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11.
The Japanese government is committed to resuming sustainable commercial whaling, both on the high seas and along the Japanese coastline. To this end scientific whaling programs are supported with public money and the byproducts of the catch are distributed to the public and utilized in a variety of ways. Here we review the policies which govern how these byproducts are disseminated within Japan, as well as how the population as a whole makes use of whale resources. Possibilities for the future, if and when the international moratorium on commercial whaling ends, are also discussed. 相似文献
12.
Shallow marine carbonate sediments near the Dry Tortugas undergo extensive biogeochemical diagenesis upon deposition, resulting
in postdepositional fabric comprised of micritic aggregates of clay-sized particles, a matrix of peloidal mud, and intraparticular
cementation. Freshly deposited primary skeletons, mostly Halimeda fragments, yield micritic aggregates of clay-sized particles, which then form peloidal mud fabric upon compaction. The cryptocrystalline
particles produced by micritization are later replaced by high magnesian calcite. Cementation is observed in the intra-particular
microenvironment. However, no inter-particular, grain-binding cement was detected throughout the gravity core samples investigated. 相似文献
13.
The heat capacity of åkermanite solid solutions was measured by a small scale adiabatic calorimeter near the incommensurate-normal (I-N) transition. The heat capacity anomalies caused by the I-N transition show the type characteristic behavior implying the presence of dynamical fluctuations. The heat capacity anomalies were observed over the whole range of the åkermanite solid solutions Ca2Mg1-xCoxSi2O7 and Ca2Mg1-x-ZnxSi2O2. With increase of Co or Zn atoms, the transition temperature, Ti, rises linearly from ca. 83° C to 220° C and to 130° C, respectively. In the system Ca2CoSi2O7-Ca2FeSi2O7 and Ca2MgSi2O7-Ca2-FeSi2O7 electronic microscopy revealed that the temperature of the heat capacity anomaly decreases with increasing Fe content, whereas the Ti rises. This unusual behavior is ascribed to the microdomains observed in high resolution lattice images. 相似文献
14.
15.
The atmospheric 3He/4He ratio has been considered to be constant on a global scale, because the residence time of helium is significantly longer than the mixing time in the atmosphere. However, this ratio may be decreasing with time owing to the anthropogenic release of crustal helium from oil and natural gas wells, although this observation has been disputed. Here, we present the 3He/4He ratios of old air trapped in historical slags in Japan and of modern surface air samples collected at various sites around the world, measured with a newly developed analytical system. In air helium extracted from metallurgical slag found at refineries in operation between AD 1603 and 1907 in Japan, we determined a mean 3He/4He ratio of (5106 ± 108) × 10-5 RHESJ (where RHESJ is the 3He/4He ratio of the Helium Standard of Japan), which is consistent with the previously reported value of (5077 ± 59) × 10-5 RHESJ for historical slags in France and United Arab Emirates and about 4% higher than that of average modern air, (4901 ± 4) × 10-5 RHESJ. This result implies that the air 3He/4He ratio has decreased with time as expected by anthropogenic causes. Our modern surface air samples revealed that the 3He/4He ratio increases from north to south at a rate of (0.16 ± 0.08) × 10-5 RHESJ/degree of latitude, suggesting that the low 3He/4He ratio originates in high-latitude regions of the northern hemisphere, which is consistent with the fact that most fossil fuel is extracted and consumed in the northern hemisphere. 相似文献
16.
17.
Peatlands are globally important long-term sinks of carbon, however there is concern that enhanced peat decomposition and moss moisture stress due to climate change mediated drought will reduce moss productivity making these ecosystems vulnerable to carbon loss and associated long-term degradation. Peatlands are resilient to summer drought moss stress because of negative ecohydrological feedbacks that generally maintain a wet peat surface, but where feedbacks may be contingent on peat depth. We tested this ‘survival of the deepest’ hypothesis by examining water table (WT) position, near-surface moisture content, and soil water tension in peatlands that differ in size, peat depth, and catchment area during a summer drought. All shallow sites (<40 cm depth) lost their WT (i.e., the groundwater well was dry) for considerable time during the drought period. Near-surface soil water tension increased dramatically at shallow sites following WT loss, increasing ~5–7.5× greater at shallow sites compared to deep sites (≥40 cm depth). During a mid-summer drought intensive field survey, we found that 60–67% of plots at shallow sites exceeded a 100 mb tension threshold used to infer moss water stress. Unlike the shallow sites, tension typically did not exceed this 100 mb threshold at the deep sites. Using species dependent water content – chlorophyll fluorescence thresholds and relations between volumetric water content and WT depth, Monte Carlo simulations suggest that moss had nearly twice the likelihood of being stressed at shallow sites (0.38 ± 0.24) compared to deep sites (0.22 ± 0.18). This study provides evidence that mosses in shallow peatland may be particularly vulnerable to warmer and drier climates in the future, but where species composition may play an important role. We argue that a critical ‘threshold’ peat depth specific for different hydrogeological and hydroclimatic regions can be used to assess what peatlands are especially vulnerable to climate change mediated drought. 相似文献
18.
