Tar ball frequency data and analytical results from a long-term beach monitoring program

Following the spill of fuel oils from the New Carissa in February 1999, approximately 300 km of beaches on the Pacific coast of North America were surveyed. A long-term observation program focused on the documentation of stranded tar balls in the vicinity of the spill site. Systematic beach surveys which were conducted over the period March 1999 to April 2001 and semi-logarithmic scale, time-series plots proved the most useful format for identifying trends. Beach monitoring continued through to August 2001. by which time 212 tar balls had been analyzed by GC/MS for their chemical characteristics. The samples of tar balls collected between February 1999 and August 2001 were qualitatively compared with New Carissa source oils (NCSO) and 101 (48%) were not consistent with NSCO. The presence of tar balls that are not related to an incident can confound attempts to define cleanup or endpoint criteria and to assess possible injury to natural resources.     

Quantities,composition, and sources of beach debris in Korea from the results of nationwide monitoring

This study assessed the levels of marine debris pollution and identified its main sources in Korea. The surveys were bimonthly conducted by NGO leaders and volunteers on 20 beaches from March 2008 to November 2009. The quantities of marine debris were estimated at 480.9 (±267.7) count ⋅ 100 m⁻¹ for number, 86.5 (±78.6) kg ⋅ 100 m⁻¹ for weight, and 0.48 (±0.38) m³ ⋅ 100 m⁻¹ for volume. The level of marine debris pollution on the Korean beaches was comparable to that in the coastal areas of the North Atlantic ocean and South Africa. Plastics and styrofoam occupied the majority of debris composition in terms of number (66.7%) and volume (62.3%). The main sources of debris were fishing activities including commercial fisheries and marine aquaculture (51.3%). Especially styrofoam buoy from aquaculture was the biggest contributor to marine debris pollution on these beaches.     

Resurvey of a reef flat in American Samoa after 85 years reveals devastation to a soft coral (Alcyonacea) community

One of the earliest quantitative surveys of soft corals, on a reef flat in Pago Pago Harbour, American Samoa, was repeated 85 years later. The alcyoniid communities there, which were the dominant benthic organisms during the initial survey, have suffered a drastic decline of 99% cover in the interim. The most likely causes of the decline are anthropogenic disturbance associated with reclamation along the harbour from the 1940s to early 1960s, compounded by chronic pollution from industrial wastewater discharge from the mid-1950s to late 1980s. The decline in one dominant species, Sinularia polydactyla, is likely to have serious consequences for the reef as unusually for a soft coral, this had been the major reef building species. Life-history traits of certain Sinularia and Sarcophyton, such as slow growth and low rates of sexual reproduction, mean they will be slower to recover from severe disturbance than many scleractinian corals.     

Updated archaeomagnetic results from Bulgaria: the last 2000 years

The necessity of compilation of worldwide archaeomagnetic results was largely discussed at the symposium on New Trends in Geomagnetism in Czechoslovakia in the summer of 1988 and at the IAGA meeting in the summer of 1989. However, the elaboration of a given dataset for a determined territory is a continuous process. The newly gathered collections and some specifications of the preliminary datings given necessitate permanent updating of the catalogues.

The aim of the present paper is to give the contemporary state of the directional and intensity archaeomagnetic results obtained in the Sofia laboratory over the last 2000 years. The revision and filling up of the dataset for the period 6000-0 years B.C. is now in preparation. Both will be sent to the Archaeomagnetic database (IAGA Working Group I-5).     

Variability in estimates of oil contamination in the intertidal zone of a gravel beach

Estimates of the surface cover of stranded oil on a gravel beach ranged between 25 and 51%. This variability is attributed primarily to wet weather conditions that altered the colour of the surface substrate, thus making identification of oil or oiled sediments difficult. Estimates and the observations from three surveys in wet weather ranged between 25 and 46%; whereas on a dry day the range from four surveys was only 42–51%. Within this small study area (7200 m²) the same observer provided estimates of the surface oil cover that ranged from 1800 to 3680 m². This wide variability for a small section of shoreline would probably be magnified during reconnaissance surveys where long sections of coast are surveyed to determine the degree of contamination. Surveys of beach contamination for cleanup decisions or for damage assessment should be conducted with regard to the environmental (weather) conditions and the degree of accuracy that is required from the survey.     

