Interaction of the Kuroshio water and shelf waterin the Tsushima Current region in summer   总被引：2，自引：0，他引：2  

Guo Binghuo  Heung-Jae Lie  Jae Hak Lee 《海洋学报(英文版)》1998,17(3):277-292

ＩｎｔｅｒａｃｔｉｏｎｏｆｔｈｅＫｕｒｏｓｈｉｏｗａｔｅｒａｎｄｓｈｅｌｆｗａｔｅｒｉｎｔｈｅＴｓｕｓｈｉｍａＣｕｒｒｅｎｔｒｅｇｉｏｎｉｎｓｕｍｍｅｒＧｕｏＢｉｎｇｈｕｏ,１Ｈｅｕｎｇ－ＪａｅＬｉｅ２ａｎｄＪａｅＨａｋＬｅｅ２（ＲｅｃｅｉｖｅｄＳｅ...  相似文献   

西太平洋赤道附近海温与中国东南沿海台风关系的初步分析   总被引：7，自引：1，他引：6  

许金镜 《台湾海峡》1998,17(3):278-281

本文对１９６０－１９９６年北太平洋月平均海表温度和中国东南沿海年台风资料的分析素材,初步揭示了两者之间联系。结果表明,西太平洋赤道附近海流区的海表温度不仅在同期具有高与台风多呈正相关关系。而且在前期存在关预测的先兆,特别是秋冬两季更加明显,具有较好的隔季相关关系。经建立预报方程,其趋势拟合率达８１．８％,试报３ａ,并准确率为６６．７％。  相似文献   

Estimation of soil moisture using deep learning based on satellite data: a case study of South Korea     

Chang suk Lee  Jun Dong Park  Jae-Dong Jang 《地理信息系统科学与遥感》2019,56(1):43-67

The Korea Meteorological Administration uses soil moisture (SM) observed by the Advanced Microwave Scanning Radiometer-2 (AMSR2) to monitor drought. However, it may not be appropriate for monitoring drought in South Korea due to significant underestimation of SM. In this study, we used a deep learning method that performs better than traditional statistical and physical models for reliable estimation of SM based on remotely sensed satellite data. For estimating SM, we carefully selected input variables that exhibit a feedback loop with SM. To build an effective deep learning model, we examined the influences of sampling criteria and input parameters as well as the accuracy of several deep neural networks. The selected model was cross-validated to determine its stability. The estimated SM using deep learning had a high correlation coefficient (R) of 0.89 and a low root mean square error (RMSE; 3.825%) and bias (?0.039%) compared to in-situ measurements. A time series analysis using dynamic time warping was conducted which showed that the estimated SM was almost similar to the in-situ SM. In order to investigate the improvement in SM estimation using our method, it was compared with the Global Land Data Assimilation System and AMSR2. Significant improvements in R and a reduction in error values by more than half were achieved using our method. The estimated SM has finer spatial resolution at 4 km, and it can be rapidly produced, which will be useful for drought monitoring over the Korean Peninsula in near-real-time.  相似文献   

桂东南古罗和王姜冲钾玄质辉长岩的成因:地球化学、锆石U-Pb年代学及Hf同位素特征制约     

农军年  郭尚宇  孙明行  唐娟红  覃瑞才  周秋娥 《现代地质》2020,34(5):1001-1014

古罗和王姜冲岩体产于扬子地块与华夏地块拼合带的西南段,对剖析华南区域构造演化过程具有重要的地质意义。古罗和王姜冲岩体主要由辉长岩及少量的闪长岩组成。LA-ICP-MS锆石U-Pb年代学分析表明,古罗和王姜冲辉长岩的侵位结晶时限分别为(163±1) Ma和(158±1) Ma,属于燕山期岩浆活动的产物。岩石无Nb、Ta负异常,具有板内钾玄岩系列特征,锆石的ε_Hf(t)值主要集中在0.7~8.3之间,其二阶段Hf模式年龄($T_{DM_{2}}$)为672~1 168 Ma,暗示其源区主要为新元古代—中元古代岩石圈地幔。综合地球化学、锆石Hf同位素组成特征及区域地质资料,认为古罗和王姜冲岩体是在板内伸展-减薄环境主要由亏损的软流圈地幔和富集的岩石圈地幔岩浆混合形成,且在上升过程中受到壳源组分混染。  相似文献   

Multiple calcrete profiles in the Tabernas Basin,southeast Spain: their origins and geomorphic implications     

