Characteristic features of infrasound waves observed in the Antarctic represent a physical interaction relating surface environment in the continental margin and surrounding Southern Ocean. Source location of several ...Characteristic features of infrasound waves observed in the Antarctic represent a physical interaction relating surface environment in the continental margin and surrounding Southern Ocean. Source location of several infrasound events is demonstrated by using combination of two array deployments along a coast of the Lützow-Holm Bay (LHB), East Antarctica, for data retrieving period in January-June 2015. These infrasound arrays being established in January 2013 clearly detected temporal variations in frequency content and propagation direction of the identified seven large events. Many of these sources are assumed to have cryoseismic origins;the ice-quakes associated with calving of glaciers, discharge of sea-ice, collision between sea-ice and icebergs around the LHB. Detail and continuous measurements of infrasound waves in the Antarctic are a proxy for monitoring regional environment as well as climate change in high southern latitude.展开更多
Characteristics and statistics of seismic tremors occurring during April 2015 were investigated by using short-period and broadband seismographs deployed at Syowa Station (SYO), in the Lützow-Holm Bay (LHB), East...Characteristics and statistics of seismic tremors occurring during April 2015 were investigated by using short-period and broadband seismographs deployed at Syowa Station (SYO), in the Lützow-Holm Bay (LHB), East Antarctica. In order to examine a relationship between surface environments in particular cryosphere variation, the MODIS satellite images were utilized for comparison with the detected tremor events. Since a large volume of sea-ice was discharged during the April, together with several large icebergs passed through from the west to the east at northern edge of the fast sea-ice of LHB, it was expected to detect seismic tremors involving cryospehre dynamics. During the month, a total number of 49 tremor events including short duration ice shocks were identified. Majority of the events (N = 39) had their duration times more than 15 minutes, which were divided into both tremors and ice shocks on the basis of experienced definition at SYO. Cryospheric sources recorded by seismic tremors were classified into several origins (collision, calving, crevassing, crashing, etc.): “crevassing events” along the large cracks inside the fast sea-ice in LHB (04 April), “discharge events” of fast sea-ice from the Bay (07 April), “collision events” between iceberg and the edge of fast sea-ice (14 April), “crashing movement” between fragmentation of fast sea-ice and packed sea-ice (18 April), and other origins. In particular, strong amplitude tremors with harmonic overtones were assumed to be occurred independently from whether condition, because these overtone tremors were identified at less stormy days by comparison with infrasound data at SYO.展开更多
Deployments of seismic stations in Antarctica are an ambitious project to improve the spatial resolution of the Antarctic Plate and surrounding regions. Several international programs had been conducted in wide area o...Deployments of seismic stations in Antarctica are an ambitious project to improve the spatial resolution of the Antarctic Plate and surrounding regions. Several international programs had been conducted in wide area of the Antarctic continent during the International Polar Year (IPY 2007-2008). The “Antarctica’s GAmburtsev Province (AGAP)”, the “GAmburtsev Mountain SEISmic experiment (GAMSEIS)” as a part of AGAP, and the “Polar Earth Observing Network (POLENET)” were major contributions to the IPY. The AGAP/GAMSEIS was an internationally coordinated deployments of more than few tens of broadband seismographs over the wide area of East Antarctica. Detailed information on crustal thickness and mantle structure provides key constraints on an origin of the Gamburtsev Mountains;and more broad structure and evolution of the East Antarctic craton and sub-glacial environment. From POLENET data obtained, local and regional signals associated with ice movements were recorded together with a significant number of teleseismic events. Moreover, seismic deployments have been carried out in the Lützow-Holm Bay (LHB), East Antarctica, by Japanese activities. The recorded teleseismic and local events are of sufficient quality to image the structure and dynamics of the crust and mantle, such as the studies by receiver functions suggesting a heterogeneous upper mantle. In addition to studies on the shallow part of the Earth, we place emphasis on these seismic deployments’ ability to image the Earth’s deep interior, as viewed from Antarctica, as a large aperture array in the southern high latitude.展开更多
