探测冰盖和多年冻土层的融冰探头研发

The exploration of ice sheets by melting vertical holes into the ground has some tradition in terrestrial glaciology. Such probes have been used since the 1960's to investigate the vertical structure of the ice in Greenland and Antarctica and in alpine glaciers. In this paper we look into the possibility to develop similar devices for use on extraterrestrial icy bodies, like e.g. the polar areas on Mars or the icy satellites of the outer solar system. We report on some basic experiments performed in the cryo-vacuum laboratory of the Space Research Institute of the Austrian Academy of Sciences, Graz. In these experiments the penetration of a simple melting probe into compact and porous water ice (with a snow-like texture) was monitored, both under vacuum conditions and under air pressure. The observed penetration speeds for a given power supply are compared with a simple mathematical model. We conclude that a miniature melting probe with small overall dimensions and a reasonable power demand could well be part of the payload of a future planetary mission, for example to the poles of Mars. Such missions are currently under discussion in several space agencies. Moreover such probes could also e? ectively be used in terrestrial environments. A possible design is presented at the end of the paper.     

由大地测量数据得到的犹他州沃萨奇断层带的全新世滑动速率：地震周期效应

在美国西部盆地山脉省的东部地区，GPS数据确定了一个宽大的现代变形带。使用覆盖在粘弹性下地壳／上地幔之上的弹性上地壳的有限元模型并结合地震周期效应，我们指出这些数据与现今的断层滑动集中在沃萨奇断层带上的模型是一致的。模拟的水平扩展速度是3．0～4．5mm／a，这也与全新世的地质数据相一致。这些模型是非一的，部分原因是大部分沃萨奇断层都处于地震周期的后期阶段，而这一时期跨断层的地表速度梯度均较低。     

新报告制定地球科学未来进程计划

上个世纪，地球科学的发展已具有很强的了解和预测地球系统事件的能力。过去的10年，定量地球科学研究蓬勃发展。随着观测系统和计算工具的进步，人们能以前所未有的时空分辨率来模拟和预测地球物理过程，地球科学也将继续加速发展。随着这些进步，需要反思地球科学研究的现状，重新评估地球科学研究发展的方向和明确能实现的现实目标。     

由ODP Leg191布设的海底井下宽频带地震仪系统

名为WP-2的新井下地震观测站由ODP Leg191成功地布设在西北太平洋海盆的ODP1179E钻孔。为了研究地球构造，WP-2台站被安置在一个独特的点位。两套宽频带地震仪用水泥固定在玄武岩层内，通过ROV号潜艇来驱动系统并检查系统的工作状态。ROV也用于回收初始数据。WP-2台站的地震噪声水平对地震观测而言是足够低的。     

穿过俄勒冈州图拉丁山脉的重力研究：波特兰都市区地壳结构的解释和地震危险性

穿过波特兰市区西部图拉丁山脉（波特兰山）的高分辨率重力测量，展现出以前根据地表地质学和航磁测绘识别出的断层的证据。本次重力测量是在1996年沿着长4．5km的双孔隧道进行的，该隧道在当时的建设中及现在一直在波特兰市区与波特兰山以西的居民区之间通轻便火车。在隧道内的重力从西到东逐渐增加，这种情况反映了隧道位于西边的图拉丁盆地低密度沉积物与其东边高密度大部分隐蔽的始新世玄武岩之间。叠加在这一梯度之上的是几个阶梯状异常，我们将其解释为密度明显差异的岩石之间断续接触的证据。这些异常的最大值发生在西尔万克里克之下，这里存在一条以前测绘出的断层。另一异常发生在距西洞口1200m处，大约是隧道与航磁异常相交汇的部位，航磁异常与西尔万断层（原来称为奥特菲尔德断层）有关。以这些重力资料为依据的岩石学横剖面显示出阶梯状异常与陡倾逆断层相一致，虽然走滑位移也许同样重要。与上方地形洼地相对应的3个重力低异常可能反映存在着剪切带。几个中等地震（M≥3．5）1991年发生在隧道当前的位置，说明这些断层中的几条或波特兰山断层带的其他断层是地震活动断层。     

Geochemistry and Petrogenesis of Intracontinental Basaltic Volcanism on the Northwest Arabian Plate,Gaziantep Basin,Southeast Anatolia,Turkey

Volcanism along the northwest boundary of the Arabian Plate found in the Gaziantep Basin, southeast Turkey, is of Miocene age and is of alkaline and calc-alkaline basic composition. The rare earth element data for both compositional series indicates spinel–peridotite source areas. The rare earth and trace elements of the alkaline lavas originate from a highly primitive and slightly contaminated asthenospheric mantle; those of the calc-alkaline lavas originate from a highly heterogeneous, asthenospheric, and lithospheric mantle source. Partial melting and magmatic differentiation processes played a role in the formation of the petrological features of these volcanics. These rocks form two groups on the basis of their ~(87) Sr/~(86) Sr and ~(143) Nd/~(144) Nd isotopic compositions in addition to their classifications based on their chemical compositions(alkaline and calc-alkaline). These isotopic differences indicate a dissimilar parental magma. Therefore, high Nd isotope samples imply a previously formed and highly primitive mantle whereas low Nd isotope samples may indicate comparable partial melting of an enriched heterogeneous shallow mantle. Other isotopic changes that do not conform to the chemical features of these lavas are partly related to the various tectonic events of the region, such as the Dead Sea Fault System and the Bitlis Suture Zone.     

