Tateyama Caldera SABO Museum

Toyama-shi, Japan

Tateyama Caldera SABO Museum

Toyama-shi, Japan
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Kang J.-H.,Korea Polar Research Institute | Son M.-H.,Pohang University of Science and Technology | Hur S.D.,Korea Polar Research Institute | Hong S.,Inha University | And 3 more authors.
Science of the Total Environment | Year: 2012

Organochlorine pesticides (OCPs) were measured in surface snow collected on a ~1400-km inland traverse beginning from the coastal regions of East Antarctica during the Japanese Antarctic Research Expedition (JARE) of 2007/2008. Of the 22 OCPs, α-hexachlorocyclohexane (HCH), γ-HCH, and hexachlorobenzene (HCB) were frequently detected in the snow with concentration ranges of 17.5-83.2, 33-137, and ND-182pgL-1, respectively. The most abundant pesticide was γ-HCH, with a mean concentration of 69.9pgL-1, followed by α-HCH, with an average concentration of 44.5pgL-1. The spatial variability of α-HCH and γ-HCH was narrow, and the concentrations of α-HCH and γ-HCH increased slightly with increasing altitude along the traverse route. Dome Fuji, the highest altitude sampling point, had the highest γ-HCH concentrations in the snow. Backward air trajectory analysis showed that the air masses at the sampling sites came mainly from the Indian and Atlantic Oceans and over the Antarctic continent, indicating that the OCPs were subjected to long-range atmospheric transport and were deposited in the surface snow. Our data suggest that the snow of Antarctica contains low levels of OCPs. © 2012.

Iwahana G.,Hokkaido University | Fukui K.,Tateyama Caldera Sabo Museum | Mikhailov N.,Altai State University | Ostanin O.,Altai State University | Fujii Y.,Japan National Institute of Polar Research
Permafrost and Periglacial Processes | Year: 2012

Perennial frost mounds are present near the edges of ponds located on the terrace between the mountain flank and a valley-bottom lake in the Akkol valley of the Russian Altai Mountains. These mounds are 10-50m in diameter and 3-6m in height. We describe one mound, identified as a lithalsa, which had been eroded so as to expose almost its entire vertical cross-section, revealing its internal structure. The frozen core consisted mainly of soil segments suspended in reticulate ice lenses with a mean thickness of 11-48mm and a maximum thickness of about 160mm. The shapes of the soil segments matched their neighbours. Other features included soil segments suspended in the ice veins shaped like 'En echelon gash veins', and the presence of a radial structure of ice-rich and sediment-rich frozen bands. These features all suggest the greater importance of a differential stress field during heaving of the mound and after ice segregation, compared to the thermal gradient and water supply. © 2012 John Wiley & Sons, Ltd.

Sugiyama S.,Hokkaido University | Fukui K.,Tateyama Caldera Sabo Museum | Fujita K.,Nagoya University | Tone K.,Hokkaido University | Yamaguchi S.,Japan National Research Institute for Earth Science and Disaster Prevention
Annals of Glaciology | Year: 2013

To investigate recent glacier changes in the Himalayan region, we carried out GPS and ground-penetrating radar (GPR) measurements at Yala Glacier, a benchmark glacier in Nepal. Glacier surface elevation and ice thickness were surveyed along a 1.5km profile from the glacier top to the terminus. Ice flow velocity was measured at five locations by surveying stakes for either 1 year or 4 day periods. Obtained surface elevation and ice velocity were compared with those measured in 1982 and 1996. The mean ice thickness along the radar profile was 36m in 2009 and the ice has been thinning at rates of-0.690.25 and-0.750.24ma-1 during the periods 1982-96 and 1996-2009, respectively. The thinning rate increases down-glacier, reaching a magnitude up to-1.8ma-1 near the terminus from 1996 to 2009. The ice velocity has reduced by >70% from 1982 to 2009 in the lower half of the glacier. By assuming a constant driving stress over the glacier, the total ice volume in 2009 was estimated as 0.061km3. Our results indicate that Yala Glacier has lost 40% of its ice volume over the last 27 years and that the rate of the mass loss has accelerated over the last decade.

