Local Spring Research Articles

VIBRATIONAL POWER FLOW ANALYSIS OF DAMAGED BEAM STRUCTURES

In view of structure-borne sound, vibrational power flow analysis is investigated for damaged beam structures. In this paper, the damage is modelled as a joint of a local spring. The damage point transfer matrix and the beam element transfer matrix are deduced, then the relations of the vibrational power flow, the position and the characteristic size of the damage are obtained combined with periodic structure theory. Based on the theoretical analysis and measurement results, the damage can be diagnosed in the next work.

Changes in clutch size, brood size and numbers of nesting Squacco Herons Ardeola ralloides over a 32‐year period in the Camargue, southern France

Changes in numbers of nesting pairs, clutch size, and brood size of Squacco Herons Ardeola ralloides in the Camargue, southern France were analysed over a 32‐year period. The annual numbers of breeding pairs [average 84 pairs pL 30 sd, n = 32 years) exhibited a possible increasing trend, but with considerable variability. This variability is associated with local spring rainfall, which may influence the available surface area of their preferred freshwater habitats. In contrast to population size, clutch size decreased substantially in recent years. Our data do not provide a causal explanation for this change in clutch size, although the reduction temporally corresponds with increasing rice cultivation and with a dramatic increase in the number of Cattle Egrets Bubulcus ibis in the Camargue.

Stage-specific habitats of Calanus finmarchicus and Calanus helgolandicus in a stratified northern Norwegian fjord

During 12 months from April 1997, Calanus spp. copepodites were sampled in the 380-m deep Saltfjord by means of a 200-μm WP-2 net at four depth intervals. Nauplii were sampled with a 100-μm bongo net. Chlorophyll a and phytoplankton were sampled with a hose in the 0–40 m depth range. Environmental variables were recorded by CTD and an in situ fluorimeter. C. helgolandicus occurred in low numbers as adults and CV during most of the year. During the spring bloom in April, it avoided the upper cold 0–50 m depth range, where C. finmarchicus reproduced. In August–September, adults of the two species were equally numerous in the 0–50 m depth range. The adult C. finmarchicus had probably developed from the local spring generation, whereas C. helgolandicus had probably been imported from shelf waters. Nauplii present in August may be attributed to both species, but they did not grow into CI locally. Therefore, C. finmarchicus CV that accumulated in September–October were more likely imported from the shelf, probably by surface advection. Predators possibly reduced numbers up to January 1998, when both species again increased, probably because of deep inflow of shelf water.

Liturgiese identiteitsvorming as antwoord op die invloed van die verbruikerskultuur

The formation of liturgical identity in response to the influence of a consumer culture Liturgy in South Africa is continually interacting with the Western cultural heritage on the one hand, and increasingly with African culture on the other hand. However, another powerful influence on the local liturgy springs from the so-called global consumer culture. A few characteristics of the latter are inter alia the following: The emphasis on what the “buyer”, the worshipper and “potential” worshipper prefer; a show business attitude resulting in transforming members of the congregation into spectators rather than participants. Furthermore the emphasis is on the pursuit of effectiveness and the utilisation of technology to attain it and the focus is specifically on the needs of the individual and not on those of the community. The continual formation of liturgical identity is the answer to the mainly detrimental cultural processes currently manifesting themselves. The point of departure in forming a cultural identity implies an in-depth study of the liturgical guidelines indicated in the Old and the New Testament and the historical development of liturgy, especially in the second, sixteenth and twentieth centuries. The following aspects should, however, also be taken into consideration: the contemporary characteristics of the local indigenous culture, beauty of God, relationship between liturgy and culture, multi-cultural enrichment of liturgy, missionary aim and eschatological focus of liturgy.

Geophysical exploration at Hishikari gold mine, Kagoshima, Japan

The Hishikari epithermal gold-silver deposit, one of the world's richest gold mines, is in northeastern Kagoshima on Kyushu Island, southwest of Japan (Figure 1). The area is characterized by volcanic activity, ranging from the active Sakurajima and Kirishima volcanoes to local hot springs.

