UT variation of internal Sq currents and the oceanic effect during 1980 March 1–18

Summary. UT variation of the internal part of S _q currents is examined using the geomagnetic data during 1980 March 1–18, and the effect of the ocean is found. The ratio of the internal currents to the external increases when the external current vortex comes above the Atlantic and Pacific Oceans, and the internal current vortex shifts to the oceans when the external vortex approaches the edge of the oceans. The existence of the ocean increases the total induced current by about 30 per cent and this amount is consistent with model calculations for S _q by previous workers.     

不同水淹环境下河口感潮湿地枯落物分解及营养动态

采用分解袋法,以我国东南沿海典型的感潮河口--闽江河口最大的鳝鱼滩湿地为研究区域,选取2个潮水水淹环境差异显著的地段(一个为近潮沟地段,另一个为远潮沟地段)为研究样地,对闽江河口主要的本地种芦苇、短叶茳芏及外来人侵种互花米草枯落物分解过程及影响因素进行研究,结果表明:(1)经常性的潮汐水淹对3种植物枯落物分解速率的影响不显著;(2)经常性的潮汐水淹促进了短叶茳芏和互花米草枯落物N、P元素的损失,但对芦苇的影响不大;(3)在2种不同的水淹环境,3种植物枯落物分解速率由快到慢的顺序均是短叶茳芏>互花米草>和芦苇,分解速率在0.003166～0.005280 d-1之间,95%干物质分解需要的时间在1.56～2.61 a之间;(4)C浓度基本稳定,N浓度呈上升趋势,总N在研究末期表现为净损失,P浓度呈较大的波动,总P在研究末期也表现为净损失;(5)具有最低C/P的短叶茳芏枯落物分解速率最快.     

Matrix and Stokes vector representations of detectors for polarized waveforms: theory, with some applications to teleseismic waves

This paper deals with the problem of detecting polarized waveforms in multivariate time series. Detectors are designed in the frequency domain using the spectral matrix and matrix-algebra, and also a Stokes vector-algebra. All the detectors are expressed as functions of inner products in real vector spaces, and consequently are extremely easy to program for digital computers, and are computationally very efficient. Several suggestions for the application of the detectors to the interpretation of teleseismic waveforms are given.     

Conservation of mass in tidal loading computations

Summary. A re-examination of methods for including mass conservation in tidal loading shows that the spherical harmonic correction of Farrell is incorrect. The effect of unconserved mass for a nearly ocean-covered earth shows that the proper spherical harmonic expansion of the Newtonian Green function is the average of the internal and external expansions.     

Assessing Uncertainty Associated with the Delineation of Geochemical Anomalies

A pedogeochemical exploratory survey of gold deposits was carried out in the region of São Sepé (southernmost Brazil). The region comprises a predominantly metamorphosed belt of volcanoclastics, sediments, serpentinites, basalts, gabbros, chert, tuffs, and banded iron formation of the Proterozoic age. The anomalies were identified first by stream sediment heavy mineral survey at the regional scale of exploration. Once spatial continuity was modeled, ordinary block kriging was performed to generate geochemical maps. Indicator block kriging also was used as an alternative in analyzing and interpreting geochemical data. A novel approach is proposed, which combines both ordinary and indicator kriging for delineating geochemical anomalies. Probability maps proved to be appropriate for selecting new sites for further exploration. Gold anomalies in soils trending NE were well defined by geostatistical analysis and subsequently confirmed by drilling.     

Mapping of Regional-scale Multi-element Geochemical Anomalies Using Hierarchical Clustering Algorithms

Natural Resources Research - Mapping of multi-element geochemical anomalies is the basic goal of stream sediment sampling in worldwide, and especially at 1:100,000 scale in Iran. In the central...     

The tidal dynamics of the Irish and Celtic Seas

Summary. Current meter data collected over periods of more than 14 day from the Irish and Celtic Seas are harmonically analysed and presented in maps of tidal stream information. Making use of the analysed current data, and by constructing time series of frictional and inertial stresses which are also harmonically analysed, harmonic constituents of the surface tidal slopes at current meter stations are obtained. Using these with data collected from offshore tide gauges, and in conjunction with coastal tide data, cotidal maps are drawn with some confidence for M ₂, S ₂, O ₁ and K ₁, the M ₂ chart resolving the discrepancy which exists between the different charts of the Celtic Sea already produced. Cotidal maps for M ₃ and M ₄ are also presented.
The mean over a tidal cycle of the energy flux for M ₂, S ₂ and O ₁ is also presented in the form of the total energy flux in these constituents which crosses different sectional lines. A flux of 44 × 10⁶ kW is observed to enter the Celtic Sea from the Atlantic and this is compared with previous estimates. An energy budget is also performed for M ₂, including all the effects of astronomical forcing and Earth tides to enable comparison to be made between the true energy inflow and the estimated frictional dissipation. Finally, comparison is made between the mean of the instantaneous energy flux and the sum of the energy fluxes associated with the major harmonics.