INTERNATIONAL INSTITUTE OF SEISMOLOGY AND
EARTHQUAKE ENGINEERING (IISEE)REPORT OF STUDY TRIP(TOHOKU)
14 – 18 November 2011

Prepared by: Nur Intan Irzwanee Nurashid
T course(Malaysia)
5/12/2011

Day 1: 14th November 2011 (Monday)
Introduction
We went to the study trip in Tohoku District which was arranged by International Institute ofSeismology and earthquake Engineering (IISEE). We left JICA Tsukuba by JICA bus at 7.40 am
on Monday 14th November 2011 heading to Hitachino-Ushiku Station. From there we took atrain to Sendai station transit at Ueno Station. It took about 2 hours and half to reach Sendai.
Upon reaching Sendai City, we went to Tohoku University.
Tohoku University
We went to Disaster Control Research (DCC) of Tohoku University
to meet Dr. Suguwara. Before leaving, we had a chance to see adamage of a building caused by the Tohoku earthquake. There was acrack at the second floor of the Civil Engineering building withapproximate height of 10 meters from the ground. From here, wevisited the damaged places hit by tsunami of the Tohoku earthquake
on March 11, 2011.

Figure 1.1. Traces of crack at Civil Engineering buildingin Tohoku University.

Arahama Beach
After that we visited Arahama area, the most devastatedarea, accompanied by Dr. Suguwara. He guided us
visiting around the inundation area. The first place westopped by was a paddy field for sediment observation
purposed. This point located within 4 km of theinundation area and totally destroyed by the tsunami inMarch 2011. After 8 months it was still undergoingreconstruction process. We found the deposit of the 869
Jogan tsunami below the volcanic ash from the 11,000 –
12,000 years ago which erupted 300 km away from this place.
Then, Dr. Suguwara guided us to a small shrine nearby. This shrine was located approximately 1
km from the coastline and the only place which was safe from the tsunami. The inundation
height in this area was about 1.5 m.
We then visited Arahama village near Arahama Beach. The population here was approximately
20,000 – 30,000 and 200 casualties reported with 1 death. According to Dr. Suguwara, 30 cm
land subsidence was observed during the earthquake and tsunami arrived 70 minutes after the1quake. A 12 meters run up and 10 meters inundation height were observed in this area. However
the watermark cannot be traced anymore. This residential area has been prohibited to live infuture.

Figure 1.2. The broken sea wall in
Arahama Beach.

Figure 1.4. Hand Auger.

Figure 1.3. Tsunami Siren collapsed in
Arahama Beach.

Figure 1.5. Deposit of the 869 Jogan tsunami.

The seawall of 5 meters height and the breakwater was broken. As this beach was a tourist
attraction, a tsunami siren had been installed. However, it was collapsed and broken.
We moved forward to another paddy field located about 2.7 km from the coastline for anothersediment observation. Hand auger was used to dig up some soil. We found the 869 Jogan deposit
and a layer of older tsunami deposit beneath. It is believed to be a tsunami soil of the tsunamithat occurred 2000 year before the Jogan tsunami. The layer below was unidentified except for
the grey layer at the bottom part identified as paleo soil which contained rice paddy field.

2Day 2: 15th November 2011 (Tuesday)On the second day, we visited Matsushima. It is a group of islands in Miyagi prefecture. The area
was protected by its natural geography and suffered less damaged from the tsunami of theTohoku Earthquake. The observed tsunami height was from 1 – 2 m. The evacuation area was
about 500 meters from the coastline and the signs were found on the sidewalk.

Figure 2.1. Small islands in Matsushima
which reduced the tsunami impact.

Figure 2.3. Evacuation area
sign on the sidewalk.

Figure 2.2. Broken tide wall in Matsushima.

Figure 2.4. View of Ishinomaki City fromHiyoriyama Park.

We then continued to Ishinomaki City. From the bus window, we could see the damages along
the way. We could see an overall damaged view of Ishinomaki City from Hiyoriyama Park. The
city was among the most seriously affected by the March 11, 2011 tsunami. The waves
inundated 600 m inland, 60 minutes after the earthquake.

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From Ishinomaki we went to Onagawa town. The 15 m height of evacuation area in the hospitalarea was flooded with tsunami up to the first floor of the hospital building. The inundation height
was approximately 20 m and the land was subsided 1.2 m.
There were a few collapsed buildings in Onagawa town. Some buildings were shifted from its
original location about 70 m away. However, they were removed when we visited there.
We observed a building which collapsed in the opposite way of the tsunami propagation
direction. It is believed that the building was collapsed due to the receding tsunami wave current.
Some other buildings were partially damaged.

Figure 2.5. The collapsed RC building inOnagawa town. View from the evacuation
point (15 m from the ground level).

