fast moving motor craft, cause coastal erosion, which may take the form of long-term losses of sediment and rocks, or merely the temporary redistribution of coastal sediments; erosion in one location may result in accretion nearby. The study of erosion and sediment redistribution is called 'coastal morphodynamics'. It may be caused by hydraulic action, abrasion, impact and corrosion.
It is believed that rip currents play a role in coastal erosion because they create rip “embayments” – or low areas on sandy beaches – that expose nearby land to higher rates of erosion by wave activity.
When rip currents pull sand offshore, they leave behind rip embayments, which become ‘erosional hot spots’ where the beach is much thinner, making the sea cliffs or land beyond these embayments more vulnerable to erosion caused by larger waves. Geologically, the currents are of importance, since they carry a suspended load of fine sediment out from the shore. Thus implicating erosion.
Information obtained from: http://en.wikipedia.org/wiki/Rip_current
To receive credit for this EARTHCACHE, please email the following answers to me: DO NOT POST YOUR ANSWERS IN YOUR LOG.
1. Please post a picture of yourself and your group along with your GPS at the posted coordinates. (Not required, but always appreciated!)
2. Standing at the posted coordinates, you will be able to look up and down the beach and also you will be able to see out onto Lake Michigan. Are you able to see a RIP Current at the time of your visit? If you can, estimate the length that the rip current extends out into the lake. Describe what you see.
3. What is your elevation at the posted coordinates?
Next, take a short walk to the coordinates for STAGE 2 of this Earthcache. Posted at the coordinates is a sign indicating the RIP CURRENT risk level.
4. Describe what you see at this stage. Based on what is posted at the time of your visit, decribe what this means.
5. Standing at Stage 2 posted coordinates, note some of the actions being taken to protect further erosion in this area.