Hydrocarbon source potential of the Proterozoic Sirban Limestone Formation,NW Himalaya,Jammu

The Proterozoic Sirban Limestone Formation (SLFm) crops out as detached allochthons in the northwest Himalaya (Jammu region, India) and has its coeval equivalents laterally disposed in the west in Salt Range, in the northwest in Abbotabad (Pakistan) and in southeast in Himachal Pradesh (India). The oil and gas occurrences have been reported from the Proterozoic successions globally and the hydrocarbon potential of the SLFm cannot be ruled out.The interbedded shales and algal laminated dolostones within the SLFm have yielded microflora comparable to those reported in the North African Neoproterozoic sandstones and the Late Proterozoic carbonates of the giant oil and gas fields of the Siberian Platform. The SLFm contains a rich and diverse biota comprising ~ 10% of the rock volume in thin section. The rich organic assemblage justified a hydrocarbon source potential analysis of the SLFm, tested in this study by Rock Eval (RE) pyrolysis.RE pyrolysis yielded a total organic carbon (TOC) content of 0.02 to 1 wt. % with very low Hydrogen Index (HI) values for the shales and TOC content averaging 0.02 wt. % for the dolostones. The organically lean shales and dolostones exhibit T_max values indicative of immature to post mature stage. But, since these values are for the samples with complex thermal and tectonic history the results may be unreliable. The highly altered organic matter and kerogen present in the SLFm had the potential to generate hydrocarbons and presently indicates no significant source potential. This study is important for understanding the hydrocarbon occurrences in the SLFm particularly in light of the recent oil and gas discoveries from the coeval Proterozoic successions.     

Drinking quality assessment of some groundwater sources along the stretch of Jhelum River in Kashmir Himalaya

The physicochemical properties and major ion chemistry of the groundwater sources from alluvial aquifers along the stretch (60 km) of Jhelum River in Kashmir Himalaya were determined in order to identify hydro-geochemical processes and their suitability for drinking purposes. The data depicted that calcium and bicarbonates were dominating among the cations and anions. The results indicate the trend of cation dominance as Ca²⁺ > Na⁺ > Mg²⁺ > K⁺, whereas anion dominance was in the order of HCO₃ ^? > Cl^? > SO₄ ^2?. Ratio of calcium to magnesium indicated the dissolution of Ca²⁺ from CaCO₃, which results in an increased levels of Ca²⁺ in the groundwater. Interpretation of Piper Trilinear plot understands the various geochemical processes affecting the groundwater quality and shows groundwater was dominated by Ca–HCO₃ type. The pH was recorded in the slightly alkalinity range 7.2–7.8 and was showing positive correlation with HCO₃ ^?. The chloro-alkaline indices revealed 86% of the sources exchange by a type of base-exchange reactions, rest by cation–anion exchange. Gibbs diagram revealed groundwater sources fall in the category of rock dominance. The concentration of the nitrogen compounds was in the progression of NO₃–N > NH₄–N > NO₂–N, and the PO₄ ^? fluctuated from 0.12 to 0.22 mg/L. Moreover, corrosivity ratio indicated that water from the majority of sources (71%) is safe to supply using pipes without any corrosive effects, while 29% of sources are corrosive in nature and need non-corrosive pipes for transporting and lifting of groundwater. The results revealed, groundwater samples were within permissible limits as prescribed by International and National standards, for drinking purposes. The State government and NGO’s can show their interest in utilizing such water resources to overcome the shortage of drinking water in a sustainable way for the daily consumption of the people living in the vicinity of Jhelum River.     

Effects of Off-fault Damage on Earthquake Rupture Propagation: Experimental Studies

We review the results of a recent series of papers in which the interaction between a dynamic mode II fracture on a fault plane and off-fault damage has been studied using high-speed photography. In these experiments, fracture damage was created in photoelastic Homalite plates by thermal shock in liquid nitrogen and rupture velocities were measured by imaging fringes at the tips. In this paper we review these experiments and discuss how they might be scaled from lab to field using a recent theoretical model for dynamic rupture propagation. Three experimental configurations were investigated: An interface between two damaged Homalite plates, an interface between damaged and undamaged Homalite plates, and the interface between damaged Homalite and undamaged polycarbonate plates. In each case, the velocity was compared with that on a fault between the equivalent undamaged plates at the same load. Ruptures on the interface between two damaged Homalite plates travel at sub-Rayleigh velocities indicating that sliding on off-fault fractures dissipates energy, even though no new damage is created. Propagation on the interface between damaged and undamaged Homalite is asymmetric. Ruptures propagating in the direction for which the compressional lobe of their crack-tip stress field is in the damage (which we term the ‘C’ direction) are unaffected by the damage. In the opposite ‘T’ direction, the rupture velocity is significantly slower than the velocity in undamaged plates at the same load. Specifically, transitions to supershear observed using undamaged plates are not observed in the ‘T’ direction. Propagation on the interface between damaged Homalite and undamaged polycarbonate exhibits the same asymmetry, even though the elastically “favored” ‘+’ direction coincides with the ‘T’ direction in this case. The scaling properties of the interaction between the crack-tip field and pre-existing off-fault damage (i.e., no new damage is created) are explored using an analytic model for a nonsingular slip-weakening shear slip-pulse and verified using the velocity history of a slip pulse measured in the laboratory and a direct laboratory measurement of the interaction range using damage zones of various widths adjacent to the fault.     