Figure 2.6. Sea water covering
the road around the building
describes the land subsidence.

Farther inland about 1-2 km from the coastline, we could still find tsunami damage. The waterlevel reached the first floor of the three storey residential apartment.
On the way to Minami Sanriku, we stopped by the Okawa Elementary School which was themost effected school in Ishinomaki. We were explained by a coordinator Mr. Okada in the bus
and we were not able to take any photos. The school was affected by the tsunami wave. From
108 pupils, about 20 – 30 pupils were taken home by their parents’ minutes after the evacuation
alert was issued. The remaining pupils and teachers were evacuating (more than half an hour
after the tsunami alert) when the tsunami came. Only 1 teacher and 3 - 4 pupils survived since
they went up to the higher ground behind the school.

4Day 3: 16th November 2011 (Wednesday)On the third day, we were at Minami-Sanriku visiting the Crisis Management Department at its
tentative location. This place was athletics and culture centre, but became tentative city hall as
the original city hall was severely damaged. 1,200 people came here after the earthquake forevacuations.
Here we met two of the survivors from the tsunami disaster, Mr. Kazuto Oikawa and Mr.
Kazuma Goto. We were accompanied by both of them to see the pictures around the town. Bothof them shared their experience with us and then after accompanied us visiting the damaged
town of Minami-Sanriku. Minami-Sanriku was largely destroyed by the tsunami of the Tohoku
earthquake with most buildings swept away by the 16 m waves and over half of the population
went missing and almost certainly dead.
Among the totally destroyed buildings was the disaster mitigation centre of 12 m height. Thebuilding was totally damaged when a 16 m of tsunami height came. 2 people died in this building
while giving evacuation instruction. A 6 m high breakwater was also broken. Land subsided
about 1 m and wave inundated 3 km inland.

Figure 3.1. Disaster Mitigation Centre in Minami Sanriku.

Mr Goto was at Tokura Junior High School located at 20 m above sea level at the time ofearthquake occurrence. Later he evacuated at the higher ground nearby his house together withhis family. Tsunami came up until the top of the first floor of the school building. The school
now is still close for renovation. It will resume its operation in April 2012.
We went to Kamaishi through Kesennuma, Rikuzen Takata and Ofunato. In Kesennuma, thefishing harbor and the break water as well were completely destroyed.
15 minutes drive from Kesennuma, we reached Rikuzen Takata. The town was completelydestroyed. The 6.5 m high of seawall was broken and not enough to protect the city against the5tsunami wave in March 11, 2011. Most of the building has swept away. Of all the damages, only
1 pine tree survived from the tsunami. It is called “a pine of hope”.
In Ofunato Bay, we found a broken monument of 1933 Showa Sanriku tsunami. About 200 m
away we found a monument of 1896 Meiji Sanriku tsunami still intact on the ground. The area
was inundated during the tsunami in March 2011.

Figure 3.2. The broken monument of 1933
Showa Sanriku tsunami in Ofunato Bay.

Figure 3.3. The 1896 Meiji Sanriku tsunami
monument in Ofunato Bay.

In Ryori area, there were a marker pole indicated that 1896 Meji Sanriku tsunami inundated inthis area as high as 38.2 m.
Later we went to Shirahama beach. The tsunami height recorded in this area was about 10 m.
The 7.6 m height of sea wall was totally damaged left only the broken tsunami gate. Temporary
barrier were set up to prevent the overflow of seawater during high tide.

Figure 3.4. The broken sea wall atShirahama Beach.

Figure 3.5. Temporary barrier toprevent overflow of sea water.

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Day 4: 17th November 2011 (Thursday)
In Kamaishi, we visited Kamaishi Port Office. Mr. Kawai Masanobu of Ministry of Land,
Infrastructure & Transport gave explanation about the condition after the tsunami disaster inMarch 2011. In the Kamaishi Port office itself tsunami height was up to approximately 1.5 m.
the watermark was still observed inside the port office.
A GPS gauge was installed 20 km from the coast and it recorded 6.7 m height of wave heightoffshore. Upon reaching the coast, the wave became 2 – 3 times larger which caused the tsunami.
Tsunami height inside the bay was between 8.1 – 11.7 m whereas tsunami height outside the bay
was between 12.5 – 18.3 m. The breakwater which was completed in 2009 reduced the tsunami
impact 40% and delayed it arrival time by 6 minutes. The breakwater then was severely damaged.
This breakwater was the deepest breakwater and one of the counter measures that have been
established in Kamaishi because it was hit by many tsunamis in the past; 1896 Meiji Sanriku
tsunami, the 1933 Showa Sanriku tsunami and the 1960 Great Chilean tsunami. The breakwater
was located at the bay mouth. It consisted of north and south part with length of 990 m and 670
m respectively. The entire 990 m length of the northside of the breakwater was broken whereas
300 m from the entrance to the south side of the breakwater remained intact but the following
370 m had sunk.
We then visited the Kamaishi port to see the breakwater closely. The port area was subsiding 0.6
m and it caused the increasing of water level.
Temporary barrier were set up to prevent theoverflow of seawater during high tide.
We also visited Unosumai beach area to observe
the tsunami damaged. The area was slightly higher
and therefore high level of tsunami wave wasn’t
expected in this area. Tsunami came inland andthe damaged nearly the first floor of the nearby
hotel which had been designated to be theevacuation building then.
Figure 4.1. The collapsed sea wall in Kamaishi Bay.
Mouth