Submarine springs of fresh water in the region from Cape Feolent to Cape Sarych

We performed a search for local coastal submarine springs of fresh water in the region from Cape Feolent to Cape Sarych (down to an isobath of 40m). Stable submarine springs of brackish water with the minimum salinity of 5.5‰ and the minimum total output of 30,000 m3/day were discovered only near the west wall of Cape Aiya. It is shown that brackish waters discharging from these springs spread over the sea surface in the form of a thin layer (up to 1 m in thickness) characterized by lower salinity, higher transparency, and an elevated content of silicic acid. We make a conjecture that the appearance of 2–3-m-thick layers of water with higher transparency and lower salinity at depths of 5–8 m is explained by the discharge of unknown bottom springs of underground fresh water.

Advective particle transport into permeable sediments—evidence from experiments in an intertidal sandflat

Advective transport of artificial and natural particles into permeable sediments was demonstrated in situ by field experiments in an intertidal Wadden Sea sandflat. Using dyed sediment, advective interfacial solute exchange was shown to reach down at least 1.5 cm below surface. Particle depth distributions depended on sediment permeability and particle size. Sandy sediments were found to efficiently trap particulate material. At the beginning of the local phytoplankton spring bloom, an average m2 of coarse‐grained sediment received 850‐mg organic carbon per day by filtration of 14 liters of overlying water per hour. We discuss the relative importance of different transport mechanisms, and data from parallel studies on natural sediments at the same site are interpreted in close correlation to the results of the in situ experiment.

Properties of the 1979 SAM II Antarctic 1.0‐μm extinction coefficients: Implications of dehydration and seasonal evolution of the Antarctic polar vortex

The present study investigates the 1.0‐μm extinction coefficient measurements obtained in the Antarctic region in 1979 from the Stratospheric Aerosol Measurement (SAM) II, with particular focus on the background aerosol properties. Correlative meteorological information from the National Centers for Environmental Prediction is incorporated in this investigation. The results indicate that the data frequency distribution of the background aerosol extinction coefficient in the local summer and fall can be adequately modeled by using a single‐mode normal distribution, and that a binormal distribution is needed for modeling the distribution in the local winter and spring because of the different characteristics of the aerosols inside and outside the polar vortex. In general, the vertical distribution of the aerosol mean extinction coefficient exhibits two regions of different seasonal variation. Above 16 km the extinction coefficient is the highest during the local summer, and the lowest during the local spring inside the polar vortex. Below 16 km the aerosol seasonal variation is more complex, but the winter enhancement of the aerosol extinction coefficient inside the Antarctic polar vortex is clearly evident. As the season changes from winter to spring, the results inside the Antarctic polar vortex also indicate a reduction in aerosol optical depth in the stratosphere, but no significant changes in the upper troposphere. The present study further indicates that the bottom of the winter polar vortex in Antarctica is located at an altitude as low as 8 to 9 km, which is about 4 to 5 km lower than the bottom of the Arctic polar vortex. This difference may be attributable to the different strengths of the winter polar vortex and the planetary wave activities between the two hemispheres. In summary, the properties of the Antarctic background aerosol are very consistent with the effect of polar stratospheric clouds on the aerosol vertical distribution through their formation, sedimention, and evaporation, and with the seasonal evolution of the polar vortex. Finally, the result of the present study provides valuable opportunities for fully utilizing the multiyear SAM II tropospheric and stratospheric measurements to investigate the aerosol climatology and long‐term variations in the Arctic and Antarctic regions.

