Separation of intrinsic and scattering seismic attenuation in the Southern Apennine zone, Italy   总被引：4，自引：0，他引：4  

F. Bianco  E. Del Pezzo  M. Castellano  J. Ibanez  F. Di Luccio 《Geophysical Journal International》2002,150(1):10-22

  相似文献   

南海西部围区中特提斯东延通道问题   总被引：9，自引：1，他引：9  

周蒂  颜佳新  丘元禧  陈汉宗  孙珍 《地学前缘》2003,10(4):469-477

通过对南海西部围区中生代岩相古地理资料的收集整理和分析,编制了该区T_2,T_3~1,T_3~2,T_3~3,J_1-J_2,J_3-K_1共6个时段的岩相古地理简图,根据其中生代海相地层的时空分布和岩相特征,讨论了尚存争议的中特提斯进入南海的通道问题。实际资料表明,黑水河盆地在三叠纪受印支运动影响完成了从海到陆的过程,之后不再出现海相沉积,中特提斯不可能从红河裂谷带进入南海。在新加坡所见的晚三叠世至早侏罗世浅海至陆相沉积代表古特提斯的残余海,到中侏罗世完全消失。早侏罗世时期在印支半岛南部出现的近南北走向的海湾可能经过泰国湾与当时的滇缅海相通;但是这个海湾浅而短暂,滇缅海能否从这里进入南海值得怀疑,更不可能是中特提斯的通道。在南海西部围区,迄今已证实的中生代洋壳碎片(蛇绿岩套)和深海沉积仅见于南部Woyla—Maratus—Lupar一线及其附近。这套延伸2000余km,从洋壳、深海到浅海岩相齐全的岩石所代表的晚侏罗世至早白垩纪世大洋应是中特提斯洋的一部分。中特提斯东延而最可能是走南路,即从班公一怒江带南下之后,经Woyla线穿过苏门答腊岛,绕加里曼丹岛南缘到Maratus线,向北再经沙巴到Lupar线,在沙捞越北部或纳土纳岛附近进入南海。  相似文献   

Structural setting of the Bay of Naples (Italy) seismic reflection data: implications for Campanian volcanism: [Tectonophysics 372 (2003) 193–213]     

Pier Paolo G. Bruno  Antonio Rapolla  Vincenzo Di Fiore 《Tectonophysics》2003,376(3-4)

  相似文献   

An estimate of hypocentre location accuracy in a large network: possible implications for tectonic studies in Italy     

Rita Di Giovambattista  Salvatore Barba 《Geophysical Journal International》1997,129(1):124-132

Data recorded by the Italian Telemetered Seismic Network (ITSN) of the Istituto Nazionale di Geofisica (ING) have been widely used in recent years to image slab structures and to find evidence for active processes along the Italian Peninsula. However, the use of seismic data for geostructural purposes may be affected by the well-known trade-off between earthquake location and seismic-velocity parameters. Furthermore, the confidence ellipse predicted by standard procedures may be inadequate for the representation of the probable error of a computed localization. This paper evaluates the probable errors on the hypocentre determinations of the seismic events recorded by the ITSN, using a Monte Carlo method.
We compute synthetic arrival times using a 1-D velocity model appropriate as an average for the Italian area. The hypocentres used are all those recorded by the ITSN during the period January 1992 to March 1994 (1972 events). Station locations are those of the current ITSN configuration. The synthetic arrival times are perturbed with a Gaussian distribution of errors and input to ING's standard hypocentral location procedure, but using crustal velocities differing by 10 per cent from those used to generate them. Each simulation is repeated at least 30 times. Average absolute shifts of hypocentres are assessed in grid cells of linear dimension 33 km covering the whole Italian region.
For regions within the ITSN, shifts are typically 5–10 km in location and up to 20 km in depth. However, for offshore and coastal regions, they are much greater: 50 km or more in both location and depth (far exceeding the equivalent uncertainties quoted by ING bulletins). Possible consequences of this are highlighted by producing a cross-section of subcrustal hypocentres from the Adriatic to the Tyrrhenian Sea, where the large uncertainty in depth precludes any confident interpretation of dipping tectonic features.  相似文献   

Paleogeography and structure of the central Mediterranean: Sicily and its offshore area   总被引：1，自引：0，他引：1  

