Blogs from the Coastal Structures Team - Tohoku, Japan Earthquake and Tsunami of 2011 - page 84

Day6—Monday,May16
Figure A.13 In Sendai, the Arahama Beach seawall's landward side shows
scour. (Source: Ron Noble)
Shigeo Takahashi informed us this morning that he needed to return immediately to
Tokyo to attend an important meeting with the government and wished us good luck
as he would not return for the last two days of our site inspections. We were very
fortunate to have his invaluable contributions during the first five days.
We got off to a slow start since one of our vans had a slight traffic accident while
driving to drop off one of our rental cars. After some delay we finally reached our
first stop, Higashi Matsushima, Nobiru Beach where we viewed a wide long stretch
of beach including jetty entrances to the Naruse River at its north end. The beach was
40 to 50 meters in width, in excellent condition, backed by a protected berm, about
1.5 meters in height, with interlocking flat scallop-shaped concrete units. Tsunami
inundation was reported to be about five meters for this area with about two meters of
berm overtopping. Both the berm and beach appeared in excellent shape as the
tsunami wave passed over, causing damage inland of the shoreline and removing
some small pieces of the pavement covering the back berm. Even the flat-rocked
revetted south entrance jetty to the river was in excellent shape. It appeared there was
minor damage on the northern side of the north jetty but we did not travel to the far
jetty for a closer inspection. We observed erosion damage to the revetted river side
slopes and a work crew was replacing temporary bank protection with more
permanent concrete armor units.