基于水文-地球物理模型的地下水污染磁电阻率异常动态监测仿真

We present a forward-modeling investigation of time-dependent ground magnetometric resistivity （MMR） anomalies associated with transient leachate transport in groundwater systems. Numerical geo-electrical models are constructed based on the hydrological simulation results of leachate plumes from a highly conceptualized landfill system and the resultant MMR responses are computed using a modified finite difference software MMR2DFD. Three transmitter configurations （i.e., single source, MMR-TE, and MMR-TM modes） and two hydrological models （i.e., uniform and faulted porous media） are considered. Our forward modeling results for the uniform porous medium indicates that the magnetic field components perpendicular to the dominant current flow contain the most information of the underground targets and the MMR-TE mode is an appropriate configuration for detecting contaminant plumes. The modeling experiments for the faulted porous medium also confirm that the MMR method is capable of mapping and monitoring the extent of contaminant plumes in aroundwater systems.     

Coccolithophores in the upwelling waters of Portugal: Four years of weekly distribution in Lisbon bay

From July 2001 to May 2005, seawater samples were collected once a week at a fixed station in Lisbon bay (38°41′N, 09°24′W) in order to describe the ecological dynamics of the coccolithophore community. The seasonal and interannual distribution patterns of the different species and their relationships with environmental parameters are addressed. The present work aimed to identify potential proxies for different local water bodies and environmental conditions. Throughout the period of study, the upwelling events were weak and progressively more persistent. High sea surface temperatures (SST) were observed earlier in the year; summers and winters were gradually warmer and colder, respectively. Salinity variations reflected the different weather conditions as they are strongly influenced by rainfall and thus by the Tagus river flow. The extended periods of weak upwelling and the overall increase in SST resulted in the development of phytoplankton populations as measured by chlorophyll a. However, the persistence of the upwelling, and thus shorter convergence periods, favoured other phytoplankton groups than coccolithophore populations as these decreased towards the end of the sampling period. The annual structure of the coccolithophore assemblage showed a pronounced and recurrent seasonal variability, mainly related with the intensity and persistence of upwelling. The highest cell densities were recorded from spring to autumn. An overall preference by most species for mature upwelled waters and low turbulent conditions was observed associated with high temperatures and salinities, although the species develop in different windows with mismatching maxima. The coccolithophores observed were capable of withstanding coastal processes such as turbulence and were well adapted to an environment rich in nutrients provided by both continental runoff and upwelling.The consistency of the results enabled local oceanographic tracers to be defined. Emiliania huxleyi and Gephyrocapsa species can be used as proxies of surface productivity waters during spring and summer while Coccolithus pelagicus indicates the presence of upwelling fronts. Calcidiscus leptoporus is a tracer of the convergence of subtropical oceanic waters onto the shelf, during winter while Coronosphaera mediterranea, Syracosphaera pulchra, Helicosphaera carteri and Rhabdosphaera clavigera revealed the presence of those waters during the short period that characterized the transition from upwelling to downwelling seasons.     

Effects of hydrocarbon contamination on a free living marine nematode community: results from microcosm experiments

Anthropogenic inputs of crude and refined petroleum hydrocarbons into the sea require knowledge of the effects of these contaminants on the receiving assemblages of organisms. A microcosm experiment was carried out to study the influence of diesel on a free living nematode community of a Tunisian lagoon. Sediments were contaminated by diesel that ranged in concentration from 0.5 to 20 mg diesel kg⁻¹ dry weight (dw), and effects were examined after 90 days. Gradual changes in community structure were revealed depending on the quantity of diesel administrated. In the medium (1 mg diesel kg⁻¹ and 5 mg diesel kg⁻¹ (dw)) and high (10 mg diesel kg⁻¹, 15 mg diesel kg⁻¹ and 20 mg kg⁻¹ (dw)) treated microcosms, most univariate measures, including diversity and species richness, decreased significantly with increasing level of diesel contamination whereas nematode assemblage from the low treated microcosm (0.5 mg diesel kg⁻¹ (dw)) remained unaffected. Results from multivariate analyses of the species abundance data demonstrated that responses of nematode species to the diesel treatments were varied: Chaetonema sp. was eliminated at all doses tested and seemed to be intolerant species to diesel contamination; Pomponema sp. and Oncholaimus campylocercoïdes were significantly affected at all diesel contamination levels but they were not eliminated, these species were categorized as “diesel-sensitive”; Hypodontolaimus colesi, Daptonema trabeculosum and Daptonema fallax which significantly increased respectively at 0.5, 1 and 5 mg diesel kg⁻¹ (dw) concentrations and appeared to be “opportunistic” species at these doses whereas Marylynnia stekhoveni which increased at all high doses (10, 15 and 20 mg diesel kg⁻¹ (dw)) seemed to be a “diesel-resistant” species.     

