Human influences at the coast | S-cool, the revision website I even think that its in human beings nature to be attracted to such things (quoted in Wijers-Hasegawa 2007). They provided an argument for the adoption of tetrapods: the dikes that suffered the least damage in 1953 had their back sides sheathed in concrete slabs, rather than leaving the usual packed clay, turf, or sand bags exposed, but even they were breached in 1959 because of the excessive storm surge and resulting water pressure in the backflow that scoured and cracked the slabs (Hosoi et al. Teaching children that Mr. Tetrapod is a natural denizen of the sea as well as their friend and protector like a policeman or firefighter aims to produce adults who are less prone to question tetrapods in the future. In coastal engineering parlance, their function is armoring, and tetrapods are often referred to as armor units. Tetrapods were not intended to be stand-alone structures, but such installations do exist on beaches in mainland Japan and Okinawa. In the modern period, ports and new industries associated with overseas import-export accelerated this development and further concentrated populations and commerce near coastlines. A comprehensive review on structural tsunami countermeasures [17] Links to a PDF for Shizen to tomoni and to the NSNBKs fiftieth-anniversary materials are available from its homepage at http://www.shouha.jp/. What is Tetrapod ? The Japanese know all this too well. But theirs is a passive adaptation to this built environment. Even if Japan Tetrapod Corporation had been able to lease its tetrapod molds to local construction companies, there was no locally owned, large-scale cement production in Okinawa until 1964. Labeled compensation politics, these funds appear to many as de-facto bribes in exchange for hosting U.S. bases. Rather, the molds used to make them, available from Fudo Tetra in sizes from 0.5 to 80 metric tons, are leased, and the concrete is poured onsite. Still, it is no surprise that inhabitants of Japan, geographically squeezed into settlement on coastal plains while at the same time exposed to seasonal typhoons and occasional tsunami, have operated under a bunker mentality and have enthusiastically deployed coastal armoring as a key defense against natures maritime threats. Much of Fudo Tetras 2018 Corporate Social Responsibility (CSR) Report emphasizes its partnership with nature and efforts at improving civil engineering technologies and construction techniques for the sake of natural and human environments. The weight and interlocking design of tetrapods work effectively against extreme weather conditions, dissipating the force of the water well. After various preliminary studies the outline took shape: a sort of sea monster with four tentacles which was patented under the name tetrapod., Pierre Danel, at the Fourth Conference on Coastal Engineering, Chicago, October 1953. Fudo Tetra has a branch office in Naha and features four Okinawa-based projects in its Tetrapod Pamphlet, including one on the cover (figure 2). Revolving around invasive tetrapodsabove, below, on, and in between themwe witness the interaction of many invasive species (including human), arguably forming new ecologies that neither exist naturally nor are consciously human-made, something we might identify as a formation born of naturally evolving unnatural selection. In recent years, environmental activists and local residents have demanded the curbing of the use of tetrapods and their removal from some areas. The data given indicates that the structures were installed between 1974 and 1983 using tetrapods and another type of wave block known as a dorosu (dolos), both from Fudo Tetra. On the topic of whether or not some people believe that the addition of concrete is ruining the visual beauty of the beachfront in Japan, Kato quickly notes that those people living in impacted coastal regions (about 130 million of them) are far more concerned about their safety than any picturesque viewespecially in the wake of 2011s devastation and continued threats. Its function is twofold: (1) to protect the finer material below it against severe wave action; (2) to dissipate the wave energy to reduce the wave run-up, overtopping and reflection. Tetrapod (structure) - Wikipedia Seen from the perspective of tetrapods, Okinawa is the most evolved prefecture in Japan. Originally created in France in the late 1940s, theyve found a real home in Japan thanks to their mother company, Fudo Tetra. Trapping sand to rebuild eroded shorelines or maintain current shoreline form. After my initial surprise, I took a seat on the short wall separating promenade from tetrapod pile and readied the flash on my film camera. Hesse, Stephen. They stand firm and upright year after year, from sunrise to sunrise, silent sentinels unmoved by summer's raging typhoons or winter's crash It looks like you're using an ad blocker. The middle ear was modified in early tetrapods. The other option, Soft Engineering , involves using natural defenses to protect the coastline. There do