The 'Old Red Sand' is a type of semicemented medium-fine sandy sediment that is red(10R_4/8) or brown red(2.5YR_4/8) in colour and is found in late Quaternary deposits. The sediments have distinctive character...The 'Old Red Sand' is a type of semicemented medium-fine sandy sediment that is red(10R_4/8) or brown red(2.5YR_4/8) in colour and is found in late Quaternary deposits. The sediments have distinctive characteristics and are a critical archive for understanding climatic changes in the coastal areas of East Asia. The ages of the late Quaternary aeolian sand dunes from Haitan Island in the coastal area of South China are still in debate. In this study, three sets of marine terraces were identified in the northern region of Haitan Island. Aeolian dune sands are well preserved on the top of these terraces. Quartz Optically Stimulated Luminescence dating and the distribution of the formation ages demonstrated that the palaeo-dunes are deposits from the middle-late period of the Late Pleistocene(Q_3^(2-3)). The period may be divided into three stages, 100-90 ka, 70-60 ka, and 40-20 ka, in which the palaeo-dunes of the first two stages are more widespread and were formed separately during a low-sea level period of the Marine Isotope Stages 5 b and 4. Several depositional palaeo-flood event records were preserved during the last stage due to the increasing gradient of mountain gullies formed during the Last Glacial Maximum.展开更多
A total of 862 benthic species were identified in the island intertidal zone in Fujian, of which 734 species are animals and 128 species algae. Determination of Jaccard's similarity index of species was made on th...A total of 862 benthic species were identified in the island intertidal zone in Fujian, of which 734 species are animals and 128 species algae. Determination of Jaccard's similarity index of species was made on the intertidal communities around 11 major islands. Based on hierarchical clustering (WPGMA) and polar ordination, the benthic communities may be classified into three types; the estu-arine type, the bay and harbour type and open sea type. The distribution of the benthic community is related to the location of the island and its habitats of which, salinity and hydrodynamics are the major factors controlling the distribution of the communities.展开更多
112 short-period seismographs were set up in the 400 km^2 area of Pingtan Island and its surrounding areas in Fujian.The combined observations of the airgun source and ambient noise source were carried out using a den...112 short-period seismographs were set up in the 400 km^2 area of Pingtan Island and its surrounding areas in Fujian.The combined observations of the airgun source and ambient noise source were carried out using a dense array to receive the 387 airgun signals excited around the island and one month of continuous ambient noise recording.The 1-D P-wave and S-wave shallow velocity model of Pingtan Island is obtained by the inversion of the airgun body wave’s first arrival time data,and the reliability of the velocity model is verified by using the surface wave phase velocity dispersion curve,which can provide initial model for subsequent 3-D imaging.The experimental results show that this experiment is a successful demonstration of local scale green non-destructive detection,which can provide basic data for shallow surface structure research and strong vibration simulation of the Pingtan Island.展开更多
Based on the typhoon track and intensity data and the precipitation data of typhoon in China during 1961–2020,the overall characteristics of the rainstorm in Fujian caused by typhoon passing though Taiwan Island were...Based on the typhoon track and intensity data and the precipitation data of typhoon in China during 1961–2020,the overall characteristics of the rainstorm in Fujian caused by typhoon passing though Taiwan Island were studied.More than 80 percent of typhoons passing though the Taiwan Island can bring heavy rain to Fujian.There are 1.5 events of typhoon rainstorm in Fujian every year,and the average annual impact days are 3.0.In terms of spatial distribution,the frequency and intensity of cross-island typhoon rainstorm decrease rapidly from the coastal areas of Fujian to the inland areas,and Zherong,Changle and Jiu xianshan stations in the coastal areas are the high value centers.The typhoon paths of cross-island typhoon rainstorm in Fujian are mainly divided into three categories:landing-Fujian type(including landing-Fujian northeast turning,landing-Fujian middle northbound and landing-Fujian south westbound),landing-Guangdong and Zhejiang type and offshore turning type,among which landing-Fujian type typhoon has the most significant influence(only the landing-Fujian type appears the rainstorm of≥50 mm·(24 h);),and the rainstorm intensity,influence range and asymmetrical structure of the rainstorm are the strongest,the most extensive and the most significant in the landing-Fujian middle northbound path.Based on the NCEP reanalysis data,the comparative analysis of the environmental fields causing the difference of precipitation intensity between the two typhoons landing-Fujian middle northbound and landing-Fujian south westbound shows that:To the landing-Fujian middle northbound track,strong wind speed area on the north side of the typhoon center leads to strong onshore winds,in the role of mountain terrain,piedmont has better convergence and very strong deep vertical upward movement,with better moisture conditions,it can send low high-energy water vapor to the middle,the precipitation dynamics and water vapor conditions are significantly stronger than the landing-Fujian south westbound track,resulting in more typhoon heavy rain.展开更多
基金funded by the National Natural Science Foundation of China (Grants Nos. 41301012, 41771020 and U1405231)Natural Science Foundation of Fujian (Grant No. 2018R1034-5)Innovation Research Team Fund of Fujian Normal University (Grant No. IRTL1705)
文摘The 'Old Red Sand' is a type of semicemented medium-fine sandy sediment that is red(10R_4/8) or brown red(2.5YR_4/8) in colour and is found in late Quaternary deposits. The sediments have distinctive characteristics and are a critical archive for understanding climatic changes in the coastal areas of East Asia. The ages of the late Quaternary aeolian sand dunes from Haitan Island in the coastal area of South China are still in debate. In this study, three sets of marine terraces were identified in the northern region of Haitan Island. Aeolian dune sands are well preserved on the top of these terraces. Quartz Optically Stimulated Luminescence dating and the distribution of the formation ages demonstrated that the palaeo-dunes are deposits from the middle-late period of the Late Pleistocene(Q_3^(2-3)). The period may be divided into three stages, 100-90 ka, 70-60 ka, and 40-20 ka, in which the palaeo-dunes of the first two stages are more widespread and were formed separately during a low-sea level period of the Marine Isotope Stages 5 b and 4. Several depositional palaeo-flood event records were preserved during the last stage due to the increasing gradient of mountain gullies formed during the Last Glacial Maximum.
