Comparison of factors affecting recruitment variability of walleye pollock Theragra chalcogramma in the Pacific Ocean and the Sea of Japan off northern Japan

2014 ◽  
Vol 80 (2) ◽  
pp. 117-126 ◽  
Author(s):  
Tetsuichiro Funamoto ◽  
Orio Yamamura ◽  
Osamu Shida ◽  
Kazuhiko Itaya ◽  
Ken Mori ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Sea Of Japan ◽  
Walleye Pollock ◽  
Theragra Chalcogramma ◽  
The Sea Of Japan ◽  
Factors Affecting ◽  
Walleye Pollock Theragra Chalcogramma ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Northern Japan

scholarly journals Long-term ocean acidification trends in coastal waters around Japan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiroshi Ishida ◽  
Ryosuke S. Isono ◽  
Jun Kita ◽  
Yutaka W. Watanabe
Keyword(s):  
Pacific Ocean ◽  
Ocean Acidification ◽  
Sea Of Japan ◽  
Ocean Current ◽  
The Sea Of Japan ◽  
Marginal Seas ◽  
The Pacific ◽  
Activity Measurements ◽  
The Pacific Ocean

AbstractThis study examines long-term ocean pH data to evaluate ocean acidification (OA) trends at two coastal research institutions located on the Sea of Japan and the Pacific Ocean. These laboratories are located away from the influences of large rivers and major industrial activity. Measurements were performed daily for the past 30 years (1980s–2010s). The average annual ocean pH for both sites showed generally negative trends. These trends were – 0.0032 and – 0.0068 year–1 (p < 0.001) at the Sea of Japan and Pacific Ocean sites, respectively. The trends were superimposed onto approximately 10-year oscillations, which appear to synchronize with the ocean current periodicity. At the Sea of Japan site, the ocean pH in the summer was higher, and the rate of OA was higher than during other seasons. Our results suggest that seasonality and ocean currents influence OA in the coastal areas of open oceans and can affect the coastal regions of marginal seas.

Three-Dimensional Seismic Velocity Structure Beneath Japanese Islands and Surroundings Based on NIED Seismic Networks Using both Inland and Offshore Events

2017 ◽  
Vol 12 (5) ◽  
pp. 844-857 ◽  
Author(s):  
Makoto Matsubara ◽  
Hiroshi Sato ◽  
Kenji Uehira ◽  
Masashi Mochizuki ◽  
Toshihiko Kanazawa ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Sea Of Japan ◽  
Velocity Structure ◽  
Seismic Velocity ◽  
The Sea Of Japan ◽  
Seismic Velocity Structure ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Seismic Networks ◽  
Japanese Islands

Tomographic analysis of the seismic velocity structure beneath oceans has always been difficult because offshore events determined by onshore seismic networks have large uncertainties in depth. In order to use reliable event locations for our computations, we have developed a method to use the hypocentral depths determined by the NIED F-net with moment tensor solutions using long-period (20-50 s) waves from offshore events away from onshore seismic networks. We applied seismic tomographic method to events occurring between the years 2000 and 2015 to generate a tomographic image of the Japanese Islands and the surrounding using travel time data picked by the NIED Hi-net, hypocenteral information for onshore earthquakes from the Hi-net, and hypocenter information for offshore events from the F-net. The seismic velocity structure at depths of 30-50 km beneath the Pacific Ocean off the east coast of northeastern Japan and onshore Japan was clearly imaged using both onshore and offshore event date. The boundary between high and low P-wave velocities (Vp) is clearly seen at the Median Tectonic Line beneath southwestern Japan at depths of 10 and 20 km. We discuss how the high-Vp lower crust and low-Vp upper crust beneath central Japan and towards the Sea of Japan are responsible for the failed rift structures formed during the opening of the Sea of Japan. Due to consequent shortening, the crustal deformation has been concentrated along the failed rift zone. Resolution of shallow structures beneath the ocean is investigated using S-net data, confirming the possibility of imaging depths of 5-20 km. In future studies, application of S-net data will be useful in evaluating whether the failed rift structure, formed during the late Cretaceous to early Tertiary, continues towards the shallow regions beneath the Pacific Ocean.

scholarly journals Spatial distribution of oxygen-18 and deuterium in stream waters across the Japanese archipelago

