利用GPS资料研究郯庐带现今的运动及变形状态

郯庐断裂带中南段在第四纪以来活断层最发育,历史上曾发生过多次中强以上地震,是我国目前主要地震活动区域之一.2008年5月12日汶川8.0级地震发生后,地下流体观测多项测震后效应在郯庐断裂带中南段部分地区一直持续存在,同时速度结构研究结果表明该区域存在发生中强以上地震的介质速度结构条件,因此,加强对郯庐带现今地壳变形特征的认识,对郯庐带未来地震危险性的判定有着重要的意义.     

郯庐断裂带中南段断层形变累积率长期变化特征

利用形变累积率方法,对郯庐断裂带中南段及其邻近区域的跨断层短水准观测资料进行了较为全面的分析研究,在分别讨论不同区域断层形变累积率中长期变化特征的基础上,结合地震活动性,探讨了该方法对中强地震判定的背景意义。研究认为,目前郯庐断裂带中南段总体处于应力的缓慢积累阶段,近期中强地震发生的能量积累尚不足,同时,郯庐断裂带中南段主干断裂沿线的各区域与整体的长期变化特征存在明显的差异,具有进一步研究的空间。     

郯庐带中南段及邻区井水位同震响应特征

分析郯庐带中南段与其邻区井水位对汶川8．0级与日本9．0级地震的同震响应特征,指出汶川地震时同震阶升井集中出现在安徽地区,之后该区发生Ms3．8中等地震的事实,指出日本地震后该区无一口同震阶升井,由此推测,未来1—2年内郯庐带中南段发生中等以上地震的可能性不大。     

郯庐断裂带庐江段土壤气地球化学特征研究

<正>郯庐断裂带庐江段是郯庐断裂带中南段地震前兆重点监视区域之一,NW向梅山-龙河口断裂、金寨-东汤池断裂、青山-晓天断裂都与郯庐断裂带交汇于此段,该段有大量的温泉出露,温泉水氡测项记录到了一些大震的同震响应、震后效应,也捕捉到了一些区域地震的前兆异常。为了更好地监视郯庐断裂带断层的活动,引进了跨断层土壤气监测新技术,探索郯庐断裂带土壤气地球化学特征,提炼适合郯庐断裂带特     

郯庐断裂带近期南段和1668年郯城8．5级地震前中段的中强地震活动比较

通过对郯庐断裂带构造进行分段分析,着重研究了1668年7月25日郯城大地震的背景、发震成因和震前异常,并对郯庐断裂带地震活动进行回顾,对比分析近年该带中南段地震活动图像、应力场特征,对郯庐断裂带南段地震活动特点进行探讨。     

郯庐断裂带中南段跨断层短水准形变特征初步分析

通过对郯庐断裂带中南段近20年的跨断层定点水准测量资料的处理与分析,初步总结了郯庐断裂带中南段断层垂直形变的时空活动特征。2000—2019年郯庐断裂带中南段断层垂直形变活动整体水平不高,平均合成速率为0.19 mm/a,但具有明显的分时活动特征。2000—2010年槐柏—宿迁段活动相对较大,新沂—临沂段活动相对较小,宿迁和新沂之间存在相对闭锁段;2011—2019年整体活动速率有所降低,但安丘测点活动速率相对2000—2011年增大明显。郯庐断裂带中南段的活动特征和近20年来该地区地震活动情况存在一定的对应关系。      

华东地区地震成组和迁移特征分析

本文对华东地区的地震成组和迁移特征进行了详细分析。 结果表明, 1700年以来华东地区可划分为四个地震活跃幕, 地震较完整的第二幕和第三幕内陆5级以上地震空间成组特征明显; 郯庐带以西(包括郯庐带)和郯庐带以东地区4级以上地震时序上具有成组发生的特点; 1900年以来郯庐带中南段5级以上地震具有自南向北定向迁移特征; 1993年以来华东内陆郯庐带及周边200 km范围内的M_L4以上地震分三组活动且自西向东迁移。 该研究结果有助于华东地区今后的地震趋势分析。     