appear to be genuine efforts in the industry to work toward greener coastal engineering solutions, but public relations campaigns are already very green now. [17] In a handful of colorful pages, the leaflet captures this recent emphasis on coastal armor units working to protect and enhance the natural as much as the human world. For now, I propose we make room to think outside the traditional dichotomies of natural/artificial and native/nonnative. Upscale hotel beach resorts not already blessed with natural beaches tend to minimize use of raw concrete to capture and secure their sands if they can, relying more on using natural rocks or building more refined structures in high-visibility areas. [18] The dolos, which is shaped like an H twisted 90 degrees at the center of the crossbar, has South African origins. They are used to protect marinas, sea wall defences and waterfronts all over the globe. The elegant combination of its physics, fabrication, installation, economics, and effectiveness is seductive to engineers, contractors, policymakers, and artists alike. They werent going anywhere; the wall of tetrapods was their home. All Betonblock moulds are made of high-quality steel and feature a rust, impact and scratch-resistant powder . Placing my pinhole camera as close to the waterline as possible to capture the fishermen brought me within view of limpets, barnacles, and snails above the surface of the clear blue-green water and small fish below (figures 23 and 24). Amniotes appeared no later than about 317 . In May 1961, the same year the papers of the Japanese coastal engineers were published, Nippon Tetrapod Co., Ltd.(Nihon Tetorapoddo Kabushiki Gaisha ) was founded in Tokyo with production and sales of tetrapods, and design and installation of the construction thereof as the primary business objectives.[6] Registered as a construction business, it added a technology research center in 1969; merged with Shutoken Printing and Binding Company, in 1972, as the surviving company; established Tetra Trading Company in 1993; changed its name to Tetra Corporation in 1995; became a subsidiary of Fudo Construction Corporation in 2004; and, a month after buying Toa Civil Engineering Company in September 2006, merged with Fudo Construction (with Fudo, the surviving company, changing its name to Fudo Tetra). Ganbokens profile indicates an early fascination with tetrapods that blossomed with the introduction of the Internet and led to his August 2006 creation of the Shha Burokku Mania Site, which became the CDOI in 2009. Given the design, it is more suited to such environments as mangrove estuaries (like those in Taiwan and the southern Ryukyus) than ocean coasts. In his eyes, the Mississippi Rivers flow into the Gulf (largely polluted with fertilizers and contaminants) is destroying the ecosystems resilience at an annual clip. This photo essay seeks to make some of these circumstances and forces visible through, ironically, what the images might lead us to think about beyond their overt visual content. Nonetheless, aside from situations where their rough concrete bulk might seem especially incongruous, tetrapods exist in plain public view on miles of Okinawas coastlines, and one is never too far from a coast. #Tetrapods #Coastal erosion protection - YouTube American writer and Japanologist Alex Kerr (2000) pulls no punches in his critique of Japans Construction State. He singles out coastal concrete, especially in Okinawa, as the prime culprit for the ruination of Japans natural coastlines. Scores of groups, online chat forums, how-to YouTube videos, and obsessively detailed printed and online guides attest to the popularity of ana-zuri. [15] The introduction to tetrapod fishing gear at https://kurashi-no.jp/I0008686 is one of the more comprehensive and best organized. A natural candidate for coastal armor, given its greater frequency of damaging storms, Okinawa nonetheless lagged behind mainland Japan because of the U.S. occupation of Okinawa until 1972, during which mainland companies like Japan Tetrapod Corporation were restricted from doing direct business in Okinawa, and the Okinawa District of the U.S. Army Corps of Engineers did not invest in this type of coastal armoring. [3] A major French naval base, Mers-el-Kbir gained notoriety for the British Royal Navys attack on it July 36, 1940, to liquidate the French fleet before it fell into German hands after the fall of France the previous month. Compared to hard engineering, soft engineering approaches are less expensive, are more long-term, attractive and sustainable as they work with natural processes. Figal, Gerald. Tetrapods and other types of [concrete] armoring can cause more damage than they prevent, because they alter ocean currents and disrupt the natural cycles of erosion and deposition that form and reshape coasts, Stephen Hesse argues in a 2007 Japan Times article. There are other concerns about breakwater barriers, too, like whether or not they have the potential to slowly increase sediment deposits by washing down the coast bit-by-bit, in turn