On March 11, 2011, the giant tsunami produced by the earthquake which started off the Pacific coast of Tohoku left over 6,000 victims in Iwate dead and missing. That was the third tsunami with the wave over 30 meters high to hit this region in the past 115 years, so the tsunami should have been anticipated to be certain to hit there.
 The author, who, as one of the local researchers, had been contributing to making various countermeasures, including tsunami hazard maps and raising the residents' awareness of crisis, had to feel discouraged to see such a large number of victims.
 A sub-committee under the Disaster Recovery Committee of Iwate Prefecture, to which the author is responsible as chair, has worked out a plan to recover Iwate from the colossal damage, with the two main pillars, namely “Recover Industry” and “Reconstruct safe towns”. However, due to the vague prospect of the nation's financial support, the actual process of recovery has not advanced far yet. Nine months after the calamity, with residents leaving their hometowns, and towns being threatened of collapse, severe winter is now going to torment the local people still further. The national government is urgently demanded to realize clearly the critical situations and to extend a stable financial support as soon as possible.

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 Strong shaking was experienced in the wide area of the northern part of Japan during the 2011 off the Pacific coast of Tohoku Earthquake of 11 March, 2011. Seismic intensities at some of the sites reached the maximum value of 7 in the intensity scale of Japan Meteorological Agency (JMA). According to the JMA, more than 30 % of wooden houses may be heavily damaged in an area with a seismic intensity of 7. However, it turned out that the damage of wooden houses was significantly small in the vicinity of K-NET Tsukidate station (MYG004) in Miyagi prefecture, which is one of the sites with a seismic intensity of 7 during the main shock. In this study we investigated site amplifications of S-waves in shallow soils near the site. We first conducted aftershock observations in the vicinity of the site by installing temporary 8 stations in a few days. We also conducted microtremor array explorations to deduce shallow S-wave velocity profiles at the aftershock observation stations. From the observed data we estimated the local site amplifications of S-waves in the shallow low-velocity layers. It is found that the predominant period of the amplification near MYG004 is about 0.2 seconds. However, the site amplification is not the same at a site with a distance of 20m from the strong motion site due to differences of surface topographical and geological conditions. Furthermore, the amplifications are also different in the area of 1km from MYG004 with changing predominant periods from 0.1 to 0.5 seconds. S-wave velocity profiles revealed in the microtremor explorations indicate that the shallow low velocity layers with a thickness of less than 10 meters are responsible to the variation of the amplification in the area. The predominant periods in the calculated 1D amplifications are similar to those observed from the aftershock observations. However, the observed amplification factor at the site near MYG004 is two times larger than the calculated one, suggesting an inappropriateness of 1D amplifications at the site.

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 The 2011 off the Pacific coast of Tohoku Earthqauke (Mw 9.0) was occurred in the plate boundary of the Pacific Plate subducting beneath Tohoku-Japan. Mito and Hitachi, Kasama which are located in the northernmost-east of the Kanto Basin, had the seismic intensity larger than 6, due to the short distance from the southern edge (off Ibaraki) of the earthquake source fault. Especially in Hokota, Ibaraki Prefectre, the seismic intensity of 6.4 and the maximum acceleration of 1762 gal were observed. However, subsurface S-wave velocity structures in the middle part of Ibaraki Prefecture was not obtained quantitatively, because of less geophysical data of velocity structures up to the seismic bed rock, which is the important factor to evaluate and predict strong ground motions. In this study, to quantitatively estimate subsurface S-wave velocity structures and evaluate strong ground motion characteristics in the middle part of Ibaraki Prefecture, especially the Higashi-Ibaraki Terrace where the permanent seismic stations such as K-NET were not installed, we performed continuous aftershock observations of off the Pacific coast of Tohoku Earthqauke (Mw 9.0). By the inversion of both results from seismic analyses of aftershock data (H/V spectral ratios of coda waves) for long periods and continuous microtremors data (cross-correlations using the seismic interferometry method) for short periods, we estimated subsurface S-wave velocity structures up to the seismic bed rock (Vs 3.2 km/sec) in the Higashi-Ibaraki Terrace. In the distribution of dominant periods of H/V spectral ratios using microtremors data recorded by additional single-station microtremors observations, we could clearly confirm the boundary of the seismic bed rock gently dipping from the center of the Higashi-Ibaraki Terrace to the Pacific Ocean. The site amplification factors obtained by the aftershock data could explain those theoretically calculated using the estimated S-wave velocity structures as to the peak periods.

