Monday, March 28, 2011

Minami-Sanriku before and after

The Sanriku coast I – Minamisanriku before and after

To the right is a Google map image of the towns we visited in April 2010 to learn how they were preparing for tsunamis. This trip was led by Nobuo Shuto and Fumihiko Imamura. We were an international busload. Minami-Sanriku was our second stop, coming up from Sendai.

If you followed the tsunami news at all, you will recognize the name of this town from the references to it as “the town that disappeared.” But many people survived, and many largely due to preparedness. We visited this town in April of 2010 to see how tsunami mitigation had developed. Minami Sanriku is no stranger to tsunamis. Here is a summary of recent historical cases.

1896 Meiji Sanriku and 1933 Showa Sanriku tsunamis. The town experienced two giant local tsunamis in recent 100 years. The Meiji Great Tsunami in 1896 showed the maximum height of about 3.5 m, and the Showa Great Sanriku Tsunami that of about 2.2 m. Information: Nobuo Shuto

Chile 1960 tsunami. The tsunami from Chile in 1960, reaching heights up to 5 m, destroyed the town and killed 41 residents. Thus in the public square near the shore there is a gift monument from Chile (a replica of an Easter Island monument) in memory of those victims. It was snowing when we were there in mid-April 2010.
"One of my neighbours who ran with her three-year-old baby strapped to her back later realised that the child had fallen off and been swept away as they struggled in the water," Shiba said. "It was terrible." "I was pregnant at the time and had to hang from the edge of a wooden roof when the water and debris gushed into my house," said Shiba, adding: "The baby died just one day after she was
born." Across Japan's Pacific coast the death toll from the 1960 quake -- the strongest on record with a magnitude of 9.5 -- reached 142. -- from 1 March 2010

Chile 2010 tsunami. When in 2010 (the 50th anniversary year of Chile 1960) Chile had another great subduction-zone earthquake and tsunami, Minamisanriku residents were ready for its arrival. The river gate (see photo) came down to keep the tsunami at bay, people evacuated to higher ground, and no one died, though there was damage to aquaculture and harbor structures.

(news article of 1 March 2010) --"Japanese grandmother Matsuko Shiba rests at an evacuation shelter in Minami Sanriku Town on February 28 2010. When Chile's massive earthquake sent a tsunami racing towards Japan at the weekend, Shiba knew to head for high ground, and for good reason. Half a century ago a killer wave from the South American country destroyed the picturesque fishing town of Minami Sanriku. Another refugee in 2010, Yoshida, watching her carefree grandson, said that her town 50 years ago received a lot of help from people across Japan. Today, she said, 'we also need to help people suffering from disasters overseas. And, we, the elderly, need to talk more about what we experienced to the younger people.' " -- from 1 March 2010

Our visit in April 2010

It was a cold, wet day when we visited Minami-Sanriku on 12 April 2010. Our leaders took us to the waterfront, where a river gate was the main point of our stop, and we also walked in the park and saw the many tsunami monuments. The rain turned to wet snow. I look around at how flat is was and how close to sea level, taking pictures of an apartment building that was clearly labeled as a vertical evacuation structure for those near the waterfront. This particular piece of land was intentionally left just as a park because at high tsunami risk, and people could evacuate to the nearby tall, reinforced concrete building if there was a tsunami warning.

These gates are meant to keep tsunamis out. I suppose they may also be used for storm surges. They take time to activate and lower the gates, and on the day we visited, they could not get the gate down. In the 2010 Chile tsunami, they had plenty of advance warning, and the gate worked. They gave us a handout describing how they were trying to decrease the time to gate lowering with the possibility of using it for locally generated tsunamis.

Below is a "before" map showing the location the three features we saw on the waterfront of Minami-Sanriku in April 2010.

11 March 2011 Tohoku earthquake and tsunami hit Minami-Sanriku

You can see below in this post-tsunami image that the 4-story building stood, and what I read makes me think that people on the top of this building, which is now half-surrounded by water, survived. It also looks like the river gate is still there, but with severe erosion around the left bank. The tsunami would have significantly overtopped the gate, and in any case, I don't think there was time to bring it down. The park's trees have been washed away, from this view it's hard to see much else, but it's likely all the monuments were toppled and transported some distance, but they may be salvaged.

NHK World, 28 March: A 4-story public apartment building in the coastal area was almost completely inundated, suggesting that tsunami up to 16 meters reached the building.