actually increasing erosion. Betonblock Tetrapod moulds The group subsequently diversified fairly quickly and occupied a diversity of habitats (saltwater, freshwater, and terrestrial) by the Early Carboniferous. The usage of tetrapods in lieu with seawalls produce better results in coastal protection as seen below: The presence of tetrapods in front of the seawall not only reduces the amount of. The answer is likely economic. In hopes of encouraging more nuanced thinking about the relationships between natural and built environments, I consider the ways local wildlife and human culture have, for better or worse, reacted and adapted to the spread of this curious concrete form. The origin of tetrapods - Understanding Evolution This example does double duty: it demonstrates that coral can naturally take to wave blocks placed in their midst and that wave blocks can serve as a substratum for the recovery of coral in places where it has weakened or died. For a demonstration of cheap and easy fishing among tetrapods with minimal gear, check out this video of two locals on the coast of Kadena Town, Okinawa, the site of the largest U.S. Air Force base in Asia at https://www.youtube.com/watch?v=GplKXLOUlmw. (What are wave-dissipating blocks? 1. [2] For starters, I almost always use analog film cameras of many varieties and formats. Given Japans geography, authors Homma Masashi and Horikawa Kiyoshi noted, human settlement has historically been concentrated among fertile coastal plains, often on reclaimed estuary land that is developed for habitation, agriculture, and fisheries utilizing the coastal areas to an utmost extent for survival as well as prosperity (Homma and Horikawa 1961, 904). After that night, I began to wonder about the capacity of tetrapods to create new, unplanned habitats, and started to seek out creatures who have adapted to living with them. Despite the fact that such construction did a better job of standing up to storms, Okinawans resisted it for private residences because of climate, cultural, and economic reasons. Moreover, 1950s Japan was still a time of getting by and making do, not one of adopting cutting-edge industrial innovations for coastal protection. Indeed, if not for the shrine and its sacred association with nirai kanai, the overseas mythical paradise of the gods, the entire area might have very well been further landfilled for commercial use or to expand the walkway to the park that lies nearby to the south. Shizen to tomoni [With nature]. ), which is full of anthropomorphized cartoon tetrapods (figure 30). A fanaticism for coastal engineering and its tetrapods is much more in otaku style. This latter phenomenon opens the way to the creation of artificial reefs, a whole other category of wave blocks and business that the NSNBK website features. Such a critique is as legitimate as it is common, and I share in the sense of loss it implies, but stopping short at the surface of the image does little to advance insights into how tetrapods have proliferated and how they have been accommodated and exploited by life around them. With promises to close the gap between development of Okinawa and that of the mainland, the Japanese government has, since reversion, provided Okinawa Prefecture support for infrastructure construction that has arguably gone beyond what is needed. [11], Of course, not all of the engineered coastline in Okinawa is armored by tetrapods, but much is. Sarah Baird is a writer and editor based in New Orleans. I had noticedeven photographedtetrapods during trips to Okinawa but had never really looked at them closely, let alone clamber among them. Because of their enormous weight and the large numbers needed for any given project, tetrapods are not factory-made and distributed. I took out a panoramic pinhole film camera and my iPhone. The beach draws more local residents than tourists, the latter coming to the area instead to visit famed Naminoue Shrine situated on the cliffs above, so grooming the beach for the tourist gaze is probably not a priority. The six sample photos, supplied by the Okinawa General Bureau that oversees development projects in Okinawa, were taken in 1997, 1999, and 2005 from between one meter above water and 5 meters below. Not all love for tetrapods is technical. Reducing wave energy impacts at or seaward of the shoreline. In their surveys of typhoon damage, Japans coastal engineers of the 1950s had brought attention to an issue that policymakers of the 1960s saw in terms of national economic development; they also, in effect, identified a market opening. Their attitude is one that feels more practical, and bleak, than anything ever expressed in the US when it comes to natural disaster prevention. Registration data and a facsimile of the Tetrapod trademark can be found at https://www.j-platpat.inpit.go.jp/web/TR/JPT_1184901/3D7C5C9BF22BF53CC2DC539667C19B34. Life with Tetrapods: The Nature of Concrete in Okinawa As in the case of Kansai International Airport (for which Fudo Tetra provided the seawall armoring), the runway is being built on an