Hydrography and circulation in the northwestern Bay of Bengal during the retreat of southwest monsoon     

V. S. N. Murty  Y. V. B. Sarma  M. T. Babu  D. P. Rao 《Journal of Earth System Science》1992,101(1):67-75

The distribution of temperature and salinity in the upper 500 m of the northwestern Bay of Bengal, adjoining the east coast of India, during the retreat of southwest monsoon (September) of 1983 is presented. This study reveals coastal upwelling (limited to the upper 40 m) induced by the local winds. Waters of higher surface salinity near the coast characterize the upwelling. The freshwater influx near the head of the Bay diluted the surface salinity to as low as 26.0 × 10⁻³. The surface circulation was weak and led to a net transport of 2.0 × 10⁶m³.s⁻¹ directed towards northeast.  相似文献   

On the stability properties of the nongeostrophic disturbances in a barotropic zonal current     

V. Brahmananda  D. Sreerama Murty 《Pure and Applied Geophysics》1972,96(1):193-204

Summary The stability properties of the nongeostrophic disturbances are studied in a barotropic zonal current. The growth rate of the nongeostrophic disturbances is increased and the instability is generally shifted towards shorter wavelengths. Even in the structure of the nongeostrophic disturbances large differences are found as compared to geostrophic disturbances.On leave from Physical Research Laboratory, Ahmedabad, India.  相似文献   

Role of dust on rainfall in northwest India     

A. S. Ramachandra Murty  Bh. V. Ramana Murty 《Pure and Applied Geophysics》1973,104(1):614-622

Summary The inter-dependences between local dust, thermal stability of the air and precipitation have been examined from the available data of two selected pairs of years for the station, Delhi, in northwest India. The indications are that the dust enters into the precipitation picture by virtue of its role in radiation balance during the relatively dry period, January to June, and by virtue of its role in cloud microstructure during the wet period, July to September.  相似文献   

Enumeration of rooted trees and its application to distributions of earthquake and acoustic-emission amplitudes     

Gurajada S. Murty 《Physics of the Earth and Planetary Interiors》1983,32(2):160-167

Closed expressions are derived for Otsuka's enumeration of rooted trees with an arbitrary but constant number of branches at each node. The generating function for these numbers is defined and used to deduce survivor functions for such trees. Under the hypothesis that the number of nodes in a tree is a measure of signal, the observed empirical relation between earthquake frequency and magnitude (and also the distribution of acoustic-emission amplitudes) can be explained. A comparison is made between this theory and Koyna tremor amplitudes observed at Gauribidanur. The model accounts for the observed deviations from the well-known Gutenberg-Richter distribution without introducing any ad hoc assumption of a cut-off magnitude.  相似文献   

Sorption of PAR–metal complexes on activated carbon as a rapid preconcentration method for the determination of Cu, Co, Cd, Cr, Ni, Pb and V in ground water     

G Chakrapani  D.S.R Murty  P.L Mohanta  R Rangaswamy 《Journal of Geochemical Exploration》1998,63(2):145-152

A simple, rapid and field-oriented preconcentration method is described for the determination of Cu, Co, Cd, Cr, Ni, Pb and V in ground water samples by flame AAS. The method is based on sorption of trace elements as metal-pyridyl azo resorcinol (M-PAR) complexes on activated carbon (AC) at pH 5.5±0.5. The effects of various parameters for quantitative sorption of M-PAR chelates on AC are discussed. The trace elements are desorbed from AC simply by treating AC with 1.6 M nitric acid, thus avoiding the tedious and time consuming operation of ashing AC. An enrichment factor of 200 or greater is easily achievable. The trace elements could be determined down to 1 ppb (V at 5 ppb) with ±15% relative error. The RSD of the method is ±15% at the practical determination limit of 1 ppb with an enrichment factor of 200. The major advantage of the method is the possibility of performing the preconcentration at the sampling site and hence a small preconcentrated volume could be sent for instrumental analysis, thus preventing sorption on a container during storage. The method has been applied to numerous ground water samples for the determination of these trace analytes at ppb levels in connection with the hydrogeochemical exploration for uranium.  相似文献   

A study of rainfall singularities,cyclonic disturbances and sea-level pressure over Southern India     

R. S. Reddy  Bh. V. Ramana Murty 《Meteorology and Atmospheric Physics》1981,30(1-2):99-109

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Crustal structure from deep seismic soundings along the Koyna II (Kelsi-Loni) profile in the Deccan Trap area, India     

K.L. Kaila  P.R.K. Murty  V.K. Rao  G.E. Kharetchko 《Tectonophysics》1981,73(4):365-384