Hirofumi Hinata Satoshi Fujii Keita Furukawa Tomoya Kataoka Masafumi Miyata Takashi Kobayashi Masahiro Mizutani Takahiro Kokai Nobuyoshi Kanatsu 《Estuarine, Coastal and Shelf Science》2011
Signals from the tsunami waves induced by the March 11, 2011 moment magnitude (Mw) 9.0 Tohoku-Oki earthquake and from subsequent resonances were detected as radial velocity variability by a high-frequency ocean surface radar (HF radar) installed on the eastern coast of the Kii Channel, at a range of about 1000 km from the epicenter along the eastern to southern coasts of Honshu Island. A time–distance diagram of band-passed (9–200 min) radial velocity along the beam reveals that the tsunami waves propagated from the continental shelf slope to the inner channel as progressive waves for the first three waves, and then natural oscillations were excited by the waves; and that the direction of the tsunami wave propagation and the axis of the natural oscillations differed from that of the radar beam. In addition, spectral analyses of the radial velocities and sea surface heights obtained in the channel and on the continental shelf slope suggest complex natural oscillation modes excited by the tsunami waves. 相似文献
19.
Masahiko Tanaka Tomoki Nakamura Takaaki Noguchi Aiko Nakato Hatsumi Ishida Toru Yada Kei Shirai Akio Fujimura Yukihiro Ishibashi Masanao Abe Tatsuaki Okada Munetaka Ueno Toshifumi Mukai 《Meteoritics & planetary science》2014,49(2):237-244
The crystallization temperatures of Itokawa surface particles recovered by the space probe Hayabusa were estimated by a plagioclase geothermometer using sodic plagioclase triclinicity. The Δ131‐index required for the thermometer, which is the difference in X‐ray diffraction peak positions between the 131 and 11 reflections of plagioclase, was obtained by a high‐resolution synchrotron Gandolfi camera developed for the third generation synchrotron radiation beamline, BL15XU at SPring‐8. Crystallization temperatures were successfully determined from the Δ131‐indices for four particles. The observed plagioclase crystallization temperatures were in a range from 655 to 660 °C. The temperatures indicate crystallization temperatures of plagioclases in the process of prograde metamorphism before the peak metamorphic stage. 相似文献
20.
Ryota Fukai Tomohiro Usui Wataru Fujiya Yoshinori Takano Ken-ichi Bajo Andrew Beck Enrica Bonato Nancy L. Chabot Yoshihiro Furukawa Hidenori Genda Yuki Hibiya Fred Jourdan Thorsten Kleine Mizuho Koike Moe Matsuoka Yayoi N. Miura Frédéric Moynier Ryuji Okazaki Sara S. Russell Hirochika Sumino Michael E. Zolensky Haruna Sugahara Shogo Tachibana Kanako Sakamoto Masanao Abe Yuichiro Cho Kiyoshi Kuramoto 《Meteoritics & planetary science》2024,59(2):321-337
Japan Aerospace Exploration Agency's Martian Moons eXploration (MMX) mission will launch a spacecraft in 2024 to return samples from Phobos in 2029. Curatorial work for the returned Phobos samples is critical for the sample allocation without degrading the sample integrity and subsequent sample analysis that will provide new constraints on the origin of Phobos and the evolution of the circum-Mars environment. The Sample Analysis Working Team of the MMX is designing the sample curation protocol. The curation protocol consists of three phases: (1) quick analysis (extraction and mass spectrometry for gases), (2) pre-basic characterization (bulk-scale observation), and (3) basic characterization (grain-by-grain observation and allocation of the sample aliquots). Nondestructive analyses within the clean chamber (e.g., visible and near-infrared spectral imaging) and outside the chamber (e.g., gas mass spectrometry) are incorporated into the curation flow in coordination with the MMX mission instrument teams for ground-truthing the remote-sensing data sets. The MMX curation/sample analysis flow enables the seamless integration between the sample and remote-sensing data sets to maximize the scientific value of the collected Phobos samples. 相似文献