2014 ◽  
Vol 11 (9) ◽  
pp. 10903-10930
Author(s):  
M. Katsuyama ◽  
T. Yoshioka ◽  
E. Konohira
Keyword(s):  
Spatial Distribution ◽  
Pacific Ocean ◽  
Sea Of Japan ◽  
The Sea Of Japan ◽  
Data Set ◽  
Japanese Archipelago ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The Japanese Archipelago ◽  
Stream Waters

Abstract. The spatial distribution of oxygen and hydrogen isotopic composition (δ18O and δ2H) of stream waters across Japan was clarified with a data set compiling sample data obtained from 1278 forest catchments during the summer of 2003. Both δ18O and δ2H values showed positive correlations with the mean annual air temperature and annual evapotranspiration, and negative correlations with latitude and elevation. Deuterium excess (d excess) values in stream waters were higher on the Sea of Japan side, and lower on the Pacific Ocean side, of the Japanese archipelago. The d excess in precipitation was generally higher in winter and lower in summer in Japan. The Sea of Japan side experiences a great deal of snowfall, and seasonal changes in monthly precipitation are rather small. In contrast, the Pacific Ocean side experiences a large amount of rainfall during summer with low levels of precipitation during the winter. Therefore, the lower d excess in stream waters on the Pacific Ocean side reflects summer precipitation, and the higher values on the Sea of Japan side are affected by delayed recharge from snowmelt. The isoscapes of stream water connote not only spatially integrated but also temporally integrated isotope signals of precipitation, and provide a framework for addressing applied hydrological, ecological, or meteorological research questions at regional scales, such as the effects of climate change.

scholarly journals Spatial distribution of oxygen-18 and deuterium in stream waters across the Japanese archipelago

2015 ◽  
Vol 19 (3) ◽  
pp. 1577-1588 ◽  
Author(s):  
M. Katsuyama ◽  
T. Yoshioka ◽  
E. Konohira
Keyword(s):  
Spatial Distribution ◽  
Pacific Ocean ◽  
Sea Of Japan ◽  
The Sea Of Japan ◽  
Data Set ◽  
Japanese Archipelago ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The Japanese Archipelago ◽  
Stream Waters

Abstract. The spatial distribution of oxygen and hydrogen isotopic composition (δ18O and δ2H) of stream waters across Japan was clarified with a data set by compiling sample data obtained from 1278 forest catchments during the summer of 2003. Both δ18O and δ2H values showed positive correlations with the mean annual air temperature and annual evapotranspiration, and negative correlations with latitude and elevation. Deuterium excess (d-excess) values in stream waters were higher on the Sea of Japan side, and lower on the Pacific Ocean side, of the Japanese archipelago. The d-excess in precipitation was generally higher in winter and lower in summer in Japan. The Sea of Japan side experiences a great deal of snowfall, and seasonal changes in monthly precipitation are rather small. In contrast, the Pacific Ocean side experiences a large amount of rainfall during summer with low levels of precipitation during the winter. Therefore, the lower d-excess in stream waters on the Pacific Ocean side reflects summer precipitation, and the higher values on the Sea of Japan side are affected by delayed recharge from snowmelt. The isoscapes of stream water connote not only spatially integrated but also temporally integrated isotope signals of precipitation and provide a framework for addressing applied hydrological, ecological, or meteorological research questions at regional scales, such as the effects of climate change.

A comparison of multiple solutions of focal mechanisms

1964 ◽  
Vol 54 (3) ◽  
pp. 927-937
Author(s):  
William Stauder
Keyword(s):  
Pacific Ocean ◽  
Focal Mechanism ◽  
Sea Of Japan ◽  
Multiple Solutions ◽  
Focal Mechanisms ◽  
The Sea Of Japan ◽  
Focal Mechanism Solutions ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Deep Focus

Abstract The occurrence of focal mechanism solutions of the same earthquake by different authors is examined. Of 42 instances of such multiple solutions for earthquakes which occurred around the borders of the Pacific Ocean, it is found that of 84 possible pairs of multiple solutions agreement is excellent in 8 cases, good in 13, fair in 19, poor in 19, and no agreement in 25. The implication for focal mechanism studies is illustrated by examining the focal mechanism solutions of deep-focus earthquakes under the Sea of Japan.

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