The crustal depth section obtained from deep seismic soundings along the Koyna II (Kelsi-Loni) profile, which lies near latitude 18°N roughly in the east-west direction in that part of the Deccan Trap Maharashtra State, India, shows a number of reflection segments below the Deccan Traps down to the Moho discontinuity. A deep fault below the Deccan Traps 13 km east of Mahad divides the entire cross-section including the Moho boundary into two crustal blocks. The reflection segments show updip towards the west coast in the western block. The Moho discontinuity which is at a depth of 39 km near the deep fault starts rising towards the coast, reaching a depth of 31.5 km at the west coast. The eastern block is thrown up by 1.5 km with respect to the western block along the deep fault. A structural contour map of the Moho discontinuity for the Koyna reservoir area has been prepared from the present results and the crustal information obtained along the Koyna I profile (Kaila et al., 1979a), shows that the deep fault in the Koyna area is aligned in the NNW-SSE direction.Refraction seismic data analysis by the wave front method reveals that the thickness of the Deccan Trap increases towards the west coast. The Deccan Trap is 600–700 m thick in the eastern region between Nira (SP 130) and Loni (SP 200) and attains a thickness of 1500 m at 10 km east of the west coast. The longitudinal wave velocity in the Deccan Traps along the profile varies from 4.8 to 5.0 km/sec and in the crystalline basement from 6.0 to 6.15 km/sec. A tentative isopach contour map of the Deccan Traps and a tentative structural contour map of the Pre-Deccan Trap contact have been prepared for the Koyna reservoir area from the results along the Koyna II and Koyna I profiles. A flexure aligned in a NNW-SSE direction, in the Pre-Deccan Trap contact, which is an expression of the deep fault into the basement, has been clearly brought out. The flexure coincides in general with the orientation of the Deccan volcanic scarp in this area.  相似文献   

A theoretical model for the attenuation and dispersion of stoneley waves at the loosely bonded interface of elastic half spaces     

G.S. Murty 《Physics of the Earth and Planetary Interiors》1975,11(1):65-79

Assuming that the interface of two loosely bonded half spaces permits a finite amount of slip, and that a simple linear relation exists between the prevailing shearing stress and the slip, a generalised secular equation for the Stoneley mode is derived and solved numerically. The two limiting cases of smooth interface and bonded interface are shown to be special cases of this general problem.For some range of values of the elastic constants of the half spaces, unattenuated and undispersed interfacial waves can propagate along the interface only when the interface is smooth or bonded. For the same combination of elastic properties of the half spaces, the loosely bonded interface will cause the interfacial wave to be attenuated and dispersed.The usefulness of this model in relation to the problem of attenuation and dispersion of elastic body waves is briefly discussed.  相似文献   

A study of the serpentinisation in the Vempalle dolomitic limestones near Pulivendala,Cuddapah District   总被引：1，自引：0，他引：1  

A. N. Vyasa Rao  M. S. Murty 《Journal of Earth System Science》1980,89(1):17-22

The calcite-dolomite ratio of the Vempalle dolomitic limestones, serpentinised dolomitic limestones, and serpentines from the mineralised zone of the asbestos is determined by infrared spectroscopy. The ratio varies between 2 and 5·4 in the dolomitic limestones, between 1 and 1·5 in the serpentinised dolomitic limestones and it is taken as zero in the serpentines as both calcite and dolomite bands are absent in their infrared absorption spectra. The release of calcite during the serpentinisation is identified, which confirms the formation of serpentine.  相似文献   

Some thermodynamical and microphysical aspects of monsoon clouds     

A Mary Selvam  A S Ramachandra Murty  R Vijayakumar  S K Paul  G K Manohar  R S Reddy  B K Mukherjee  Bh. V. Ramana Murty 《Journal of Earth System Science》1980,89(2):215-230

The thermodynamical and microphysical characteristics of monsoon clouds in the Poona, Bombay and Rihand regions were investigated using extensive aircraft in-cloud observations. The number of clouds sampled at Poona, Bombay and Rihand is 2199, 169 and 104 respectively. The temperatures inside the cloud are colder than its environment at Poona and Rihand. The maximum difference is about 3°C at the cloud base level and the difference decreased with height. At Bombay the difference is less than 1°C and at some levels the temperatures inside the cloud are warmer than its environment. The lapse rates of temperatures inside the cloud are slightly less than those in the immediate environment of the cloud. The environmental lapse rates are nearly equal to the saturated adiabatic value. The positive increments in liquid water content (LWC) are associated with the increments in temperature inside the cloud. Similarly positive increments in temperatures inside the cloud are associated with the increments in temperature of its immediate environment at the same level or the layer immediately above. The maximum cloud lengths observed at Poona and Bombay respectively are 14 and 3 km. The horizontal cross-section of LWC showed a maximum number of 13 peaks in clouds at Poona while only 7 peaks were observed at Bombay. The location of maximum LWC in the horizontal cross-section is more or less at the centre of the cloud. The LWC profile showed an increase with height from the base of the cloud at Poona and Bombay. There is no marked variation of LWC with height at Rihand. The total droplet concentration at different altitudes at Poona and Bombay is in the range 28–82 cm^?3. The size distribution of cloud droplets experienced a broadening effect with increase in height from the cloud base at Poona. The broadening effect at Bombay is not as marked as that at Poona.  相似文献