David J. Nash  Roger F. Smith 《地球表面变化过程与地形》1998,23(11):1009-1029

The paper describes a sequence of Pliocene(? ) to Quaternary age calcretes developed within alluvial fan and fluvial gravels in the Tabernas Basin, Almería Province, southeast Spain. Calcrete profiles are described from sites adjacent to major tributaries of the Rambla de Tabernas. Six distinct calcrete units are identified within the basin. These have variable distributions but have developed in an identifiable evolutionary sequence. Two pairs of calcrete units are widely present across the basin preserving two former land surfaces. Each of the former land surfaces has been planated and subsequently buried by alluvial fan or fluvial gravels. A massive calcrete unit is present at the base of each gravel sequence, immediately in contact with the underlying bedrock, with a less well developed calcrete unit situated at the top of the gravel sequence. The lowest two calcrete units within the basin are more spatially restricted and are confined to the floors and flanks of incised drainage lines. The geochemistry, macro- and micromorphological properties and geomorphological positions of the calcrete units are outlined and, on the basis of this information, their mode of origin identified. Two main modes of calcrete genesis appear to be present: massive calcretes situated in direct contact with bedrock are suggested to have formed by groundwater processes, whilst calcretes situated at the top of gravel sequences are likely to have developed by pedogenic processes. Calcrete genesis is subsequently considered in the context of the reconstruction of the early phases of landscape development, and is suggested to have been controlled by phases of uplift and stability within the Tabernas Basin. © 1998 John Wiley & Sons, Ltd.  相似文献   

东南沿海干热岩资源成因模式探讨及勘查进展     

李亭昕  蔺文静  甘浩男  岳高凡  张德龙  王贵玲 《地质力学学报》2020,26(2):187-200

干热岩是一种重要的地热资源,绝大部分以开采地壳中生代以来中酸性侵入岩体中所蕴含的热量为主。东南沿海地区是中国最主要的高放射性花岗岩分布区,发育大面积的中生代酸性花岗岩体,是寻找干热岩的良好靶区。通过研究东南沿海大地构造背景、区域大地热流分布、地壳厚度、居里面埋深及新构造等条件,分析了东南沿海干热岩资源的赋存背景,对福建地区是否存在干热岩进行了探讨,并通过控热构造分析提出了东南沿海干热岩资源的成因模式,初步建立了东南沿海干热岩成藏的三元聚热模型,总结了漳州、惠州等地区的干热岩资源靶区勘查进展,相关研究为今后中国东南沿海地区干热岩勘查评价提供了基础。   相似文献   

A study of igneous rocks related to Zn–Pb mineralization in the Shinyemi and Gagok deposits of the Taebaeksan Basin,South Korea     

Jieun Seo  Seon‐Gyu Choi  Minho Koo  Chang Whan Oh  In&#x;Chang Ryu  Gilljae Lee 《Resource Geology》2020,70(3):215-232

The Shinyemi and Gagok deposits, located in the Taebaeksan Basin, South Korea, display Zn–Pb mineralization along a contact between Cretaceous granitoids and Cambrian–Ordovician carbonates of the Joseon Supergroup. The Shinyemi mine is one of the largest polymetallic skarn‐type magnetite deposits in South Korea and comprises Fe and Fe–Mo–Zn skarns, and Zn–Cu–Pb replacement deposits. Both deposits yield similar Cretaceous mineralization ages, and granitoids associated with the two deposits displaying similar mineral textures and compositions, are highly evolved, and were emplaced at a shallow depth. They are classified as calc‐alkaline, I‐type granites (magnetite series) and were formed in a volcanic arc. Compositional variation is less in the Shinyemi granites and aplites (e.g., SiO₂ = 74.4–76.6 wt% and 74.4–75.1 wt%, respectively) than in the Gagok granites and aplites (e.g., SiO₂ = 65.6–68.0 wt% and 74.9–76.5 wt%, respectively). Furthermore, SiO₂ vs K/Rb and SiO₂ vs Rb/Sr diagrams indicate that the Shinyemi granitoids are more evolved than the Gagok granitoids. Shinyemi granitoids had been already differentiated highly in deep depth and then intruded into shallow depth, so both granite and aplite show the highly evolved similar chemical compositions. Whereas, less differentiated Gagok granitoids were separated into two phases in the last stage at shallow depth, so granite and aplite show different compositions. The amounts of granites and aplite are similar in the Shinyemi deposit, whereas the aplite appears in an amount less than the granite in the Gagok deposit. For this reason, the Shinyemi granitoids caused not only Fe enrichment during formation of the dolomite‐hosted magnesian skarn but also was associated with Mo mineralization in the Shinyemi deposit. Zn mineralization of the Gagok deposit was mainly caused by granite rather than aplite. Our data suggest that the variation in mineralization displayed by the two deposits resulted from differences in the compositions of their associated igneous intrusions.  相似文献   