The town hall was a three story building in the center of town. The mayor, Jim Sato, was one of about 8 or 10 that survived on the top of it, by clinging to things like steel railings, while about 20 others were washed off the top of the building, about 13 meters high. After the tsunami the building is a skeletal wreck--I saw images on an NHK documentary last weekend. The nearby hospital (the largest building complex in this oblique view) withstood the tsunami, with staff moving patients higher and higher, to the fifth floor; the tsunami reached the fourth floor (from NHK documentary).

16 March – town 10,000 missing:

19 March – situation terrible, some reason for hope:

Although the numbers of dead and missing are increasing, there are now about 10,000 survivors accounted for; the mayor holds out hope that many still not documented left town for other places, but the fatalities are sure to rise:

When the Observer asked mayor Sato to account for the discrepancy, he said the problem lay in the manner of counting. "At first we assumed only the 7,000 at the public shelters had survived, but we realise now that many others sought refuge with friends or left the town. That was our mistake. I still can't tell you how many are dead. We still don't know how to make an accurate estimate."

From IOC/UNESCO report of 28 March 2011

Minami-Sanriku T







7 km2 flooded of 164 total

  • Many areas are inundated
  • Tsunami ht by Waseda U. Evacuation building: 15.4 m

There are many terrible images of this fishing village post-tsunami, but I am choosing to focus on the survivors such as these children in an evacuation center at a secondary school in Minami-Sanriku.

Photograph: Stephen Morrison/EPA

Saturday, March 26, 2011

Simon Winchester in Newsweek – bad science


Besides his bad science, Winchester suggests that potential survivors should give up hope, and this is not true [see my prior blog]:

I surely hope that Mr. Winchester is not claiming any scientific background (he has an undergraduate geology degree from Ozford) in the case of this essay, in which he badly misrepresents scientific and cultural knowledge, to the point of potential harm in future events, and insult to Japanese victims and survivors.

I only hesitate to write this because it will bring further attention to this awful essay, which in turn might cause Mr. Winchester sell more books. I am speaking only to the tsunami, and related geological comments; for more about the seismicity issues, see:

Here are some excerpts from the Winchester’s essay (his quotes are in italics, with points of particular contention in red), with my comments (particular rebuttals in blue), especially with reference to the tsunami:

I. …all geological events are sudden, and all are unexpected if not necessarily entirely unanticipated….

Jody remark: The first phrase is a tautology, completely depending on the definition of “geological event.” As geologists, we recognize many “events” in the geological record that are perhaps “sudden” on a geological time scale, but not on a human time scale. If you want to sell more of your books, then this would be a good description of a “geological event.” Moreover, these events are not unexpected, they just may be hard to predict, though Winchester later contradicts himself by predicting the San Andreas fault will be the next to go (the most egregious part of the essay, see Christie Rowe’s link). A counter-example of something that has become predictable in many cases would be volcanic eruptions, though, like the 2011 Tohoku events, the scale can be beyond what was formally anticipated.

II. ….At first, the shock was merely a much stronger and longer version of the temblors to which most Japanese are well accustomed. There came a stunned silence, as there always does. But then, the difference: a few minutes later a low rumble from the east, and in a horrifying replay of the Indian Ocean tragedy of just some six years before, the imagery of which is still hauntingly in all the world’s mind, the coastal waters off the northern Honshu vanished, sucked mysteriously out to sea….

Jody remark: it was not mysterious at all to the Japanese, they are well educated for what to expect after a large earthquake, if they are on the coast. All the tsunami warnings went off, many people who had the opportunity escaped. It’s only true that this tsunami was larger than formally planned for.

III. ….The rumbling continued, people then began to spy a ragged white line on the horizon, and, with unimaginable ferocity, the line became visible as a wall of waves sweeping back inshore at immense speed and at great height. Just seconds later and these Pacific Ocean waters hit the Japanese seawalls, surmounted them with careless ease, and began to claw across the land beyond in what would become a dispassionate and detached orgy of utter destruction….

Jody remark: Well, I guess it’s fair to say that tsunamis are “dispassionate and detached.” However, by the time the tsunami approached the shore, it was not moving at immense speed (see below), and the heights until it came onshore (and in that case particularly in steep regions) are also not great. It took minutes to tens of minutes for these waves to hit the seawalls. The destruction was indeed terrible, but many reinforced concrete structures survived.

IV. ….But in this corner of northeast Japan, with its wide plains of rice meadows and ideal factory sites and conveniently flat airport locations, there may well be a great deal of inland—but there is almost no uphill….

Jody remark: Winchester has decided to focus only on the Sendai plain, whereas the majority of the affected region is not at all flat. And then his problem is, that by focusing on Sendai, the following points he makes are even more mistaken.