山东跨断层短水准异常的可能物理机理

针对2006—2008年郯庐断裂带中南段的高峰头、武胜、甘霖等跨断层短水准测量出现的显著异常变化,基于华北南部地区地震活动增强的力学背景分析和华北南部地区与青藏高原东北缘地质构造的关联性特征,分析表明,该远场异常变化可能与汶川8.0级地震的孕育和发生有关。     

2021年11月17日江苏大丰海域MS5.0地震震源深度对比分析

选取江苏测震台网震中距2°以内18个地震台站记录清晰的波形资料,使用单纯形、LocSAT、HypoSAT地震定位方法,分别采用华南速度模型、郯庐断裂带中南段速度模型以及IASP91全球速度模型,重新测定江苏大丰海域M_S5.0地震震源深度,对获取的深度值进行对比分析。结果表明:3种地震定位方法测定的震源深度结果接近,约为11 ± 2 km;HypoSAT定位方法计算结果较为稳定,IASP91、郯庐断裂带中南段模型均适用于该区域震源深度计算。      

郯庐断裂带中南段应力场及变形特征

收集郯庐断裂带中南段及附近区域2009年以来的小震初动资料,利用格点尝试法求得51个台站的综合机制解和167次小震的震源机制解,采用Michael的应力张量求解方法获得区域应力场分布;同时利用震源机制三角形分类方法,对51个台站综合机制解的变形形式进行分类,探讨其空间分段特征。结果表明:研究区域的主压应力方向以NEE和近EW向为主,沿郯庐断裂带中南段由北往南,主压应力方向由NEE向逐渐偏转为近EW向;郯庐断裂带中南段变形特征存在局部差异,山东段以走滑型机制为主,兼有部分正断层震源机制;江苏段及安徽北段,郯庐断裂带带内及其东侧集中表现为逆冲断层类型,西侧则以走滑型为主;安徽段南端,郯庐断裂带东西两侧,震源机制分别以走滑型和正断型机制为主。     

Contribution to the knowledge of the magmatic evolution by the study of the variation of the coefficient of viscosity

The determination of the coefficient of viscosity of eruptive products gives useful elements to the knowledge of possible variations of composition and physical conditions of the magmas.     

Pictorial Series of the Manifestations of the Dynamics of the Earth

Studia Geophysica et Geodaetica -     

Evolution of the Source of the Active Region of the Sun

Geomagnetism and Aeronomy - The magnetic evolution of the active region of the Sun at the level of the photosphere has been studied. Magnetic synoptic maps of the 2007 Kitt Peak Observatory were...     

Magnetic stratigraphy of the Ordovician in the lower reach of the Kotuy River: the age of the Bysy-Yuryakh stratum and the rate of geomagnetic reversals on the eve of the superchron

Until recently, the existing data prevented the geophysicists from accurately dating the Bysy-Yuryakh stratum, which outcrops in the middle reach of the Kotuy River, constraining the time of its formation to a wide interval from the end of the Late Cambrian to the beginning of the Silurian. The obtained paleomagnetic data unambiguously correlate the Bysy-Yuryakh stratum to the Nyaian regional stage and constrain its formation, at least a considerable part of it, by the Tremadocian. This result perfectly agrees with the data on the Bysy-Yuryakh conodonts studied in this work and yields a spectacular example of the successful application of paleomagnetic studies in solving important tasks of stratigraphy and, correspondingly, petroleum geology. Within the Bysy-Yuryakh stratum, we revealed a large normal-polarity interval corresponding to the long (>1 Ma) period when the geomagnetic reversals were absent. This result, in combination with the data for the Tremadocian and Middle–Upper Cambrian sequences of the other regions, indicates that (1) the rate of occurrence of the geomagnetic reversals on the eve of the Ordovician Moyero superchron of reversed polarity was at most one reversal per Ma; (2) the superchron does not switch on instantaneously but is preceded by a certain gradual change in the operation conditions of the dynamo mechanism which, inter alia, manifests itself by the reduction of the frequency of geomagnetic reversals with the approach of the superchron. This finding supports the views according to which a process preparing the establishment of the superchrons takes place at the core–mantle boundary.     

