昆仑山口西8.1级大震前后重力场动态变化

2001年11月14日17时26分,在新疆、青海交界处的昆仑山(36.2°N,90.9°E)发生8.1级地震.震后又相继发生5次5级以上的强烈余震.其主震和余震基本上都在东昆仑断裂带的两侧或断裂带上.这次地震虽然没有人员伤亡的报道,但研究大震前后震中周围地区局部重力场动态变化情况,研究大地震与局部重力场动态变化之间的相关性,对捕捉地震前兆减轻未来地震的灾害,却具有极高的科学研究价值.     

海湾区海水中的溶存甲烷 Ⅱ.浓度、海气交换通量

本文基于日本东京湾、伊势湾和浜名湖的调查资料，详细地比较了这3个海湾海水中的溶存甲烷浓度、饱和度。表层海水中，溶存甲烷浓度以供名湖最高，达95nmol／dm3，伊势湾和东京湾相近，分别为41nmol／dm3和37nmol／dm3；其表层测定浓度是其平衡浓度的13～78倍，并分别计算了这3个海湾中甲烷的海气交换通量；用平均值外推法得出全球海洋环境中总的甲烷海气交换通量为6．3Tg／a。     

一种新型简易自动采水浮标系统的研制和试用

本文首先介绍了研制自动采水浮标的目的意义及其结构、工作原理、主要性能，其次通过几次试用条件及结果的讨论，说明这种自动采水浮标结构简单，操作方便，获取的资料可靠，是研究大风浪条件下悬沙运移的一种新型简易的理想仪器，最后根据实用情况提出了改进和完善的方向。     

The distribution of methane in the Tokyo-wan

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The distribution of methane in the Tōkyō-wan

Eleven stations were occupied in the Tokyo-wan during a study on the distribution of methane in this autrophic coastal environment in August of 1993.The principal features of the observed methane included the following 6 points: (1) Excess methane in the surface layer from 1.5 times to greater than 25 times solubility equilibrium with the atmosphere.(2) The methane concentration in the upper water displayed a maximum wne around Station 5 and the second highest in bottom water at Stations 1 and 2,probably because there was the front resulting from the chemical processes.(3) Cotrelations between methane and other parameters exhibited correspondences and the methane distribution being mainly controlled by physical processes.(4) In some'stations,vertical profiles revealed associations between methane and Chl a and the relationships between methane with Chl a or nitrite have shown good linear cortelations.It is postulated that some methane is formed in situ.(5) The calculated flux of methane acrbss the air-sea interface was about 71 μmol/(m²·d).(6) Some methane might be produced along with the organic matter decomposition in bottom water.Others might be due to the methane fluxes into the bottom water from the anoxic sediment inside the bay,which are believed to be the main methane source.     

A finite volume solution of wave forces on submarine pipelines

In this paper, a numerical model is established for simulating the wave forces on a submarine pipeline. A set of two-dimensional Navier–Stokes equations is discretized numerically with a finite volume method in a moving mesh system. After each time step, the mesh is modified according to the changed wave surface boundary. The deffered correction second-order upwind scheme (SUDC) is adopted here to discretize the convective fluxes. The effects of the clearance between the pipeline and the seabed, water depth and wave height on wave forces are studied, respectively. The results by the numerical simulation agree well with the experimental data and theory value.     

第六次南极考察—长城站越冬气象考察报告

本文以中国第六次南极考察队在长城站观测到的气象资料与历史资料对照分析,介绍了长城站的天气特征,如气旋的来源、移动规律,海雾的特点,降水情况,特别是夏季的降水情况。较详细地介绍了1990年长城站的天气状况。 总结了长城站气压、风、气温、云、日照、降水及蒸发等项目的观测工作。对关城站的天气预报工作也作了总结,特别是极地气旋的预报和各天气要素的预报方法。并以1990年1月16日营救遇暴风雪的考察队员预报为实例,介绍了一次成功的预报。     

Wave-Induced Seepage Force Acting on Cylinder Groups

Wave-induced seepage force acting on cylinder groups is studied by using Biot consolidation theory in this paper. Both tandem arrangement and side by side arrangement are considered simultaneously. The variations of the coefficient of grouping effect with the distance between cylinders for different KD are discussed. In order to verify the numerical solution, several sets of experiments are conducted. The agreement between numerical and experimental solutions is satisfactory.     

A summary of seismic activities in and around China in 2021

In this article, we review the general characteristics of seismicity in and around China and the overall statistics of earthquake damage in 2021, focusing on several significant events and related scientific topics. Among them, the largest event is the M_S 7.4 Madoi earthquake in Qinghai Province, northwest China. The event marks another M_S ?≥ ?7 earthquake occurring near the boundary of the Bayan Har Block that has ended a remarkable quiescence of the M_S ?≥ ?7 earthquakes within the Chinese mainland. In addition, the M_S 6.4 Yangbi earthquake in Yunnan Province, southwest China draws the most attention because of its abundant foreshocks, which are well recorded by the densely distributed seismic stations in the surrounding regions. Regarding this event, we review several recent publications focusing on the Gutenberg-Richter b-value change and the physical mechanism of foreshocks associated with this sequence. The M_S 6.0 Luxian earthquake in Sichuan Province, southwest China has caused serious damage with a relatively low magnitude, partly because the focal depth of the mainshock is relatively shallow (3.5 ?km). It is another strong earthquake occurring within the southeast Sichuan basin with low historical seismicity yet has increased significantly since 2015, probably due to shale gas development and associated hydraulic fracturing.