We report new petrological, phase equilibria modeling, and fluid inclusion data for pelitic and mafic granulites from Rundv?gshetta in the highest-grade region of the Neoproterozoic Lützow-Holm Complex(LHC),East ...We report new petrological, phase equilibria modeling, and fluid inclusion data for pelitic and mafic granulites from Rundv?gshetta in the highest-grade region of the Neoproterozoic Lützow-Holm Complex(LHC),East Antarctica, and provide unequivocal evidence for fluid-rock interaction and high-temperature metasomatism in the presence of brine fluid. The studied locality is composed dominantly of well-foliated pelitic granulite(K-feldspar+quartz+sillimanite+garnet+ilmenite) with foliation-parallel bands and/or layers of mafic granulite(plagioclase+orthopyroxene+garnet+ilmenite+quartz+biotite). The boundary between the two lithologies is defined by thin(about 1 -20 cm in thick) garnet-rich layers with a common mineral assemblage of garnet+plagioclase+quartz+ilmenite+biotite ? orthopyroxene. Systematic increase of grossular and decrease of pyrope contents in garnet as well as decreasing Mg/(Fe+Mg) ratio of biotite from the pelitic granulite to garnet-rich rock and mafic granulite suggest that the garnet-rich layer was formed by metasomatic interaction between the two granulite lithologies. Phase equilibria modeling in the system NCKFMASHTO demonstrates that the metasomatism took place at 850 -860℃, which is slightly lower than the peak metamorphism of this region, and the modal abundance of garnet is the highest along the metapeliteemetabasite boundary(up to 40%), which is consistent with the field and thin section observations. The occurrence of brine(7.0 -10.9 wt.% Na Cleqfor ice melting or 25.1 -25.5 wt.% NaC leqfor hydrohalite melting) fluid inclusions as a primary phase trapped within plagioclase in the garnet-rich layer and the occurrence of Cl-rich biotite(Cl = 0.22 -0.60 wt.%) in the metasomatic rock compared to that in pelitic(0.15 -0.24 wt.%) and mafic(0.06-0.13 wt.%) granulites suggest infiltration of brine fluid could have given rise to the high-temperature metasomatism. The fluid might have been derived from external sources possibly related to the formation of major suture zones formed during the Gondwana amalgamation.展开更多
Color measuring is characterized by high resolution,high efficiency,and low cost. The application becomes increasingly common for tracing sediment sources and climate variation. Borehole LZ908 in the south coastal pla...Color measuring is characterized by high resolution,high efficiency,and low cost. The application becomes increasingly common for tracing sediment sources and climate variation. Borehole LZ908 in the south coastal plain of the Laizhou Bay in northeast China,was used,of which the top 54 m containing all marine facies was focused,to test the feasibility of colorimetry as a climate indi-cator using visible light reflectance spectra and L＊a＊b＊measurement results. The results show a good correction between lightness and calcium carbonate content in marine-terrigenous deposits;therefore,these deposits can be used as a proxy to study climate changes. Factor-analysis on the first derivative values of the raw visible light reflectance spectra produced three principal factors corresponding to goethite,organic matter,and hematite. Down hole variations in the three fac-tor scores,lightness,calcium carbonate content,and grain size were quite consistent. Moreover,high lightness and low factor scores in goethite,hematite,and organics indicated glacial regression deposits,while low lightness and high factor scores in goethite,hematite,and organics indicated interglacial transgression deposits.展开更多
The maximum of k numerical functions defined on , , by , ??is used here in Statistical classification. Previously, it has been used in Statistical Discrimination [1] and in Clustering [2]. We present first some theore...The maximum of k numerical functions defined on , , by , ??is used here in Statistical classification. Previously, it has been used in Statistical Discrimination [1] and in Clustering [2]. We present first some theoretical results on this function, and then its application in classification using a computer program we have developed. This approach leads to clear decisions, even in cases where the extension to several classes of Fisher’s linear discriminant function fails to be effective.展开更多
