Marine terrace - Video Learning - WizScience.com

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• published: 04 Sep 2015
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A "marine terrace", "coastal terrace," "raised beach" or "perched coastline" is a relatively flat, horizontal or gently inclined surface of marine origin, mostly an old abrasion platform which has been lifted out of the sphere of wave activity . Thus it lies above or under the current sea level, depending on its time of formation. It is bounded by a steeper ascending slope on the landward side and a steeper descending slope on the seaward side . Due to its reasonably flat shape it is often used for anthropogenic structures like settlements and infrastructure. The platform of a marine terrace usually has a gradient between 1°- 5° depending on the former tidal range with commonly a linear to concave profile. The width is very variable, reaching up to 1000 m, and seems to differ between northern and southern hemisphere. The cliff faces, delimiting the platform, can vary in steepness depending on the relative roles of marine and subaerial processes. At the intersection of the former shore platform and the rising cliff face it commonly retains a shoreline angle or inner edge which indicates the location of the shoreline at the time of maximum sea ingression and therefore a paleo sea level. Sub-horizontal platforms usually terminate in a low tide cliff and it is believed that the occurrence of these platforms depends on tidal activity. Marine terraces can extend for several tens of kilometers parallel to the coast. Older terraces are covered by marine and/or alluvial or colluvial materials while the uppermost terrace levels usually are less well-preserved. While marine terraces in areas of relatively rapid uplift rates can often be correlated to individual interglacial periods or stages, those in areas of slower uplift rates may have a polycyclic origin with stages of returning sea levels after times of exposure to weathering. Wiz Science™ is "the" learning channel for children and all ages. SUBSCRIBE TODAY Disclaimer: This video is for your information only. The author or publisher does not guarantee the accuracy of the content presented in this video. USE AT YOUR OWN RISK. Background Music: "The Place Inside" by Silent Partner (royalty-free) from YouTube Audio Library. This video uses material/images from https://en.wikipedia.org/wiki/Marine+terrace, which is released under Creative Commons Attribution-Share-Alike License 3.0 http://creativecommons.org/licenses/by-sa/3.0/ . This video is licensed under Creative Commons Attribution-Share-Alike License 3.0 http://creativecommons.org/licenses/by-sa/3.0/ . To reuse/adapt the content in your own work, you must comply with the license terms.