R. Catalano  P. Di Stefano  A. Sulli  F.P. Vitale 《Tectonophysics》1996,260(4):291-323

The geology of the mainland and offshore of Sicily is illustrated by a few geologic sections and seismic profiles across the late Cenozoic orogenic belt of central and western Sicily and across the Sardinia Channel and Sicily Straits. This belt is the result of several tectonic events. Deformation involved mainly the sedimentary cover of the old African continental margin characterized by a broad basinal domain, flanked along its external (southern) margin by a shallow-water carbonate platform attached to Africa in the Triassic. Compressional deformation started in the more internal basinal rock assemblages overlying a thinned crust. The most important structural characteristic of the early phase of thrusting is the duplex pile forming the bulk of the chain in Central Western Sicily. The structure consists of a basal allochthon, made up of Permian to Middle Triassic layers, an intermediate duplex wedge, composed of competent Mesozoic carbonates, and a roof complex, including Upper Mesozoic-Lower Tertiary less competent rocks. Large-scale clockwise rotation of the thrusts accompanied transpressional movements in the hinterland during the Pliocene. Right oblique reverse faults modified the previous tectonic contacts between the allochthons in the hinterland zones. Contemporaneous south-directed imbrications affected the southern external areas, progressively incorporating foreland and piggyback basins. Development of the Gela Thrust System appears to be linked to the transpressional event; its accretion is also related to contemporaneous underthrusting at deeper levels of Mesozoic carbonate substratum. The older buried thrust sheets were pushed up to the surface breaching the deformed Tertiary cover of the Gela TS. Northwards in the belt post-Messinian normal growth faults opened half graben whose sedimentary fill underwent structural inversion. Alternation of extension and compression tectonics characterizes the Sicilian continental margin in the last million years.  相似文献   

Doubtful Events Reported in Current Italian Earthquake Catalogues: The Medieval Earthquakes of Subiaco (Central Italy)     

Di Giovambattista  Rita  Tertulliani  Andrea  Zaccaria  Mari 《Natural Hazards》1997,16(1):39-55

Within the framework of a study of the seismicity of the Aniene Valley (Central Italy), we analysed the medieval earthquakes of Subiaco (1216, 1227, 1299), the largest events reported for the area. Our main goal was to investigate some doubtful events reported in earthquake catalogues and, as such, currently utilised for seismic hazard estimates. A careful screening of the oldest available sources and their filiation pattern up to the present pointed out the uncertainty on the date and nature of these phenomena. A multidisciplinary approach based on the joint analysis of archaeological, geomorphologic and historical evidence allowed us to propose new interpretations concerning these events and their significance for the assessment of seismic hazard in the Aniene Valley. The main conclusion is that the dates of the 1216 and 1227 events are fairly unsupported. In particular, the 1216 earthquake could be dated back to between AD 1159 and 1181.  相似文献   

    

S. Falsaperla  S. Alparone  S. D'Amico  G. Di Grazia  F. Ferrari  H. Langer  T. Sgroi  S. Spampinato 《Pure and Applied Geophysics》2005,162(12):2583

  相似文献   

珠江口盆地白云凹陷新生代构造演化动力学   总被引：42，自引：0，他引：42  

孙珍 庞雄钟志洪  周蒂陈长民  郝沪军何敏黄春菊  许鹤华 《地学前缘》2005,12(4):489-498

白云凹陷构造演化史的研究对在白云凹陷开展油气勘探和深水沉积研究具有重要的意义。通过对断裂与沉积结构平面和剖面特点的分析,结合岩浆活动特点,文中提出白云凹陷是一个复式地堑,推测这种结构特点与凹陷下地壳的强烈韧性减薄和颈缩变形有关,表现为热岩石圈的伸展。其发育机制推测与白云凹陷位于构造转换带上有关,特殊的构造位置使白云凹陷成为强烈构造变形区,岩石圈地壳强烈减薄,伴随伸展过程和地幔上涌,脆性地壳或上地幔中部分熔融物质的出现导致岩石圈强度的急剧降低,在区域伸展应力场下以韧性流变方式减薄。岩浆在构造转换带下聚集并发育主岩浆房,由于白云凹陷南北边缘没有发育正断裂系统,岩浆主要沿垂直伸展的方向运移,因此在珠琼运动一幕和二幕南南东向伸展应力作用下,岩浆向白云凹陷的东部和西部运移至北西向基底深大断裂处,那里由于北西向断裂表现为左行张剪性质而成为压力较低的地区,从而成为岩浆上涌和侵位的地方。在岩浆聚集的地区,活动岩浆体附近的脆性变形被分散的韧性变形所取代,因此在凹陷的东北和西南两个角上,发育了张性和张剪性小断裂群,由于热岩石圈弹性较差,白云凹陷长期持续沉降。白云凹陷的断裂活动和沉积演化史还受到南海海盆扩张活动的影响。  相似文献   

Environmental effects of the December 28, 1908, Southern Calabria–Messina (Southern Italy) earthquake     

V. Comerci  E. Vittori  A. M. Blumetti  E. Brustia  P. Di Manna  L. Guerrieri  M. Lucarini  L. Serva 《Natural Hazards》2015,76(3):1849-1891

  相似文献   

Increasing flood risk under climate change: a pan-European assessment of the benefits of four adaptation strategies   总被引：4，自引：0，他引：4  

Lorenzo Alfieri  Luc Feyen  Giuliano Di Baldassarre 《Climatic change》2016,136(3-4):507-521

  相似文献