共查询到20条相似文献，搜索用时 359 毫秒
1.
地球动力学观测技术在西班牙Lanzarote火山预测中的应用研究 总被引：1，自引：0，他引：1
中国和西班牙合作在西班牙Ｌａｎｚａｒｏｔｅ火山地球动力学实验里开展了对地球动力学观测技术与仪器的研究，并对监测和长期实验结果进行了解释。用合作研究的先进仪器和观测技术监督并获取火山及地震的前兆地壳变动信息，对于探索预测火山爆发规律，推动地球动力学观测技术和仪器的发展以及深入研究对火山和地震等灾害的防御对等等，将具有十分重要的科学价值。 相似文献
2.
主要介绍中国、西班牙两国在Lanzarote火山与地球动力学实验场 12年的合作监测研究。1991年以来 ,中西双方共同在Lanzarote岛火山活动地区建立了Cueva和Timanfaya 2个监测站 ,进行地壳变动和地热流动态监测研究。对合作研制的 2 9台 (套 )监测仪器开展长期稳定实验 ,积累了大量观测资料和数据。初步分析表明 :仪器运行良好 ,记录长期稳定可靠 ;Cueva站的仪器记录主要反映区域或全球地球物理环境或动力学效应 (如海潮、固体潮等 ) ,应变潮汐和倾斜潮汐的O1波、M2 波具有较高精度 ,显示火山目前活动微弱 ;Timanfaya站的仪器记录主要反映局部的火山活动信息 ,显示火山仍在活动但呈下降趋势。为今后火山喷发演变过程的监测研究和进一步合作奠定了基础 相似文献
3.
4.
A. A. Malovichko D. Yu. Mekhrushev S. V. Gorozhantsev A. V. Shevchenko 《Seismic Instruments》2012,48(1):45-50
The location features and equipment of the Neytrino seismic station are described. The examples of registering various weak
local seismic events, which may be of paramount importance in researching the nature of geodynamic processes around the Elbrus
volcanic center, are presented. 相似文献
5.
根据P波走时反演重建的三维速度图像,研究东秦岭造山带莫霍面的展布性态结果表明,在华北板块南缘潼关-登封-阜阳-线、商丹主缝合带北侧卢氏-奕川-方城-信阳-线和扬子板块北缘佛坪-陨西-武当山-枣阳-线莫霍面沿着造山带走向呈带状隆起而介于这三条带间,莫霍面均不同程度地下陷因此,东秦岭造山带在岩石圈缩短方向上莫霍面的展布目前仍然存在着很大的非均一性结合造山带地质、岩石地球化学和同位素年代学综合分析,认为造成莫霍面这一展布格局,主要与该碰撞造山带在不同演化时期各岩石构造单元中发生不同性态的岩石圈-软流圈和壳-幔间物质与能量的相互作用方式不一所造成的大陆动力学过程不同有关加上碰撞期后造山带深部岩石圈均衡在不同岩石构造单元中的差异,形成了东秦岭造山带目前莫霍面的展布。 相似文献
6.
Fumarole thermal monitoring is a useful tool in the evaluation of volcanic activity, since temperatures strongly relate to the upward flux of magmatic volatiles. Once depurated from meteorological noise, their variations can reflect permeability changes due to crustal stress dynamics eventually associated to seismic activity. In this work, we discuss a fumarole temperature record acquired in the period September 2009–May 2012 at Vulcano island (Italy), during which changes of volcanic state, local seismic activity and teleseisms occurred. Apart from positive thermal anomalies driven by increments in volcanic activity, we observed 3 episodes at least of concurrence between tectonic earthquakes and fumarole temperature increments, with particular reference to the local August 16th, 2010 Lipari earthquake, the March 11th, 2011 Sendai–Honshu (Japan) earthquake and a seismic swarm occurred along the Tindari-Letojanni fault in July–August 2011. We interpreted the seismic-related anomalies as “crustal fluid transients”, i.e. signals of volcanogenic vapour flow variations induced by stress-induced permeability changes. From this perspective fumarolic activity can be considered as a tracer of geodynamic instability but, since seismic and volcanic phenomena are in mutual cause-effect relationships, a multidisciplinary observation system is mandatory for correctly addressing thermal data interpretation. 相似文献
7.