文摘A total of 862 benthic species were identified in the island intertidal zone in Fujian, of which 734 species are animals and 128 species algae. Determination of Jaccard's similarity index of species was made on the intertidal communities around 11 major islands. Based on hierarchical clustering (WPGMA) and polar ordination, the benthic communities may be classified into three types; the estu-arine type, the bay and harbour type and open sea type. The distribution of the benthic community is related to the location of the island and its habitats of which, salinity and hydrodynamics are the major factors controlling the distribution of the communities.
基金sponsored by the Key Technologies R&D Program of Fujian Earthquake Agency(G201703)the Seismic Science and Technology Spark Program,CEA(XH19023Y)
文摘112 short-period seismographs were set up in the 400 km^2 area of Pingtan Island and its surrounding areas in Fujian.The combined observations of the airgun source and ambient noise source were carried out using a dense array to receive the 387 airgun signals excited around the island and one month of continuous ambient noise recording.The 1-D P-wave and S-wave shallow velocity model of Pingtan Island is obtained by the inversion of the airgun body wave’s first arrival time data,and the reliability of the velocity model is verified by using the surface wave phase velocity dispersion curve,which can provide initial model for subsequent 3-D imaging.The experimental results show that this experiment is a successful demonstration of local scale green non-destructive detection,which can provide basic data for shallow surface structure research and strong vibration simulation of the Pingtan Island.
基金sponsored by the General project of Science and Technology Department of Fujian Province (2021J01456)the Major Science and the Technology project of Fujian Provincial Key Laboratory of Hazardous Weather(2020TF04)。
文摘Based on the typhoon track and intensity data and the precipitation data of typhoon in China during 1961–2020,the overall characteristics of the rainstorm in Fujian caused by typhoon passing though Taiwan Island were studied.More than 80 percent of typhoons passing though the Taiwan Island can bring heavy rain to Fujian.There are 1.5 events of typhoon rainstorm in Fujian every year,and the average annual impact days are 3.0.In terms of spatial distribution,the frequency and intensity of cross-island typhoon rainstorm decrease rapidly from the coastal areas of Fujian to the inland areas,and Zherong,Changle and Jiu xianshan stations in the coastal areas are the high value centers.The typhoon paths of cross-island typhoon rainstorm in Fujian are mainly divided into three categories:landing-Fujian type(including landing-Fujian northeast turning,landing-Fujian middle northbound and landing-Fujian south westbound),landing-Guangdong and Zhejiang type and offshore turning type,among which landing-Fujian type typhoon has the most significant influence(only the landing-Fujian type appears the rainstorm of≥50 mm·(24 h);),and the rainstorm intensity,influence range and asymmetrical structure of the rainstorm are the strongest,the most extensive and the most significant in the landing-Fujian middle northbound path.Based on the NCEP reanalysis data,the comparative analysis of the environmental fields causing the difference of precipitation intensity between the two typhoons landing-Fujian middle northbound and landing-Fujian south westbound shows that:To the landing-Fujian middle northbound track,strong wind speed area on the north side of the typhoon center leads to strong onshore winds,in the role of mountain terrain,piedmont has better convergence and very strong deep vertical upward movement,with better moisture conditions,it can send low high-energy water vapor to the middle,the precipitation dynamics and water vapor conditions are significantly stronger than the landing-Fujian south westbound track,resulting in more typhoon heavy rain.
文摘对闽南沿海兄弟屿西南部的侵入岩开展了LA-ICP-MS锆石U-Pb年代学及全岩地球化学研究,获得2组锆石^(206)Pb/^(238)U加权平均年龄,其中(241±3.6) Ma为岩体侵入年龄(印支期),(141±5.1) Ma可能为后期热液事件年龄(燕山期)。岩石属高钾钙碱性弱过铝质花岗岩,轻、重稀土分馏程度强烈,具有中强的Eu负异常(δ Eu 0.39~0.45)和富集大离子亲石元素特征,显示S型花岗岩。其构造背景可能与古太平洋板块及滨海断裂带等活动有关,兄弟屿的侵入岩体发现为该地区构造-岩浆演化提供新的时空约束信息。
