Tsunami

Tsunami (津波) is phenomenon of raise of the level of water of sea for several meters, that causes destructions in the low–level coastal area if not well protected. Usually tsunamis happen soon (within several minutes) after strong earthquakes. Often, tsunamis are interpreted as surface waves with long wavelength (say, several kilometers), that concentrate in the coastal zone due to the second-order nonlinearity and the group velocity - phase velocity mismatch. Sometimes, the level of water goes down before the significant raise up. There is big article about tsunami at Wikipedia.

Tsunami in Japan
Tsunami often happen in Japan. There exist several kinds of warnings and protection.

Short scale warning
After earthquakes, the trunami warnings appear at the special site http://www.jma.go.jp/jma/indexe.html in order to alert some tourists who stay at the beach browsing internet. The tsunami warning looks similar to this: Tsunami Warning/Advisory// Issued at 17:22 JST 07 Dec 2012 ******************Headline****************** Tsunami Warnings (Tsunami) have been issued for the following coastal regions of Japan: MIYAGI PREF. Evacuate immediately to safe place away from the shore in the above coastal regions. Tsunami advisories are currently in effect in other coastal regions of Japan.

The information about earthquake is also provided. Here is example of such a message: ******* Earthquake Information ******** Occurred at 	17:18 JST 07 Dec 2012 Region name 	SANRIKU OKI Latitude	37.8N Longitude	144.2E Depth 	about 10 km Magnitude 	7.3

Long scale warnings
No one ancient rocks with warning 此処より下に家を建てるな marking the highest historic floodings was reported to be covered at the tsunami. In such a way, one should not say that "unexpectedly high tsunami came".

Any attempt to build-up any constructions below the ancient rocks should be explicitly declared at the construction. Below are two projects of such warnings:

A. This home is build below the ancient marks of tsunami. The builder hopes, that this home is strong enough and the people at the second floor are save even at strong tsunami.

B. This home is build below the ancient marks of tsunami. The builder hopes, that the strong tsunami will not come soon, but if strong earthquake happens, the people should pick up their money and their most important documents and run either up the hill or just out from the sea.

Such warnings do not cost much but they will show certain honesty with respect to the people living in the coastal zone or visiting it. Such warnings are necessary tribute for the ancestors who tried to do that they coluld for several generations ahead.

Protecting walls
The walls along the coast, as well as levi along the revers, were supposed to protect buildings from the tsunami. The video records indicate that they do not help. Contrary, they make waterfalls, increasing the destructive ability of tsunami.

Water, jumping from the protecting wall or levi, moves buildings easier than just flood. The wall concentrates the energy of the raising water; the water-fall breaks the nearby buildings. The constructions picked up by the waterfall in vicinity of the protecting wall, move and kick the buildings behind, causing the chain of destruction.

Contrary, the water, just running along the streets, forward and back, does not seem to bring strong destructions. The people saved at the second floor of the strong buildings made many videos confirming this.

On the other hand, very high and very strong protective walls may have sense. According to the Mainichi Shinbun, the Onagawa nuclear plant survived the 2011.03.11 tsunami just due to the engineer Yanosuke Hirai, who insisted to built-up the 14.8-meter-tall shield, instead of the 12 m high shield proposed in the basic project. The tsinami 2011.03.11 is estimated to be 13 meter high. .

Big tsunamis
The big tsunami of 2011 March 11 is considered as the main reason of the Fukushima disaster: water covered the emergency generators that were supposed to provide the cooling of the shut-down nuclear reactors at the Fukushima nuclear plant. The decay heat was expected to boil and to vaporize the nuclear fuel into the atmosphere, but the suicide workers were able to recover the cooling during March–April, preventing the total contamination of the Honshu island.

One estimates, over Japan, there are hundreds of monuments that indicate the dangerous zones. The hundreds-year letters at the special stones say:"Do not build any homes below this point" (此処より下に家を建てるな). These stones are reported to protect the citizen who followed the advice of the ancestors and build their homes only above such marks. However, in some cases, the constructors overestimate the ability of the protecting walls to resist tsunami; then some cities are destroyed as the Minami-Sanriku was completely washed-out in 2011 March 11. Some constructions were supposed to be tsunami–resistant, but they fail, killing those who tried to use them as refuges; but many ot those who flee, especially if with cars, survive .