V. The most egregious, partly because it causes potential survivors to give up hope:

….And so the reality is this: if a monstrous wave is chasing you inland at the speed of a jetliner, and if the flat topography all around denies you any chance of sprinting to a hilltop to try to escape its wrath, then you can make no mistake—it will catch you, it will drown you, and its forces will pulverize you out of all recognition as a thing of utter insignificance, which of course, to a tsunami, all men and women and their creations necessarily must be….

Jody remark: Completely bad science about tsunami speed, and anyone who watched the tsunami cross the Sendai plain, with any experience in watching tsunami videos, would marvel at how slow and almost stately it was, albeit still terrifying. Reinforced concrete along the shore and inland (such as the airport building) survived, and many people survived here by moving quickly away from the shoreline as soon as shaking stopped. They were not ignorant of tsunami threat. And, as anyone who would care to look up “tsunami” in any reasonable reference knows, they move at the speed dependent on the square root of water depth (see footnote), hence the tsunami as it approached Sendai already was moving much more slowly than a jetliner (“jetliner” is the speed over the deep ocean, several kms deep; see footnote) and was moving even more slowly as it cross the Sendai plain. I guess on the Sendai plain you could say it was the speed of a jetliner as it taxis… not trivial to outrun, but there was advance time.

Bottom line: I agree with Mr. Winchester that the Earth can throw punches beyond the scale of local human survival, though except for asteroid impacts, these remain local events on a global scale and have not brought an end to the human species, which would be a real “geological event.”

Besides his bad science, though, Winchester suggests that potential survivors should give up hope, and this is not true [see my prior blog]:


The speeds as the tsunami crossed the plain are not trivial, but given that people had natural and human warning systems, and that they had 10s of minutes to start their escape, most would have made it.

Speed of a tsunami –example of Sendai plain


Water depth






over the deep ocean




at the edge of the shelf




"as it approaches"




beginning to be visible from ground level




at Sendai airport, max




crossing the plain, typical




Tsunami wave speed = √(gh) --this is the basic “shallow water wave equation”

= [square root of (g times h), where g is gravitational acceleration, it’s ~9.8 m/sec/sec on Earth’s surface; and h is water depth]

These speeds are calculated without consideration of viscosity, which was higher than water on the Sendai plain, because of mud and vegetation, and this would cause a lower speed.

Tuesday, March 22, 2011

More than half full -- the survivors

The basic message of this post: many survived and you can, too.

A couple years after the big Sumatra tsunami in 2004, I spent a long weekend on the coast of Oregon with a dear friend. I visit shorelines a lot as a coastal geologist, but I also love to visit them just for their subtle to spectacular beauty. When I am there, I do look around and think about what I will do and where I will go if I feel an earthquake. I also bring up the subject of tsunamis when I meet people on the coast, and ask them what their plan is. One man in this town said if he felt an earthquake he was going to “kiss his a— good-bye” (the idiom means to “give up and die”). I responded that he had an easy evacuation because there were hills right behind the narrow town along the beach.

Last night Tanioka-san and I had a chance to talk – he’s very tired from so much work, including trips to Tokyo to start reviewing what happened, and running a big public forum in Sapporo on Sunday. Yuichi was kind enough to answer some questions for me at the end of his day – it was after 8 PM when we met. We talked some science and then started reflecting on the people, both the victims and also the tsunami scientists who have been responsible for disaster planning and mitigation, and how terrible they feel. I think the hardest stories to hear are about residents in these towns who went up onto vertical evacuation structures and were washed away in some cases (not all), because the tsunami was bigger than anyone had planned for.

I said we need to tell the scientists and the planners involved that they did indeed save lives, many lives.

Tanioka repeated to me a story he heard about Kamaishi town. The children there had been trained to lead people to high ground. They did as trained, but when they watched the tsunami approaching, they realized that they were not high enough, so they led people to higher ground. All these people survived.

So let’s focus on the survivors. I look again at the grim statistics for number of dead and missing and then compare them to the vast number of refugees – the many many people who survived. Many of them survived because they had the knowledge and opportunity to do the right thing. It’s hard on the tsunami research community right now to feel the losses due to what didn’t go right, but let’s focus on what did go right, and how the next time it happens, the preparation and response of people at risk can save lives.

We learn these lessons by talking with survivors. Brian Atwater spearheaded a brochure that teaches some basic lessons, based on interviews with survivors from the giant 1960 Chile tsunami and elsewhere

English: (below the main points with a little annotation from observations so far in 2011 Japan):


1) Many Will Survive the Earthquake – look at videos from Japan; little obvious damage before the tsunami arrival; afterwards, towns gone

2) Heed Natural Warnings – don’t wait for official warnings if you feel an earthquake, see strange water behavior, hear roaring water

3) Heed Official Warnings – just don’t wait for them if you sense any of the natural warnings and you are near the shore!