SPRING, POND AND RIVER WATER CHEMISTRIES DERIVED FROM A TEA PLANTATION IN CENTRAL SHIZUOKA PREFECTURE

To investigate the influence of chemical fertilizers on groundwatear and surfacewater neighboring tea plantations in central Shizuoka prefecture, a time series of chemical compositions and nitrogen isotopic ratios within local wells, springs, rivers and ponds were studied.The pH of spring and pond water in some areas maintained basic acidity with neither any noticeable changes in nitrogen isotopic ratios nor any disappearance of nitrate within the ponds and low concentrations of chlorophyll and phosphorus.Therefore, the activities of photosynthesis in the ponds of this area were very low due to low concentrations of phosphorus. However, the pH of spring water in the other areas maintained basic neutrality to alkali with high concentrations of C2+a and SO2-4 and low concentrations of NO-3 because of soil and fertilizer improvement.Concentrations of Al, Co, Ni, Zn and Mn ions in the groundwater and surface water increased with the decrease of pH values.Then, soil and fertilizer improvemenit si important.

Analysis on Steady-State Vibration of Nonlinear System by Convolution Integral.

A method for analyzing steady state vibration of a system with localized nonlinear springs by convolution integral is proposed. Scale of the nonlinear problem can be reduced by using localization of the nonlinear springs in the method. First, equation of motion with the convolution integral of nonlinear restoring force which is treated as an external force is made, second, a set of nonlinear algebraic equations on discrete-time history of unit period is derived and finally the nonlinear algebraic equations is solved with the harmonic balance method. Stable and unstable condition of the steady state vibration can be distinguished by the present method and the impulse response required can be also measured in the experiment because of the merit of the convolution integral. Two examples are shown and the validity of the method is discussed in comparison with Runge-Kutta-Gill method or the experiment.

Influent rivers: a pollution threat to Schwyll Spring, South Wales?

Abstract A number of influent rivers cross the southern outcrop of the Carboniferous Limestone in South Wales. They lose a proportion of their flow to groundwater via both discrete sinks and leaky river beds. These influent rivers represent a pollution threat to local springs that is dependent upon many factors including antecedent conditions, pollutant type, the location of pollutant loss and the nature and volume of influent flow. An attempt is made to define the catchment area of Schwyll Spring public water supply, near Bridgend in South Wales, prior to considering the potential for pollution from influent rivers.

Coccolithophore export production, species composition, and coccolith-CaCO 3 fluxes in the NE Atlantic ( [formula omitted] and [formula omitted

Coccolithophores were examined in two sediment traps, deployed for one year (April 1989 to April 1990) at approximately 1 km water depth, in the subtropical NE Atlantic at 34° N 21° W (station NABE-34) and in the temperate NE Atlantic 48° N 21° W (station NABE-48) as part of the JGOFS North Atlantic Bloom Experiment (NABE). At both stations, maximum coccolith and coccosphere fluxes were recorded during local spring bloom periods. The average coccolith and coccosphere fluxes at NABE-34 were 1.12×10 9 m −2 d −1 and 4.90×10 6 m −2 d −1 , respectively. At this station coccoliths from 51 taxa were identified. A marked seasonal change was noticed in relative abundances of Emiliania huxleyi and deep photic zone species: E. huxleyi dominated during spring, while in late autumn the coccolith assemblage was dominated by Florisphaera profunda and the coccosphere assemblage by G. flabellatus and Algirosphaera spp.. Emiliania huxleyi was the most abundant species in the overall coccolith and coccosphere assemblages with 69% and 64%, respectively. At NABE-48, the average daily fluxes were significantly lower, with 3.88×10 8 coccoliths m −2 d −1 and 8.45×10 5 coccospheres m −2 d −1 , and only 36 taxa were recorded in the trap samples. Emiliania huxleyi was the dominant species in the coccolith assemblage throughout the year with 72%, and showed maximum fluxes during spring 1990. Coccolithus pelagicus exhibited a distinct seasonal pattern, with maximum fluxes in early June 1989, probably related to the development of a mesoscale cyclonic eddy in the vicinity of the trap site. Holococcolithophore fluxes were highest during maximum sea surface temperatures in summer. The coccosphere assemblage was dominated by Gephyrocapsa spp., Syracosphaera spp., and E. huxleyi. Estimated CaCO 3 fluxes of coccoliths, coccospheres, and calcareous dinophytes were compared with the CaCO 3 content in the fine (<32 μm) fraction. The annual mass estimated CaCO 3 flux of coccoliths and coccospheres was 5.1 g m 2 yr at NABE-34 and 2.7 g m 2 yr at NABE-48, and that of calcareous dinophytes 0.9 and 0.1 g m 2 yr , respectively. These summed mass estimated values contributed on average only 55% at NABE-34 and 60% at NABE-48 to the fine fraction CaCO 3.

