Storm-damaged saline-contaminated boreholes as a means of aquifer contamination

Saline water from a storm surge can flow down storm-damaged submerged water supply wells and contaminate boreholes and surrounding aquifers. Using data from conventional purging techniques, aquifer test response analysis, chemical analysis, and regression analysis of chloride/silica (Cl/Si) ratio, equations were derived to estimate the volume of saline water intrusion into a well and a porous media aquifer, the volume of water needed to purge a well shortly following an intrusion event, and the volume of water needed after delay of several or more months, when the saline plume has expanded. Purging time required is a function of volume of water and pumping rate. The study site well is located within a shoreline community of Lake Pontchartrain, St. Tammany Parish, in southeastern Louisiana, United States, which was impacted by two hurricane storm surges and had neither been rehabilitated nor chlorinated prior to our study. Chemical analysis of water samples in fall 2005 and purging of well and aquifer in June 6, 2006, indicated saline water had intruded the well in 2005 and the well and aquifer in 2006. The volume of water needed to purge the study well was approximately 200 casing volumes, which is significantly greater than conventionally used during collection of water samples for water quality analyses.     

全球沉积岩数据库(SEDBA)及其在中国的发展

一、前言全球沉积岩数据库(简称SEDBA)是在日本奈良大学Niichi Nishiwaki-Nakajime教授领导下,于1988年开始执行的IGCP(International Geological Correlation Programme)第269项研究项目。建立SEDBA的目的是储存、检索和使用沉积岩数据,实现沉积岩数据的国际共享。在IGCP 269 项目执行期间(1988—1992),将完成SEDBA原型数据库的设计和建立,包括数据表格式的设计、数据表使用说明书的编写和出版、数据代码及词表的制定和编辑、数据结构的确定、应用数据库技术在计算机上实现对SEDBA数据库文件的管理等。迄今为止,已有22个国家及地区的60余位学者参与了SEDBA的研究和设计工作,     

The impact of oil-derived products on the behaviour and biochemistry of the eleven-armed asteroid Coscinasterias muricata (Echinodermata)

The present study examines the impact of exposure to oil-derived products on the behaviour and physiology of the Australian 11-armed asteroid Coscinasterias muricata. Asteroids were exposed to dilutions of water-accommodated fraction (WAF) of Bass Strait stabilised crude oil, dispersed oil or burnt oil (n = 8) for 4 days whereby, prey-localisation behaviour was examined immediately after exposure, and following 2, 7, and 14 days depuration in clean seawater. The prey-localisation behaviour of asteroids exposed to WAF and dispersed oil was significantly affected though recovery was apparent following 7 and 14 days depuration, respectively. In contrast, there was no significant change in the prey-localisation behaviour of asteroids exposed to burnt oil. Behavioural impacts were correlated with the total petroleum hydrocarbon concentrations (C6-C36) in each exposure solution, WAF (1.8 mg l(-1)), dispersed oil (3.5 mg l(-1)) and burnt oil (1.14 mg l(-1), respectively. The total microsomal cytochrome P450 content was significantly lower (P(Dunnett test) < 0.01) in asteroids exposed to dispersed oil than in any other asteroids, whilst asteroid alkaline phosphatase activity was not significantly affected (P(ANOVA) = 0.11). This study further documents the deleterious impact of dispersed oil to marine organisms and supports further research in the area of in situ burning as a less damaging oil spill response measure towards benthic macro-invertebrates.     

Observations of HCN in comet P/Halley

We present observations of the HCN J = 1-0 rotational transition at 3.4 mm wavelength in comet P/Halley. The data were obtained during a total of 56 individual observing sessions between November 1985 and May 1986 and represent the first time that a cometary parent molecule has been so extensively monitored. The HCN production rate is well correlated with the total visual magnitude of the comet, and comparison of the HCN production to the total gas production of the comet indicates that it is a relatively minor constituent with 0.1% the abundance of H2O. Comparison of HCN and CN production suggests that HCN is a major parent molecule of CN, but probably not the sole parent. HCN spectra obtained by binning the data with heliocentric distance show that the line width, and thus the parent outflow velocity, increases with decreasing heliocentric distance, and that there is a tendency for the lines to be blue shifted due to anisotropic outgassing from the nucleus. Finally, there is evidence of day-to-day time variability in the total HCN emission and in the hyperfine ratios. The time variation of the total emission is consistent with the known time variable behavior of the comet, and detailed comparisons to optical data, where possible, confirm this interpretation. However, non-LTE values of the hyperfine ratios are not consistent with theoretical modeling of the excitation of these transitions.     

Impacts of gold mine waste disposal on deepwater fish in a pristine tropical marine system

Little is known about the impacts of mine waste disposal, including deep-sea tailings, on tropical marine environments and this study presents the first account of this impact on deepwater fish communities. The Lihir gold mine in Papua New Guinea has deposited both excavated overburden and processed tailings slurry into the coastal environment since 1997. The abundances of fish species and trace metal concentrations in their tissues were compared between sites adjacent to and away from the mine. In this study (1999-2002), 975 fish of 98 species were caught. Significantly fewer fish were caught close to the mine than in neighbouring regions; the highest numbers were in regions distant from the mine. The catch rates of nine of the 17 most abundant species were lowest, and in three species were highest, close to the mine. There appears to be limited contamination in fish tissues caused by trace metals disposed as mine waste. Although arsenic (several species) and mercury (one species) were found in concentrations above Australian food standards. However, as in the baseline (pre-mine) sampling, it appears they are accumulating these metals mostly from naturally-occurring sources rather than the mine waste.