This fine resolution basin database provides basin model over 10ha sub-basins of the Sanriku coastal area located in the north west Pacific side of Japan. The data contain watershed boundary and flow path data about the target area created by use of a 10m digital elevation model (DEM). Using this data, the coverage area was increased over 721.66km2 compared to the low resolution public data set provided by the government. It increased the coastline coverage from 17% to 84% compared with the low resolution data set in 1km grid. For use in the coastal area or river discharge model, this data also contains the overall drainage basin boundary at the river mouth. The area of this survey was highly damaged by the tsunami on The 2011 Great East Japan Earthquake and post-disaster anthropogenic impact. Thus, this database will be of interest in the context of changes in land use and river discharge to assess both post-disaster anthropogenic impacts on the ecosystems.
The JAMSTEC Model Intercomparison Project (JMIP) provides a first opportunity to systematically compare multiple global models developed and/or used in JAMSTEC with the aim of moving toward better weather and climate predictions. Here, we evaluate climate simulations obtained from atmospheric models (AFES and MIROC5), atmospheric model with slab ocean (NICAM.12), and fully coupled model (SINTEX-F1 and SINTEX-F2). In these simulations, the sea surface temperature is fixed (for AFES and MIROC5) or nudged (NICAM.12, SINTEX-F1, and SINTEX-F2) to the observed historical one. We focus on the climatology and variability of precipitation and its associated phenomena, including the basic state, the energy budget of the atmosphere, extratropical cyclones, teleconnection, and the Asian monsoon. We further discuss the possible causes of similarities and differences among the five JMIP models. Though some or most of the dynamical and physical packages in the JMIP models have been developed independently, common model biases are found among them. The AFES and MIROC5, and the SINTEX-F1 and SINTEX-F2, show strong similarities. In many respects, NICAM.12 shows unique characteristics, such as the distributions of precipitation, shortwave radiation, and explosive extratropical cyclones and the onset of the Asian summer monsoon. To some extent, the similarities and differences among the JMIP models overlap with those among the Coupled Model Intercomparison Project Phase-5 (CMIP5) models, suggesting that JMIP can be used as a simple and in-depth version of CMIP to investigate the mechanisms of model bias. We suggest that this JMIP framework could be expanded to an intercomparison of weekly-to-seasonal scale weather forecasting; here, more fruitful discussion is expected through intensive collaboration among modeling and observation groups.
海洋研究開発機構(JAMSTEC)は2007年に策定した「データ・サンプルの取り扱いに関する基本方針」に基づき,JAMSTECに帰属するデータ・サンプルを管理,公開し,その幅広い利用を推進している.調査航海で採取された生物サンプルについては,その情報をJAMSTECの情報管理部署がデータベースに登録し一元的に管理しつつも,サンプル自体は採取した研究者らがJAMSTEC内外の各機関に持ち帰って利用しており分散的に管理されている.つまり,生物サンプルは情報管理部署とJAMSTEC内外の研究者らによる共同管理体制をとっている.この生物サンプルの共同管理体制は一見特殊にも見えるが,自機関に帰属するサンプルについて,その所在を把握し,管理していくためには必然的な仕組みだとも言える.また,データベースを公開しており,登録されたサンプルに対して他者が利用申請をする機会を提供している.JAMSTECのサンプルには,これまで博物館やバイオリソースセンター等に保存され提供されてきたサンプルのように永続的に保存されるサンプルも含まれるが,研究者らが日々利用し消費されていくサンプルが多い.このため,JAMSTECの生物サンプル管理と利用の仕組みは,これまで他機関が実施してきた仕組みよりも広範なサンプルの利用機会を拡大しているものであり,サンプルから最大限の科学的成果を生み出し,社会に役立てていくことを目指すものである.
Top predators play an important role in maintaining biomass and biodiversity of most ecosystems. However, functional roles of the top predators in deep sea are still poorly understood. Large, predatory sharks are considered as the top predators in the deep sea, some of which are known to have a long-life span and a long-term maturation period. Most studies of the sharks have been conducted using lethal methods such as deep-sea trawls without attention to their vulnerability. It is urgent to develop non-lethal approaches for the shark studies. An autonomous in situ biopsy equipment is one solution, which collect a small amount of soft tissues non-lethally from the target fish. For developing the equipment, we conducted static penetration tests using three types of biopsy needles, i.e., conical, bevel, and trigonal pyramid shapes with the tip angles of 20, 30 and 40 degrees. Three species of deep-sea sharks, the roughskin dogfish Centroscymnus owstonii, the kitefin shark Dalatias licha, and the rough longnose dogfish Deania hystricosa, were applied for the penetration tests. The lowest penetration forces were 22.1 N on the skin of D. hystricosa using the trigonal pyramid needle with the tip angle of 30 degrees, 65.3 N on that of C. owstonii, and 95.3 N on that of D. licha both using the trigonal pyramid needle with the tip angle of 20 degrees. The highest forces were recorded on the D. licha skins among the three sharks using any types of needles, which were 3.6 to 6.0 times larger than that of D. hystricosa and 55.3 times larger than that of the chub mackerel Scomber japonicus. We concluded that the trigonal pyramid with the tip angle of 20 or 30 degrees is the most suitable shape for our biopsy needle and that the shooting force has to be larger than 95.3 N for collecting tissues from hard-skin species such as D. Licha.