Fujita K.,Nagoya University | Hiyama K.,Nagoya University | Iida H.,Tateyama Caldera SABO Museum | Ageta Y.,Nagoya University
Water Resources Research | Year: 2010

We describe four decades of temporal fluctuations in the ablation of the Hamaguri-yuki snow patch in the northern Japan Alps. Annual ablation depth through the melting season shows a significant correlation with the initial depth (at the beginning of the melting season), whereas a less significant correlation is found with a temperature index that is generally believed to correlate well with ablation. The scale effect of the snow patch, which appears to modify the wind speed over the patch, has a more significant effect on snow ablation than does the radiation shadowing effect of surrounding mountains. In the case of a thinner and therefore smaller initial springtime snow patch, the speed of the local wind may be reduced over the snow surface, thereby suppressing ablation, whereas wind speed is not reduced (and ablation is not suppressed) in the case of a thicker snow patch. This self-regulating feedback means that over the past four decades, the thickness of the snow patch has fluctuated in a manner that is largely independent of summertime temperature. Our findings also suggest that the self-regulating feedback, which influences ablation, allows some small wind-drifted glaciers to survive, whereas previous studies reported enhanced accumulation at such glaciers via a similar topographic effect on wind speed and suppressed ablation via the shading effect of surrounding mountains on solar radiation. © 2010 by the American Geophysical Union.

Nuimura T.,Nagoya University | Fujita K.,Nagoya University | Fukui K.,Tateyama Caldera Sabo Museum | Asahi K.,Ritsumeikan University | And 2 more authors.
Arctic, Antarctic, and Alpine Research | Year: 2011

We evaluated elevation changes at four sites on debris-covered ablation area of Khumbu Glacier, Nepal Himalaya, since 1978. In 2004, we carried out a ground survey by differential GPS in the upper- and lowermost areas of the ablation area. The amount of surface lowering was calculated by comparing digital elevation models (DEMs) with 30-m grid size, as generated from survey data corrected in 1978, 1995, and in the present study. Because we could not access the middle parts of the debris-covered area due to surface roughness, for this area we used an ASTER-DEM calibrated by the ground survey data. The amount of surface lowering during the period 1978-2004 was insignificant near the terminus. A remarkable acceleration of surface lowering was found in the middle part of the debris-covered ablation area, where the glacier surface is highly undulating. In the uppermost area, surface lowering has continued at a steady rate. Surface flow speeds have decreased since 1956, revealing that the recent decrease in ice flux from the upper accumulation area would have accelerated the rate of surface lowering of the debris-covered area of Khumbu Glacier during the period 1995-2004. © 2011 Arctic, Antarctic, and Alpine Research.

Sugiyama S.,Hokkaido University | Enomoto H.,Japan National Institute of Polar Research | Fujita S.,Japan National Institute of Polar Research | Fukui K.,Tateyama Caldera Sabo Museum | And 3 more authors.
Journal of Glaciology | Year: 2012

During the Japanese-Swedish Antarctic traverse expedition of 2007/08, we measured the surface snow density at 46 locations along the 2800km long route from Syowa station to Wasa station in East Antarctica. The mean snow density for the upper 1 (or 0.5)m layer varied from 333 to 439 kgm -3 over a region spanning an elevation range of 365-3800ma.s.l. The density variations were associated with the elevation of the sampling sites; the density decreased as the elevation increased, moving from the coastal region inland. However, the density was relatively insensitive to the change in elevation along the ridge on the Antarctic plateau between Dome F and Kohnen stations. Because surface wind is weak in this region, irrespective of elevation, the wind speed was suggested to play a key role in the near-surface densification. The results of multiple regression performed on the density using meteorological variables were significantly improved by the inclusion of wind speed as a predictor. The regression analysis yielded a linear dependence between the density and the wind speed, with a coefficient of 13.5 kgm -3 (m s -1) -1. This relationship is nearly three times stronger than a value previously computed from a dataset available in Antarctica. Our data indicate that the wind speed is more important to estimates of the surface snow density in Antarctica than has been previously assumed.

Arimoto I.,Tokyo University of Agriculture and Technology | Goto Y.,Tateyama Caldera Sabo Museum | Nagai C.,Tokyo University of Agriculture and Technology | Furubayashi K.,NPO Study Group of Ptarmigan Conservation
Mammal Study | Year: 2011

We examined food habits and home-range elevations of Japanese black bears (Ursus thibetanus japonicus) in relation to Fagaceae mast production in Toyama Prefecture. Nine bears (four males and five females) fitted with GPS collars were tracked for various periods from July to December in 20052007. We investigated the food habits of each bear using traces found at GPS-fix locations. Bears selectively fed on Fagus crenata mast when F. crenata and Quercus crispula mast was abundant and consumed Q. crispula and Q. serrata mast when F. crenata mast was scarce. When both F. crenata and Q. crispula mast was scarce, bears fed on multiple alternatives, such as Diospyros kaki. Home-range elevations of bears also differed among years in response to vertical distributions of available foods. Individual bears captured in the Q. serrata zone (lower elevation) and F. crenata zone (higher elevation) tended to eat Q. serrata and Q. crispula acorns, respectively, when F. crenata mast was not available. Therefore, food habits and home-range elevations of bears were influenced greatly by fluctuations in Fagaceae mast production and the species' vertical distribution, as well as by factors such as food preference for F. crenata mast and food resource distribution around the home ranges. © the Mammalogical Society of Japan.

