A note on the lithosphere thickness and heat flow density of the Indian Craton from MAGSAT data     

Ranjit Kumar Sarkar  Dilip Kumar Saha 《Acta Geophysica》2006,54(2):198-204

The Curie depth map of India compiled from MAGSAT data has been used for preparing the lithosphere thickness and the surface heat flow density maps of the Indian Craton, utilizing the concept of magnetothermometry. The lithosphere thicknesses of the major Indian geological units/provinces, as obtained from the prepared map, are found to be in reasonably good agreement with the previously published values for these regions. Also, the surface heat flow density values obtained from the prepared maps closely follow the previously published results. The maps are useful in providing first order estimates of lithosphere thickness and surface heat flow density of the important geological units/provinces of India.  相似文献   

Auto-correlation analysis of wave heights in the Bay of Bengal   总被引：1，自引：0，他引：1  

Abhijit Sarkar  Jignesh Kshatriya  K. Satheesan 《Journal of Earth System Science》2006,115(2):235-237

Time series observations of significant wave heights in the Bay of Bengal were subjected to auto-correlation analysis to determine temporal variability scale. The analysis indicates an exponential fall of auto-correlation in the first few hours with a decorrelation time scale of about six hours. A similar figure was found earlier for ocean surface winds. The nature of variation of auto-correlation with time lags was also found to be similar for winds and wave heights  相似文献   

Soil resource appraisal towards land use planning using satellite remote sensing and gis a case study in patloinala micro-watershed, district puruliya, west bengal     

Dipak Sarkar  S. K. Gangopadhyay  A. K. Sahoo 《Journal of the Indian Society of Remote Sensing》2006,34(3):245-260

Visual interpretation of IRS ID LISS-III fused with PAN data (1:12,500 scale) ofPatloinala micro-watershed of Puruliya district, West Bengal was carried out for delineating the physiographic units based on the variations in image characteristics. The major physiographic units identified were upland(Tanr), medium land(Baid), and low land(Bahal andKanali). The satellite remote sensing data coupled with ground truth were translated in terms of soils using composite interpretation map as base. The abstraction level attained was phases of soil series based on Soil Taxonomy. On the basis of physiographic variation and soil or soil site characteristics such as texture, depth, slope, erosion etc. the problem areas were identified and land use plan has been suggested for the overall development of the micro-watershed.  相似文献   

Numerical study of the effects of urban heat island on the characteristic features of the sea breeze circulation     

Abhijit Sarkar  R. S. Saraswat  A. Chandrasekar 《Journal of Earth System Science》1998,107(2):127-137

A two-dimensional numerical model is employed to study the effect of the coastal urban heat island on the sea breeze front and the thermal internal boundary layer height. The temperature at the land surface is determined by solving an energy budget equation. The effect of the urban heat island is studied by varying the width of the region and its intensity. During the early afternoon, the presence of the urban heat island enhances the strength of convergence of the sea breeze front and also reduces its inland penetration. The presence of the urban heat island causes increased thermal internal boundary layer height. Larger urban width causes larger vertical velocity and higher thermal internal boundary layer. Stronger convergence and higher thermal internal boundary layer are also obtained in case of larger heat island intensity.  相似文献   

Nature, origin and evolution of the granitoid-hosted early Proterozoic copper-molybdenum mineralization at Malanjkhand, Central India – a reply     

S. C. Sarkar  S. Kabiraj  S. Bhattacharya  A. B. Pal 《Mineralium Deposita》1997,32(6):622-622

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Methane emissions from rice fields amended with biogas slurry and farm yard manure     

Goutam Debnath  M. C. Jain  Sushil Kumar  K. Sarkar  Suresh K. Sinha 《Climatic change》1996,33(1):97-109

In an experiment on methane-emission measurements from rice fields amended with urea, biogas spent slurry (BSS) + urea, and farm yard manure (FYM) + urea, three distinctive peaks in the methane emissions were observed at 15, 46, and 69 days after transplanting (DAT) due to the availability of readily degradable C-sources. In all cases, the highest peak was at 69 DAT. The steepest Eh drop to a minimum of -320 mV was reached within two weeks of submergence. pH ranged between 7.5 and 8.5. The combined fertilization (FYM + urea) plot showed the maximum emission rate of 4.86 mg m^–2 h^–1 with a total load of 49.44 kg ha^–1 and was 2.3 times higher than (BSS + urea)-treated plot (22.08 kg ha^–1). Grain yields in urea, (BSS + urea) and (FYM + urea) plots were 3.34, 2.94, and 2.85 t ha^–1 respectively, suggesting that biogas slurry is a preferred source over FYM causing lesser environmental pollution without any significant reduction in grain yield.  相似文献   

Selection of optimum frequency of a wind scatterometer     

Abhijit Sarkar  Raj Kumar  Mannil Mohan 《Journal of Earth System Science》1988,97(2):192-192

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Geology of the area around Katta,sindhudurg district,Maharashtra. Based on aerospace data     

P. K. Sarkar  G. R. Soman 《Journal of the Indian Society of Remote Sensing》1986,14(2):43-51

Geological studies of the area around Katta, in the southern part of the Ratnagiri District of Maharashtra, were carried out with the help of visual remote sensing techniques using LANDSAT imageries on 1:250,000 scale and aerial photographs on 1:60,000 scale. The major stratigraphic units represented in the area under study are the Archean Complex, Kaladgi Supergroup, Deccan Trap, Laterite and Alluvium. The Kaladgis unconformably overlie the Archean metasediments and also at places exhibit faulted contacts with the latter. The major part of the area is covered by a thick evergreen vegetation. The interpretation followed by field work and laboratory work revealed the following:

1. The different lithologic units could be delineated on the aerial photographs.
2. Different lineaments marked on the imagery were found to be due either to faults or fracture zones. Some of the older faults appear to have been rejuvenated after the formation of the laterites.
3. Some of the lithologic horizons can be identified on the Landsat imagery by virtue of their spatial signatures.

These studies indicate that even in the area covered with thick vegetation, aerospace imagery in appropriate band and data scale can provide significant geological information.  相似文献   

Estimation of hypocentral parameters of local earthquakes when crustal layers have constantP-velocities and dipping interfaces     

Irene Sarkar  R. Chander  K. N. Khattri  V. K. Gaur 《Journal of Earth System Science》1987,96(3):229-238

The paper describes an algorithm for estimating the hypocentral coordinates and origin time of local earthquakes when the wave speed model to be employed is a layered one with dipping interfaces. A constrained least-squared error problem has been solved using the penalty function approach, in conjunction with the sequential unconstrained optimization technique of Fiacco and McCormick. Joint confidence intervals for the computed parameters are estimated using the approach of Bard for nonlinear problems. These results show that when a hypocentre lies outside the array of recording stations and head waves from a dipping interface are involved, then its inclination must be taken into account for dip angles exceeding 5°.  相似文献   

New seismological results on the tectonics of the Garhwal Himalaya     

K N Khattri  Ramesh Chander  V K Gaur  I Sarkar  Sushilkumar 《Journal of Earth System Science》1989,98(1):91-109

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