Vertical heterogeneities of hydraulic aquitard parameters: preliminary results from laboratory and in situ monitoring

Abstract

A borehole is developed in a shallow multi-layered aquifer and used to derive the porosity, specific storage and hydraulic conductivity of the aquitard. Local values of hydrodynamical parameters are estimated from petrophysical analysis of core samples, and the empirical relationship between porosity and permeability. Vertical diffusivity is determined from the response of the aquitard to a loading cyclic signal using pressure records at different depths. Hydraulic conductivities deduced from the petrophysical analysis ranged from 10^?8 to 10^?10 m s^?1 and are comparable with those of facies of marine/lacustrine clay observed in samples. The permeability values calculated based on diffusivity are within the range 10^?9 to 10^?11 m s^?1 with a quasi-systematic bias of one order of magnitude. These values are average for a larger part of the aquitard and correspond to an integrated value. The methodology retained for the aquitard characterization is discussed with emphasis on the implications for the management of a complex aquifer system.

Citation Larroque, F., Cabaret, O., Atteia, O., Dupuy, A., and Franceschi, M., 2013. Vertical heterogeneities of hydraulic aquitard parameters: preliminary results from laboratory and in situ monitoring. Hydrological Sciences Journal, 58 (4), 912–929.     

Interpretation of groundwater level monitoring results in karst aquifers: examples from the Dinaric karst

The paper presents an attempt to determine the characteristics of karst aquifers using information on groundwater level (GWL) in natural holes and boreholes with different data quantity and time resolution of GWL measurements. In this paper the particulars of karst aquifers were analysed for four examples from the Dinaric karst. In all four study areas, aquifers are formed in bare, deep and well‐developed Dinaric karst consisting of Cretaceous limestones. The first example represents a wide area of Imotsko polje in the karst. The aquifer was analysed on the basis of infrequent water level monitoring in natural karst water features (jamas, lakes, wells) and discharges of springs and rivers. The karst aquifer in this example is complex, non‐homogenous and variable in space and time, which is frequent in the Dinaric karst. Regardless of the aforementioned it was possible to determine its elementary characteristics. The second example represents 10 wells used for the water supply for the city of Pula. The GWL and salinity were measured once a week in the period between 1981 and 1996. Even though these measurements were relatively infrequent in space and time, they served as bases for assessment of average and maximum aquifer conditions as well as boundaries of saltwater intrusion. In the third example only a portion of aquifer of the karst spring Blaz, which is in the contact with the Adriatic Seas, has been analyzed. It is a spring with an intrusion of salt water. For purposes of study of saltwater intrusion, 26 piezometers were drilled in its vicinity in which GWL, salinity and temperature were measured once a day during 168 days, a period comprising one complete cycle of seawater intrusion and retreat. These measurements proved the existence of dispersed discharge from the aquifer into the sea and its non‐homogeneity in space. In the fourth example GWL was measured continuously in 10 deep (up to 300 m) piezometers in the hinterland of the Ombla Spring catchment. The measurement period lasted 2 years (January 1988 to December 1989). The analyses are made with hourly data. The results made it possible to determine numerous characteristics of the karst aquifer and a significant non‐homogeneity of groundwater distribution in karst aquifers, depending more on the underground karst phenomena than the surface karst forms. Copyright © 2000 John Wiley & Sons, Ltd.     

陕西地震监测台网在汶川地震监测中的应用

介绍陕西地震监测台网及运行情况,总结分析该台网在四川汶川8.0级地震速报、震型判定、余震预测和地震烈度划分、抗震救灾等方面的作用,探讨了地震监测台网建设及防震减灾相关问题。     

Soil moisture–temperature relationships: results from two field experiments

This paper analyses data from two field experiments in Chickasha, Oklahoma, and Tifton, Georgia, carried out in July 1999 and June 2000 respectively. The observations on soil moisture at two depths, viz. 0–2·5 and 0–5·0 cm, surface temperature, and temperatures at 1, 5 and 10 cm depths are analysed. The relationship between the soil moisture and the temperature variability in time is examined as a function of vegetation type and location. Results from these experiments show that, during drydown, surface temperature shows an increase that corresponds to a decrease in the soil moisture. Linear models for prediction of soil moisture (at both depths) using surface temperature observations are examined. Copyright © 2003 John Wiley & Sons, Ltd.     

