10 Years of the optical &; UV monitor (OM) on-board <Emphasis Type="Italic">XMM-Newton</Emphasis>     

Antonio Talavera  OMCal Team 《Astrophysics and Space Science》2011,335(1):291-296

The XMM-Newton X-ray observatory was launched at the end of 1999 and it is still successfully operated. In addition to the X-ray instruments, the payload carries a small telescope, the Optical Monitor, which provides simultaneous imaging and spectroscopic observations in the optical and UV ranges. In this report we review the status of the OM and its main achievements after 10 years of operations. We also introduce the XMM-OM Serendipitous Ultra-violet Source Survey (SUSS) Catalogue.  相似文献   

The reflection seismic survey of project TIPTEQ—the inventory of the Chilean subduction zone at 38.2° S     

K. Groß  U. Micksch  TIPTEQ Research Group  Seismics Team 《Geophysical Journal International》2008,172(2):565-571

We describe results of an active-source seismology experiment across the Chilean subduction zone at 38.2°S. The seismic sections clearly show the subducted Nazca plate with varying reflectivity. Below the coast the plate interface occurs at 25 km depth as the sharp lower boundary of a 2–5 km thick, highly reflective region, which we interpret as the subduction channel, that is, a zone of subducted material with a velocity gradient with respect to the upper and lower plate. Further downdip along the seismogenic coupling zone the reflectivity decreases in the area of the presumed 1960 Valdivia hypocentre. The plate interface itself can be traced further down to depths of 50–60 km below the Central Valley. We observe strong reflectivity at the plate interface as well as in the continental mantle wedge. The sections also show a segmented forearc crust in the overriding South American plate. Major features in the accretionary wedge, such as the Lanalhue fault zone, can be identified. At the eastern end of the profile a bright west-dipping reflector lies perpendicular to the plate interface and may be linked to the volcanic arc.  相似文献   

Dawn; the Vesta–HED connection; and the geologic context for eucrites,diogenites, and howardites     

Harry Y. McSween Jr.  Richard P. Binzel  M. Cristina De Sanctis  Eleonora Ammannito  Thomas H. Prettyman  Andrew W. Beck  Vishnu Reddy  Lucille Le Corre  Michael J. Gaffey  Thomas B. McCord  Carol A. Raymond  Christopher T. Russell  the Dawn Science Team 《Meteoritics & planetary science》2013,48(11):2090-2104

The Dawn mission has provided new evidence strengthening the identification of asteroid Vesta as the parent body of the howardite, eucrite, and diogenite (HED) meteorites. The evidence includes Vesta's petrologic complexity, detailed spectroscopic characteristics, unique space weathering, diagnostic geochemical abundances and neutron absorption characteristics, chronology of surface units and impact history, occurrence of exogenous carbonaceous chondritic materials in the regolith, and dimensions of the core, all of which are consistent with HED observations and constraints. Global mapping of the distributions of HED lithologies by Dawn cameras and spectrometers provides the missing geologic context for these meteorites, thereby allowing tests of petrogenetic models and increasing their scientific value.  相似文献   

A first deep seismic survey in the Sea of Marmara: Deep basins and whole crust architecture and evolution     

Mireille Laigle  Anne Becel  Batrice de Voogd  Alfred Hirn  Tuncay Taymaz  Serdar Ozalaybey  Members of SEISMARMARA Leg Team 《Earth and Planetary Science Letters》2008,270(3-4):168-179

Increased source strength, streamer length and dense spatial coverage of seismic reflection profiles of the SEISMARMARA Leg 1 allow to image the deep structure of the marine North Marmara Trough (NMT) on the strike-slip North Anatolian Fault (NAF) west of the destructive Izmit 1999 earthquake. A reflective lower crust and the Moho boundary are detected. They appear upwarped on an E-W profile from the southern Central Basin eastwards, towards more internal parts of the deformed region. Thinning of the upper crust could use a detachment suggested from an imaged dipping intracrustal reflector that would allow upper crustal material to be dragged from beneath it and above the lower crust, accounting for the extensional component but also southwest motion of the southern margin of the NMT. Sections across the eastern half of the NMT, crossing the Cinarcik and Imrali basins, reveal several faults that are active reaching into the basement and have varying strike and proportions of normal and strike-slip displacement. They might be viewed as petals of a large scale negative flower-structure that spreads over a width of 30 km at surface and is rooted deeper in the lithosphere. Under the Central Basin a very thick sediment infill is revealed and its extensional bounding faults are active and imaged as much as 8 km apart down to 6 km depth. We interpret them as two deep-rooted faults encompassing a foundering basement block, rather than being merely pulled-apart from a jog in a strike-slip above a décollement. The deep-basin lengthening would account for only a modest part of the proposed 60 km finite motion since 4 Myr along the same direction oblique to the NMT that sidesteps the shear motion from its two ends. Thus differential motion occurred much beyond the deep basins, like subsidence involving the NMT bounding faults and the intracrustal detachments. The complex partitioned motion localized on active faults with diverse natures and orientations is suggested to represent the overburden deformation induced from horizontal plane simple shear occurring in depth at lithospheric scale, and in front of the North Anatolian Fault when it propagated through the region.  相似文献   

