More imagery--Minami Sanriku and beyond -- and tsunami erosion

The oblique air photo above (by "yaozy"), available on Google Earth, shows dramatic tsunami scour features in the Minami Sanriku harbor. It also gives a better sense of the area I walked around in April of 2010. Finally I can faintly see the baseball diamond near the (destroyed) river gate, and get a sense of the tsunami erosion around the large apartment building at the shoreline, a building designated for vertical evacuation. I still don't know how many people used this building for evacuation, and if so, did they successfully get onto the roof because the upper floor was flooded.

I have been readjusting to life back in Seattle, trying to finish up several manuscripts that got pushed aside by the events of 11 March. These manuscripts deal with neotectonics and tsunami history of the Kamchatka Peninsula.

The other day, we were trying to imagine "life before Google Earth." I remember life before photocopy machines, let alone word processing! I was rereading a classic, early article by Minoura on a Kamchatka tsunami deposit, and wondering if we could relocate his sites. So much of Minoura-san's materials will have been destroyed by the earthquake in Sendai. I realized his work was not only before Google Earth and GIS, but probably done without GPS.... Though we had handheld GPS in our post-tsunami survey in Nicaragua in 1992, it wasn't working very well. Funny, there were two sets of maps -- the Nicaraguans had maps prepared by the Soviet Union for the Sandinista regime, and we from the U.S. had maps prepared by the U.S. Defense Mapping Agency, which said "destroy after using." The "KGB" maps were more accurate than the "CIA" maps.... Of course, air photos are still the best for on-the-ground location, though post-tsunami, things change. And some countries are not so enthusiastic about providing/ making public their air photos. How things are changing now with so much on the web.

Meanwhile (back to the present), thanks to Paleoseismicity:
http://www.facebook.com/pages/Paleoseismicity/139495536098998

for posting some good links, such as:
http://google-latlong.blogspot.com/2011/04/post-japan-earthquake-panoramas-in.html
The title of this panorama project should be "japan-tsunami-panoramas" though.

From Google Earth, I found a newly acquired image of the harbor of Minami Sanriku that shows clearly severe tsunami erosional features, which by their looks are mostly from the outflow -- Bre MacInnes will be interested to see these. Part of her dissertation was about tsunami erosion, particularly by the 2006 (or 2007) central Kurils tsunamis.

Here is a before image of the Minami Sanriku harbor from June 2010:


and the same view from 6 April 2011:


and my rough attempt (I did not orthorectify the images) to outline before and after shorelines, as well as the scour ponds made by the tsunami:


OK, back to my manuscripts.

