Regional tectonic deformation setting before the Ms8.1 earthquake in the west of the Kunlun Mountains Pass

This paper gives a preliminarily study of the regional tectonic deformation setting before the M_s8.1 earthquake that occurred in the west of the Kunlun Mountains Pass; in the study, the data of the velocity field of crustal horizontal movement during 1991-2000 observed by GPS in and around the Qinghai-Tibet block and those of gravity reiteration in 1998 and 2000 were used. Analysis shows that the preparation and occurrence of this large earthquake are related to the horizontal movement and deformation setting in a large region and might be attributed to the block activity on a relatively large scale. Within the Qinghai-Tibet block, the region of left-lateral shear deformation is of a very large extent. This large earthquake occurred right in such a place where the left-lateral shear strain along the fault strike had the highest rate and the planar dilatation strain was tensile, which was on the margin of negative value region of abnormal gravity variation. The regional tectonic deformation setting can help the huge left-lateral strike-slip rupture to develop.

     

从知识管理到知识经营--日本知识管理研究发展现状

介绍了日本近年来知识管理研究发展现状,重点介绍了野中郁次郎等人的相关成果.为我国知识管理研究提供参考.     

昆仑8.1级地震前青藏块体东北缘构造运动特征

利用青藏块体东北缘1993、1999和2001年的GPS观测资料和1980年以来的跨断层流动形变资料，分析了昆仑8．1级地震前青藏块体东北缘地区水平运动演变与断层异常活动的一些特征。结果显示：震前水平运动与变形强度减弱，断层形变异常发育。结合块体和构造研究认为，青藏块体内部8．1级大震的蕴育和发生，对块体边界构造区域影响显著；震后调整和应力转移可能加速块体东北部某些构造部位应变能的积累。     

中国七大地区“气候变化—作物产量—经济影响”综合评价

农业作为响应气候变化最敏感的领域之一,未来作物产量可能受到深刻影响。量化气候变化冲击作物产量导致的最终经济影响,需要综合“气候变化—作物产量—经济影响”开展链式研究。文中采用系统回顾和Meta回归分析方法整合了55篇文献的667项研究结果,推导出我国七大地区主要作物（水稻、玉米、小麦）产量与地区内未来温度和降水变化的定量关系,并将其作为农业部门的损失量代入改进的多区域投入产出模型,量化七大地区内与地区间遭受的经济波及影响（ERE)。结果显示：(1)气候变化对我国作物产量的影响主要体现在温度升高上,每升温1℃减产2.6%~12.7%,东北和西北地区作物受升温影响最显著;(2) 气候变化导致的作物减产将对经济产生更严重的波及影响,GDP因作物减产每下降1%将额外产生17.8%的波及影响;(3) 21世纪末,若不考虑CO₂肥效作用,作物减产导致的ERE将占GDP的-0.1%~13.6%（负值表示收益),最悲观情况下ERE与当前我国农业总产值相当（2012年为基准年);(4)不同地区受ERE影响程度的差异较大,因各区之间产业结构、贸易联系及经济发展程度存在差异,西南地区遭受本区及来自其他地区的ERE比华东地区高2.8~8.5倍。     

Mapping the resting cysts of dinoflagellate Alexandrium catenella along the coast of Qinhuangdao,China

Dinoflagellate Alexandrium catenella is a cosmopolitan bloom-forming species with complex life cycle, the formation and germination of resting cysts are critical for its bloom dynamics. In the coastal waters of Qinhuangdao, A. catenella has been identified as the major causative agent for paralytic shellfish poisoning, but there is little knowledge concerning its resting cysts in this region. In this study, three surveys were carried out along the coast of Qinhuangdao from 2020 to 2021 to map the distribution of A. catenella resting cysts, using a quantitative PCR (qPCR) assay specific for A. catenella. The resting cysts were detected in surface sediments during all the three surveys, and their distribution patterns were similar. High abundance of resting cysts (maximum 1 300 cysts/g sediment (wet weight)) were found in a region (119.62°E–119.99°E, 39.67°N–39.98°N) northeast to the coastal waters of Qinhuangdao, where surface sediments were mainly composed of clay and silt (percentage above 50%). Prior to the formation of the A. catenella bloom in March 2021, the abundance of A. catenella vegetative cells in seawater had extremely significant positive correlation with the abundance of resting cysts in surface sediments, reflecting the important role of resting cysts in the initiation of A. catenella blooms. As far as we know, this is the first report on the distribution of A. catenella cysts along the coast of Qinhuangdao. The results will offer a sound basis for the future monitoring and mitigation of toxic A. catenella blooms and paralytic shellfish poisoning events in this region.