Influence of instruments on the H/V spectral ratios of ambient vibrations   总被引：3，自引：3，他引：0  

Bertrand Guillier  Kuvvet Atakan  Jean-Luc Chatelain  Jens Havskov  Matthias Ohrnberger  Fabrizio Cara  Anne-Marie Duval  Stratos Zacharopoulos  Paula Teves-Costa  The SESAME Team 《Bulletin of Earthquake Engineering》2008,6(1):3-31

For an optimal analysis of the H/V curve, it appears necessary to check the instrument signal to noise ratio in the studied frequency band, to ensure that the signal from the ground noise is well above the internal noise. We assess the reliability and accuracy of various digitizers, sensors and/or digitizer-sensor couples. Although this study is of general interest for any kind of seismological study, we emphasize the influence of equipment on H/V analysis results. To display the impact of the instrumental part on the H/V behavior, some series of tests have been carried out following a step-by-step procedure: first, the digitizers have been tested in the lab (sensitivity, internal noise...), then the three components sensors, still in the lab, and finally the usual user digitizers-sensors couple in lab and outdoors. In general, the digitizer characteristics, verified during this test, correspond well to the manufacturer specifications, however, depending on the digitizer, the quality of the digitized waveform can be very good to very poor, with variation from a channel to another channel (gain, time difference etc.). It appears very clearly that digitizers need a warming up time before the recording to avoid problems in the low-frequency range. Regarding the sensors, we recommend strongly to avoid the use of “classical” accelerometers (i.e., usual force balance technology). The majority of tested seismometers (broadband and short period, even 4.5 Hz) can be used without problems from 0.4 to 25 Hz. In all cases, the instrumentation should be checked first to verify that it works well for the defined study aim, but also to define its limit of use (frequency, sensitivity...).  相似文献   

东海陆架的古河道和古三角洲   总被引：27，自引：5，他引：22  

刘振夏  Serge Berne  L'ATALANTE科学考察组 《海洋地质与第四纪地质》2000,20(1):9-14

基于１９９６年中法东海海洋地质调查电火花单道地震资料,确定了晚更亲世早期和中期长江（黄河）水下三角洲的分布范围和大致时间。中更新世晚期东海陆架为一自西南向东北倾斜的河流冲积平原,晚更新世以来自西北方向的大型河流的三角洲受此控制主要发育在东北部较低地区。东海陆架较大古河道多发育在末次冰期中的亚间冰期（氧同位素３期）。  相似文献   

蛇绿岩建造非金属矿床成矿系列初步探讨     

鱼海麟 《青海国土经略》1995,(2)

我国蛇绿岩分布广泛。蛇绿岩中有着成因上和时空上紧密联系的一系列非金属矿床,它们构成了蛇绿岩建造非金属矿床成矿系列。这一成矿系列中的主要非金属矿有橄榄岩、玄武岩、蛇纹岩、石棉、滑石、玉石类等等,主要的成矿作用有岩浆作用、接触变质作用、交代蚀变作用等。其成矿作用和矿床分布模式有明显规律,这些规律对于地质勘查、资源开发等都具有重要的意义。  相似文献   

Summary of recent volcanic activity     

Smithsonian Institution's Scientific Event Alert Network 《Bulletin of Volcanology》1988,50(2):132-134

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辽宁西部八家子多金属矿田控矿构造型式     

陈荣度  苏传玉 《国土资源》1991,(4)

本文分析了八家子多金属矿田的地质构造特征,提出该区的构造型式为一个滑脱—逆冲推覆构造。它是在北西问南东方向的侧向挤压作用下,由八家子附近的中上元古界与古生界地质块体,沿着与基底花岗岩的界面自北西向南东滑移造成的。主要表现特征是:在前缘形成了呈铲式的收缩型滑脱断层、逆冲断层等挤压性构造,在后缘则出现张裂带并陷落成盆地,两侧发育具有转换断层性质的走滑断层。逆冲断层及边界走精断层是区内主要控矿构造。八家子滑脱—逆冲推覆构造的主要活动时期为三叠纪晚期,结束于早侏罗世。  相似文献   

Summary of recent volcanic activity     

Smithsonian Institution's Scientific Event Alert Network 《Bulletin of Volcanology》1988,50(5):356-358

  相似文献