Ostracoda as an aid in identifying 2004 tsunami sediments: a report from SE coast of India

Four short core samples were collected from the creek, estuarine regions of southeast (SE) coast of India affected by the 2004 Asian Tsunami. The study is aimed to signify the importance of ostracoda species in identifying major natural events (e.g. Tsunamis) in the coastal regions. The presence of many marine ostracoda species in the beach areas and the comparative studies with earlier reports from SE coast indicate that these species were brought by the high-energy tsunami waves. The depositional feature of ostracoda species in the beach and estuarine region also infers on the nature and force of tsunami waves in a particular region. The results clearly support that microfossils can be used to identify the major natural events close to coastal regions.     

Multi temporal ERS-1 SAR data for identification of rice crop

Microwave sensors having all-weather capabilities provide an opportunity to monitor rice grown in monsoon season. An attempt has been made to identify rice crop using multitemporal ERS-1 SAR data in C-band (5.3 GHz). Data acquired on August 15 (D1), September 19 (D2), October 24 (D3) and November 28 (D4) 1993 were taken. Combinations of data acquired on different dates were used for identification of rice crop. Single-date IRS-1B LISS II data in visible and NIR bands acquired on October 23, 1993 was also used for comparison of estimated rice area. Analysis of the results has shown that a combination of SAR data acquired at the tillering (August), booting (September) and heading (October) stages of rice crop enabled identification and area estimation of rice crop grown under lowland conditions. Single-date SAR data acquired in the month of October was found to be better for identification of rice compared to other dates.     

Use of breakdown coefficients in turbulent jets to determine the universal exponent μ

Second-order moments of the breakdown coefficients q _r,l of the squared velocity derivative in plane and circular jets indicate a value of the exponent which is larger than that obtained by other methods using the same data or that previously reported by other workers using the same method on atmospheric data. The difference may be due to a failure of the present data to satisfy the first condition of scale similarity, possibly because of the relatively small Reynolds numbers of the laboratory flows. The dependence of the variance of ln q _r,l on the length scale l appears to be independent of Reynolds number.     

Cornish mackerel

Port Phillip Bay receives the industrial and domestic effluents from Melbourne and a recent survey revealed an accumulation of a variety of heavy metals in bottom sediments. These studies have now been extended to survey the accumulation in oysters and mussels, and in most areas in the Bay these bivalves are heavily contaminated with cadmium. Oysters accumulate more of this metal than mussels.     

The behaviour of short-lived radiogenic lead isotopes (214Pb and212Pb) in groundwaters and laboratory leaching experiments

The concentrations of²¹⁴Pb (half-life=26.4minutes) and²²Rn (half-life=3.84days) have been measured in deep groundwaters of Gujarat, India. The results show that the abundance of²¹⁴Pb in the water is only ～25% of that expected from its production through the radioactive decay of dissolved²²²Rn. This deficiency if modelled in terms of a first-order removal, yields a residence time of ～10 minutes for²¹⁴Pb in these waters. The estimated residence time for²¹⁴Pb is the shortest observed for any nuclide in natural water systems and suggests that reactive nuclides lead like could be removed from aqueous phases to adjoining solid surfaces on extremely short time scales. Results of laboratory experiments using the²¹²Pb-²²⁴Ra pair are compatible with the observed fast removal of²¹⁴Pb from groundwaters.Re-evaluation of²³⁴Th residence times in these waters using a model with a recoil flux of²³⁴Th into aqueous phase, the same as that of²²²Rn, yields values in the range of 23 to<176 minutes, very similar to that of²¹⁴Pb. This “concordancy” in the residence times seems to suggest that the geochemical behaviour of²³⁴Th and²¹⁴Pb in these waters is quite similar.     

Human genome behaviour: a powerful mechanism for optimizing the use of space technology in surveying networks design

An approach based on the behaviour of human genome is developed to efficiently provide a general framework for optimizing the use of space technology in surveying networks design. The developed approach attempts to apply the successful self-organizing principles based upon the biological evolution to artificial intelligence. It mimics the phenomena of natural selection observed in nature to achieve its goals by continuously adopting a population of candidate solutions and improving its performance over successive generations. The goal of adaptation is to find the best solution that optimizes the design of a surveying network based on the use of satellite observations. This network can be defined as a set of stations, co-ordinated by a series of sessions formed by placing receivers on the stations. The problem is to search for the best order for observing these sessions to give the best observation schedule at minimum cost. The obtained results prove the effectiveness of the developed technique in term of solution quality and computational efforts. The Corresponding Author in formed me that his address is likely to change soon. Please contact me, leick@spatial.maine.edu for the latest on this change.     