artificial island created by landfill secured with a perimeter of seawalls reinforced by tetrapods. It has supported conservation and beautification efforts by donating portions of sales of silicone bracelets to coral transplantation projects and through activities such as organizing coastal cleanups. It may look sharp, but you can actually hug it. [12] The majority of sandy public-access beaches on Okinawa Island, on the other hand, have been engineered, shaped by the effects of groins, seawalls, and jetties constructed from the shoreline. How are sea walls used to protect the coast? Journal of the Japanese Forest Society 97 (3): 143152. Various coastal management strategies are employed, each coming with a number of advantages and disadvantages. Unfortunately, the tetrapods did nothing to mitigate the slumping. The manifestations of this love are too numerous and too variedand too fascinatingto present a full survey here, but I would like to conclude by introducing this phenomenon as a next-stage evolution of tetrapod-generated ecologies, moving onto land and inhabiting the world of popular culture and consumer goods in which tetrapods have become cute and cool. Before looking at what this particular odd artifact is doing in Okinawa, lets review its origins and global spread. McCormack, Gaven. Also, it is manufactured by pouring concrete into molds. Note the connection between a safe and secure society (which in this context means physically safe and economically secure) and a preserved marine environment within a redefined ecosystem that naturalizes artificial structures. https://apjjf.org/-Stephen-Hesse/2481/article.html. Providing or enhancing important shoreline habitat. The dispersal of backflow water pressure was precisely one of the aims of Danels tetrapod design; his experiments indicated that a semi-open structure of heavy, interlocked, rough rounded forms was superior to surfaces of flat concrete slabs and square concrete blocks in dispersing wave energy while standing up to water pressure. It is an industrial product, but it is still cute. Figal, Gerald. Why did I get so excited? And when I ask about the Gulf Coasts current problem with erosion (a complex situation encompassing massive tasks likesediment management), Kato says that, unlike in Japan, the interior of the US seems to be working against the coast as much, if not more, than the ocean. When their seaside structures have faced the erosive effects of ceaseless waves and damage from periodic storms, people have acted to protect their expanding economic and territorial interests, typically by hardening harbors and coastal settlements with breakwaters and seawalls of wood, stone, concrete, and steel. The document " Coastal Dune Protection and Restoration" from Woods Hole Sea Grant and Cape Cod Cooperative Extension provides excellent details and illustrations of the process. Tetrapods have been instrumental in the protection of the coast and many tourist attractions for a number of years. Coastal areas are used for tourism, fishing, industry, trade and transport. Prices for Okinawa and Hokkaido Prefectures run about 9 percent higher than the rest of Japan, with a standard 4-ton mold costing 10,530 with tax (about US$100) for a two-month lease, not including maritime shipping costs to remote islands or ground transportation within remote islands. 2007. A close-up of the T-shaped head at this beach reveals a line of hundreds of tetrapods piled over a submerged breakwater in front of the structure to absorb and dissipate the brunt of the wave energy directed at the jetty (figure 7). These functions require a heavy, but porous armour. Sea walls usually have promenades so people can walk along them. Fudo Tetra sponsors educational events to familiarize children with tetrapods, including the opportunity to make your own miniature concrete specimens (figure 31). When the balance breaks down between the sand flowing in and out, thats when the erosion startsand the waters in the Gulf are already shallow.. Introduction: Tetrapod are organisms that have four feet. A marker for the Grave of Amamichu (a female deity credited, along with her partner, Shirumichu, with creating the first inhabitants of the Ryukyu Islands) on one of the outcroppings drew my interest, but I ended up spending far more time on the other outcropping where the lifeforms among the tetrapods stacked along the outer wall of a wide concrete extension captured my attention (figure 20). Okuyama, pictured here with a colleague from the Sendai Bay South Coast Office, proves there is a lot of literature on the topic. This summary of evidence provides indicative costs and guidance for coastal erosion and flood management activities. If concrete had a life, I think a tetrapod is the orthodox way that concrete should evolve (quoted in Hesse 2007, 9). Within the year, a plush tetrapod was manufactured and marketed as a gray felt-covered cushion called Tetogurumi. Naha: Okinawa-ken. https://cross-currents.berkeley.edu/e-journal/issue-30/figal. These structures accumulate sand transported