Application of remote sensing in the study of geoenvironmental aspects of rajghat dam project

This study was conducted on the Rajghat dam project situated in Lalitpur district of Uttar Pradesh, India, the remote sensing techniques have been proved to be very efficient in identification of geoenvironmental aspects of the study area. In the present paper IRS IA LISS II data has been used. The various thematic maps have been generated and integrated on 1,50,000 scale. Geology, geomorphology, Hydro-geomorphotogy, structure, soils and erosion, landuse / landcover helped in identification of the potential zones for developmental planning and forecasting limitations to their implementation with seasonal accuracy. Lineaments and their intersections appear to be potential sites for groundwater. Betwa drainage basin is suitable for surface reserviour and check dams. The study shows that the integration of all attributes provides more accurate results in identification of geoenvironmental characteristics.     

Dinoflagellates in a mesotrophic,tropical environment influenced by monsoon

The changes in dinoflagellate community structure in both – the water column and sediment in a mesotrophic, tropical port environment were investigated in this study. Since the South West Monsoon (SWM) is the main source of climatic variation, observations were made during two consecutive post-monsoon periods (2001 and 2002) and the intervening pre-monsoon period (2002). The pre-monsoon period supported a more diverse dinoflagellate community in the water column compared to both post-monsoon periods. Heterotrophic dinoflagellates were abundant in the water column as well as sediment. A seasonal cycling between vegetative and resting cysts of autotrophic and heterotrophic dinoflagellates governed by the environmental characteristics of the study area was observed. Temperature, salinity and suspended particulate matter were the main factors affecting dinoflagellate community structure in both the water column and sediment. The dominant dinoflagellates in the water column differed during both post-monsoon periods that followed two dissimilar monsoon events. Prorocentroids and gonyaulacoids dominated the water column subsequent to the 2001 SWM, whereas dinophysoids and unidentified tiny dinoflagellates dominated during the next post-monsoon period. The 2001 SWM started in May, peaked during June–July and reduced gradually to end in October. The 2002 SWM was erratic; it started late (in June) and ended earlier (in September). These observations highlight the potential of the SWM to influence the community structure of dinoflagellates in tropical waters and points to the importance of long-term studies to discern robust variations in dinoflagellate communities in response to fluctuating monsoon regimes.     

Toward petascale earthquake simulations

Earthquakes are among the most complex terrestrial phenomena, and modeling of earthquake dynamics is one of the most challenging computational problems in science. Computational capabilities have advanced to a state where we can perform wavefield simulations for realistic three-dimensional earth models, and gain more insights into the earthquakes that threaten California and many areas of the world. The Southern California Earthquake Center initiated a major earthquake research program called TeraShake to perform physics-based numerical simulations of earthquake processes for large geographical regions, at high resolution, and for high frequencies. For a large scale simulation such as TeraShake, optimization problems tend to emerge that are not significant in smaller scale simulations. This involves both large parallel computation and also massive data management and visualization coordination. In this paper, we describe how we performed single-processor optimization of the TeraShake AWM application, optimization of the I/O handling, and optimization of initialization. We also look at the challenges presented by run-time data archive management and visualization. The improvements made to the TeraShake AWM code enabled execution on the 40k IBM Blue Gene processors and have created a community code that can be used by seismologists to perform petascale earthquake simulations.