钻孔千斤顶压裂测量技术的发展和原地测量     

Yokoyama T  Ogawa K  Sano O  Hirata A  Mizuta Y  徐伟 《国际地震动态》2011,(1):67-76

为了测量距地表1 000 m以下位置的地壳应力状态,我们研究并开发了钻孔千斤顶压裂技术.技术的原理是:当钻孔千斤顶对钻孔壁加载时,与钻孔轴向平行的方向将会产生两个相对的新裂隙;卸载之后,如果千斤顶对钻孔壁的同一个地方进行施压,这对裂隙将会再次张开.与钻孔轴向垂直的平面上的两个主应力的大小和方向分别是由重张压力和裂隙的方...  相似文献   

Pressure-induced structural evolution of pyrite-type SiO<Subscript>2</Subscript>     

Yasuhiro Kuwayama  Kei Hirose  Nagayoshi Sata  Yasuo Ohishi 《Physics and Chemistry of Minerals》2011,38(8):591-597

The equation of state and pressure-induced structural evolution of pyrite-type SiO₂ have been investigated based on synchrotron X-ray diffraction measurements in a diamond-anvil cell. The Rietveld refinement revealed that the oxygen coordinate x of pyrite-type SiO₂ increases with increasing pressure. The SiO₆ coordination polyhedra of pyrite-type SiO₂ is less compressible than the unit cell, and the increase in x induces a rotation of the SiO₆ coordination polyhedra to fill the blank space in the unit cell. Thus, the volume reduction in pyrite-type SiO₂ is achieved mainly by the rotation of the SiO₆ polyhedra, rather than by the compression of the SiO₆ polyhedra. In addition, the increase in x with increasing pressure enhances a distortion of the coordination polyhedra of pyrite-type SiO₂, implying that pyrite-type SiO₂ is not likely to transform into a fluorite-type structure at higher pressures.  相似文献   

Olivine-rich exposures in the South Pole-Aitken Basin     

Satoru Yamamoto  Ryosuke Nakamura  Tsuneo Matsunaga  Yoshiko Ogawa  Yoshiaki Ishihara  Tomokatsu Morota  Naru Hirata  Makiko Ohtake  Takahiro Hiroi  Yasuhiro Yokota  Junichi Haruyama 《Icarus》2012,218(1):331-344

The distribution and the geological context of the olivine-rich exposures in the South Pole-Aitken (SPA) Basin on the Moon were investigated based on the spectral data obtained from the Spectral Profiler (SP) and Multiband Imager (MI) onboard the Japanese lunar explorer Kaguya/SELENE. The olivine-rich exposures are found only in the peak rings or central peaks of the Schrödinger basin and Zeeman crater, which are located in the outer region of the SPA Basin and not in the center region. On a localized scale, the olivine-rich materials are exposed on landslide features on the crater walls or sloped wall of the central peaks or the peak rings. Another observational finding is the co-existence of olivine-rich and plagioclase-rich materials on a kilometer scale spanning most of the olivine-rich sites in the Schrödinger basin. Pyroxene-rich materials are found in fresh craters outside the peak rings or the central peaks with olivine-rich materials. Based on these results, the following scenario are proposed: (1) the impact to form the SPA Basin melted a large amount of the lunar upper mantle and crust, and distributed the melted materials to the outer region; (2) local differentiation of melted materials hid the olivine-rich materials in the center region of the SPA Basin; (3) later impacts that formed the Schrödinger and Zeeman craters excavated and exposed the olivine-rich materials to the surface again; and (4) space weathering and regolith gardening obscured the olivine-rich spectra at the exposure sites, but recent, small scale impacts or landslides on the sloped wall exposed fresh olivine-rich materials, allowing the identification of the olivine-rich exposures by spectral remote-sensing. This suggests that several, different scale events play an important role in forming the surface distributions of originally deep-seated materials on the Moon, as well as on other planetary bodies.  相似文献   

Major and trace element abundances in volcanic glass shards in visible tephras in SG93 and SG06 drillcore samples from Lake Suigetsu,central Japan,obtained using femtosecond LA–ICP–MS     

Seiji Maruyama  Keiji Takemura  Takafumi Hirata  Tohru Yamashita  Tohru Danhara 《第四纪科学杂志》2020,35(1-2):66-80

