Prediction of maximal daily average values of relativistic electron fluxes in geostationary orbit during the magnetic storm recovery phase

The relation of the maximal daily average values of the relativistic electron fluxes with an energy higher than 2 MeV, obtained from the measurements on GOES geostationary satellites, during the recovery phase of magnetic storms to the solar wind parameters and magnetospheric activity indices has been considered. The parameters of Pc5 and Pi1 geomagnetic pulsations and the relativistic electron fluxes during the prestorm period and the main phase of magnetic storms have been used together with the traditional indices of geomagnetic activity (A _E, K _p, D _st). A simple model for predicting relativistic electron fluxes has been proposed for the first three days of the magnetic storm recovery phase. The predicted fluxes of the outer radiation belt relativistic electrons well correlate with the observed values (R ∼ 0.8–0.9).     

Tectonics and metallogeny of the junction zone between the North Asian craton and Pacific tectonic belt

The tectonics and metallogeny of the junction zone between the North Asian craton and Pacific tectonic belt are considered. This zone is characterized by a wide variety of structures superposed on the metamorphic basement, which was formed in the course of a multistage geologic development of the craton from the Precambrian to the Cenozoic. They are related to the craton evolution and its response to the collision and subduction processes in the adjacent orogenic belt, processes in the passive and active continental margins, and plume magmatism. The geological structure of the region includes blocks of metamorphic rocks of the Aldan–Stanovoi shield, Paleoproterozoic volcanogenic troughs, Mesoproterozoic–Neoproterozoic and Early Paleozoic structures of the platform cover, Late Paleozoic volcanic and terrigenous troughs, structures of the Late Mesozoic Okhotsk–Chukotka volcanic belt of the active continental margin, and Late Cretaceous riftogenic structures formed in response to plume magmatism. In total, six metallogenic epochs are recognized in the development of ore mineralization: Archean–Early Paleoproterozoic, Late Paleoproterozoic, Mesoproterozoic, Neoproterozoic, Late Paleozoic, and Late Mesozoic. The minerageny of the junction zone between the craton and Pacific belt is highly diversified, being characterized by distinct evolution in time and space. Each development stage features its own set of mineral resources.     

Solar rotation velocity as determined from sunspot drawings of J. Hevelius in the 17th century

Using two original copies of Hevelius' Selenographia and reducing spot positions with two different methods, we found that the solar angular rotation velocity at the beginning of the Maunder minimum was about the same as today. The gradient of the differential rotation was slightly steeper than given in modern reductions, but not significantly different. These findings are in contradiction to those published by Eddy et al. (1976).     

Geology and tectonics of the Themis Regio-Lavinia Planitia-Alpha Regio-Lada Terra area,Venus: Results from Arecibo image data

New radar images obtained from the Arecibo Observatory (resolution 1.5–4.0 km) for portions of the southern hemisphere of Venus show that: the upland of Phoebe Regio contains the southern extension of Devana Chasma, a rift zone extending 4200 km south from Theia Mons and interpreted as a zone of extension; Alpha Regio, the only large region of tessera within the imaged area, is similar to tessera mapped elsewhere on the planet and covers a smaller percentage of the surface than that observed in the northern high latitudes; the upland made of Ushas, Innini and Hathor Montes consists of three distinct volcanic constructs; Themis Regio is mapped as an ovoid chain of radar-bright arcuate single and double ring structures, edifices and bright lineaments. This area is interpreted as a region of mantle upwelling and on the basis of apparent split and separated features, a zone of localized faulting and extension. Linear zones of deformation in Lavinia Planitia are characterized by lineament belts that are often locally elevated, are similar to ridge belts mapped in the northern high latitudes and are interpreted to be characterized mainly by compression; radar-bright lava complexes within Lavinia Planitia are unique to this part of the planet and are interpreted to represent areas of eruption of high volumes of extremely fluid lava; the upland of Lada Terra is bound to the north by a linear deformation zone interpreted as extensional, is characterized by large ovoids and coronae, is interpreted to be associated with an area of mantle upwelling, and is in contrast to the northern high latitude highland of Ishtar Terra. Regions of plains in the southern hemisphere cover about 78%; of the mapped area and are interpreted to be volcanic in origin. Located within the area imaged (10–78 S) are 52 craters interpreted to be of impact origin ranging from 8 to 157 km in diameter. On the basis of an overall crater density of 0.94 craters/10⁶ km², it is determined that the age of this part of the Venus surface is similar to the 0.3 to 1.0 billion year age calculated for the equatorial region and northern high latitudes. The geologic characteristics of the portion of the Venus southern hemisphere imaged by Arecibo are generally similar to those mapped elsewhere on the planet. This part of the planet is characterized by widespread volcanic plains, large volcanic edifices, and zones of linear belt deformation. The southern hemisphere of Venus differs from northern high latitudes in that tessera makes up only a small percentage of the surface area and the ovoid chain in Themis Regio is unique to this part of the planet. On the basis of the analysis presented here, the southern hemisphere of Venus is interpreted to be characterized by regions of mantle upwelling on a variety of scales (ovoids, region made up of Ushas, Innini and Hathor Montes), upwelling and extension (Themis Regio) and localized compression (lineament belts in Lavinia Planitia).     

Intercomparison of measurements of stratospheric hydrogen fluoride

Observations of the vertical profile of hydrogen fluoride (HF) vapor in the stratosphere and of the vertical column amounts of HF above certain altitudes were made using a variety of spectroscopic instruments in the 1982 and 1983 Balloon Intercomparison Campaigns. Both emission instruments working in the far infrared spectral region and absorption instruments using solar occultation in the 2.5m region were employed. No systematic differences were seen in results from the two spectral regions. A mean profile from 20–45 km is presented, with uncertainties ranging from 20% to 50%. Total columns measured from ground and from 12 km are consistent with the profile if the mixing ratio for HF is small in the tropophere and low stratosphere.     