Is the biomass burning source of CO decreasing?

To investigate secular changes in CO and CH4, we examined monthly means of tropospheric measurements made from samples collected at 19 fixed sites in the National Oceanic and Atmospheric Administration (NOAA) Climate Monitoring and Diagnostics Laboratory (CMDL) global cooperative flask sampling network. The CH4 data are available for the period 1984–1995. A somewhat shorter time series is available for CO (1989–1995). The data were analyzed to extract a consistent pattern of change in time and in latitude. The most important preliminary finding is that the patterns of CO and CH4 change appear to resemble that of biomass burning. That is, there is maximum change during local spring in both northern and southern hemispheres. If we attribute a significant part of the change in CH4 trend (3–6 ppb/yr) to biomass burning, the corresponding change in CO is approximately 2–5 ppb/yr. This would explain the bulk of the observed change in CO (4–7 ppb/yr).

Interaction between karst, water and agriculture over the climatic gradient of Israel

The dry climate of Israel and the karstic nature of its rocks have always imposed human innovation for utilisation of water resources and agriculture. Large perennial karst springs are available only in the lowlands, but sophisticated water supply systems were built both in the lowland and highland regions. Marl layers interbedded within carbonates give rise to local perched springs and allow terrace construction. Deforestation has taken place for some 4000 years, causing intense soil erosion, but terraces have reduced this impact.

Long‐term Stratospheric Aerosol and Gas Experiment I and II measurements of upper tropospheric aerosol extinction

A detailed analysis has been made of Stratospheric Aerosol and Gas Experiment I and II aerosol extinction data for the upper troposphere (6‐km altitude to the seasonally averaged tropopause) taken between 1979 and 1998. An improved method of separation of the volcanic and surface‐derived components of the aerosol optical depth has been used. The mean extinction, at a wavelength of 1.02 μm, of the nonvolcanic component of the upper tropospheric aerosol is found to increase from approximately 1×10−4 km−1 at 70°S to about 7 times that value at 70°N. Maximum downward transfer of volcanic material into the upper troposphere is observed to take place in local spring in each hemisphere, occurring at a latitude of 70°S or greater in the southern hemisphere and at about 50°N in the northern hemisphere. The almost 20‐year data sequence (1979–1981, 1984–1991, 1994–1998) has been examined for evidence of any long‐term trends in the aerosol optical depth of the upper troposphere. It is unlikely that any change in the upper tropospheric 1‐μm aerosol optical depth greater than 1% per year has taken place when averaged over either hemisphere.

Modern hot spring geochemistry at the Tanlu fault and Jiaoliao block in eastern China

The δD, δ18O values of the hot springs are always more negative than those of the local cold springs. The main cause for the ocrurrence is physically isotope fractionation during the deep circulating process of the groundwater. The relational expression between the δD, δ18O values and the maximum circulating depths of the groundwaters is given. The gases escaped from the geothermal fluid are mostly crust-derived gases in the studied area. The compressive structure of the Tanlu fault could extend to the deep crust, and basically stop the ascent of deep-seated gases towards the surface.