Trace fossils of an amalgamated storm-bed succession from the Jurassic of the Kachchh Basin,India:The significance of time-averaging in ichnology

The uppermost part of the Upper Bathonian Sponge Limestone member, Patcham Formation, of the Jhura Dome of Kachchh Mainland is a thickening-and shallowing-upward succession topped by medium-to thick-bedded hummocky cross-stratified grainstones deposited by storm waves. Occasionally, thin, commonly lenticular, intraclastic-bioclastic silty marl intercalations between the grainstones are highly bioturbated, in contrast to the grainstones, in which, for the most part, trace fossils occur scattered. Large exposures of bedding planes of the grainstones allow the detailed investigation of ichnological features, whereas the high density of traces in the soft marls precludes the identification of any ichnotaxa. Eighteen ichnotaxa have been recorded including Ophiomorpha, Thalassinoides, Taenidium, Gyrophyllites, Chondrites, Dactyloidites, Teichichnus, Bolonia, and Ancorichnus. Except for Ophiomorpha nodosa and Thalassinoides, which generally indicate moderate to high energy conditions and are the dwelling burrows of suspension-feeding to omnivorous crustaceans, the ichnotaxa represent a deposit-feeding behaviour of their producers and thus are characteristic of low-energy environments. The trace fossils form three ichnoassemblages characterized by(1) Ophiomorpha nodosa and Thalassinoides suevicus,(2)?Thalassinoides isp. A, Taenidium, and Bolonia lata,and(3) Ancorichnus. The dominance of traces of deposit-feeders in rocks indicative of high-energy events is counterintuitive and points to their non-contemporaneity. The sediments were deposited during brief highenergy events, whereas the trace fossils were produced when, after waning of storms low-energy conditions prevailed. This time-averaging is particularly pronounced in trace fossils that extend vertically downwards and may reach strata deposited under distinctly different conditions. Thus, environmental interpretations based on trace fossils should refer to colonisation surfaces rather than to the sediment surrounding the trace fossils. In the latter case, interpretations may be erroneous, especially when erosion subsequently destroyed sedimentary evidence of their original environment.     

Morphological and molecular evidence supports the first occurrence of two fishes,Siganus sutor(Valenciennes, 1835)and Seriolina nigrofasciata(Rüppell, 1829)(Actinopterygii:Perciformes), from marine waters of Odisha coast,Bay of Bengal,India

Marine ecosystems provide a wide variety of diverse habitats that frequently promote migration and ecological adaptation. The extent to which the geographic distribution of marine organism has reshaped by human activities remains underappreciated. The limitations intrinsic to morphology-based identification systems have engendered an urgent need for reliable genetic methods that enable the unequivocal recognition of fish species,particularly those that are prone to overexploitation and/or market substitution. In the present study, however, an attempt has been taken to identify two locally adapted fish species, Siganus sutor(Valenciennes, 1835) and Seriolina nigrofasciata(Rüppell, 1829) of order Perciformes, which happens to be the first record in Odisha coast,Bay of Bengal. The diagnostic characteristics of Siganus sutor are: dorsal fin XIII-10, anal fin VII-9, pectoral fin 15,pelvic fin II-3, while that of Seriolina nigrofasciata dorsal fin VI-I-35, anal fin I-17, pectoral fin 16, pelvic fin 5. All COI barcodes generated in this study were matched with reference sequences of expected species, according to morphological identification. Bayesian and likelihood phylogenetic trees were drawn based on DNA barcodes and all the specimens clustered in agreement with their taxonomic classification at the species level. The phylogeographic studies based on haplotype network and migration rates suggest that both the species were not panmitic and the high-frequency population distribution indicates successful migration. The result of this study provides an important validation of the use of DNA barcode sequences for monitoring species diversity and changes within a complex marine ecosystem.     

地下水气体组分的潮汐变化

我们观察了日本中部Omaezaki地区地下水气体组分时间序列数据的周期性变化,Omaezaki是日本地震预报目录中即将到来的Tokai地震前兆信号观察的重要地区.我们已经开始在一口100 m深的井中对地下水中气体组分进行持续监测.