A tetrapod is a form of wave-dissipating concrete block used to prevent erosion caused by weather and longshore drift, primarily to enforce coastal structures such as seawalls and breakwaters. Tetrapods are made of concrete, and use a tetrahedral shape to dissipate the force of incoming waves by allowing water to flow around rather than against them, and to reduce displacement by interlocking.[1] [2]
Tetrapods were originally developed in 1950 by Pierre Danel and Paul Anglès d'Auriac of Laboratoire Dauphinois d'Hydraulique (now Artelia) in Grenoble, France, who received a patent for the design.[3] The French invention was named French: tétrapode, derived from Greek Greek, Modern (1453-);: tetra- and Greek, Modern (1453-);: -pode, a reference to the tetrahedral shape. Tetrapods were first used at the thermal power station in Roches Noires in Casablanca, Morocco, to protect the sea water intake.[4] [5]
Tetrapods have become popular across the world, particularly in Japan. In 2007, it was estimated that up to 12 percent of Japan's 35000km (22,000miles) coastline was "semi-natural", defined as having been partially altered by roads or tetrapods. Their proliferation on the island of Okinawa, a popular vacation destination in Japan, has made it difficult for tourists to find unaltered beaches and shoreline, especially in the southern half of the island.[6]