4) Expect Many Waves – some people in Chile died because they went back too soon. In Crescent City, CA, the largest wave is typically around #7, a couple hours after the first.

5) Head for High Ground and Stay There – see number 4

6) Abandon Belongings

7) Don’t Count on the Roads – can be earthquake damaged

8) Go to an Upper Floor or Roof of a Building if you cannot get to high ground.

9) Climb a Tree if you can’t get to a building

10) Climb onto Something that Floats if you can’t climb a structure – last ditch

11) Expect the Waves to Leave Debris

12) Expect Quakes to Lower Coastal Land

13) Expect Company – survivors will need to be sociable

14) This is my own addition – Much attention goes to the giant events we have had recently, but many tsunamis are not as large as these biggest ones, but still require your attention. It’s a cliché, but true—better safe than sorry.

Read the stories in this brochure, and read these stories about the survivors of Kesennuma City, trying to get back on their feet. Life does and will go on:

from 17 March:

from 22 March:

Right: Women walk through debris in Kesennuma, Miyagi Prefecture, northern Japan on Wednesday, March 16, 2011, after Friday's powerful earthquake-triggered tsunami hit Japan's east coast. Picture: AP Photo/Shizuo Kambayashi

Monday, March 21, 2011

Read and weep

A family photograph is half buried in the sand and mud in Rikuzentakata, in Iwate prefecture, northeast Japan March 13, 2011. REUTERS/Lee Jae-Won

Already the tsunami is old news. The nuclear reactor situation (which actually is tsunami news) is ongoing, the situation at least has not worsened for the last couple days, with some hopeful signs. Libya has been bombed.

It's the first day of spring, but it is still winter in northern Japan. Below is the latest bulletin from IOC/UNESCO summarizing the situation town by town.

I don't need iodine tablets, I need "heart" medicine.

IOC/UNESCO Bulletin No. 6

As of 21 March 2011

(Including summary of Bulletin No. 1 – 5)

Casualties by the Earthquake and Tsunami

As of 09:00z 21 Mar 2011

The National Police Agency

  • Dead: 8,649
  • Missing: 13,261
  • Road destruction: 1,703
  • Bridge destruction: 51
  • Railway destruction: 15

Number of Evacuees at each Prefecture;

· Aomori: 367

· Iwate: 45,468

· Miyagi: 131,554; including from Fukushima

· Yamagata: 3,858; including from Miyagi and Fukushima

· Fukushima: 131,665

· Tokyo: 546; From Miyagi and Fukushima

· Ibaragi: 3,928; including from Fukushima

· Tochigi: 3,0688; including from Fukushima

· Gunma: 2,983; including from Fukushima and Miyagi

· Saitama: 3,729; under survey

· Chiba: 1,220; including from Fukushima and Miyagi

· Kanagawa: 252; from Fukushima

· Niigata: 7,849; from Fukushima

· Yamanashi: 457; from Fukushima and Miyagi

· Nagano: 193; from Fukushima

· Shizuoka 163; from Fukushima

As of 05:00Z 21 March 2011

The Japanese Fire and Disaster Management Agency (FDMA)

  1. Dead: 8,019 persons
  2. Missing: 10,512 persons
  3. Injured: 2,928 persons
  4. Fires: 326 events (325 fires were already extinguished)
  5. Number of evacuees: 312,792

(Note: Numbers are based on the report from each Prefecture)

C: City, T: Town, V: Village

Local G: Information is taken from web of each municipality


City, Town, Village & Population



Note: Tsunami related disaster

(Whole area / inundation area in km²)


Hakodate C



Local G

  • One man dead by drowning
  • 128 houses flooded
  • 5 fishing boats; sinking
  • Flood area; Benten, Suehiro, Toyokawa, Oote, Wakamatsu, Kaigan, Minato-Chou


Hachinohe C




305 / 2


  • Wide-area are inundated

Misawa C



Local G

  • 30 houses: flood
  • Evacuation shelter was closed 15 March

Hashikami T

94 / 0.5


  • JR Train stop: Tohoku-Akita shinkansen, Ofunato, Kitagami, Kamaishi, Yamada lines etc ( Recovering; no prospect)

Miyako C




1,260 / 9


  • Severe tsunami damages
  • More than 10 villages are completely destroyed

Ofunato C




323 / 6


  • More than 300 houses flow out
  • Many houses are flooded
  • 3,498 houses are completely destroyed
  • Especially Suesaki and Hosoura regions are severely damaged.
  • No communication system