Tectonic and seismic conditions for changes in spring discharge along the Garni right lateral strike slip fault (Armenian upland)

This study presents the relationship between local seismicity and springs discharge, in which the microseismicity modifies the state of stress of the aquifer matrix and these modifications of the local stress control the aquifer behaviour from an example of a basaltic reservoir crossed by a seismic fault. Along the right-lateral Garni seismic wrench fault, the distribution in space and time of more than 500 micro-earthquakes has been studied providing a pattern of stress distribution. Together with this tectonic survey, the hydrographs of springs issuing from an aquifer located in basaltic lava flows and crossed by the fault have been gauged for 4 years. According to its tectonic, geologic and hydrodynamic properties, the reservoir has been divided in to several parts. The hydrological behaviour of the reservoir and of each of its parts has been modelled, based on the rainfall and hydrodynamic properties of the basaltic reservoir and of nearby reservoirs. The model allows us to define the ‘normal behaviour’ of the springs, when their discharge is not affected by an earthquake. Anomalies to the normal hydrometric curves are defined, and correlated to small (M < 3.5) earthquakes along the Garni fault. We propose that the circulation of underground water in the area around the fault depends largely on the fracture pattern of the basalts and the aquifer basement, as pointed out from field observations. Changes in spring discharges are explained by variations in the state of stress around the Garni fault, induced by the alternation of elastic strain and stick-slip movement on the fault, and by creep far from the fault. A model of stress distribution is proposed which explains changes in fracture charateristics before and after earthquakes.

Tectonic and seismic conditions for changes in spring discharge along the Garni right lateral strike slip fault (Armenian Upland)

This study presents the relationship between local seismicity and springs discharge, in which the microseismicity modifies the state of stress of the aquifer matrix and these modifications of the local stress control the aquifer behaviour from an example of a basaltic reservoir crossed by a seismic fault.Along the right-lateral Garni seismic wrench fault, the distribution in space and time of more than 500 micro-earthquakes has been studied providing a pattern of stress distribution. Together with this tectonic survey, the hydrographs of springs issuing from an aquifer located in basaltic lava flows and crossed by the fault have been gauged for 4 years. According to its tectonic, geologic and hydrodynamic properties, the reservoir has been divided in to several parts. The hydrological behaviour of the reservoir and of each of its parts has been modelled, based on the rainfall and hydrodynamic properties of the basaltic reservoir and of nearby reservoirs.The model allows us to define the ‘normal behaviour’ of the springs, when their discharge is not affected by an earthquake. Anomalies to the normal hydrometric curves are defined, and correlated to small (M < 3.5) earthquakes along the Garni fault. We propose that the circulation of underground water in the area around the fault depends largely on the fracture pattern of the basalts and the aquifer basement, as pointed out from field observations. Changes in spring discharges are explained by variations in the state of stress around the Garni fault, induced by the alternation of elastic strain and stick-slip movement on the fault, and by creep far from the fault. A model of stress distribution is proposed which explains changes in fracture charateristics before and after earthquakes. © Elsevier, Paris

Climate and change in clines for melanism in the two–spot ladybird, Adalia bipunctata (Coleoptera: Coccinellidae)

The polymorphic two-spot ladybird, Adalia bipunctata, shows clinal variation in the frequency with which melanic and non-melanic morphs occur. Here we show that the clines in melanism in The Netherlands have changed over the past two decades: they have become shallower. This change has coincided with an increase in local ambient spring temperatures at most meteorological stations close to the sampling sites. The potential contribution of thermal melanism to the change in the shape of the clines is discussed.

Stable isotope compositions of waters and sulfate species therein, Death Valley, California, USA: Implications for inflow and sulfate sources, and arid basin climate

In this study, 95 water samples were collected in Death Valley between May 1992 and March 1994. The isotope compositions of these waters range from −15.2‰ to +2.8‰ for δ 18O and from −109% to −21% for δD. Rain, snow, and shallow spring waters derived from melting snow on the mountains fall on the meteoric water line (MWL). Salt pan brines fall on a local evaporation line with a slope of 3.6, indicating strong evaporation. Regional spring waters have low δ values, reflecting a different origin from the modern precipitation in Death Valley. At least three major sulfate sources were identified by the isotope data from sulfate in these waters: (1) atmospheric sulfate in precipitation; (2) dissolved sulfate from the local spring flow system; (3) dissolved marine sulfate from Paleozoic carbonate rocks in the regional groundwater system. The isotopic variations of these waters and sulfate therein reflect changing and/or mixing of sources in the basin.