Estimation of Tsunami-Inundated Areas in Asahi City, Chiba Prefecture, after the 2011 Tohoku-Oki Earthquake

2013 ◽  
Vol 29 (1_suppl) ◽  
pp. 201-217 ◽  
Author(s):  
Yoshihisa Maruyama ◽  
Ken Kitamura ◽  
Fumio Yamazaki
Keyword(s):  
Satellite Images ◽  
Pacific Coast ◽  
Field Survey ◽  
Source Region ◽  
Tsunami Propagation ◽  
Chiba Prefecture ◽  
The Pacific ◽  
Significant Damage ◽  
Collapsed Buildings ◽  
The Relationship

The 2011 off the Pacific coast of Tohoku-oki earthquake triggered an extremely large tsunami. The authors conducted a field survey in Asahi City, Chiba Prefecture, after the occurrence of the earthquake. Although located farther away from the source region of the earthquake, there was still significant damage in this area. Tsunami-inundated areas in Asahi City were identified from the map developed by disaster relief volunteers and the satellite images captured after the event. Polygons to demonstrate the tsunami-inundated areas were developed in the geographic information system. The authors compared the identified affected areas with the existing tsunami hazard map of Asahi City. The relationship between the tsunami-inundated areas and the locations of seawalls and tide-prevention forests was evaluated. In addition, a numerical simulation of tsunami propagation was performed and the ratio of totally collapsed buildings to the total number of buildings, that is, damage ratio, in terms of the estimated inundation depths was evaluated.

scholarly journals Subsidence by liquefaction-fluidization in man-made strata around Tokyo bay, Japan: from geological survey on damaged part at the 2011 off the Pacific Coast of Tohoku Earthquake

2015 ◽  
Vol 372 ◽  
pp. 221-226
Author(s):  
O. Kazaoka ◽  
S. Kameyama ◽  
K. Shigeno ◽  
Y. Suzuki ◽  
M. Morisaki ◽  
...  
Keyword(s):  
Pacific Coast ◽  
Tohoku Earthquake ◽  
Geological Survey ◽  
Japan Meteorological Agency ◽  
Tokyo Bay ◽  
Great Earthquake ◽  
Reclaimed Land ◽  
Chiba Prefecture ◽  
Detailed Classification ◽  
The Pacific

Abstract. Geological disaster by liquefaction-fluidization happened on southern part of the Quaternary Paleo-Kanto submarine basin at the 2011 Earthquake off the Pacific Coast of Tohoku. Liquefaction-fluidization phenomena occurred mainly in man-made strata over shaking 5+ intensity of Japan Meteorological Agency scale. Many subsided spots, 10–50 m width, 20–100 m length and less than 1 m depth, by liquefaction-fluidization distributed on reclaimed land around northern Tokyo bay. Large amount of sand and groundwater spouted out in the terrible subsided parts. But there are little subsidence and no jetted sand outside the terrible subsided part. Liquefaction-fluidization damaged part at the 1987 earthquake east off Chiba prefecture re-liquefied and fluidized in these parts at the 2011 great earthquake. The damaged area were more wide on the 2011 earthquake than the 1987 quake. Detailed classification maps of subsidence by liquefaction-fluidization on the 2011 grate earthquake were made by fieldwork in Chiba city around Tokyo bay. A mechanism of subsidence by liquefaction-fluidization in man-made strata was solved by geological survey with continuous large box cores on the ACE Liner and large relief peals of the cores at a typical subsided part.

scholarly journals Is there an association between elongation factor 1-α overdominance in the seastar Pisaster ochraceus and “seastar wasting disease”?

2015 ◽  
Author(s):  
John Wares ◽  
Lauren Schiebelhut
Keyword(s):  
North America ◽  
Environmental Conditions ◽  
Pacific Coast ◽  
Elongation Factor ◽  
Mortality Rates ◽  
Wasting Disease ◽  
Pisaster Ochraceus ◽  
The Pacific ◽  
The Relationship ◽  
Elongation Factor 1

In recent years, a massive plague has killed millions of seastars, of many different species, along the Pacific coast of North America. This disease, known as 'seastar wasting disease' (SSWD), is thought to be caused by viral infection. In the affected seastar Pisaster ochraceus, previous work had identified that the elongation factor 1-α locus harbored an intronic insertion allele that is lethal when homozygous yet appears to be maintained at moderate frequency in populations through increased fitness for heterozygotes. The environmental conditions supporting this increased fitness are unknown, but overdominance is often associated with disease. Here, we evaluate seastars from 3 regional populations of P. ochraceus to identify the relationship between SSWD and genotype. Although our data suggest that there may be decreased infection or mortality rates in individuals that are heterozygous at this locus, the effect is small and not statistically significant.

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