新青丸KS-16-E01航海で，瀬戸内海の海域にある中央構造線断層帯西端の詳細マッピング，基礎地質情報取得を目的として，佐田岬半島沖において，海底地形，浅層構造，重力調査を行った．調査域東側の詳細海底地形には，強い潮流により形成されたと考えられるサンドウェーブ構造が見られた．調査域の西側はサンドウェーブが発達せず，比較的滑らかな海底地形である．中央構造線断層帯に対応するような段差地形，横ずれ断層の活動によって形成されたと考えられる窪みが見られた．調査域西側のサブボトムプロファイラ記録からイメージされる浅層構造には，完新世と更新世の堆積層境界と解釈できる音響層序，断層と考えられる堆積層構造の上下方向のずれが確認された．中央構造線に沿って重力異常の急変帯があり，海岸沿いの南東側が高異常，北西側が低異常となっている．重力異常は海底近くの堆積層より深部の基盤構造を反映するものと思われる．重力異常から推定される基盤構造の形状は，リストリック断層を伴うハーフグラーベン構造と調和的である．
I have developed a method to measure relative traveltimes of teleseismic P-wave between two stations as a function of frequency. The method includes an automated correction for the dispersion effects caused by the crustal reverberations at stations. Relative traveltime is computed by cross-correlating the corrected P-wave waveform at a station with that at the other station at ten narrow frequency bands from 0.03 to 0.77 Hz. This method was applied to the seismograms including the broadband ocean-bottom seismograph (BBOBSs) data from the TIARES and Polynesian BBOBS networks in French Polynesian region and the NOMAN network in northwest Pacific Ocean. Obtained relative travel time data have been used to improve the spatial resolution in the previous seismic velocity model using finite frequency P wave traveltime tomography.
Tadai 2 Powered X-ray di ff raction analysis is a fundamental method to quantitative analysis of mineral composition in sediments and rocks. RockJock program, which was developed by Eberl (2003) in USGS, is distributed free of charge, and is based on the Solver function in Microsoft Excel. More than 90 minerals can be determined to quantitative mineralogical composition, therefore, most of sediments and rocks retrieved by deep ocean drilling programs can be applied. It is quite easy to use the RockJock software, whereas the accuracy and the problems was not investigated enough. In addition, an approach to treat the small amount of samples and a method to evaluate amorphous bearing materials are not well established. Therefore, we report these concerns involved in RockJock programs using sediment core samples from D / V Chikyu Expedition and standard pure materials. Our results show that we can use RockJock program for small amounts of samples and amorphous bearing materials. Our results suggest that it is necessary to select the suitable condition according to the minerals composed in samples to improve the solution. We can recycle standardless XRD data measured on board D / V Chikyu for the quantitative
We reinvestigated tephra and cryptotephra stratigraphy of the Late Pleistocene deep-sea C9001C cores collected during the D/V Chikyu shakedown cruise. We identified 26 glass shard concentration horizons (spikes) corresponding to four previously reported tephras (G1, G2, G3, and G4 from top to bottom). We newly found three visible tephras and 19 nonvisible cryptotephras (G0.0-0.9, G1.1-1.4, G2.1-2.5, and G3.1-3.3). We newly correlated spike G0.2 with the Towada-Hachinohe (To-H: MIS 1/2, 15 ka), G0.5 with the Towada-Biscuit 2 (To-BP2: MIS 2, 18 ka), G1.1 with the Komagatake-i (39 ka), G1.2 with the Kutcharo-Shoro (MIS 3, 40 ka), and G3.3 with the Sambe-Kisuki (MIS 5c, 100 ka) tephras. Spikes G2.2, G2.3, and G2.4 may correlate with the Towada tephra series (seven correlative candidates), spike G3.1 with an Ontake volcano tephra (MIS 5b-5c), and spike G3.2 with the Towada-Castera or Towada-Aosuji (both MIS 5b-5d) tephra. We classified spike G0.1 as reworked materials of the underlying spike G0.2 (To-H), and the combinations of spikes G0.3 and G0.4 and of G0.8 and G0.9 as the result of repeated reworking of the underlying spikes G0.5 (To-BP2) and G1 (To-Of), respectively. We also classified spikes G1.3 and G1.4 as reworked mixtures of Shikotsu-1 tephra with glass shards from other tephras. The upward decrease of the glass shard populations above spikes G3 and G4 is interpreted as indicating immediate reworking of the tephras after initial emplacement. Whether or not a marine tephra is preserved depends on depositional and post-depositional processes and not simply on the eruptive volume or the distance from source. Nevertheless, cryptotephras recognized by glass shard concentration horizons in marine cores can provide additional datum planes and contribute to marine tephrostratigraphy.