Cowpea, string Bean, or Macassar bean [Vigna unguiculata (L.) Walp] presents a short life cycle, low water requirement, develops in soils of low fertility, and has the ability to fix nitrogen from the air. In the Cerr...Cowpea, string Bean, or Macassar bean [Vigna unguiculata (L.) Walp] presents a short life cycle, low water requirement, develops in soils of low fertility, and has the ability to fix nitrogen from the air. In the Cerrado, the oxisols occupy practically all the flat to soft-wavy areas with little reserve of nutrients for the plants, in general, they are soils with great limitations of fertility. A source of alternative phosphate fertilization is the use of reactive natural phosphates. The reactive natural phosphate of Bayóvar presents intermediate solubility between the sources of soluble phosphates and the natural phosphates. In this context, the objective was to evaluate the initial development of Cowpea beans fertilized with the natural Bayóvar phosphate used for cultivation of the Brazilian Cerrado Oxisol. The experimental design was completely randomized, with six doses of phosphorus (0, 100, 200, 300, 400, 500 mg·dm-3) using natural Bayovar phosphate as a source in four replications. The species used in this study was the legume cowpea bean [Vigna unguiculata (L.) Walp] cultivar Tumucumaque. The treatments were applied using the natural phosphate Bayóvar as a source of phosphorus (29% of P2O5). At 33 DAS (days after sowing), the variable number of leaves of the Cowpea bean was analyzed and at 40 DAS, the variables plant height, SPAD chlorophyll index (Soil Plant Analysis Development) and stem diameter were analyzed. For all variables analyzed there was a significant effect. The initial development of the cowpea bean cultivated in the Brazilian Cerrado Oxisol was significantly influenced by the Bayóvar natural phosphate fertilization with the best phosphorus (P2O5) doses in the range of 200 to 350 mg·展开更多
为更好地进行网络管理和网络安全维护,通过研究加密流量的内容统计特征,提出基于M-序列检验的网络数据随机性评估算法(network data randomness estimation,NDRE)以识别加密流量。采用M-序列检验方法对序列随机性进行量化;根据负载序列...为更好地进行网络管理和网络安全维护,通过研究加密流量的内容统计特征,提出基于M-序列检验的网络数据随机性评估算法(network data randomness estimation,NDRE)以识别加密流量。采用M-序列检验方法对序列随机性进行量化;根据负载序列长度,自适应训练得到最优化参数集;利用最小风险贝叶斯准则,对加密流量进行识别。实验结果表明,与基于熵的方法相比,在控制一定计算复杂度的情况下,NDRE精确度有较大提高。展开更多
文摘Characteristic features of infrasound waves observed in the Antarctic represent a physical interaction relating surface environment in the continental margin and surrounding Southern Ocean. Source location of several infrasound events is demonstrated by using combination of two array deployments along a coast of the Lützow-Holm Bay (LHB), East Antarctica, for data retrieving period in January-June 2015. These infrasound arrays being established in January 2013 clearly detected temporal variations in frequency content and propagation direction of the identified seven large events. Many of these sources are assumed to have cryoseismic origins;the ice-quakes associated with calving of glaciers, discharge of sea-ice, collision between sea-ice and icebergs around the LHB. Detail and continuous measurements of infrasound waves in the Antarctic are a proxy for monitoring regional environment as well as climate change in high southern latitude.
文摘Characteristics and statistics of seismic tremors occurring during April 2015 were investigated by using short-period and broadband seismographs deployed at Syowa Station (SYO), in the Lützow-Holm Bay (LHB), East Antarctica. In order to examine a relationship between surface environments in particular cryosphere variation, the MODIS satellite images were utilized for comparison with the detected tremor events. Since a large volume of sea-ice was discharged during the April, together with several large icebergs passed through from the west to the east at northern edge of the fast sea-ice of LHB, it was expected to detect seismic tremors involving cryospehre dynamics. During the month, a total number of 49 tremor events including short duration ice shocks were identified. Majority of the events (N = 39) had their duration times more than 15 minutes, which were divided into both tremors and ice shocks on the basis of experienced definition at SYO. Cryospheric sources recorded by seismic tremors were classified into several origins (collision, calving, crevassing, crashing, etc.): “crevassing events” along the large cracks inside the fast sea-ice in LHB (04 April), “discharge events” of fast sea-ice from the Bay (07 April), “collision events” between iceberg and the edge of fast sea-ice (14 April), “crashing movement” between fragmentation of fast sea-ice and packed sea-ice (18 April), and other origins. In particular, strong amplitude tremors with harmonic overtones were assumed to be occurred independently from whether condition, because these overtone tremors were identified at less stormy days by comparison with infrasound data at SYO.