The major and trace element concentrations of volcanic glass shards from visible tephra layers in the SG93 and SG06 cores from Lake Suigetsu, central Japan, were determined by femtosecond laser ablation–inductively coupled plasma–mass spectrometry. The glass-shard analyses, together with the petrographic properties of the tephra samples, allow the Suigetsu tephra layers to be broadly classified into tephras derived from calderas on Kyushu Island, and from Daisen and Sambe volcanoes in the Chugoku district of southwest Japan. The layers correlated with tephras from Kuju caldera and Daisen volcano, and with the younger Sambe tephras, have adakitic elemental features. A Suigetsu tephra sample correlated with the Sambe−Kisuki tephra based on petrographic properties has an elemental pattern similar to that of the Toya tephra from Hokkaido Island, northeast Japan. This match implies that tephras from northeast Japan, as well as Kyushu–Chugoku tephras, are possible correlatives of the Suigetsu tephra layers. Both petrographic properties and major–trace element data of volcanic glass shards are essential for robust tephra correlations, and hierarchical cluster analysis proved additionally useful in statistically evaluating relationships among the tephras.  相似文献   

Contribution of abiogenic and biogenic particles to trace-metal composition of phytoplankton assemblages in seawater of Shimizu Port, Japan     

Masahiro Sakata  Masaki Yamada  Satoshi Mitsunobu  Yasuhiro Senga 《Journal of Oceanography》2012,68(5):807-813

The contribution of abiogenic and biogenic particles to trace-metal (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Ti, V, and Zn) composition was investigated for phytoplankton (primarily diatoms) collected in Shimizu Port, a coastal seawater region. Except for Cd, the trace metals occurred predominantly in lithogenic or nonlithogenic abiogenic particles associated with plankton. In contrast, it is likely that Cd in seawater is taken up intracellularly, and not adsorbed extracellularly by phytoplankton. The lower P-normalized quotas of Cd in Shimizu Port than in offshore regions may be because plankton are dominated by diatoms.  相似文献   

Geochemical Assessment of a Subtropical Reservoir: A Case Study in Curitiba,Southern Brazil     

Ricardo Henrique Moreton Godoi  Patricia Y. Hirata  Andre V. L. Bitterncourt  Ana F. L. Godoi  Miguel Jafelicci Jr  Francisco J. dos Santos  Rafael Bini  Liuz F. Zara  Cynara L. N. Cunha  Ana P. K Soares  Eduardo F. Gobbi  Sanja Potgieter‐Vermaak  José E. F. C. Gardolinski  José M. Reis Neto  Giuliana Gatto Rotondo  Rene van Grieken 《洁净——土壤、空气、水》2012,40(4):364-372

Suspended particles and dissolved substances in water provide reactive surfaces, influence metabolic activity and contribute to the net sediment deposition. It therefore plays an important part in the ecology and quality of the water mass. The water quality in reservoirs is crucial and it is naturally maintained by flushing and sedimentation, which continuously remove phosphorus from the water. In some reservoirs, however, these removal processes are countered by recycling of ions which could play a key role to start and/or maintain the eutrophic state. The combination of macro‐, trace‐ and microanalysis techniques can be useful to trace pollution sources through a chemical fingerprint, whether be during an acute environmental disaster or a long‐term release of pollutants. The water quality and total metal content of reservoir sediments were assessed in a reservoir, situated in the capital of the Paraná State, in the South‐Eastern part of Brazil. The goal of this paper was to determine the metal presence in the sediment and metal and ionic speciation in the Green River reservoir water. Water and bed sediment samples, collected from various sites during 2008 and 2009, were investigated using XRF, ICP‐OES, ICP‐MS, XRD and zeta potential measurements. Based on the results, the heavy metal concentration and chemical composition of the suspended matter in the water samples, as well as the sediment's chemical composition will be discussed.  相似文献   

Comment on “Evaluation of palaeo-oxygenation of the ocean bottom cross the Permian–Triassic boundary” by Kakuwa (2008): Was the Late Permian deep-superocean really oxic?     