Performance of intertidal topography video monitoring of a meso-tidal reflective beach in South Portugal

This study discusses site-specific system optimization efforts related to the capability of a coastal video station to monitor intertidal topography. The system consists of two video cameras connected to a PC, and is operating at the meso-tidal, reflective Faro Beach (Algarve coast, S. Portugal). Measurements from the period February 4, 2009 to May 30, 2010 are discussed in this study. Shoreline detection was based on the processing of variance images, considering pixel intensity thresholds for feature extraction, provided by a specially trained artificial neural network (ANN). The obtained shoreline data return rate was 83%, with an average horizontal cross-shore root mean square error (RMSE) of 1.06 m. Several empirical parameterizations and ANN models were tested to estimate the elevations of shoreline contours, using wave and tidal data. Using a manually validated shoreline set, the lowest RMSE (0.18 m) for the vertical elevation was obtained using an ANN while empirical parameterizations based on the tidal elevation and wave run-up height resulted in an RMSE of 0.26 m. These errors were reduced to 0.22 m after applying 3-D data filtering and interpolation of the topographic information generated for each tidal cycle. Average beach-face slope tan(β) RMSE were around 0.02. Tests for a 5-month period of fully automated operation applying the ANN model resulted in an optimal, average, vertical elevation RMSE of 0.22 m, obtained using a one tidal cycle time window and a time-varying beach-face slope. The findings indicate that the use of an ANN in such systems has considerable potential, especially for sites where long-term field data allow efficient training.     

Studies of volcanic ash from two recent Central American eruptions

The 1971 eruptions of Cerro Negro volcano in Nicaragua and Fuego volcano in Guatemala produced ash blankets with minimum volumes of 7 × 10⁷ m³ and 6 × 10⁷ m³, respectively. Seven new chemical analyses show that ash produced by both eruptions was basaltic and similar to previously — erupted lavas of both volcanoes. Both ash blankets were sampled areally and stratigraphically before they were affected by rain. Chemical analyses of soluble materials leached from these ashes show that near the end of both eruptions the concentrations of soluble materials increased by about an order of magnitude. These changes are believed to reflect changes in the composition of eruptive gases.     

Indicators of microbial beach water quality: Preliminary findings from Teluk Kemang beach,Port Dickson (Malaysia)

This study aims to determine the concentrations of total coliforms and Escherichia coli (E. coli) in beach water, Teluk Kemang beach. This study was also aimed to determine relationship between total coliforms, E. coli and physicochemical parameters. As perceived health symptoms among beach visitors are rarely incorporated in beach water studies, this element was also assessed in this study. A total of eight water sampling points were selected randomly along Teluk Kemang beach. Total coliforms concentrations were found between 20 and 1940 cfu/100 ml. E. coli concentrations were between 0 and 90 cfu/100 ml. Significant correlations were found between total coliforms and E. coli with pH, temperature and oxidation reduction potential. Skin and eyes symptoms were the highest reported though in small numbers. Microbiological water quality in Teluk Kemang public beach was generally safe for recreational activities except sampling location near with sewage outfall.     

