When megathrusts occur, the water above would be displaced. This cause waves to be created on the surface of the water and they can propagate over long distances. The waves also travel faster and creates larger crest when they encounter shallow waters (lecture 8, slide 13). Therefore, the tsunami wave can reach great heights when it hit the shore. Being close to the shoreline at a subduction zone can be very dangerous if a megathrust occurs.
Ved : Cloud seeding Dikes - Holland Thames barrier Sea wall A seawall is a coastal defense system, constructed where the sea (or other coastal water bodies), impact directly upon the coastal land. The purpose of a seawall is to protect areas of human habitation, conservation and leisure activities from the action of tides and waves. As a seawall is a man made structure made of cement, it will interfere with the land and water sediment exchanging. Seawalls are classified as : “A hard engineering shore based structure used to provide protection and to lessen coastal erosion.”.
Rogue Waves Description Rogue waves are surface waves over water that are unpredictable and have unnaturally large amplitude. To be classified a rogue wave, a wave must be more than twice the significant wave height, or the average of the largest third of waves in a given period of time. These waves are dangerous, even to large ships, and can even flow ashore, pulling people into the water. Research on the topic is still ongoing so there are many different proposed mechanisms for the creation of rogue waves.
Breakwaters, seawalls, and groins are types of hard stabilization. Near the shore, breakwaters protect boatsfrom big crashing waves by producing a quiet water zone. Sea walls armor the coast anddefend structures from the force of crashing waves. Groins maintain or widen beaches thatlose a great deal of
Soft Engineering Soft engineering techniques deploy the use of more natural measures utilising sustainable ecological principles to improve the resistance of coastland areas to erosion and flooding. This is achieved through utilising vegetation (mangroves) and other natural systems like dunes and beaches which absorb and eventually adapt to becoming more accommodative of the impacts felt via wave action, resulting in little or no destruction (or more stable conditions) at the land- water interface/boundary (Geography LWC, 2015). Some advantages (pros) of soft engineering coastal management practices are that they are generally less expensive as opposed to hard engineering measures; they’re more attractive since they blend in with the natural environment; and they provide more long term-sustainable solutions without disrupting natural processes and ecosystems. Its disadvantages/ cons however is that there is a lower likelihood of resistance to severe storms with the exception of some soft engineering techniques like the planting of mangroves; there is need for frequent monitoring and maintenance in some cases; it may be a time consuming process before these natural systems can effectively provide optimum resistance (for instance-the time taken for afforestation or for the growing/ replanting of mangroves) and lastly, there is a periodic
Surprisingly, there are also tsunamis are caused by landslides under the water and they are called a submarine landslide. Often, these occur by earthquakes as well. These happen under the water and can cause the biggest and most harmful of all of the tsunamis ( Springer,
Standing at the end of the Silver Beach pier, I can almost feel the tension growing and intensifying as the waves rise up and up, and then suddenly collapse and slam against the side of the pier heads. The waves rise and fall, rise and fall, but they never stop rolling. Whether they are growing larger or tumbling down, they never stop. The never ending movement of the waves reminds me of my relationship with my family. We go through obstacles like every other family.
A world class professional surfer named Rick “Frosty” Hesson, who has surfed the biggest waves on the planet once said, “If you're having a bad day, catch a wave.” Surfing can be stress relieving, fun, or even competitive. At times surfing can be very dangerous, from surf spots getting too crowded, polluted waters, or drowning. Human nature is underhanded. The tides are always changing, new sets are forming, and the undertow is contemporary.