Kuji C




623 / 4

Local G

  • 145 houses are destroyed
  • 572 boats; damaged

Rikuzen-Takata C




232 / 9


  • Extremely severe damages
  • Widely inundation
  • No communication system
  • 3,600 houses are damaged

Kamaishi C




441 / 7


  • Coast-Guard building inundated up to 2nd floor
  • Fire Office building is flooded
  • No communication system

Otsuchi T




201 / 4

Ogasawara; Iwate U. (14 Mar)

  • Whole town is severely damaged
  • No communication system

Yamada T




263 / 4

  • No communication system

Iwaizumi T




993 / 1

  • No communication system
  • 40 houses are flooded

Tanohata V





  • 249 houses flow out
  • 148 houses are destroyed
  • No communication system

Fudai V



70 / 0.5


  • Ootanabe and Horiuchi fishing ports are severely damaged.

Noda V




81 / 2

  • Tsunami flow over the village government building
  • Severe damage in the central village
  • 400 houses in the Motomura District are severely damaged
  • No communication system

Hirono T


303 / 1

Local G

  • No dead
  • 3 houses; flooded
  • 98 fishing boats: flow out or damaged
  • JR train bridge collapsed


Sendai C





  • 295 bodies are recovered (Not included in this table yet)
  • 296,323 houses: power cut as of 17 March


58 / 20

Sendai - Wakabayashi

48 / 29

Sendai- Taihaku

228 / 3

Ishinomaki C




556 / 40


  • Wide areas are inundated. Difficult for rescue work

Shiogama C




18 / 5

Local G

Kesennuma C




333 / 15


  • Many people are isolated due to inundation of wide area

Natori C



Under survey

100 / 27


  • Many areas are inundated

Tagajo C



Under survey

20 / 6

Iwanuma C



Under survey

61 / 29

Higashi-Matsushima C




102 / 36

Watari T




73 / 35

Local G

Yamamoto T




64 / 24

Local G

  • Evacuation Order is issued at 05:52 from local G.
  • Major tsunami attacking around 06:30 Z

Matsushima T




54 / 2

Shichigahama T




13 / 6

Local G

  • Tsunami height was more than 10 m
  • All facilities along coast were completely destroyed
  • No communication system

Rifu T




45 / 0.5

  • Tsunami sediment in Hamada and Suga district is about 3 cm thicknesses.

Onagawa T





  • About 630 people need to be rescued
  • Many areas are inundated

Minami-Sanriku T



Under survey

164 / 7


  • Many areas are inundated


Iwaki C




Local G

  • Tsunami severely damaged area; from Kunohama to Onahama district
  • Some areas of above are completely destroyed

Souma C



198 / 29


  • Severe tsunami damages

Minami-Souma C




399 / 27

Hirono T




Naraha T




Tomioka T




Okuma T




Futaba T




Namie T



Shinchi T




46 / 11


Kita-Ibaragi C



Local G

  • Some houses; flooded

Hitachi C



Local G

  • 35 houses: completely destroyed by tsunami, and 50 houses: partially destroyed, 556 houses; inundation
  • Tsunami damages at Kawajiri, Aise, Kawarako and Kujihama Ports.

Oarai T



Local G

  • About 2,000 houses; flooded

Kamisu C

Local G

  • 5 houses flooded
  • 2 vessels: capsizal
  • 1 vessel: stranding
  • 12 boats: sinking
  • 5 boats: stranding on shore


Choshi C



Local G

  • 32 houses flooded

Asahi C



Local G

  • 112 houses flooded
  • 254 houses were completely destroyed by tsunami
  • 537 houses were partially destroyed by tsunami
  • 85 houses were completely destroyed by earthquake
  • 772 houses were partially destroyed by earthquake

Sousa C

Local G

  • 18 houses flooded

Yokoshiba-Hikari T

Local G

  • 14 houses flooded
  • Boats are damaged
  • Port facility is damaged

Sanbu C


Local G

  • 243 houses flooded

Kujyukuri T

Local G

  • 161 houses flooded

Oami-Shirasato T

Local G

  • No tsynami damage

Shirako T

Chousei V

Ichinomiya C



Local G

  • 58 houses flooded; Kaigan and Omura District
  • Farm: 3 ha inundated

Isumi C

Local G

  • 19 houses flooded

Onjyuku T

Katsuura C

Kamogawa C

Minami-Bousou C

Tateyama C

Chiba C

Local G

  • 2 houses flooded


Shimoda C


Local G

  • 13 houses; flooded