Sugiyama S.,Hokkaido University | Enomoto H.,Kitami Institute of Technology | Fujita S.,Japan National Institute of Polar Research | Fukui K.,Tateyama Caldera Sabo Museum | And 2 more authors.
Annals of Glaciology | Year: 2010

As a joint contribution of Japan and Sweden to the International Polar Year 2007-09, a field expedition between Syowa and Wasa stations in East Antarctica was carried out in the 2007/08 austral summer season. Along the 2800km long expedition route, the dielectric permittivity of the upper 1m snow layer was measured at intervals of approximately 50km using a snow fork, a parallel-wire transmission-line resonator. More than 2000 measurements were performed under carefully calibrated conditions, mostly in the interior of Antarctica. The permittivity ε' was a function of snow density as in previous studies on dry snow, but the values were significantly smaller than those reported before. In the light of the dielectric mixture theory, the relatively smaller ε' obtained in this study can be attributed to the snow structures characteristic in the studied region. Our data suggest that the permittivity of snow in the Antarctic interior is significantly affected by weak bonding between snow grains, which is due to depth-hoar formation in the extremely low-temperature conditions.

Osada K.,Nagoya University | Shido Y.,Nagoya University | Iida H.,Tateyama Caldera SABO Museum | Kido M.,Toyama Prefectural Environmental Science Research Center
Atmospheric Environment | Year: 2010

Atmospheric deposition is an important removal process of aerosol particles and gases from the atmosphere. To elucidate the relative contributions of wet and dry processes and in-cloud and below-cloud scavenging based on deposition amounts in winter at Mt. Tateyama, central Japan, we obtained daily samples (December, 2006-March, 2007) of size-segregated aerosol particles and precipitation at Senjyugahara (SJ; 475 m a.s.l.) and vertical samples of spring snow cover at Murododaira (MR, 2450 m a.s.l., 13 km distance from SJ) on the western flank of Mt. Tateyama. The NH 4 + and nssSO 4 2- in aerosols were mostly found in the fine fraction (<2 μm), although Na +, NO 3 -, and nssCa 2+ were mainly detected in the coarse fraction (>2 μm). Average ionic concentrations (μg g -1) in precipitation at SJ were higher about 3.8 for Na + and nssCa 2+, 3.4 for NO 3 -, 3.7 for NH 4 +, 2.5 for nssSO 4 2- than those at MR, whereas cumulative precipitation amounts at SJ and MR were, respectively, 84 and 175 cm of water equivalent. Wet and dry deposition amounts during the study period were estimated for sites using size-segregated aerosol data, winter averages of HNO 3, NH 3, and SO 2 concentrations, and dry deposition velocities. Particle-dry deposition comprised about 3% (Na +) to 11% (NH 4 +) of the total deposition at MR. The maximum amounts of gas dry deposition were estimated, respectively, as 4, 13, and 3% of the total deposition at MR for NH 4 +, NO 3 -, and nssSO 4 2-. The relative contributions of below-cloud scavenging (BCS) between MR and SJ were estimated as considering the wet only deposition amount at MR. Higher contributions of BCS were obtained for Na + (56%) and nssCa 2+ (45%), whereas BCSs for NH 4 +, NO 3 -, and nssSO 4 2- were lower than 28%. Ionic constituents existing predominantly in the coarse fraction showed a large contribution of BCS. © 2009 Elsevier Ltd. All rights reserved.

Uemura R.,University of Ryukyus | Masaka K.,University of Ryukyus | Fukui K.,Tateyama Caldera Sabo Museum | Iizuka Y.,Hokkaido University | And 2 more authors.
Geophysical Research Letters | Year: 2016

The sulfur stable isotopic values (δ34S) of sulfate aerosols can be used to assess oxidation pathways and contributions from various sources, such as marine biogenic sulfur, volcanoes, and sea salt. However, because of a lack of observations, the spatial distribution of δ34S values in Antarctic sulfate aerosols remains unclear. Here we present the first sulfur isotopic values from surface snow samples along a latitudinal transect in eastern Dronning Maud Land, East Antarctica. The δ34S values of sulfate showed remarkably uniform values, in the range of 14.8–16.9‰, and no significant decrease toward the inland part of the transect was noted. These results suggest that net isotopic fractionation during long-range transport is insignificant. Thus, the δ34S values can be used to infer source contributions. The δ34S values suggest that marine biogenic sulfur is the dominant source of sulfate aerosols, with a fractional contribution of 84 ± 16%. ©2016. The Authors.

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