There were Unosumai Elementary School and Kamaishi East Junior High School nearby, which
located out of the inundation area in the tsunami hazard map. They made a wise decision toevacuate to a higher ground. No casualties reported from both schools. Students from bothschools were well educated regarding such disaster.
In Aneyoshi District of Miyako City, there was a monument of the 1896 Meiji Sanriku tsunami.
The monument marked the inundation limit of the Meiji Sanriku tsunami in 1896 with 30 – 40 m
runup in this area. In March 2011, inundation height was between 19 – 23 m with 40 m runupwith limited inundation area compared to the Meiji Sanriku inundation area.
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Next we visited Miyako City. The building was located along the Heigawa River. On March
2011, the city was devastated by the tsunami of the Tohoku earthquake. The wave overflowed
over the tide wall and damaged the first floor of the Miyako City Hall building. By now,watermarks have been cleaned up. The inundation depth was 4 – 5 m and runup 37.9 m almost
equaling to the 38.2 m record of 1896 Meiji Sanriku tsunami.

Figure 4.2. 1933 Showa Sanriku tsunami in
Jodogahama Beach.

Figure 4.3. 1960 Chillean tsunami in
Jodogahama Beach.

In Jodogahama beach area, 2 monuments were here as the evidence this area was hit by Showa
Sanriku and Chilean tsunami in 1933 and 1960 respectively. Jodogahama beach was also
damaged by tsunami in March 11. 2011. The place now has been restored and no debris can befound here. However the trace of water level can be seen from the hills and trees nearby.

8Day 5: 18th November 2011 (Friday)
On the final day, we visited Taro area in Iwate Prefecture. The town had two 10 meter tallseawalls to prevent flooding from tsunami. The seawalls were designed to divert tsunami water
to the side of the town, so that the damage of the residential area was minimized from tsunami as
high as 15 m. However, the seawall did not protect the town when an earthquake andtsunami struck Japan on 11 March 2011 with a height estimated from 12 m to 37.9 m. The
residential area was totally destroyed and the areas now are in clearing process. There were a few
buildings still standing only with its outer frame intact. One of them is Taro Kanko Hotel.

Figure 5.1. Embankment in Taro.

Figure 5.2. The road in Taro wasdesigned for easier evacuation.

We went up to the higher ground which had been designed as the evacuation place in this area.
According to the local resident that we met there, about 40 – 50 peoples came here forevacuation. The road in this town had been designed in such a way to make it easier forevacuation. It didn’t have this normal 90 degrees corner instead it was built as in diamond shape
to make the road bigger for easy evacuation escaped (Figure 5.2). We went to the Taro Kanko
Hotel to have a better look of the damaged. Damaged can be observed up until level 3 of thebuilding, which was about 12 m from ground level.
Both Meiji Sanriku and Showa Sanriku tsunami has inundated this area in 1896 and 1933
respectively and devastated the town. The water level from both events were marked on the rockas shown in Figure 5.4. Clearly, the tsunami from the Tohoku earthquake was larger than both
Meiji and Showa Sanriku tsunami. The evidence can be observed from the debris found higher
than the Meiji Sanriku water level mark.
Our final destination was Koborinai Port in Miyako City. The highest run up of March 11, 2011
tsunami was recorded in this small fishing port at 37.9 m. The tsunami went up the valley and it
was explained be the debris we found up side the valley. The port was located in low land,
sandwiched between two mountains which may have contributed to the big wave size.
There were voluntaries collecting and clearing the debris in the port area.
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Figure 5.3. The damaged building in Taro.

Figure 5.4. The previous tsunami waterlevels were mark on the rock.

Figure 5.5. Koborinai Port.

Conclusion
Although Japan is well prepared for the tsunami disaster with its great sea wall, break water, dike
as well as controlling forest also the awareness and education, this huge disaster cannot be
prevented as in total. This strong tsunami wave cause massive damage few kilometers from thebeach. Therefore, we cannot underestimate the power of tsunami,

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