Development of a New Method of Extraction of Interstitial Water from Low‐Porosity Consolidated Sediments Recovered During Super‐Deep Drilling Projects

During the Integrated Ocean Drilling Program (IODP) Expedition 338, several methods were tested for the extraction of interstitial water in consolidated, low‐porosity deep‐sea sediments from Site C0002 in the Kumano Basin. On the basis of those tests, we propose a modified ground rock interstitial normative determination (GRIND) method of extraction of interstitial water. In separate runs of the new method, sediment samples were ground in a ball mill with either ultrapure water or a solution of HNO₃. The interstitial water was then extracted with a conventional squeezer. Sufficient solution was extracted by this method to analyse most major and a few minor components of interstitial water that were comparable to those previously reported for samples extracted by the conventional squeezing method. The new method requires much smaller amounts of sediment than that of the conventional method and will be useful for analysis of samples recovered during super‐deep drilling programmes.     

Landscape dynamics in Hokersar Wetland, Jammu & Kashmir—An application of geospatial approach

Geospatial presentation of habitat has become a key issue for planning conservation and management of any ecosystem. Hokersar wetland, one of the best resorts of migratory waterfowl in Kashmir, is under anthropogenic pressure and siltation due to floods. This has resulted in the degradation and change in the habitat quality of varied aquatic flora and fauna. Moreover, the seasonal changes affect the water level and land cover characteristics of the landscape. In the present study temporal mapping of the wetland has been carried out using the data sets for the autumn and spring seasons to assess the land cove/land use dynamics. The temporal change analysis, in the urban sprawl and the wetland, has been carried out to assess the rate of changes in the wetland and its environs. The wetland initially comprised of patch of marshy waterfowl habitat with some open water bodies. It has been fragmented into a large number of land uses because of anthropogenic activities. The increase in the settlement has been observed proportionate to the rate of fragmentation in the wetland. This study has created an information base, which will help to design conservation schemes for long term maintenance of the wetland.     

Trace elements in groundwater of Hindon-Yamuna interfluve region, Baghpat district, Western Uttar Pradesh

The present study was carried out in parts of Hindon-Yamuna interfluve region to evaluate the concentration of trace elements (Al, Cr, Mn, Fe, Ni, Co, Cu, Zn, As, Se, Cd, B and Pb) in groundwater. Pre-monsoon groundwater samples were collected in 2007 from 22 locations distributed throughout the study area, and were analyzed using Inductive Coupled Plasma Mass-Spectrophotometer (ICPMS). Trace element analyses show high concentration levels for Al and Cr in almost all groundwater samples. Relatively high values are also reported for Pb, Se, Fe and Mn (as per B.I.S (1991) standard for drinking water) in few samples. These high concentrations of metal ions in groundwater were probably due to discharge of untreated effluents from Textile, dyeing and other industries. As far as Al is concerned, its source is rather enigmatic.     

The influence of a salt dome on the diagenesis of organic matter in the Jeanne d'Arc Subbasin of the northeast Grand Banks of Newfoundland

This study elucidates the geothermal influence of a salt dome on the diagenesis of organic matter present in sedimentary sequences directly overlying the salt strata. Despite similarities in geological setting, geochemical characteristics in sedimentary column and proximity of location (～3 km), the exploratory wells Adolphus 2-k-41 and D-50 drilled on the crest and flank of a salt dome respectively, show considerable differences in the quantitative and qualitative distribution of hydrocarbons. The well drilled on the crest of the salt dome tested oil of 31°APl gravity. The concentrations of gaseous (C₁-C₄) and heavy (C₁₅⁺) hydrocarbons of this well were several times higher than those found in the corresponding sequences of a flank well. The coloration studies of isolated kerogen and gas chromatographic investigations of hydrocarbons suggest that the organic matter present in Adolphus 2-k-41 has undergone a greater degree of thermal alteration than that of D-50. The heat radiating from the salt strata is believed to be responsible for the early diagenesis of the organic matter.     

Climate links and recent extremes in antarctic sea ice, high-latitude cyclones, Southern Annular Mode and ENSO

In this article, we study the climate link between the Southern Annular Mode (SAM) and the southern sea-ice extent (SIE), and discuss the possible role of stationary waves and synoptic eddies in establishing this link. In doing so, we have used a combination of techniques involving spatial correlations of SIE, eddy streamfunction and wind anomalies, and statistics of high-latitude cyclone strength. It is suggested that stationary waves may be amplified by eddy anomalies associated with high latitude cyclones, resulting in more sea ice when the SAM is in its positive phase for most, but not all, longitudes. A similar association is observed during ENSO (La Ni?a years). Although this synergy in the SAM/ENSO response may partially reflect preferential areas for wave amplification around Antarctica, the short extent of the climate records does not allow for a definite causality connection to be established with SIE. Stronger polar cyclones are observed over the areas where the stationary waves are amplified. These deeper cyclones will break up and export ice equatorward more efficiently, but the near-coastal regions are cold enough to allow for a rapid re-freeze of the resulting ice break-up. We speculate that if global warming continues this same effect could help reverse the current (positive) Antarctic SIE trends once the ice gets thinner, similarly to what has been observed in the Northern Hemisphere.     

Characterization of locally available soil as a liner material for solid waste landfills in Sri Lanka

This study aimed to develop a low-cost and effective clay liner material for solid waste landfills in Sri Lanka. A locally available clayey soil and its admixtures with 5 and 10% bentonite were examined for this purpose. Laboratory experiments to determine soil plasticity and swell index were carried out on the tested samples. Hydraulic conductivity (k) tests were carried out in the laboratory using water and an aqueous solution of CaCl₂ on unconsolidated samples prepared by either dry or slurry packing and pre-consolidated samples with five different consolidation pressures (p) from 10 to 200 kPa. Measured liquid limits for tested admixtures increased with increasing bentonite contents and correlated well with measured values of the swell index. The difference in permeant solutions had little effect on measured k values for both unconsolidated and pre-consolidated samples. The hydraulic conductivities were highly affected by changing p, i.e., the k values decreased on two orders of magnitude as p increased from 10 to 200 kPa. The Kozeny–Carman equation, a theoretical permeability model that expresses the k-porosity relationship, was applied to measured data including reported values. Results showed the Kozeny–Carman equation captured well the porosity-dependent k values for tested soils and their admixtures with bentonite under a wide range of void ratios, suggesting that the Kozeny–Carman equation is a useful tool to estimate the magnitude of k values for differently compacted soil and its bentonite admixtures.     

Farm income,inequality, and poverty among farm families of a flood-prone area in Bangladesh: climate change vulnerability assessment

GeoJournal - This paper examines the farm income differences, income inequality of farm households, parameters of income variability that ascertain vulnerability levels, and cost-income variability...