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 Our concern for radioactivity or radiation has become higher after the accident of Fukushima Daiichi Nuclear Power Plant. It is important that we know the personal radiation dose. Environmental radiation dose rate monitoring and mapping in the eastern part of the 23 wards of the Tokyo metropolitan area was performed after the accident. Monitoring of the dose rate was measured in the outdoor and the room of the wooden mortar 2-story house at northern Sumida-ku, Tokyo. The dose rate was measured twice a day after the explosion accident on March 15 using Myrate pocket survey meter. The maximum dose rate was 1μSv/h which measured on March 15, 2011. However the radioactive nuclides did not fall out then. It rained on March 21 and 22, then the radionuclide fell out on the ground surface. There are not large fluctuations of the dose rate afterwards by November 25, 2011. Energy spectrum was measured by using the gamma ray spectrometer to estimate sources of radiation nuclides. Radioactive tellurium 132, iodine 132 of tellurium daughter, iodine 131, cesium 134 and cesium 137 were detected by response matrix method (Minato, 2011). The radioactivity of iodine 131 was detected 12 kBq/m² on March 23, however, the radioactivity decreased remarkably after one week. The radioactive nuclei fell out just after accident outbreak, and few radioactive nuclei fall out at present. The radioactive cesium was already absorbed and immobilized on the surface of concrete, asphalt or soil.
 Dose rate mapping performed in the eastern part of the 23 wards of the Tokyo metropolitan. The measurement range is approximately 10km east-west and 15km north-south. The measurement points are 566. Distribution of the dose rate tends to gradually become low in the northeast part towards the southwestern part. However there is locally higher value. Such that place is the slope of levees which faces to the northeast or the super levees which are planted trees in. Dose rate values accord roughly with the data of Ministry of Education, Culture, Sports, Science and Technology. Dose rate distribution of Katsushika-ku, Tokyo before the accident was shown in Hosoda et al. (2011). The dose rate before the accident was low in many places of the green tract of land, and concrete and asphalt were high in many places. The tendency reversed after the accident, namely the increase of the dose rate is remarkable in the green tract of land. The average dose rate before the accident was 39nGy/h in Katsushika-ku. However the average dose rate after the accident increased to 158nGy/h. There was the area where the ratio increased to approximately 4 times before the accident in Tokyo.

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 Remarkable surface raptures appeared along the Yunodake Fault in Iwaki City, Fukushima Prefecture, are estimated to be generated with an earthquake (M7.0) on April 11, 2011 in southeastern Fukushima Prefecture, which occurred one month after the Great East Japan Earthquake (M 9.0) on March 11, 2011. We conducted a CSAMT survey and a seismic reflection survey to investigate the underground structure of the southern end part of the fault. For the CSAMT survey, six survey lines were arranged perpendicular to the fault's direction (NW-SE), and the transmitter current source, with a 2km length, was set at about 5 km southeastward from the survey area. A 2D inversion was carried out for each survey line using TM-mode apparent resistivity data. For the seismic reflection method a survey profile with a length of approximately 1.8 km are arranged along the road including southernmost line of the CSAMT method. As a result, lateral resistivity changes were clearly recognized in the 2D resistivity sections at the locations of the fault. High resistivity zones (10∼100 Ωm) were detected in the northeastern side of the fault, while low resistivity zones (3∼10 Ωm) were located at the southwestern side. The boundary of these resistivity zones was estimated as the boundary of lithology created by the active fault. On the other hand, a lateral resistivity change was not detected clearly on the southeastern most survey line, where the earthquake fault was not confirmed on the ground surface. However, the analyzed section of the seismic reflection survey on the same survey line indicated a fault at another location, a few hundreds meters shifted southwestward, with discontinuity and flexure changes in the reflectors.

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 A land type 3D laser scanner was applied to desaster investigation caused by the earthquake on March 11, 2011 near Yunotake Fault in Iwaki Joban area. The targets of 3D laser scanner investigation are a deformed building, slop collapse, and a destroyed banking structure. From this study it is shown that; (A) From the scanned data of damaged building we can reconstruct an image the original building structure and can estimate deformation amounts and angles. (B) In the case of natural slope collapse, the range of the collapsed ground and its quantity were able to be estimated quickly by using 3D laser scanner data. (C) In the case of the destroyed banking structure, the influence range of the surface displacement by collapse of banking is identified. The land type 3D laser scanner can be applied to investigation of disaster area safely and quickly without closing the targets. Using these properties of this method, this method can provide a fundamental data set required for restoration and restoration of an earthquake disaster.

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 The 2011 off the Pacific coast Tohoku Earthquake triggered powerful tsunami that caused major damage of the coast of from Kanto through Tohoku. However, house damages caused by strong ground motion of this earthquake was not so heavy relatively to its magnitude and seismic intensities. Although house damages was not so heavy on the whole, there are houses seriously damaged by the earthquake in Monou-Cho, Ishinomaki City, Miyagi Prefecture, Japan. The locations of damaged houses are limited in Monou-Cho. To figure out the cause of such local earthquake damage, we conducted investigation of house damages and microtremor measurements three months after the earthquake. We classified each house into 6 damage ranks according to the house damage investigation. The number of seriously damaged houses classified to rank A and B is 10 (approx. 3%) and its location is limited around the City Hall of Monou-Cho. Microtremor measurements was conducted at 46 points and predominant frequency of H/V spectrum ratio varied from 1 to 4Hz. Locations of seriously damaged houses classified to A and B correspond to points with predominant frequency over 2.5Hz. Housed would collapsed because of resonance phenomenon between strong motion and surface geology with predominant frequency over 2.5Hz.

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