Blogs from the Coastal Structures Team - Tohoku, Japan Earthquake and Tsunami of 2011 - page 72

As we learned in an afternoon seminar prepared by PARI, 319 fishing ports were
damaged by the tsunami at an estimated cost of ¥93 billion; 18,936 fishing vessels are
damaged or lost, with an additional cost of ¥123.7 billion. There is some general
agreement that the harbors provided some protection for the inland areas when
compared with the unprotected areas adjacent to the ports.

Dr. Takahashi discussed some modeling work completed recently for the earthquake-
tsunami event. One of his examples was from Kamaishi, where the harbor is
protected by southern and northern breakwaters with a 30-meter gap. The
breakwaters were designed and built over a 20-year period, using normal storm wave
conditions; no tsunami waves were included in the design. Although these
breakwaters suffered significant damage during the tsunami, modeling indicates that
the inland inundation was almost six meters less than what would have occurred
without the breakwaters (the community experienced eight meters with the
breakwater, but would likely have had 13.8 meters without the structures). Similar
but less dramatic decreases in inundation occurred at Ofunato.

Following the seminar and congenial dinner with several colleagues from the seminar,
we prepare for an early morning flight to Misawa. From there we will start our own
investigation, hoping to see many other examples of success or partial success from
which to learn how to make coastal communities more resilient to future disasters
while maintaining the major functions and attributes that attract people and industry
to the coast. The next blog will be from the Tohoku region and will include photos of
the areas.

Day2—Thursday,May12

Our team consisting of 10 people, 5 from
COPRI (Lesley Ewing, Ron Noble, Jim
Marino, Bryan Jones & Catherine Petroff)
and 5 from PARI (Shigeo Takahashi,
Haruyuki Kojima, Yoji Tanaka, Kojiru
Suzuki & Yoshitaka Matsuzaki) departed
Haneda airport in Tokyo around 8:00 am
arriving in Misawa shortly after 9:00 am.
After renting two vans and one car, and
having a quick breakfast at the airport we
headed south-eastward to the tsunami
impacted coastline arriving at our first
stop, Momoishi Fishing Port at 11:00 am.
This fishing port had a tsunami barrier 5
meters in height, which had been
overtopped. The breakwater protecting this
harbor had also been breached.

Figure A.1 Noda Seawall, looking
inland from the ocean (Source: Ron
Noble)

Continuing south, mostly on Highway 45,
we arrived at the Port of Hachinohe at