文摘Deployments of seismic stations in Antarctica are an ambitious project to improve the spatial resolution of the Antarctic Plate and surrounding regions. Several international programs had been conducted in wide area of the Antarctic continent during the International Polar Year (IPY 2007-2008). The “Antarctica’s GAmburtsev Province (AGAP)”, the “GAmburtsev Mountain SEISmic experiment (GAMSEIS)” as a part of AGAP, and the “Polar Earth Observing Network (POLENET)” were major contributions to the IPY. The AGAP/GAMSEIS was an internationally coordinated deployments of more than few tens of broadband seismographs over the wide area of East Antarctica. Detailed information on crustal thickness and mantle structure provides key constraints on an origin of the Gamburtsev Mountains;and more broad structure and evolution of the East Antarctic craton and sub-glacial environment. From POLENET data obtained, local and regional signals associated with ice movements were recorded together with a significant number of teleseismic events. Moreover, seismic deployments have been carried out in the Lützow-Holm Bay (LHB), East Antarctica, by Japanese activities. The recorded teleseismic and local events are of sufficient quality to image the structure and dynamics of the crust and mantle, such as the studies by receiver functions suggesting a heterogeneous upper mantle. In addition to studies on the shallow part of the Earth, we place emphasis on these seismic deployments’ ability to image the Earth’s deep interior, as viewed from Antarctica, as a large aperture array in the southern high latitude.
基金Partial funding for this project was produced by a Grant-in-Aid for Scientific Research (B) from Japan Society for the Promotion of Science (JSPS) (No. 26302009)the NIPR General Collaboration Projects (No. 2634) to Tsunogae
文摘We report new petrological, phase equilibria modeling, and fluid inclusion data for pelitic and mafic granulites from Rundv?gshetta in the highest-grade region of the Neoproterozoic Lützow-Holm Complex(LHC),East Antarctica, and provide unequivocal evidence for fluid-rock interaction and high-temperature metasomatism in the presence of brine fluid. The studied locality is composed dominantly of well-foliated pelitic granulite(K-feldspar+quartz+sillimanite+garnet+ilmenite) with foliation-parallel bands and/or layers of mafic granulite(plagioclase+orthopyroxene+garnet+ilmenite+quartz+biotite). The boundary between the two lithologies is defined by thin(about 1 -20 cm in thick) garnet-rich layers with a common mineral assemblage of garnet+plagioclase+quartz+ilmenite+biotite ? orthopyroxene. Systematic increase of grossular and decrease of pyrope contents in garnet as well as decreasing Mg/(Fe+Mg) ratio of biotite from the pelitic granulite to garnet-rich rock and mafic granulite suggest that the garnet-rich layer was formed by metasomatic interaction between the two granulite lithologies. Phase equilibria modeling in the system NCKFMASHTO demonstrates that the metasomatism took place at 850 -860℃, which is slightly lower than the peak metamorphism of this region, and the modal abundance of garnet is the highest along the metapeliteemetabasite boundary(up to 40%), which is consistent with the field and thin section observations. The occurrence of brine(7.0 -10.9 wt.% Na Cleqfor ice melting or 25.1 -25.5 wt.% NaC leqfor hydrohalite melting) fluid inclusions as a primary phase trapped within plagioclase in the garnet-rich layer and the occurrence of Cl-rich biotite(Cl = 0.22 -0.60 wt.%) in the metasomatic rock compared to that in pelitic(0.15 -0.24 wt.%) and mafic(0.06-0.13 wt.%) granulites suggest infiltration of brine fluid could have given rise to the high-temperature metasomatism. The fluid might have been derived from external sources possibly related to the formation of major suture zones formed during the Gondwana amalgamation.