Relationship between the seismicity and geologic structure of the Blanco Transform Fault Zone

Morphologic studies of an oceanic transform, the Blanco Transform Fault Zone (BTFZ), have shown it to consist of a series of extensional basins that offset the major strike-slip faults. The largest of the extensional basins, the Cascadia Depression, effectively divides the transform into a northwest segment, composed of several relatively short strike-slip faults, and a southeast segment dominated by fewer, longer faults. The regional seismicity distribution (m _b 4.0) and frequency-magnitude relationships (b-values) of the BTFZ show that the largest magnitude events are located on the southeast segment. Furthermore, estimates of the cumulative seismic moment release and seismic moment release rate along the southeast segment are significantly greater than that of the northwest segment. These observations suggest that slip along the southeast segment is accommodated by a greater number of large magnitude earthquakes. Comparison of the seismic moment rate, derived from empirical estimates, with the seismic moment rate determined from plate motion constraints suggests a difference in the seismic coupling strength between the segments. This difference in coupling may partially explain the disparity in earthquake size distribution. However, the results appear to confirm the relation between earthquake size and fault length, observed along continental strike-slip faults, for this oceanic transform.     

辽河盆地西部凹陷沙河街组古近系页岩气成藏地质条件研究

在辽河盆地各构造单元中以西部凹陷湖泊沉积持续时间最长,是研究辽河盆地沙河街组页岩气成藏的良好地区.本次在大量的资料收集、整理和分析的基础上,对辽河盆地西部凹陷沙河街组页岩气成藏地质条件进行初步分析,结果表明：本区的暗色泥岩主要发育在半深湖-深湖环境中,暗色泥岩具有厚度大、连续性强、分布广的特点.有机质丰度较高,TOC平均值在2.18%左右.干酪根类型以II型为主,偏向产气.有机质成熟度基本大于0.59%,表明泥页岩已基本进入大量排烃阶段.脆性矿物总量达到43.1%~61.5%,有利于页岩气开采.在页岩气成藏的地质因素分析基础上,综合研究认为,清水洼陷是沙河街组页岩气富集的有利区域.     

观测应变阶在地震应力触发研究中的应用

对中国钻孔应变台网观测到的昆仑山口西MS8.1大地震的应变阶资料的研究结果表明:① 很多观测值与静力位错理论计算值不符合；② 北方地震较活跃地区的很多台站观测到异常大的应变阶，而南方构造运动较不活跃地区的台站虽然也观测到地震波动，但是应变阶不明显. 由此推断，地震的触发（可能是动态触发）作用对远场的实际地震应变变化具有重要影响. 也就是说，远场的构造活动（可能是断层活动）是否曾被地震触发，可能决定当地的应变场变化的主要特征. 进一步对昌平台1999年3月11日张北地震与1999年11月1日大同地震的观测资料对比分析表明:断裂带的分布情况对实际地震应变变化有直接影响. 这证明观测到的异常大的地震应变阶可能是地震触发了当地的断层活动的表现.      

Suspended sediment concentration in a buoyant plume: Fraser River,Canada

A study of suspended sediment concentration in the buoyant plume of the Fraser River, Canada, showed that unstratified flow conditions at the river mouth caused resuspension of sandy bed material and high concentrations of coarse sediment. When flow at the mouth was stratified, sediment was fine-grained and concentrations were low. Application of a multivariate model revealed that suspended sediment concentration along the plume axis was controlled primarily by distance seaward of the river mouth, secondly by tidal height, and least by sediment concentration in the river.     

Distribution and ecology of Nectocarcinus antarcticus and N. bennetti (Brachyura: Portunidae) in the New Zealand region

The distributions of two swimming crabs endemic to the New Zealand region are described, mostly from material obtained at 118 of 2544 New Zealand Oceanographic Institute benthic stations sampled.

Nectocarcinus antarcticus (Jacquinot) was found within the geographic limits 34°S‐51°S and 166° E‐176° W, with concentrations around Cook Strait, the Chatham Rise, Foveaux Strait, and the Auckland Is. N. bennetti (Takeda & Miyake) occurred between 44° S and 53° S, and 165° E and 180°, most frequently in the south and west, on the ‘highs’ of the Campbell Plateau. Although the distributions overlap between 44° S and 51° S, and this overlap zone produced most of the available material, only one joint occurrence of the two species was noted. This apparent separation was not satisfactorily explained by any of the ecological factors recorded. The depth ranges of both species were broadly similar (0–550 m for TV. antarcticus, 20–474 m for JV. bennetti); both were most frequently obtained at depths less than 200 m. Both occurred primarily on the coarser sediment grades, though N. antarcticus occupied a broader range of grades than N. bennetti.

The size ranges of the two species were similar; carapace lengths were 8.0–62.0 mm for N. antarcticus and 5.8–68.0 mm for N. bennetti. The larger specimens of both species were found towards the southern limits of distribution. Larger specimens of N. antarcticus were absent from depths greater than 120 m; smaller N. antarcticus and all N. bennetti occurred throughout their respective depth ranges. Ovigerous N. antarcticus (smallest, 8.8 mm carapace length) were obtained at depths of 17–263 m from May to October; ovigerous N. bennetti (smallest 36.1 mm) were from depths of 150–183 m in May only.