Yasuhiro Kato  Yukio Isozaki 《Global and Planetary Change》2009,69(1-2):79-81

Nearly 15 years after the proposal of the superanoxia concept (Isozaki, Y., 1994. Superanoxia across the Permo–Triassic boundary: record in accreted deep-sea pelagic chert in Japan. In: Embry, A.F., Beauchamp, B., Glass, D.J. (Eds.), Pangea: Global Environments and Resources. Memoir, Canadian Society of Petroleum Geologists, 17, pp. 805–812.), it is an appropriate timing to re-evaluate its geological context with the updated dataset. Kakuwa (Kakuwa, Y., 2008. Evaluation of palaeo-oxygenation of the ocean bottom across the Permian–Triassic boundary. Global and Planetary Change 63, 40–56.) lately discussed that the deep-sea anoxia across the Permian–Triassic boundary (P–TB) may have been much shorter than previously proposed, on the basis of ichnofabrics and geochemical data; however, his interpretations of the data do not appear straightforward nor persuading, and thus his claim is likely misled. Here we raise comments to his explanation on the following four issues: 1) invalid application of ichnofabric indices for shallow sea sediments to deep-sea cherts, 2) misinterpretation of Ce anomaly as a redox indicator, 3) improper application of various redox sensitive trace elements, and 4) questionable interpretations of δ³⁴S data of pyrites.  相似文献   

Formation age of the lunar crater Giordano Bruno     

Tomokatsu Morota  Junichi Haruyama  Hideaki Miyamoto  Chikatoshi Honda  Makiko Ohtake  Yasuhiro Yokota  Tsuneo Matsunaga  Naru Hirata  Hirohide Demura  Hiroshi Takeda  Yoshiko Ogawa  Jun Kimura 《Meteoritics & planetary science》2009,44(8):1115-1120

Abstract— Using the Terrain Camera onboard the Japanese lunar explorer, SELENE (Kaguya), we obtained new high‐resolution images of the 22‐kilometer‐diameter lunar crater Giordano Bruno. Based on crater size‐frequency measurements of small craters (<200 m in diameter) superposed on its continuous ejecta, the formation age of Giordano Bruno is estimated to be 1 to 10 Ma. This is constructive evidence against the crater's medieval age formation hypothesis.  相似文献   

Influence of Surface-Based Stable Layer Development on Asian Dust Behaviour Over Tokyo     

Nobumitsu Tsunematsu  Hironori Iwai  Shoken Ishii  Motoaki Yasui  Yasuhiro Murayama  Kohei Mizutani 《Boundary-Layer Meteorology》2009,131(2):263-275

The relationship between local meteorological fields and the behaviour of airborne Asian dust that arrived in the Tokyo metropolitan area on 1 April 2007 with the passage of a synoptic-scale cold front has been investigated through Doppler lidar observations, experiments using a regional atmospheric numerical model, and analyses of surface and upper-air meteorological observations. Results of the Doppler lidar observations showed that the Asian dust passed above the metropolitan area with strong south-westerly winds with speeds of 15–26 m s⁻¹. Meteorological fields reproduced by the numerical experiments showed the development of a surface-based stable layer in the metropolitan area caused by nocturnal radiational cooling near the ground surface and south-westerly warm air advection at upper levels. The blocking effect of the mountainous region located to the west of the metropolitan area induced an area of stagnant air inside the metropolitan area and promoted the stable layer development. Although strong downdrafts prevailed in the upper air, the airborne Asian dust did not spread to the ground when the stable layer was formed. These results strongly indicate that the developed stable layer prevented strong downdrafts from spreading to the ground, acting as an obstacle to the transport of the Asian dust particles from the upper air towards the ground. This is considered to be one of the main causes of the low appearance frequency of Asian dust phenomena near the ground in the Tokyo metropolitan area and eastern Japan.  相似文献   

Effects of physical changes in the ocean on the atmospheric pCO2: glacial-interglacial cycles     

Takasumi Kurahashi-Nakamura  Ayako Abe-Ouchi  Yasuhiro Yamanaka 《Climate Dynamics》2010,35(4):713-719

Based on LGM experiments with an atmosphere–ocean general circulation model, we systematically investigated the effects of physical changes in the ocean and induced biological effects as well on the low atmospheric CO₂ concentration (pCO₂) at the last glacial maximum (LGM). Numerical experiments with an oceanic carbon-cycle model showed that pCO₂ was lowered by ~30 ppm in the LGM ocean. Most of the pCO₂ reduction was explained by the change in CO₂ solubility in the ocean due to lower sea surface temperature (SST) during the LGM. Moreover, we found that SST changes in the high-latitude Northern Atlantic could explain more than one-third of the overall change in pCO₂ induced by global SST change, suggesting an important feedback between the Laurentide ice sheet and pCO₂.  相似文献