One estimates, between the earthquake that causes a tsunami and the dangerous flow, the people usually have several minutes for escape, especially if they run away from the sea immediately. According to the movies, the main danger at Tsunami is not namely water, but the constructions and cars picked-up by the flow. Some concrete multi-store parkings may resist tsunami, and many videos of tsunamis are filmed from such constructions or natural hills. Perhaps, with building of the metal-concrete homes of several stores, the danger of tsunamis can be significantly decreased.

Danger of ocean tsunami
The main danger of tsunami does not come just from the water, but from the human-made objects: protecting walls that make waterfalls, the constructions that are crashed by these waterfalls (kicking out other constructions), cars that are not parked in a strong garages and therefore are picked up by the flow, the unmanned boats that were not driven into the sea immediately after the earthquake, and so on. Video shows that boats that leave from the port soon after the earthquake, are safe. The same applies also to the boats reasonably tied at sufficient altitude; other boats are smashed into the buildings, cars, bridges, and destroyed.

The correct preparation to tsunami should be not only building of the "protecting walls", but design of the buildings, car parkings, shops, hotels, homes in such a way, that the water may freely come to the streets and equally free to leave back to the sea, without to flood the operational rooms of a nuclear plant, without to pick up any human, without to pick up any car, without to break any building.

All constructions below the ancient marks must be explicitly marked with visible signs. The building of the protecting walls, that are not designed to resist the flooding, corresponding to the ancient marks, should be prohibited.

Tsunami at rivers
Termin "tsunami" is used for strong floading of rivers, that can carry out the cars and destroy the communications.

2012.07.07, such a "tsunami" is reported at river Bakanka; city Krymsk suffered a lot. The 7meter waves and 10^2 dead were reported ; then the estimate raised to 10^3. The governor of region Aleksandr Tkachev is believed to be guilty for poor organizing of handling of artificial water reservoirs, poor organization of the rescue and misinformation of population . One says, the water raised for several meters after midnight, and do not believe that such a raise could be result of just a rain; before the food, the population were not evacuated, nor even alerted. Officials have not been able to explain the large number of deaths, except by saying that the water swelled in the local Bakanka river and the disaster struck while Krymsk residents were asleep . Many respondents indicate that the tsunami resulted from a sudden release of water from an artificial water reservoir. The Emergencies Ministry says no water drain from reservoirs has been registered. . At the official site of Krymsk administration , the information about raise of level of water did not appear even after the floading (by 2012.07.08) For the explanation of source of that tsunami, Aleksandr Tkachev had suggested the estimate of the precipitation due to the rain in the mounts as 300 liters per square centimeter during a half-day . Inconsistency of such an estimate is an argument in support of the hupothesis that the 7 meter tsunami-like soliton wave had been created at the sudden release of water from the Neberdjaevskoe reservior, converting the flooding to the catastrophe.

2017.05.16, strong tsunami–like flooding in Minvody (минводы), Russia is reported

Keywords
Earthquake, Fukushima disaster, Onagawa nuclear plant, Japan

Movies of tsunami
http://www.youtube.com/watch?v=O4_QNqUuUCc fjmfjm8008 on Mar 11, 2011 東北地方太平洋沖地震　 千葉県山武市蓮沼の津波の一部始終です. 2分20秒に津波が到達します. 2011年3月11日大震災の映像です. The 2011 off the Pacific coast of Tohoku Earthquake TSUNAMI in Chiba prefecture Japan. 11/Mar./2011

http://news.discovery.com/earth/japanese-coast-guard-over-tsunami-waves-video-110321.html Christina Reed. Mon Mar 21, 2011 05:38 PM ET (Boats with engine and crew, that head into the ocean, do well, but those without engine "up" are in problems. The dams and levees seem to just worsen the effect, giving the waves an additional turbulence and acceleration just before the constructions)

http://www.youtube.com/watch?v=_b-2iByqHVI Tsunami ravaging Kesennuma port Uploaded by Remispecialized on Mar 27, 2011 Original video from: http://www.youtube.com/user/joeyd55

http://www.youtube.com/watch?v=BAuWa77vYDU jhn1203 on Jun 17, 2011. New footage of the Japan Tsunami

http://www.youtube.com/watch?v=QralDndMCeQ Dutchmusicfull on Jun 18, 2011

http://www.youtube.com/watch?v=yiENf1f1tIA sean12772 on Mar 20, 2011

http://www.youtube.com/watch?v=4Nxeav0ivhM SEAMANpl on Oct 14, 2010 Ships in rough seas.