On the determination of the non-linearity of the gravimeter scale

Summary The results of two different methods of the determination of the non-linearity of the gravimeter scale are compared; the economy is discussed as well.     

Influence of the topography of the surface of the Earth on vertical sounding of the temperature profile

Atmospheric temperature and humidity fields as well as information on other meteorological parameters are nowadays retrieved from radiance measurements recorded by operational meteorological satellites. Up to now, the inversion procedures used only take into account crude information on the topography of the Earth’s surface. However, the applied radiative transfer codes have to consider the Earth’s surface as the lower boundary of the atmospheric model and, therefore, need a more precise mean elevation and a classification of the roughness of the Earth’s surface. The influence of the topography of the Earth surface on retrieved temperature profiles is studied by using a physico-statistical inversion method. An objective analysis is made of the more precise mean elevation and derivation of roughness parameters using a new high-resolution digital elevation model (DEM) with a resolution of 500 m×500 m. By means of a geomorphological process and a newly developed topography rejection test, areas with a high surface roughness are localized and singled out. The influence of topography on the retrieved temperature profiles is illustrated by case studies. Changes are found predominantly in areas with a high variation of topography. Using the new high-resolution DEM and the topography rejection test, the geographical position of the calculated temperature profiles tends to be shifted towards areas with a small vertical variation of topography. The mean elevation determined by the new elevation model better characterizes the area observed. Hence, the temperature profiles can be calculated down to lower atmospheric levels. Furthermore, a guess profile better describing the atmospheric situation is selected by the more precise elevation. In addition, the temperature profiles obtained near the coast are improved considerably by the more precise determination of the surface property ‘sea’ and ‘land,’ respectively. Integration of an independent physical information such as topography leads, on average, to a slight improvement of the results of the physico-statistical inversion procedure. In some cases, however, significant improvements have been achieved regarding the desired accuracy of temperature profiles of the order of 1 K. In future, the spatial resolution of new high-resolution sounding instrumentation on the next generation of operational meteorological satellites will be increased. To exploit the resolving power of this new instrumentation, the different variation of the topography of the Earth surface, especially in regions with a high variation of topography, can be taken into account more precisely by using a high-resolution DEM.     

The effect of the pollution of the ground layer of the atmosphere on the albedo

Summary A simple model is proposed suitable for studying the effect of the ground layer of the atmosphere, polluted by aerosol, on the albedo. This model is founded on solving the equation of transfer of radiative energy. The numerical results are discussed, particular attention being paid to the analysis of errors due to neglecting the multiple reflection of solar radiation on the aerosol particles. A method which would also include the multiple reflection is proposed, and the conditions under which the presence of the aerosol is responsible for an increase or decrease of the solar radiation balance on the Earth's surface, are analysed.     

On the solution of the reverse problem of geodesics with the help of the chord

Резюме Дается вывод формул для вычислений длины хорды, длины и азимутов нормаляных сечений и длины геодезической линии эллипсоида. Применяются тригонометрические функции данных величин и постоянные принятого ргфгргнц-эллипсоида, что является целесообразным при использовании вычислителQjных машин, особенно автоматов. Рабочие формулы рекомендуются в форме (8–11).

---

---

Dedicated to Professor František Fiala on His 85th Birthday

---

Address: Veveři 95, Brno.     

Evolutionary Changes in the Configuration of the Magnetic Field of the Solar Corona in the Epoch of the Minimum

Geomagnetism and Aeronomy - The evolution of the magnetic configuration in the solar corona is studied. The curvature of the K-corona helmets obtained from an analytical approximation of the...