     

Distribution Patterns of Synechococcus Indicated Their Environmental Constraints and Related Geochemical Processes in the Yellow Sea

Synechococcus is a widely distributed photosynthetic pico-phytoplankton,which contributes mainly to carbon fixation and maintains the stability of the marine ecosystem.To investigate its distribution patterns in the Yellow Sea,seawater samples were collected during September 2018.Results of flow cytometry analysis showed that the Synechococcus abundance ranged from 6.36×10² to 4.51×10⁴ cells mL^?1,which correlated with salinity(P<0.01)and temperature(P<0.05).At deeper off-shore sites,Synecho-coccus showed high abundance at the subsurface thermo-halocline,which was in accordance with chlorophyll a(Chl a)content along the vertical column.Based on the high-throughput sequencing data of rpoC1(partial gene encoding RNA polymerase),two Synechococcus subclusters,S5.1 and S5.2,were found to coexist in the studied area.Several clades of S5.1,including Clades I,II,and III,were the dominant components,accounting for 6.63%,26.11%,and 45.5%of the total genus,respectively.Redundancy analysis(RDA)showed that nitrite was the main environmental factor that explained the genus composition among samples.Fur-thermore,co-occurrence network revealed that the main phyla that coexisted with Synechococcus were Proteobacteria,Bacteroidetes,Actinobacteria,Planctomycetes,and Verrucomicrobia,which were involved in the carbon(C),nitrogen(N),sulfur(S),and manga-nese(Mn)cycles.Overall,Synechococcus exhibited biogeographic distribution correlated with temperature-salinity and nitrite in the Yellow Sea,and their geochemical function showed diverse but should be further verified in the future.     

青海门源MS6.9地震前后甘青地区应力变化特征研究

选取甘—青地区地球物理台网钻孔应变2021年1月至2022年1月数据计算其面应变相关系数、主应变、主方位角并进行投影,以面应变相关系数和数据精度进行质量控制,以主应变、主方位角及其地图投影分析甘—青区域钻孔应变的空间分布特征和时间变化特征。分析发现2021年主应变、主方位角及其地图投影变化能清晰地映证该区域构造运动,2022年1月8日门源6.9级地震时钻孔应变主方位角、最大主应变投影同震变化与此次地震地表同震位移场、应变场变化一致。上述发现为研究区域地质构造变化,对该地区地震危险性跟踪及短临跟踪提供参考。     

2022年1月8日青海门源MS6.9地震前地磁垂直强度极化异常变化特征

基于甘青川地区的14个地磁台站秒采样资料,对2022年1月8日青海门源M_S6.9地震前地磁垂直强度极化异常的时空变化特征进行分析研究。计算结果显示,在2021年10月底出现了地磁极化超阈值高值异常变化,异常台站主要分布在青海、甘肃和四川地区,异常出现后73天发生了门源地震,震中位于极化高值异常阈值线附近。研究还发现,此次地磁极化异常具有一定的时空变化特征,时间上,不同台站极化异常具有较好的时间同步性;空间上,极化异常高值区呈现出沿震中附近出现后不断扩展最终再向震中收缩的特点。此外,各地磁极化异常台站的归一置零极化值、异常持续时间与震中距存在较好的负相关性,异常台站距离地震震中越近,其归一置零极化值越高,异常持续时间也越长,这一特征符合地震电磁扰动信号的衰减特征。根据极化异常和地震的时空关系分析认为,此次地磁极化高值异常对应了之后在异常高值区边缘发生的门源M_S6.9地震。     

2022年6月1日四川芦山6.1级地震应急产品及震源参数初步分析

北京时间2022年6月1日17时0分四川雅安市芦山县(30.37°N,102.94°E)发生6.1级地震,中国地震台网中心于震后3min发布自动速报结果、震后9min发布正式速报结果,同时联合多家单位启动地震应急产品产出工作,共产出震源参数、历史地震、地震构造、震源机制、余震精定位、推测烈度和震源破裂过程等9类应急产品。结果显示,本次地震发生在龙门山断裂带,位于青藏高原巴颜喀拉地块、岷山构造带、川滇构造带的交汇处;震源机制解表明该地震为一次逆冲型事件;余震精定位结果显示余震展布呈近NE向,与震中区域断裂走向基本一致;烈度速报推测极震区烈度达Ⅸ度,区域面积约2km²,Ⅷ度及以上区域总面积约197km²,涉及四镇一乡。