scholarly journals Concentrations and activity ratios of 228Ra and 226Ra in surface seawater along the Pacific coast of Japan

2011 ◽  
Vol 1 (1) ◽  
pp. 183-188 ◽  
Author(s):  
T. Ohta ◽  
Y. Mahara ◽  
T. Kubota ◽  
J. Sato ◽  
T. Gamo
Keyword(s):  
Pacific Coast ◽  
Tokyo Bay ◽  
Surface Seawater ◽  
Sagami Bay ◽  
Surface Salinity ◽  
Shelf Sediment ◽  
The Pacific ◽  
Activity Ratios ◽  
Pacific Coast Of Japan ◽  
The Kuroshio

AbstractWe measured the 228Ra/226Ra activity ratios in surface seawater along the Pacific coast of Japan at five ports around the island of Izu-Oshima (n = 29), at Atami in Sagami Bay (n = 13), and at Umizuri Park in Tokyo Bay (n = 14). We also conducted these measurements along a transect from the open Pacific Ocean across the Kuroshio to the mouth of Tokyo Bay (n = 7). The activity ratios decreased with increasing salinity of the sampling sites. The 228Ra/226Ra activity ratios in surface seawater along the coast gradually decreased after at the end of autumn and were lowest in winter and the beginning of spring. The surface salinity along the coast decreased from summer into autumn and increased from winter to the beginning of spring. The activity ratios decreased with the increase of salinity.The variation in activity ratios at the three coastal sites is possibly caused by differing contributions of surface seawater from the Kuroshio and surrounding open ocean. The different patterns and ranges of variation in the 228Ra/226Ra activity ratios in surface seawater at Izu-Oshima, Atami, and Umizuri Park may reflect both the amount of water from the Kuroshio and vicinity, and the local bathymetry, because continental shelf sediment is the source of Ra isotopes in surface seawater.

An Oceanic Impact of the Kuroshio on Surface Air Temperature on the Pacific Coast of Japan in Summer: Regional H2O Greenhouse Gas Effect

2015 ◽  
Vol 28 (18) ◽  
pp. 7128-7144 ◽  
Author(s):  
Hiroshi G. Takahashi ◽  
Sachiho A. Adachi ◽  
Tomonori Sato ◽  
Masayuki Hara ◽  
Xieyao Ma ◽  
...  
Keyword(s):  
Heat Flux ◽  
Air Temperature ◽  
Interannual Variation ◽  
Pacific Coast ◽  
Surface Air Temperature ◽  
The Pacific ◽  
Sst Warming ◽  
Pacific Coast Of Japan ◽  
The Kuroshio ◽  
Kuroshio Region

Abstract This study used a 4-km resolution regional climate model to examine the sensitivity of surface air temperature on the Pacific coast of Japan to sea surface temperature (SST) south of the Pacific coast of Japan during summer. The authors performed a control simulation (CTL) driven by reanalysis and observational SST datasets. A series of sensitivity experiments using climatological values from the CTL SST datasets over a 31-yr period was conducted. The interannual variation in surface air temperature over the Pacific coast was well simulated in CTL. The interannual variation in SST over the Kuroshio region amplified the interannual variation in surface air temperature over the Pacific coast. It was found that 30% of the total variance of interannual variation in surface air temperature can be controlled by interannual variation in SST. The calculated surface air temperature on the Pacific coast increased by 0.4 K per 1-K SST warming in the Kuroshio region. Note that this sensitivity was considerably greater during nighttime than during daytime. Concurrent with the warming in surface air temperature, downward longwave radiation at the surface was also increased. In summer, the increase in latent heat flux was considerably larger than that in sensible heat flux over the ocean because of SST warming, according to the temperature dependence of the Bowen ratio. This implies that the primary factor for the increase in surface air temperature in summer is increased moisture in the lower troposphere, indicating that the regional warming was caused by an increase in H2O greenhouse gas.

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 Palinurid phyllosoma larvae and their distribution in winter off the Pacific coast of Japan

2002 ◽  
Vol 68 (sup1) ◽  
pp. 194-197 ◽  
Author(s):  
TAKU YOSHIMURA ◽  
KENJI MORINAGA ◽  
SHIGERU SHIRAI ◽  
HIROSHI YAMAKAWA
Keyword(s):  
Pacific Coast ◽  
The Pacific ◽  
Phyllosoma Larvae ◽  
Pacific Coast Of Japan

scholarly journals Tsunami records due to the 2010 Chile Earthquake observed by GPS buoys established along the Pacific coast of Japan

2011 ◽  
Vol 63 (6) ◽  
pp. e5-e8 ◽  
Author(s):  
Teruyuki Kato ◽  
Yukihiro Terada ◽  
Hitoyoshi Nishimura ◽  
Toshihiko Nagai ◽  
Shun’ichi Koshimura
Keyword(s):  
Pacific Coast ◽  
Tsunami Records ◽  
The Pacific ◽  
Chile Earthquake ◽  
Pacific Coast Of Japan
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