京津水准复测与垂直形变特征

利用京津城际铁路水准测量资料,绘制了京津地区垂直形变图,发现京津城际铁路水准复测结果同样也出现了与首都圈地区同期水准测量相一致的"南升北降"垂直形变异常现象.分析认为应加强首都圈乃至华北地区的形变监测,为判定形变发展趋势提供依据.     

The 2009 paroxysmal explosions at Stromboli (Italy): magma mixing and eruption dynamics

Three small-scale paroxysmal explosions (also called major explosions) interrupted ordinary mild Strombolian activity at Stromboli on May 3, November 8 and 24, 2009. Products were largely confined to the summit area, except in the November 24 event, during which coarse pumiceous lapilli reached the coast. Emission of crystal-poor pumice closely mingled with crystal-rich products characterized the three events. The textural and chemical study of minerals and glassy matrices revealed that the two end-members are mingled together physically in the May 3 and November 24 pumice, whereas November 8 products contain heterogeneous glass with intermediate compositions derived from chemical mixing between crystal-rich and crystal-poor magmas. We here discuss the different degrees of interaction between the two magmas in the three explosions in terms of magma dynamics during small-scale paroxysms.     

Threshold for initiation of motion of unimodal and bimodal sediments

Experimental data,obtained from previous studies,on Critical Tractive Stress(CTS) of non-uniform sediments, have been used to verify the adequacy of existing relationships for CTS of non-uniform bimodal sediments.Keeping in view the performance of such relationships,a new relationship for computation of dimensionless CTS of individual size fraction of non-uniform unimodal and bimodal sediments has been proposed in the form of power law.The coefficient and exponent of the proposed power law have been empirically correlated with sediment characteristics for available sediment data.The proposed relationship has been validated with independent flume and field data to assess their applicability for unimodal and bimodal sediments.     

Do Solar Flares Affect Total Ozone?

An analysis of total ozone from Hradec Králové (50.25°N, 15.21°E) and of radio wave absorption in the lower ionosphere at 1539 kHz (reflection point 50.3°N, 11.8°E) shows that there is no detectable effect of strong solar flares in total ozone, no correlation between total ozone and absorption on a day-to-day time scale, and that strong solar flares do not affect this correlation. Thus the long-term correlation of monthly average values (Alberca et al., 1996) is not reproduced on a day-to-day time scale, and the effects of strong geomagnetic storms in total ozone (Latovika et al., 1992; Mlch and Latovika, 1996) have no counterpart in effects of strong solar flares.     

工程水准复测垂直形变分析

利用京沪高铁京津段的八期工程水准复测资料,绘制了2007年3月-2011年3月间的京津地区垂直形变图,并对京津沿线地区近期垂直形变趋势进行了分析研究.研究结果表明,2009年3月至2011年3月期间,不同地点出现了正速率变化,与以往对于这一区域负速率变化的地面沉降规律形成了一个“反向”变化,显示出区域应力场受外部干扰和影响后的变化特征.为分析研究首都圈地区今后一段时间的地壳垂直形变趋势提供依据.     

Electric conductivity of Fe-Ti minerals

a mua n¶rt;um u mnama auum uma mnam 200–900°C ¶rt; ummuu u ama Fe-Ti ua (amum,amum, uum u mu). n numa ¶rt;a n¶rt;m mun au mn¶rt;mu u au uu amuauu. a ma u mm naam n¶rt;u m-auu m¶rt;.     

НЕКОТОРЫЕ СВЯЗЫ ЭЛЕКТРИЧЕСКИХ ПАРАМЕТРоВ ГОРНЫХ ПОРоД И ИХ ХИМИЧЕСКОГО СОСТАВА

au aa ¶rt;a, nuau uuu ma n¶rt; u m muu uu, n¶rt; m¶rt;a nm (). u a m u ¶rt; uuu ma u muuu uuau.

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Summary Analysis of the data set describing the chemical composition of the rocks and their electrical parameters was performed by the principal component method. Some relations between chemical composition and electrical parameters were established.

     

Demand Forecast of Geological Disaster Rescue Equipment Based on "Scenario-Task"

Geotechnical and Geological Engineering - The suddenness, complexity, and devastation of major geological disasters make it necessary to improve the efficiency of disaster rescue. At present, the...     

Groundwater residence time downgradient of Trench No. 22 at the Chernobyl Pilot Site: Constraints on hydrogeological aquifer functioning

Following the explosion of reactor 4 at the Chernobyl power plant in northern Ukraine in 1986, contaminated soil and vegetation were buried in shallow trenches dug directly on-site in an Aeolian sand deposit. These trenches are sources of radionuclide (RN) pollution. The objective of the present study is to provide constraints for the Chernobyl flow and RN transport models by characterising groundwater residence time. A radiochronometer ³H/³He method (t_1/2 = 12.3 a) and anthropogenic tracers including CFC and SF₆ are investigated along with the water mass natural tracers Na, Cl, ¹⁸O and ²H.     

The silicon isotopic composition of surface waters in the Atlantic and Indian sectors of the Southern Ocean

We report here the silicon isotopic composition (δ³⁰Si) of dissolved silicon (DSi) from 42 surface water samples from the Drake Passage, the Weddell Gyre, other areas south of the Southern Boundary of the Antarctic Circumpolar Current (ACC), and the ACC near the Kerguelen Plateau, taken between the beginning of February and the end of March 2007. From the beginning to end of the cruise (ANTXXIII/9), DSi diminished in the Antarctic by 50 μmol L⁻¹ while concentrations of nitrate + nitrite and phosphate showed no net decline, indicating that the high seasonal Si/N removal ratios well known for the Southern Ocean may be more related to the strength of the silicate pump in the Southern Ocean than to the instantaneous Si/N uptake ratio of diatoms. The δ³⁰Si of DSi in samples containing more than 20 μM DSi were strongly negatively correlated to DSi concentrations, supporting the use of δ³⁰Si as a proxy for DSi removal. The “open system” fractionation observed, ε = −1.2 ± 0.11‰, agrees well with results from previous work in other areas, and the estimate of the initial δ³⁰Si of DSi of +1.4‰ is not far off observations of the δ³⁰Si of DSi in Winter Water (WW) in this area. Results were used to model DSi draw down in the past from the δ³⁰Si of sediment cores, although isotopic fractionation during silica dissolution appeared to influence the δ³⁰Si of some surface water samples, inviting further study of this phenomenon.