The geodynamic setting of the Bikou volcanic group is a critical question to trace the Precambrain tectonic framework and evolution for the Yangtze plate. This study has suggested that the Bikou volcanic group is composed of several residual oceanic crust units: MORB (mid-ocean ridge basalt), Alk-OIB (alkaline ocean island basalt) and Th-OIB (tholeiitic ocean island basalt) as well as subduction-related volcanic rocks. According to field observation, those distinct rocks occurred collectively in form of tectonic contact, implying that the Bikou volcanic group was an ophiolitic mélange. Coupled with geochronological data, a perished oceanic basin at the northern margin of the Yangtze block during Neoproterozoic was tested by this ophiolitic mélange. Meanwhile, the isogeochemical data suggest that the ocean occurred in the Southern Hemisphere identical to Indian, South Atlantic and South Pacific oceans in terms of their Dupal anomalies, and the original source of the rocks could be probably mixing by EMI and EMII component caused by dehydration melting of subducting oceanic crust during subduction process. On the basis of geochemical characteristics of the studied rocks, the Bikou volcanic group could imply that a partial breakup event occurred in the northern margin of Yangtze plate during the Neoproterozoic era.
相似文献8.
Abstract The pre-Oligocene structure of southwest Mexico, south of the trans-Mexico volcanic axis, is investigated from Taxco (Guerrero state, abbreviation: Gro) to the Pacific coast. Three volcano-sedimentary units are recognized; from east to west the calc-alkaline Teloloapan, tholeiitic Arcelia and calc-alkaline Zihuatanejo suites. Structural and stratigraphic data show that the Teloloapan volcanic arc, active during ?Late Jurassic and early Cretaceous, was built upon continental basement. The Teloloapan lavas are overlain by the Albian–Cenomanian Morelos platform carbonates and followed by the Upper Cretaceous Mexcala flysch. In contrast, the Arcelia pillow lavas are associated with sandstones and cherts of Albian-?Cenomanian age. The Zihuatanejo arc was also installed upon continental basement and its magmatic activity was in part coeval with Arcelia magmatism. Unlike the almost undeformed Zihuatanejo volcanic rocks, all the other volcanic units are involved in east-vergent thrusting and recumbent folding associated with ductile tectonics, as well as the Late Cretaceous Mexcala flysch overlying the Morelos platform carbonates. Contrasting with previous views, the present results do not support a major mid-Cretaceous thrusting event in the study area. The new geodynamic interpretation proposed here considers that the Arcelia rocks were formed in a marginal basin situated east of the Zihuatanejo arc. Closure of this basin in Paleocene times is responsible for the east vergent thrust tectonics in SW Mexico. 相似文献
9.
The presence of continuous upper crustal blocks between the Iberian Betics and Moroccan Rif in the western and middle Alboran Sea, detected with tomography, can add new information about the lithosphere structure and geodynamic evolution in this region. A large volume of seismic data (P and S wave arrival times) has been collected for the period between 1 December 1988 and 31 December 2008 by 57 stations located in northern Morocco (National Institute of Geophysics, CNRST, Rabat), southern Portugal (Instituto de Meteorologia, Lisbon) and Spain (Instituto Geografico National, Madrid) and used to investigate the lithosphere in the western Alboran Sea region. We use a linearized inversion procedure comprising two steps: (1) finding the minimal 1-D model and simultaneous relocation of hypocenters and (2) determination of local velocity structure using linearized inversion. The model parameterization in this method assumes a continuous velocity field. The resolution tests indicate that the calculated images give near true structure imaged at 5 km depth for the Tanger peninsula, the Alhoceima region and southern Spain. At 15, 30 and 45 km depth we observe a near true structure imaged in northern Morocco, and southern Spain. At 60 and 100 km, southern Spain and the SW region of the Alboran Sea give a near true structure. The resulting tomographic image shows the presence of two upper crustal bodies (velocity 6.5 km/s) at 5–10 km depth between the Betics, Rif, western and central Alboran Sea. Low velocities at the base of these two bodies favor the presence of melt. This new evidence proves that the Tethysian ocean upper crust was not totally collapsed or broken down during the late Oligocene–early Miocene. These two blocks of upper crust were initially one block. The geodynamic process in the eastern of the Mediterranean is driven by slab rollback. The delamination process of the lithospheric mantle terminates with the proposed slab rollback in the western part of the Mediterranean. This can be explained by the removal of the major part of the lithosphere beneath the area, except in the SW part of the Alboran Sea where a small part of the lithospheric mantle is still attached and is extends and dips to SE beneath the Rif, slowly peeled back to the west. A second detached lithospheric mantle is located and extends to eastern part of the Rif and dips to the SE. The removal of lithosphere mantle from the base of the crust was replaced and heated by extrusion of asthenospheric material coming from depth to replace the part of crust detached. A combination of isostatic surface/topographic uplift and erosion induced a rapid exhumation and cooling of deep crustal rocks. 相似文献
10.