A fifty-year production and economic assessment of common property-based management of marine living common resources: A case study for the women divers communities in Jeju,South Korea     

Jae-Young Ko  Glenn A. Jones  Moon-Soo Heo  Young-Su Kang  Sang-Hyuck Kang 《Marine Policy》2010

We examined the conditions of successful common property-based management for coastal marine living resources, using a case of historically and anthropologically well established women divers communities on Jeju Island, South Korea, focusing on their decentralized work rules and production records. Due to their tight social network and work rule, the women divers have harvested coastal marine living resources with limited fishing pressure exclusively from their village fishing grounds for over 400 years. However, their harvest patterns have been mostly reactive to market prices, eventually requiring direct governmental regulations such as total allowable catch in some cases. Most recently, the communities have been experiencing multiple challenges: their aging population, water pollution in the coastal zone, competition with cultured products and imported seafood, and expanding barren grounds. These challenges demand a multi-scale/dimensional response if the women divers communities are to keep their village fishing grounds and communities sustainable.  相似文献   

湘东南地区中、新生代山体隆升过程的热年代学研究   总被引：16，自引：0，他引：16  

柏道远  黄建中  孟德保  马铁球  王先辉  张晓阳  陈必河 《地球学报》2006,27(6):525-536

湘东南地区位于南岭中段北缘。本文应用热年代学方法,测定了湘东南地区5个侵入体的热历史,进而分析湘东南中新生代的隆升过程,并结合区域构造背景,对热演化过程与构造发展过程之间的关系进行了探讨。研究结果表明,湘东南地区中新生代山体隆升过程总体上分为由较快速→快速→缓慢→快速的4个阶段,222～146.Ma期间以0.069mm/a的平均速率较快隆升,146.4～94.11Ma期间以0.113～0.186mm/a的平均速率快速隆升,94.11～14.8Ma期间以0.014～0.028mm/a的平均速率缓慢隆升,14.8Ma～0.0Ma以0.143～0.295mm/a的平均速率快速隆升。晚近时期的隆升总体呈加速趋势。隆升过程在空间上具有非均匀性,不同岩体间隆升过程存在差异。地壳隆升过程在时间上具有明显的互补性,早期具较快速或较大幅度隆升的岩体,通常伴随着晚期相对较慢和较小幅度的隆升。根据热年代学分析结果,结合区域构造背景和其它地质资料,推断五峰仙、大义山、骑田岭等地区在中三叠世后期因构造叠置增厚了4100～7700m以上,证明印支运动早期为强烈的陆内挤压造山运动。燕山晚期岩体隆升和降温由早期构造剥蚀和晚期风化剥蚀造成,并具有良好的盆地沉积响应。湘东南地区晚近时期的快速隆升是区域性整体抬升。  相似文献   

Pathways of organic matter through food webs of diverse habitats in the regulated Nakdong River estuary (Korea)     

Eun Jung Choy  Soonmo An  Chang-Keun Kang 《Estuarine, Coastal and Shelf Science》2008

The benthic macroinvertebrates of the Nakdong River estuary were sampled at three different habitats: two salt marsh (Scirpus triqueter and Phragmites australis) beds and a bare intertidal flat. Fishes were sampled in the main channel. The trophic importance of marsh vascular plants, microphytobenthos, and riverine and channel particulate organic matter to macroinvertebrate and fish production was studied using stable carbon and nitrogen isotope tracers. There was a dramatic change in coverage of macrophytes (salt marshes and seagrass) after the construction of an estuarine barrage in 1987 in the Nakdong River estuary, with the S. triqueter bed increasing, the P. australis bed decreasing, and Zostera marina habitats being nearly lost. Although the invertebrate δ¹³C were within a narrower range than those of the primary producers, the values varied considerably among consumers in these habitats. However, the isotope signatures of consumers showed similarities among different habitats. Cluster analysis based on their isotopic similarity suggested that the isotope variability among species was related more to functional feeding groups than to habitats or taxonomic groups. While δ¹³C values of suspension feeders were close to that of the channel POM (mainly phytoplankton), other benthic feeders and predators had δ¹³C similar to that of microphytobenthos. Isotopic mixing model estimates suggest that algal sources, including microphytobenthos and phytoplankton, play an important role in supporting the benthic food web. Despite the huge productivity of emergent salt marshes, the contribution of the marsh-derived organic matter to the estuarine food webs appears to be limited to some nutrition for some invertebrates just within marsh habitats, with little on the bare intertidal flats or in the channel fish communities. Isotope signatures of the channel fishes also confirm that algal sources are important in supporting fish nutrition. Our findings suggest that benthic and pelagic microalgae made a large contribution to consumer diets, while marsh plants may not have a large role in supporting food webs in this estuarine system.  相似文献