The origin of Samoa: new evidence from Sr, Nd, and Pb isotopes

We report Sr, Nd and Pb isotope ratios and parent and daughter element concentrations in 34 volcanic rocks from Samoa. The highly undersaturated post-erosional volcanics, which have erupted in Recent to Historic time along a 250-km-long fissure, have isotopic compositions that define fields distinct from those of the tholeiitic to alkalic lavas of the older Samoan shield volcanoes. Most shield lavas have²⁰⁶Pb/²⁰⁴Pb of 18.9–19.4,⁸⁷Sr/⁸⁶Sr of 0.7045–0.7055 and⁸⁷Sr/⁸⁶Sr (to 0.7075). In general, isotopic compositions of the shield lavas are similar to those of the Marquesas and Society Islands. Post-erosional samples have lower²⁰⁶Pb/²⁰⁴Pb and¹⁴³Nd/¹⁴⁴Nd and higher⁸⁷Sr/⁸⁶Sr than most shield lavas. The most striking feature of the post-erosional data is a negative correlation between²⁰⁷Pb/²⁰⁴Pb and²⁰⁶Pb/²⁰⁴Pb. This suggests that post-erosional lavas are derived from mixtures of the shield source and a high-²⁰⁷Pb/²⁰⁴Pb,⁸⁷Sr/⁸⁶Sr, low-²⁰⁶Pb/²⁰⁴Pb and¹⁴³Nd/¹⁴⁴Nd post-erosional source which may contain recycled ancient sediment. This enriched mantle domain may also underlie the Ontong-Java and Manihiki Plateaus to the north and west. Although both the Samoan shield and post-erosional lavas show chemical characteristics often associated with mantle plumes, only the shield volcanism can plausibly be related to a plume. The post-erosional eruptions appear to be the result of flexure and rifting due to plate bending at the northern termination of the Tonga Trench.     

Volatile and trace elements in basaltic glasses from Samoa: Implications for water distribution in the mantle

We report volatile (H₂O, CO₂, F, S, Cl) and trace element data for submarine alkalic basalt glasses from the three youngest Samoan volcanoes, Ta'u, Malumalu and Vailulu'u. Most samples are visibly sulfide saturated, so have likely lost some S during fractionation. Cl / K ratios (0.04–0.15) extend to higher values than pristine MORBs, but are suspected to be partly due to source differences since Cl / K roughly varies as a function of ⁸⁷Sr / ⁸⁶Sr. There are no resolvable differences in the relative enrichment of F among sources, and compatibility of F during mantle melting is established to be nearly identical to Nd. Shallow degassing has affected CO₂ in all samples, and H₂O only in the most shallowly erupted samples from Vailulu'u. Absolute water contents are high for Samoa (0.63–1.50 wt.%), but relative enrichment of water compared to equally incompatible trace elements (Ce, La) is low and falls entirely below normal MORB values. H₂O / Ce (58–157) and H₂O / La (120–350) correlate inversely with ⁸⁷Sr / ⁸⁶Sr compositions (0.7045–0.7089). This leads us to believe that, because of very fast diffusion of hydrogen in mantle minerals, recycled lithospheric material with high initial water and trace element content will lose water to the drier ambient mantle during storage within the inner Earth. The net result is the counter-intuitive appearance of greater dehydration with greater mantle enrichment. We expect that subducted slabs will experience a two-stage dehydration history, first within subduction zones and then in the ambient mantle during long-term convective mixing.     

Asia-Pacific mussel watch: monitoring contamination of persistent organochlorine compounds in coastal waters of Asian countries

Contamination of persistent organochlorines (OCs) such as PCBs (polychlorinated biphenyls), DDT and its metabolites (DDTs), HCH (hexachlorocyclohexane) isomers (HCHs), chlordane compounds (CHLs), and HCB (hexachlorobenzene) were examined in mussels collected from coastal waters of Asian countries such as Cambodia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, Philippines, Far East Russia, Singapore, and Vietnam in 1994, 1997, 1998, 1999, and 2001 to elucidate the contamination status, distribution and possible pollution sources and to assess the risks on aquatic organisms and human. OCs were detected in all mussels collected from all the sampling sites investigated. Considerable residue levels of p,p(')-DDT and alpha-HCH were found in mussels and the concentrations of DDTs and HCHs found in mussels from Asian developing countries were higher than those in developed nations suggesting present usage of DDTs and HCHs along the coastal waters of Asian developing countries. On the other hand, lower concentrations of PCBs detected in mussels from Asian developing countries than those in developed countries indicate that PCBs contamination in mussels is strongly related to industrial and activities. To our knowledge, this is a first comprehensive report on monitoring OCs pollution in the Asia-Pacific region.     

Enumeration of the bacterial contamination of bivalves in monitoring the marine bacterial pollution

Marine organisms such as shellfish are capable of filtering large amounts of sea water and of retaining pathogenic bacteria. This property constitutes a way for evaluating the level of bacterial contamination in sea water. Despite some limitations, the use of shellfish as concentrating material appears to improve the bacterial enumeration results both in accuracy and consistency.