Dense matter in strong gravitational field of neutron star

Mass, radius and moment of inertia are direct probes of compositions and Equation of State (EoS) of dense matter in neutron star interior. These are computed for novel phases of dense matter involving hyperons and antikaon condensate and their observable consequences are discussed in this article. Furthermore, the relationship between moment of inertia and quadrupole moment is also explored.     

Financing marine protected areas in Jamaica: An exploratory study

The establishment of marine protected areas (MPA) has been a common government response to increasing fishing, tourism and other human activities that lead to decline in coral and marine resources. MPAs often suffer inadequacy of funds and simply become “paper parks”. This study makes a case for the feasibility of a self-financing mechanism for MPAs by estimating potential surplus benefit that recreational users may gain from MPAs in Jamaica. These same recreational users in turn, might be willing to pay a small portion of that gain toward the management costs. With the help of a travel cost model and the visitors’ willingness to pay (WTP) estimates, we show that the management costs of the park amount to a negligible amount; less than 0.1% of the annual total WTP. Furthermore, using these WTP estimates and the findings from other stakeholders’ surveys (hotels, tour operators, etc.), the paper provides insights on user-supported funding policies, such as taxes and fees, which might sustain the operations of MPAs in Jamaica and the broader Caribbean region.     

Ground-based calibration and characterization of the Fermi gamma-ray burst monitor detectors

One of the scientific objectives of NASA’s Fermi Gamma-ray Space Telescope is the study of Gamma-Ray Bursts (GRBs). The Fermi Gamma-Ray Burst Monitor (GBM) was designed to detect and localize bursts for the Fermi mission. By means of an array of 12 NaI(Tl) (8 keV to 1 MeV) and two BGO (0.2 to 40 MeV) scintillation detectors, GBM extends the energy range (20 MeV to > 300 GeV) of Fermi’s main instrument, the Large Area Telescope, into the traditional range of current GRB databases. The physical detector response of the GBM instrument to GRBs is determined with the help of Monte Carlo simulations, which are supported and verified by on-ground individual detector calibration measurements. We present the principal instrument properties, which have been determined as a function of energy and angle, including the channel-energy relation, the energy resolution, the effective area and the spatial homogeneity.     

Long-term shoreline changes of Mulki-Pavanje and Nethravathi-Gurupur estuaries,Karnataka

Significant morphological changes are noticed in the Nethravathi-Gurupur and Mulki-Pavanje estuaries. Satellite images of IRS-1A and 1B on multispectral bands and multidates (1988–1993) were made use of in addition to aerial photographs (photographed in 1979) and Survey of India Topographical maps (surveyed during 1910 and 1967). The Nethravathi-Gurupur estuary has slightly shifted northward whereas the Mulki-Pavanje estuary has shifted northward considerably. The multidated data product study reveals advancement of land.     

Image and non-image parameters of atmospheric Cherenkov events: a comparative study of their γ-ray/hadron classification potential in ultrahigh energy regime

In this exploratory simulation study, we compare the event-progenitor classification potential of a variety of measurable parameters of atmospheric Cherenkov pulses which are produced by ultrahigh energy γ-ray and hadron progenitors and are likely to be recorded by the TACTIC (TeV atmospheric Cherenkov telescope with imaging camera) array of atmospheric Cherenkov telescopes. The parameters derived from Cherenkov images include Hillas, fractal and wavelet moments, while those obtained from non-image Cherenkov data consist of pulse profile rise time and base width and the relative ultraviolet to visible light content of the Cherenkov event. It is shown by a neural-net approach that these parameters, when used in suitable combinations, can bring about a proper segregation of the two event types, even with modest sized data samples of progenitor particles.