http://www.youtube.com/watch?v=6Gw54iSiRH8 dschwartz1114 on Mar 11, 2011. Boat may escape.

http://www.youtube.com/watch?v=tYEAtl8f6r4  TsunamiCollection on Feb 2, 2008 Roof of a car may be a refuge.

http://www.youtube.com/watch?v=GJLT0tm-jWw 3/11/2011 Otsuchi Japan Dramatic Earthquake, Escape and Tsunami footage. (Car escapes from tsunami) bnvn1 on Mar 13, 2011

http://www.youtube.com/watch?v=mj8FuhMpHxE Shocking - Many cars escaping from Tsunami - Japan 3.11. YamachanUS on Mar 26, 2011

Movies of floodings similar to tsunami
http://www.youtube.com/watch?v=caNP0PXZHSk&NR=1 Cezar0051 on Jul 4, 2011

http://www.youtube.com/watch?v=NPwJm8KZND8&NR=1 starkproject on Jul 1, 2010. Из-за ливня в Киеве вода залила ст.м. Харьковская

http://www.youtube.com/watch?v=3KuC2ff-Gmk ValeriiZhelezniakov. Jul 5, 2011. Ливень в Харькове 04.07.2011. Заплыв на дистанцию - улица Героев.

http://www.youtube.com/watch?v=_qFmLY6EXgs&NR=1 yurakl64zx on Jul 4, 2011. Потоп в Харькове 04.07.2011 возле М. Студенческая

http://www.rt.com/news/toll-dead-region-floods-633/ Over a hundred killed as tsunami-like flood hits southern Russia (VIDEO, PHOTOS) Published: 07 July, 2012, 13:30 Edited: 08 July, 2012, 06:54

Additional links
http://www.iwate-np.co.jp/cgi-bin/topnews.cgi?20110403_11 ここより下に家を建てるな　宮古、集落守った石碑 (2011/04/03, In Japanee).

http://tamutamu2011.kuronowish.com/kokoyorisitani.htm 岩手県宮古市の姉吉（あねよし）に建つ「大津浪記念碑」 １８９６（明治２９）年６月１５日午後７時３２分３０秒に発生した地震（震源は岩手県上閉伊郡釜石町〈現・釜石市〉の東方沖２００km. ... １９３３（昭和８）年３月３日午前２時３０分に、発生した昭和三陸地震（震源は岩手県上閉伊郡釜石町〈現・釜石市〉の東方沖約２００Ｋｍ.  (In Japanese)

http://www.heraldsun.com.au/news/breaking-news/japanese-fishing-boat-found-floating-off-canada-more-than-a-year-after-tsunami/story-e6frf7k6-1226309024929 Japanese fishing boat found floating off Canada more than a year after tsunami. March 24, 2012 5:47PM.  The 46-metre vessel was about 222km off British Columbia's Queen Charlotte Islands, KING 5 News reported. Japanese officials said the boat was lost from Hokkaido after the March 11, 2011, earthquake and tsunami, according to Canada's CHAN-DT. Its owner is also listed as missing, but is not believed to have been on board. The boat - the first piece of large tsunami debris to reach North America - would have reached the coast in about 50 days, but will be removed before then.

http://japandailypress.com/mayor-of-tsunami-devastated-town-in-fukushima-facing-criminal-negligence-2810379 Adam Westlake. Mayor of tsunami-devastated town in Fukushima facing criminal negligence. August 28, 2012. While Jin Sato, Mayor of the town Minamisanriku, in Fukushima Prefecture, was originally praised as a hero for his dedication to sending tsunami warning messages to the public last year, he is now looking at charges of professional negligence for the deaths of 41 public officials.

2015.06.24. https://www.youtube.com/watch?v=PjtoOMIk-D4 Шокирующее видео цунами в Японии. Новые кадры. meteor777hits. Published on Jun 24, 2015. Шокирующее видео цунами в Японии. Кто не спрятался я не виноват