by wave-driven longshore drift, depositing it on the updrift side of the structure, thus building up the beach on the updrift side at the expense of the loss of deposits on the downdrift side. If the absence of algae is prolonged, the coral becomes overly stressed and vulnerable to dying. Available online at http://www.shouha.jp/block1/. It might be only a matter of time until we see tetrapods featured in a travel guide to Okinawa. One of the main features of the Tetrapod is its shape, providing a better breakwater effect. Consider one of several examples from Okinawa, three breakwaters situated in Naha Port. The NSNBK, the wave-dissipating block industry association to which Fudo Tetra and fourteen other Japanese wave block companies belong, has been pushing that idea for at least a decade, although from a different angle. Revetment - Wikipedia Also is lethally dangerous to swimmers and surfers as well as shipping and recreational boaters 14 Q What is the meaning of hold the line? https://www.youtube.com/watch?v=GplKXLOUlmw, http://www.shouha.jp/case1/100/103_1/168.php, http://www.shouha.jp/case1/100/102/243.php, http://www.fudotetra.co.jp/csrreport.html, http://ganboken.blog26.fc2.com/blog-category-2.html, http://s04.megalodon.jp/2009-0429-1819-50/portal.nifty.com/2008/02/15/b/, http://gigazine.net/news/20091030_danchidanchi_dpz/, Publication Ethics & Malpractice Statement, Creative Commons Attribution-NonCommercial-NoDerivs 3.0 United States License. It stops the waves from beating down on the shore, whether during a gales of a tsunami or the daily lap of erosion. 1. A chronological examination of the proceedings of the Conference of Coastal Engineering, the flagship international gathering of field specialists, offers hints about the tetrapods foothold in Japan. Its inventor, Eric Mowbray Merrifield, did not patent the design. What are the advantages and disadvantages of coastal Defences? For some fans, its emotional and physical. Making tetrapods couldn't be easier with a Betonblock mould. Advantages - Builds up a large beach which, as well as providing protection from erosion, can attract tourists. Life with Tetrapods: The Nature of Concrete in Okinawa. Cross-Currents: East Asian History and Culture Review(e-journal) 30: 150170. As of February 2019, there were 123 entries. Unfortunately, the tetrapods did nothing to mitigate the slumping. In Japan, this technique can be found in some locations, but the severity and frequency of natural disaster means that it simply cant provide enough support to be used as a primary means of protection. In its brief historical outline of wave-dissipating blocks in Japan, the Nihon Shha Nagatame Burokku Kykai (Japan Wave-Dissipating Block Association; hereafter, the NSNBK) highlights the 1960s as the decade of their rapid spread in Japan, following the 1960 publication of government plans for coastal protection and the first of a series of seaport development plans in 1961 (Nihon Shha Nagatame Burokku Kykai 2017, 4). The advantages of Betonblock tetrapod moulds. For example: in the US, beach nourishmentwhere sand from outside locations is used to fill in eroding beacheshas long been a popular plan of attack for coastal defense schemes. The Damages of Coastal Dikes and River Levees and Their Restoration. Coastal Engineering Proceedings 1 (7): 964986. [20] See details at http://www.shouha.jp/case1/100/102/243.php. The well-prepared mainstream visitor to Okinawathe kind who pores over standard travel guides and promotional materialwill likely know about the famed hoshizuna (star sand), minuscule exoskeletons of a tiny marine organism. Danel, Pierre, and Louis Greslou. They often increase erosion in other places further down the coast. tetrapods coastal protection advantages and disadvantages Approaches, aims, advantages and disadvantages: Managed retreat Sometimes seen as the 'do nothing' approach. Unless there is a reason to specify Fudo Tetras actual product, I use lowercase tetrapod generically to refer to the original four-footed block and other types of wave-dissipating blocks. http://www.shouha.jp/50th/data/leaflet.pdf. Tetrapods represent the latest refinementor evolutionary step, if you willto this particular approach to securing coastlines for human life and exploitation. Reversion opened the floodgates to mainland businesses and brought massive construction to Okinawa, buoyed by special development funds and finance loans from Tokyo. If you look closely at tourist guides to beaches in Okinawa, however, tetrapods are sometimes visible in the background, especially of public-access beaches, because most of those photos have been artificially enhanced. Viewed as more environmentally friendly, as this approach tries to work with natural processes to reduce, rather than prevent erosion. Coastal Dune Protection and Restoration | Coastal Processes, Hazards Whereas rocks would, eventually, wash away, the weight and puzzle-piece styling of the Tetrapod allows them to stand firm against the elements, come what may.
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