基金The National Natural Science Foundation of China under contract No. 40602018the Chinese Offshore Investigation and Assessment ("908" Program) under contract No. 908-01-ZH2the Marine Welfare Research Project under contract No. 200805063
文摘Color measuring is characterized by high resolution,high efficiency,and low cost. The application becomes increasingly common for tracing sediment sources and climate variation. Borehole LZ908 in the south coastal plain of the Laizhou Bay in northeast China,was used,of which the top 54 m containing all marine facies was focused,to test the feasibility of colorimetry as a climate indi-cator using visible light reflectance spectra and L＊a＊b＊measurement results. The results show a good correction between lightness and calcium carbonate content in marine-terrigenous deposits;therefore,these deposits can be used as a proxy to study climate changes. Factor-analysis on the first derivative values of the raw visible light reflectance spectra produced three principal factors corresponding to goethite,organic matter,and hematite. Down hole variations in the three fac-tor scores,lightness,calcium carbonate content,and grain size were quite consistent. Moreover,high lightness and low factor scores in goethite,hematite,and organics indicated glacial regression deposits,while low lightness and high factor scores in goethite,hematite,and organics indicated interglacial transgression deposits.
文摘The maximum of k numerical functions defined on , , by , ??is used here in Statistical classification. Previously, it has been used in Statistical Discrimination [1] and in Clustering [2]. We present first some theoretical results on this function, and then its application in classification using a computer program we have developed. This approach leads to clear decisions, even in cases where the extension to several classes of Fisher’s linear discriminant function fails to be effective.
文摘Cowpea, string Bean, or Macassar bean [Vigna unguiculata (L.) Walp] presents a short life cycle, low water requirement, develops in soils of low fertility, and has the ability to fix nitrogen from the air. In the Cerrado, the oxisols occupy practically all the flat to soft-wavy areas with little reserve of nutrients for the plants, in general, they are soils with great limitations of fertility. A source of alternative phosphate fertilization is the use of reactive natural phosphates. The reactive natural phosphate of Bayóvar presents intermediate solubility between the sources of soluble phosphates and the natural phosphates. In this context, the objective was to evaluate the initial development of Cowpea beans fertilized with the natural Bayóvar phosphate used for cultivation of the Brazilian Cerrado Oxisol. The experimental design was completely randomized, with six doses of phosphorus (0, 100, 200, 300, 400, 500 mg·dm-3) using natural Bayovar phosphate as a source in four replications. The species used in this study was the legume cowpea bean [Vigna unguiculata (L.) Walp] cultivar Tumucumaque. The treatments were applied using the natural phosphate Bayóvar as a source of phosphorus (29% of P2O5). At 33 DAS (days after sowing), the variable number of leaves of the Cowpea bean was analyzed and at 40 DAS, the variables plant height, SPAD chlorophyll index (Soil Plant Analysis Development) and stem diameter were analyzed. For all variables analyzed there was a significant effect. The initial development of the cowpea bean cultivated in the Brazilian Cerrado Oxisol was significantly influenced by the Bayóvar natural phosphate fertilization with the best phosphorus (P2O5) doses in the range of 200 to 350 mg·
文摘为更好地进行网络管理和网络安全维护,通过研究加密流量的内容统计特征,提出基于M-序列检验的网络数据随机性评估算法(network data randomness estimation,NDRE)以识别加密流量。采用M-序列检验方法对序列随机性进行量化;根据负载序列长度,自适应训练得到最优化参数集;利用最小风险贝叶斯准则,对加密流量进行识别。实验结果表明,与基于熵的方法相比,在控制一定计算复杂度的情况下,NDRE精确度有较大提高。