在总结、讨论冲绳海槽弧后张裂构造的地形地貌、地球物理场和动力背景特征的基础上,归纳出海槽北、中、南三段之间的差异,以及它们在陆坡、槽底、岛坡上的不同表现特征.槽底雁行排列的地堑及断层斜切入陆坡,伴随的断块隆眷作用往南加强,使得钓鱼岛一赤尾屿隆起带区别于其北边的陆架外缘隆起带,吕宋岛向台湾的碰撞挤压引起的旋张活动加强了海槽南段的地壳拉张,从北往南岛坡侧都可以追踪出双列岛孤特性.海槽内部构造现象不能为笼统的构造动力背景所能完全解释,需要对各个典型中央地堑的具体深入探测研究.鉴于地堑、地垒、断层以及它们所界定的构造单元和它们内部发生的岩浆作用各有特点,最后讨论了各个地段中央地堑的构造属性、动力要素的差异及变化规律,以期为海槽构造动力的进一步深入研究提供借鉴参考. 相似文献
11.
我国地震的现今地球动力学研究的进展与方向 总被引：2，自引：0，他引：2
本文从活动构造、大陆地壳形变与现代地壳运动、地震活动区与大震震源区的深部探测及动力学、大陆强震区的地壳介质结构与地震成因、构造的物理及数值模拟、大陆岩石圈动力学以及地球动力学模型研究七个方面扼要介绍了近年来我国开展的与地震有关的现今地球动力学研究进展和取得的一系列新认识以及研究动向。在此基础上提出了微动态地球动力学，上地幔的非均匀性、深浅部构造关系及其动力学和地球动力学模型的理论研究三个应该优先发展的研究领域。 相似文献
12.
A. A. Malovichko I. P. Gabsatarova R. R. Kashirgova S. M. Dolov 《Seismic Instruments》2012,48(3):256-269
Geodynamic conditions in the territory of the Kabardino-Balkar Republic are characterized by a high variety of processes: seismic events of different classes, including swarms of weak earthquakes and the technogenic phenomena (chemical explosion), local geodynamic processes around the Elbrus volcanic center, and various exogenous processes, such as landslides, mud flows, and rock-ice slides. The possibilities of researching all these phenomena with use of a regional network of digital seismic stations are considered in the present article. 相似文献
13.
Izvestiya, Physics of the Solid Earth - The main results obtained at the Institute of Physics of the Earth of the Russian Academy of Sciences (IPE RAS) in the numerical geodynamic modeling of the... 相似文献
14.
G. Budetta D. Condarelli M. Fytikas N. Kolios G. Pascale A. Rapolla E. Pinna 《Bulletin of Volcanology》1984,47(3):447-466
A program of geophysical research was carried out as a preliminary stage of study of the Santorini volcanic group. This area is of remarkable geothermal and volcanological interest, and the definition of a volcanological structural model is the starting point for an understanding of the local geodynamic processes. Gravity, magnetic and geoelectrical data proved that:
- the core of the volcanic edifice consists of a sedimentary-metamorphic basement;
- the basement is tectonically disturbed and a linear tectonic system produces a graben-type structure in the middle part of the area.
15.
本文立足对地球物理学科发展态势的分析认识,通过解剖华北克拉通研究实例,对地球内部结构探测研究,特别对壳幔结构的地震学探测研究,对中国近20多年的发展做了回顾;探讨了从区域问题认识全球构造的研究思路. 相似文献
16.