Genotype and environment interaction effect on yield of cotton under naturally salt stress condition

Thirteen genotypes of cotton developed through hybridization and mutation breeding techniques were evaluated during two consecutives years 2002-03-04 on eight locations covering most of the area of Punjab province including Faisalabad, Toba Tek Singh and Jhang. The eight sets of experiments were conducted in the naturally highly saline sodic soils, EC ranges from 7.8–36.1 d/Sm, pH=8.1–8.8, SAR=10.1–40.5, Saturation percentage 31.3–40.8 and texture Sandy Clay loam and Clay loam. The seed yield data was collected at maturity and stability parameters were computed to know genotypic environment interaction and varietals performance. The combined analysis of variance showed highly significant variance in case of varieties, locations and varieties x environment (Lin) also showed highly significant differences. It means that genotypes exhibited different behavior in different locations/environments which is due to their different genetic make up. The behavior may be cross over (in which significant change in ranking order occurs from one environment to another) or cross over nature (in which case the ranking of genotypes remains constant across environments and the interaction is significant because of change in the magnitude of response) depending upon the ranking order of genotypes performance under different environments. In our study only S-12 behavior was of almost non cross over nature, while others had cross over type of interaction. Based on over all seed yield cotton variety NIAB-999 and CIM-707 produced highest seed yield cotton (3.2 t/ha, 3.17t/ha). The lowest seed yield cotton was noted in S-12 (1.86 t/ha). All the three parameters of stability i.e. overall mean seed yield cotton, regression coefficient and standard deviation to regression provided clear evidence that variety NIAB-999 and CIM-707 produced maximum stable yield compared to S-12.     

The Use Of Environmental Isotopes And Chloride As Natural Tracers To Investigate The Effects Of Depressurisation Of A Coastal Aquifer For Lignite Mining,India

In order to mine lignite from the Neyveli opencast mines, about 200 km south of Madras, India, the Neyveli aquifer has been undergoing depressurisation continuously for almost three decades. To gain insight into the aquifer hydrodynamics, environmental-isotope and chloride measurements on selected groundwater samples were initiated two decades ago, and detailed studies were undertaken during 1985–91. This article demonstrates the effect of large-scale groundwater withdrawals on the hydrologic regime and the effects on environmental chloride and isotopic distributions. A feature common to both the radiocarbon and chloride data of 1991 is their marked variation in a small area between the recharge zone and the mine area where pumping is concentrated. Furthermore, an excellent correlation exists between the temporal increase in the apparent radiocarbon ages of groundwater sampled in 1991 and 1985 and the corresponding lowering of potentiometric levels. Isochlors based on 1991 and 1985 data also indicate a changed hydrologic regime. In certain areas, heavy withdrawals have resulted in increased groundwater salinity.     

Rn solution by the circulating fluids in a “hot dry rock” geothermal reservoir

The mechanism of²²²Rn release into fracture fluids by direct alpha-recoil, lattice and grain boundary/micro-crack diffusion is discussed. Experimental measurements of²²²Rn release into surrounding air and water phases have been made for crystalline rock specimens with well defined surface areas. The²²²Rn flux from an infinite plane surface and hence the effective diffusion length of²²²Rn in the rock matrix has been estimated.The²²²Rn flux from plane crystalline rock surfaces has been used in conjunction with a simple hydrological model of the reservoir to calculate the²²²Rn content of the return fluids of a geothermal doublet circulation system. For given production rate and piezometric difference between the injection and production wells, the²²²Rn content of the return fluid is dependent upon the distribution of flow path lengths and fracture apertures in the reservoir. Matching of the calculated and experimental²²²Rn contents of the return fluids has been used to select appropriate parameters for the reservoir model and hence to estimate the extent of the heat-transfer surface. The model estimates the fracture width of the flow paths, total swept surface area and fracture volume within the reservoir.     

Geodynamic evolution and crustal growth of the central Indian Shield: Evidence from geochemistry of gneisses and granitoids

The rare earth element patterns of the gneisses of Bastar and Bundelkhand are marked by LREE enrichment and HREE depletion with or without Eu anomaly. The spidergram patterns for the gneisses are characterized by marked enrichment in LILE with negative anomalies for Ba, P and Ti. The geochemical characteristics exhibited by the gneisses are generally interpreted as melts generated by partial melting of a subducting slab. The style of subduction was flat subduction, which was most common in the Archean. The rare earth patterns and the multi-element diagrams with marked enrichment in LILE and negative anomalies for Ba, P and Ti of the granitoids of both the cratons indicate interaction between slab derived melts and the mantle wedge. The subduction angle was high in the Proterozoic. Considering the age of emplacement of the gneisses and granitoids that differs by ∼ 1 Ga, it can be assumed that these are linked to two independent subduction events: one during Archaean (flat subduction) that generated the precursor melts for the gneisses and the other during the Proterozoic (high angle subduction) that produced the melts for the granitoids. The high values of Mg #, Ni, Cr, Sr and low values of SiO₂ in the granitoids of Bastar and Bundelkhand cratons compared to the gneisses of both the cratons indicate melt-mantle interaction in the generation of the granitoids. The low values of Mg#, Ni, Cr, Sr and high values of SiO₂ in the gneisses in turn overrules such melt-mantle interaction.