To better understand cetacean immunology, it is important to develop markers that identify specific leukocyte populations. We created a monoclonal antibody (mAb) library against leukocytes of the beluga whale (Delphinapterus leucas), and established five hybridoma clones that produce mAbs. Three of these mAbs (ID: BW-3C3, BW-2G4, and BW-2G6) react with mononuclear leukocytes including lymphocytes and monocytes. mAb BW-3C3 react to a fraction of the lymphocytes. The mAb-positive cells were identical to cells that also stained with polyclonal anti-whale IgM antibodies, indicating that the mAb BW-3C3 specifically reacts to B lymphocytes. mAb BW-2G4 specifically binds to monocytes that possess a reniformed nucleus. mAb BW-2G6 was found to bind to heterogeneous lymphocytes, namely, anti-whale IgM antibody-positive and -negative lymphocyte populations. This indicates that this mAb reacts with B and non-B lymphocyte fractions. The other two mAbs (ID: BW-4B10 and BW-4G12) react with polymorphonuclear granulocytes. Double staining with Giemsa-eosin showed that mAb BW-4B10 and mAb BW-4G12 specifically identify neutrophils and eosinophils, respectively. This panel of mAbs will be a useful tool for classifying leukocytes and for determining their localization in different tissues, which in turn would contribute to our understanding of cetacean immunology and allow evaluation of leukocyte function in infectious diseases.
We developed a new sequential chemical separation technique of Sr, Nd and Pb for isotope analysis. Chemical separation of these elements with high efficiency, high purity and low chemical blank was achieved by four steps of column chromatography using extraction resins as well as cation exchange resin with small column volumes. TRU resin, used in the second step of our separation scheme, extracts rare earth elements from sample solution with high efficiency. However, we found that the retention rate of Nd and the other rare earth elements on the TRU column is sensitive to the total amount of Fe loaded on the TRU column. Therefore, controlling the sample size by means of Fe concentration is essential in achieving high recovery rate of Nd when using TRU resin. Our chemical separation technique allows analyzing Sr-Nd-Pb isotopes from small sized samples such as micro-milled silicates and several pieces of foraminiferal carbonates.
We report radiolarian fossils from sedimentary rocks recovered from off southeast Boso Peninsula, central Japan to determine the age of the rocks. Rock samples were collected from sites D03 and D04 on the steep slopes close to the Katsuura Submarine Canyon using a dredge during the cruise KT-12-35. The radiolarian assemblages suggested a geologic age of 8.84–7.74 Ma (middle Late Miocene) for the site D03 (southeast slope of the Awa-Bank) and two geologic ages of 4.5–4.3 Ma (middle Pliocene) and 11.8–9.0 Ma (early Late Miocene) for the site D04 (north slope from the Katsuura Submarine Canyon). These ages correspond to depositional ages of the Amatsu Formation of the Miura Group (forearc basin deposits), the Nishizaki Formation (accretionary prism) and the Minami-Boso Group (trench slope basin deposits) exposed on the Boso Peninsula.
Shallow sub-seafloor structure in the vicinity of Iheya-Minor Ridge was acquired using Sub-Bottom Profiler equipped on R/V Kaimei in KM17-12C cruise. Normal faults and downward warping stratification indicate regional subsidence of the studied area. The profiles also suggest local-scale compression folds that may associate with the intrusive volcanism of the ridge.
An analytical method for determining the stable isotope ratios of Ba was developed by using thermal ionization mass spectrometry (TIMS) and the 130Ba–135Ba double-spike total evaporation method (DS-TEV). We determined the isotope ratios of the 130Ba–135Ba double spike to be 134Ba/130Ba = 0.076623, 135Ba/130Ba = 1.081975, and 137Ba/130Ba = 0.209356 by using the intercept values of the mass-dependent fractionation lines and mixing line.