An analysis of the structural lineaments, as observed on the middle and upper slopes of Etna volcano, was made with the aim of checking stress distribution within the volcanic structure. The observed features suggest that the deformation pattern of the volcanic edifice is compatible with a deviating stress field dominated by an E-W sinistral shear, with the maximum stress axes being oriented NE (σ1) and NW (σ3) respectively. Such a framework appears to be consistent with the active regional stress field, as deduced from structural data and focal mechanism analyses. The role of the active stress field in the penetration, uprising and eruption of magma in the Etnean area is therefore discussed and some more general suggestions about the geodynamic evolution of eastern Sicily are made. 相似文献
17.
Christina Flechsig Tobias Fabig Carsten Rücker Claudia Schütze 《Studia Geophysica et Geodaetica》2010,54(3):443-463
The Cheb Basin, located in the western Eger (Ohře) Rift, is part of the European Cenozoic Rift system. Although presently
non-volcanic, it is the most active area within the European Rift with signs of recent geodynamic activity like emanations
of mantle derived CO2, and the repeated occurrence of swarm earthquakes, which are common features in active volcanic regions. It is assumed that
the fluids, uprising in permeable channels, play a key role for the genesis of these earthquake swarms. 相似文献
18.
José Fernández José M. Carrasco John B. Rundle Vicente Araña 《Bulletin of Volcanology》1999,60(7):534-544
In this paper we study the application of different geodetic techniques to volcanic activity monitoring, using theoretical analysis. This methodology is very useful for obtaining an idea of the most appropriate (and efficient) monitoring method, mainly when there are no records of geodetic changes previous to volcanic activity. The analysis takes into account the crustal structure of the area, its geology, and its known volcanic activity to estimate the deformation and gravity changes that might precede eruptions. The deformation model used includes the existing gravity field and vertical changes in the crustal properties. Both factors can have a considerable effect on computed deformation and gravity changes. Topography should be considered when there is a steep slope (greater than 10°). The case study of Teide stratovolcano (Tenerife, Canary Islands), for which no deformation or gravity changes are available, is used as a test. To avoid considering topography, we worked at the lowest level of Las Cañadas and examined a smaller area than the whole caldera or island. Therefore, the results are only a first approach to the most adequate geodetic monitoring system. The methodology can also be applied to active areas where volcanic risk is not associated with a stratovolcano but instead with monogenetic scattered centers, especially when sites must be chosen in terms of detection efficiency or existing facilities. The Canary Islands provide a good example of this type of active volcanic areas, and we apply our model to the island of Lanzarote to evaluate the efficiency of the monitoring system installed at the existing geodynamic station. On this island topography is not important. The results of our study show clearly that the most appropriate geodetic volcano monitoring system is not the same for all different volcanic zones and types, and the particular properties of each volcano/zone must be taken into account when designing each system. 相似文献
19.
Volcanism in the Mediterranean fold belts is dominantly related to plate-convergence processes. The occurrence of highly potassic and often leucite-bearing lavas is a typical feature of many Neogene to Quaternary volcanic provinces in the Mediterranean area.The paper describes possible relationships between the Aeolian island arc and the Roman comagmatic region and presents petrological evidence for an ultrapotassic province within the Cypriot-Taurus arc of Turkey. It is thus a contribution to the controversy about tectonic setting and geodynamic significance of the highly potassic volcanism of the Mediterranean suite. 相似文献
20.
在整理和分析了703口钻井测温资料的基础上，编制了济阳坳陷现今地温梯度分布图、4～6km深度的地温分布图和下第三系沙四段顶界面地温分布图. 研究表明：济阳坳陷的现今地温梯度平均为35.5℃/km，其中沾化、东营、车镇和惠民等4个主要凹陷地温梯度平均值分别为36.1℃/km、35.5℃/km、35.4℃/km和34.6℃/km，外围的潍北凹陷为35.0℃/km. 地温和地温梯度分布主要受凸凹相间的构造格局控制，与基底埋深有关，表现为凸起区高、凹陷区低的特征. 另外，济阳坳陷一些地温梯度相对较高的地区与新生代的火山岩分布基本吻合. 盆地基底埋深，即盆内凸起凹陷的分布，受盆地形成过程中岩石圈伸展控制，火山岩的分布也与岩石圈伸展作用有关，所以，济阳坳陷的地温场分布特征是由构造演化决定的. 研究结果还表明，济阳坳陷大部分地区沙四段目前还处在油气液态窗内. 相似文献