Tohoku coast -- Focus on Survivors

It's hard sometimes to think about statistics when peoples' lives are involved, but I found the data below heartening. Despite the widespread devastation in these towns, preliminary data show that really, most people survived. Early statistics used the total population of these towns, but these data attempt to count only the part of the population that was in the inundated area. The table is ordered from most to least casualities (= dead plus missing). I added the survivors columns, which therefore are ordered from least to most survivors, top to bottom. So the bad news comes first Preliminary table of survivors within inundated region of Iwate, Miyagi and Fukushima prefectures*
Prefecture	Township	Population within the inundated area (a)	Dead + Missing (b)	% casualites (a)/(b)x100	Survivors	% survivors
Iwate	Otsuchi	7839	1616	20.6	6223	79.4
Iwate	Rikuzen-Takada	13547	2459	18.2	11088	81.8
Miyagi	Onagawa	8816	1504	17.1	7312	82.9
Miyagi	Natori	12132	1873	15.4	10259	84.6
Iwate	Kamaishi	9331	1306	14.0	8025	86.0
Miyagi	Shiogama	173	23	13.3	150	86.7
Fukushima	Minami-Souma	13919	1474	10.6	12445	89.4
Miyagi	Yamamoto	9341	788	8.4	8553	91.6
Miyagi	Minami-Sanriku	13306	1090	8.2	12216	91.8
Iwate	Yamada	11721	911	7.8	10810	92.2
Miyagi	Kesennuma	29648	2138	7.2	27510	92.8
Fukushima	Namie	2749	186	6.8	2563	93.2
Miyagi	Ishinomaki	102670	5520	5.4	97150	94.6
Miyagi	Higashi-Matsushima	32993	1713	5.2	31280	94.8
Fukushima	Souma	9227	408	4.4	8819	95.6
Iwate	Miyako	24937	1083	4.3	23854	95.7
Iwate	Tanohata	1075	38	3.5	1037	96.5
Iwate	Ofunato	15500	494	3.2	15006	96.8
Fukushima	Futaba	1061	32	3.0	1029	97.0
Fukushima	Shinchi	4258	118	2.8	4140	97.2
Miyagi	Iwanuma	7310	183	2.5	7127	97.5
Fukushima	Okuma	1053	24	2.3	1029	97.7
Miyagi	Watari	13186	284	2.2	12902	97.8
TOTAL		345792	25265	7.3	320527	92.7
						Average survival rate within inundated area: 92.7%
Statistics Bureau & Director-General for Policy Planning of Ministry of Internal Affairs & Communications
released "Populations and Number of families within the Expected Inundation Areas" in Japanese.
http://www.stat.go.jp/data/chiri/map/index.htm
Inundation areas are estimated by aerial and satellite photos; not the survey on site.
*The table prepared by Yamamoto, Masahiro (Jody B. added survivor columns).

Minami-Sanriku update

See my previous blog for more background on Minami-Sanriku.
Only some survive on top of the town disaster management center Pictures: Shinichi Sato/AP
http://au.news.yahoo.com/thewest/a/-/world/9136912/photos-reveal-tsunami-desperation/

"Chilling new photographs show people desperately clinging to a mast on a roof as the Japanese tsunami destroys the building beneath them.

In the combination of three photos, taken by Shinichi Sato amidst the March 11 disaster, survivors cling to an antenna tower and handrails on the roof of the Minamisanriku Government Disaster Readiness Center in Minamisanriku, north-eastern Japan.

About 30 people fled to the roof of the three-storey building and climbed higher as the tsunami rushed in. Only nine people survived and about 20 were swept to their deaths."

A young female official who kept delivering the evacuation message to townspeople until the last moment has not been found. Tanioka says the story of her bravery and dedication is now nationally known.

Lensman braved tsunami

Wednesday, April 6, 2011 http://search.japantimes.co.jp/cgi-bin/nn20110406f3.html

"MINAMISANRIKU, Miyagi Pref. (Kyodo) When the municipal disaster prevention building in Minamisanriku, Miyagi Prefecture, was engulfed by the tsunami on March 11, its officials clinging to the top of the structure, a local photographer captured the drama in a series of pictures.

The photos, made available by Shinichi Sato, show the three-story building completely submerged by the wall of water except for its antenna and rooftop fence, to which Mayor Jin Sato and nine other survivors from the office clung.

(Shinichi) Sato, 45, who ran a photo studio in his home until the tsunami hit, captured the scene from an elementary school overlooking the town.

'A tsunami will come,' he thought soon after the powerful earthquake struck. He first instructed his family to evacuate, then took his camera and drove to a hilly area where he could see the town below.

As Sato continued pressing the camera shutter, he was oddly calm and didn't feel terrified, he said. Sato is now photographing the recovery effort."

From a Rapid Damage Assessment and Need Survey

The report has high-resolution images from a number of the towns including and south of Minami-Sanriku. It is about 7 Mb and was provided to me by Tom Banse of Public Radio Olympia Bureau. Support public radio!

The report has high-resolution images from a number of the towns including and south of Minami-Sanriku. It is about 7 Mb and was provided to me by Tom Banse of Public Radio Olympia Bureau. Support public radio!