Several buried paleo-channels are located on the continental shelf of the western Yellow Sea. Research on the paleochannels is significant for both theoretical studies and practical applications. In this paper, we ana...Several buried paleo-channels are located on the continental shelf of the western Yellow Sea. Research on the paleochannels is significant for both theoretical studies and practical applications. In this paper, we analyse and discuss the mineralogy of sediments in a core(SYS-0803) recovered from a buried paleo-channel on the continental shelf of the western Yellow Sea. The aim is to determine the provenance of sediments that fill the paleo-channel. The heavy mineral assemblage of sediments in the core consists of schistose minerals, common hornblende, epidote, and ilmenite. The light mineral assemblage consists of plagioclase, quartz, lithic fragments, and K-feldspar. Analysis of the compositional maturity of the sand fraction revealed a quartz/feldspar ratio of < 1. A relatively high percentage of smectite is recorded throughout the entire paleo-channel fill, with the greatest percentage in the middle to lower parts. The detrital mineral assemblage and clay mineral content indicate that the paleo-channel sediments were sourced mainly from the Huanghe River during the last glacial period.展开更多
Coastal management in China is confronted with an urgent choice between natural restoration and maintenance of existing seawalls and reclaimed land for economic development.A key criterion for making this decision is ...Coastal management in China is confronted with an urgent choice between natural restoration and maintenance of existing seawalls and reclaimed land for economic development.A key criterion for making this decision is the resilience to coastal flooding,which depends on the ability to predict tidal level.Tidal duration asymmetry(TDA)is a key parameter in determination of the arrival and duration of flood tides.This study selected the western inner shelf of the Yellow Sea(WYS)as the study area and investigated the responses of TDA to different shoreline configurations and relative sea level rise.The responses of TDA to shoreline reconstruction yielded spatial variability locally and remotely.In the nearshore area,the responses of TDA to the complex ocean environment mainly originated from the combined functions of reflection,bottom friction,and advection,which controlled the energy transfer from M2 or S2 constituents to their overtides or compound tides.The sensitivity of TDA to coastline typologies was not limited to coastal waters but could stretch over the entire inner shelf.The vulnerability of tidal responses was due to the displacement of the M2 amphidrome of the Kelvin wave on the WYS,which in turn changed tidal energy fluxes over the regime.The relative sea level rise could intensify the feedback of TDA to seawalls and land reclamation.展开更多
Ocean acidification(OA)is a persistent challenge for humans and is predicted to have deleterious effects on marine organisms,especially marine calcifiers such as coral and foraminifera.Benthic foraminifera is an impor...Ocean acidification(OA)is a persistent challenge for humans and is predicted to have deleterious effects on marine organisms,especially marine calcifiers such as coral and foraminifera.Benthic foraminifera is an important component of sediment in the continental shelf,while little is known about the impact of ocean acidification on benthic foraminifera both at the community and individual level and associated calcium carbonate deposition.We conducted eight months continued culture experiment under the scenario of 400,800,1200 and 1600 ppm pCO_(2)gradients on living benthic foraminifera from four stations in the continental shelf of the West Pacific Ocean.Statistic results showed OA had a negative effect on the abundance of benthic foraminifera.In contrast,the diversity increased roughly under OA conditions implying OA might stimulate the emergence of rare species and promote community diversity to some extent.In addition,we confirmed that the offshore area wasn’t the refuge for benthic foraminifera while the nearshore one had more resistance to moderate acidification.Calcareous species Protelphidium tuberculatum was the dominant species occupying on average 75%in all treatments and its shell diameter,weight and thickness showed a decrease,indicating the decrease of calcification of benthic foraminifera.A relationship between the weight of P.tuberculatum and pCO_(2)(R^(2)=0.96)was established.Based on the present work,calcareous benthic foraminifera deposited 8.57104 t calcium carbonate per year and this might reduce by nearly half and 90%under 800 and 1200 ppm scenarios,which indicates a biocalcification crisis under ongoing OA.This work shows an analogy for palaeoceanic OA and also provides new insights into the sediment of calcium carbonate in the future.展开更多
基金supported by the National Natural Science Foundation of China(No.41476051)China-ASEAN maritime cooperation fund(Comparative Study of Holocene Sedimentary Evolution of the Yangtze River Delta and the Red River Delta)+2 种基金the National Natural Science Foundation Project(No.41606059)Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology Foundation Project(No.MRE201309)the Shandong Provincial Natural Science Foundation,China(No.ZR2016DL04)
文摘Several buried paleo-channels are located on the continental shelf of the western Yellow Sea. Research on the paleochannels is significant for both theoretical studies and practical applications. In this paper, we analyse and discuss the mineralogy of sediments in a core(SYS-0803) recovered from a buried paleo-channel on the continental shelf of the western Yellow Sea. The aim is to determine the provenance of sediments that fill the paleo-channel. The heavy mineral assemblage of sediments in the core consists of schistose minerals, common hornblende, epidote, and ilmenite. The light mineral assemblage consists of plagioclase, quartz, lithic fragments, and K-feldspar. Analysis of the compositional maturity of the sand fraction revealed a quartz/feldspar ratio of < 1. A relatively high percentage of smectite is recorded throughout the entire paleo-channel fill, with the greatest percentage in the middle to lower parts. The detrital mineral assemblage and clay mineral content indicate that the paleo-channel sediments were sourced mainly from the Huanghe River during the last glacial period.
