Images

Understanding coastal jetties
Mouth of Columbia River, south jetty Just as bridges provide safe passage over rivers, gorges or other depressions, jetties built by the U.S. Army Corps of Engineers help ocean-going vessels move between coastal rivers and the Pacific Ocean. Simply put, jetties are rock fingers which stretch out into the ocean from the beaches, essentially extending the mouths of the rivers well into the sea. Jetties were never intended to be used for recreational purposes. Powerful waves remove or shift even the largest boulders from the jetties, while underwater currents penetrate the structure, and remove smaller rocks and sand from inside the jetty, creating unique dangers. Some dangers are apparent, such as slippery rock surfaces and strong waves overtopping the structure. Other dangers are hidden and include open crevasses, sinkholes and caverns that are caused by the ocean eroding away stones and sand just below the surface of the jetty. Learn more about coastal jetties at http://www.nwp.usace.army.mil/pa/docs/pubs/jetty.pdf

Download Image: Full Size (5.85 MB)
Tags: COAST
Photo by: Billie Johnson |  VIRIN: 110607-A-KK463-104.JPG