海洋研究開発機構は，船舶や各種観測機器およびスーパーコンピュータを有しており，現場観測と数値シミュレーション双方から海洋地球科学の課題にアプローチすることができる．我々は，全球非静力学モデルNonhydrostatic ICosahedral Atmospheric Model（NICAM）を用いた準実時間予測計算システムを地球シミュレータ上に構築し，機構による集中観測プロジェクトにおいて実利用した．即ちインドネシアを中心とする海大陸とその周辺海域を対象とする国際キャンペーンYears of the Maritime Continent（YMC; 海大陸研究強化年）において，海洋地球研究船「みらい」による集中観測期間中（MR17-08, MR15-04），準実時間計算を実行し，現場の最新の情報や観測地点付近の気象予測情報を共有することにより，多面的な現象理解と観測の円滑な実行の一端を担った．また，「みらい」北極航海（MR17-05C）では，機動的観測の最適化を目的として，初めて極域を対象とする準実時間予測を実施した．今後，様々な緯度帯での観測との比較検証を積み重ね，予測技術の高度化に取り組む．
Shinkaia crosnieri, a galatheid crab, has ectosymbiotic bacteria on its ventral setae, and forms very dense crowds in hydrothermally active regions and seep areas. They feed on the symbiotic bacteria and do not chase other animals for predation. To study how they move and behave in jostling crowds, we developed a vital staining to mark their individuals and trace them by using a camera on a remotely operated vehicle (ROV). Among the various dyes examined, Coomasie Brilliant Blue R250 (CBB) stained the galatheid crab the darkest, and its color lasted for more than 5 months in the laboratory at 4–5°C. The ventral setae were strongly stained, while the dorsal shell was weakly stained. The stained galatheid crab survived for more than 8 months. For the in situ staining of S. crosnieri at the Iheya North hydrothermal field in the Okinawa Trough, Japan, we applied a dye solution mixture (20 L) containing CBB and Acid Blue 161 to the galatheid crab population through a funnel equipped on the ROV Hyper-Dolphin. After staining for approximately 5 minutes, more than 18 individuals of S. crosnieri were dyed blue. They were disturbed by the staining process but seemed to be unharmed. The dyed galatheid crabs were identified by the ROV one and two days post staining. They seemed to remain at the place where they were stained.
The geographical distribution and geological occurrence of diatom ooze and diatomite–diatomaceous sediments were reviewed in and around the middle-high latitude of the North Pacific Ocean including the Bering and Japan seas. Diatoms are the most abundant microfossils found in the bottom sediments of the northern North Pacific Ocean, and the marginal Bering, Okhotsk and Japan seas. The marginal basins in the middle-high latitude of the North Pacific Ocean were formed by tectonic and volcanic activities in the late Oligocene–early Miocene. The early middle Miocene diatomite intercalated with siliceous sandstone to siltstone was deposited in shallow basins. The middle-late Miocene diatomite and diatomaceous mudstone was formed by global cooling and increased primary productivity under anoxic bottom-water conditions at bathyal depths. The late Miocene to early Pliocene diatomite and diatomaceous siltstone formed under oxic bottom-water conditions is widely distributed. During the late Pliocene-Pleistocene, turbidity sands and/or silts capped and diluted the diatomaceous sediment. The timing of these changes in sedimentary facies is simultaneous in the North Pacific region.
We conducted marine seismic surveys using a multichannel seismic reflection (MCS) system and ocean bottom seismographs in the southern part of the Japan Sea including the western Yamato Basin, starting in 2014, as part of the research project “Integrated Research Project on Seismic and Tsunami Hazards Around the Sea of Japan” funded by the Ministry of Education, Culture, Sports, Science and Technology of Japan. The objective in these surveys is to reveal the distribution of the active faults, and the relationship between the crustal structure and the tectonic history in the southern Japan Sea. In this data paper, we describe the acquisition and processing of the MCS data obtained by these surveys.
海底の継続的なモニタリングを可能とする手法として，通信と電力を常時供給可能なケーブル式海底観測システムが広く活用されつつある．ケーブル式観測システムは，ケーブルに損傷を与えないよう海底熱水活動や急峻な地形を避けて常温の海底面上に構築されることが多い．しかし，高温の熱水が吹き出す海底熱水活動を継続的にモニタリングするためのケーブル式観測システムを構築する手法は確立されていない．そこで，本論文では，海底熱水活動域にケーブル式観測システムを構築するための事前調査航海において求められる調査内容を明らかにすると共に，地理情報システム（Geographic Information System: GIS）を用いて，航跡や観測結果の管理，情報の統合を地理空間上で行うことで，ケーブル式観測システムの敷設・配置に必要な情報収集や計画立案を効率的に実施可能とする手法を提案する．海中作業ロボット（Remotely Operated Vehicle: ROV）を用いた実際の海底熱水活動域での調査航海において提案手法を実践することでその妥当性を実証すると共に，海底熱水活動や海底面温度マッピングを行い，得られた熱水活動分布やそれに基づくケーブル式観測システムの配置計画についても議論することを目的とする．
米国，カナダ，フランス，及び英国における海洋観測データの公開に対する制限についてJAMSTECと同様の分野の研究を行っている公的機関の例を調査した結果を報告する．ここで疑問点は「近年の情報公開の流れにもかかわらず，開示しなくてもよい種類のデータがあるのか?」である．いずれの国でも個人情報，国防，及び商業上の秘密は開示義務を免れる．