基金supported by the Joint Foundation of the Ministry of Education(Grant No.8091B022123)the Water Science and Technology Project of Jiangsu Province(Grant No.2022023)+1 种基金the Project of the Key Technologies of Port Engineering Construction under Medium and Long Period Wave Conditions(Grant No.ZJ2015-1)the Open Funding from the Key Laboratory of Port,Waterway and Sedimentation Engineering of the Ministry of Communications in 2023(Grant No.Yk223001-3).
文摘Coastal management in China is confronted with an urgent choice between natural restoration and maintenance of existing seawalls and reclaimed land for economic development.A key criterion for making this decision is the resilience to coastal flooding,which depends on the ability to predict tidal level.Tidal duration asymmetry(TDA)is a key parameter in determination of the arrival and duration of flood tides.This study selected the western inner shelf of the Yellow Sea(WYS)as the study area and investigated the responses of TDA to different shoreline configurations and relative sea level rise.The responses of TDA to shoreline reconstruction yielded spatial variability locally and remotely.In the nearshore area,the responses of TDA to the complex ocean environment mainly originated from the combined functions of reflection,bottom friction,and advection,which controlled the energy transfer from M2 or S2 constituents to their overtides or compound tides.The sensitivity of TDA to coastline typologies was not limited to coastal waters but could stretch over the entire inner shelf.The vulnerability of tidal responses was due to the displacement of the M2 amphidrome of the Kelvin wave on the WYS,which in turn changed tidal energy fluxes over the regime.The relative sea level rise could intensify the feedback of TDA to seawalls and land reclamation.
基金supports from the following projects:the National Natural Science Foundation of China(Nos.41976058,U1906211)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB42000000)Natural Science Foundation of Shandong Province(Grant No.ZR2021QD004)。
文摘Ocean acidification(OA)is a persistent challenge for humans and is predicted to have deleterious effects on marine organisms,especially marine calcifiers such as coral and foraminifera.Benthic foraminifera is an important component of sediment in the continental shelf,while little is known about the impact of ocean acidification on benthic foraminifera both at the community and individual level and associated calcium carbonate deposition.We conducted eight months continued culture experiment under the scenario of 400,800,1200 and 1600 ppm pCO_(2)gradients on living benthic foraminifera from four stations in the continental shelf of the West Pacific Ocean.Statistic results showed OA had a negative effect on the abundance of benthic foraminifera.In contrast,the diversity increased roughly under OA conditions implying OA might stimulate the emergence of rare species and promote community diversity to some extent.In addition,we confirmed that the offshore area wasn’t the refuge for benthic foraminifera while the nearshore one had more resistance to moderate acidification.Calcareous species Protelphidium tuberculatum was the dominant species occupying on average 75%in all treatments and its shell diameter,weight and thickness showed a decrease,indicating the decrease of calcification of benthic foraminifera.A relationship between the weight of P.tuberculatum and pCO_(2)(R^(2)=0.96)was established.Based on the present work,calcareous benthic foraminifera deposited 8.57104 t calcium carbonate per year and this might reduce by nearly half and 90%under 800 and 1200 ppm scenarios,which indicates a biocalcification crisis under ongoing OA.This work shows an analogy for palaeoceanic OA and also provides new insights into the sediment of calcium carbonate in the future.
