002162   Asthana A K L;Sah M P (NO, Wadia Institute of Himalayan Geology, Dehra Dun-248 001, Email: aklasthana@wihg.res.in) : Landslides and cloudbursts in the Mandakini basin of Garhwal Himalaya. Himalayan Geol 2007, 28(2), 59-67.

Landslide causes widespread damage in the Himalayan region. The lithotectonic set up and prevailing geomorphic conditions play an important role in the distribution of landslide and mass movement activity. Area of Mandakini Basin, the proximity of MCT and Vaikrita thrust are structurally weak zone making the rocks further-weak in the study area of Mandakini Basin. The area suffers from large, medium and small landslides every year in monsoon season. Along with the inherent lithological and structural characteristics tectonic activity, climatic characteristics, deforestation and destabilization of slope due to construction have increased the probability of landslides in these fragile ecosystems. Construction of roads for developmental activity leading to removal of lateral support particularly in the dip slope faces of mountains has led to some massive landslides in the Mandakini Basin. High intensity rainfall and cloudburst are much frequent in the Mandakani Basin which accelerate the landslides and cause wide spread damages in the area.

10 illus, 15 ref

002161   Ahmed M;Das P K;Phukan S (Geological Sic Dep, Gauhati Univ, Guwahati-768 104) : Physico-chemical and petrographic characters of eocene coal occurring in Rangsokham area, east khasi hills Meghalaya (India). Ultra Scient phys Sci 2006, 18(2), 251-8.

The Lakaday Sandstone Member of the Sheila Formation of Jaintia Group (Eocene) houses two thin and impersistant coal seams in and around Rangsokham area near Mawsynram of East Khasi Hills district of Meghalaya. Deals with the characters of coal collected from the bottom seam of Rarigsohkham area. The seam is about 1 m. in thickness and is bottomed and topped by thin carbonaceous shales. The other associated litho units are shales along with dominant sandstone which are often current bedded.

11 illus, 3 tables, 10 ref

002160   Adekanmbi O H;Sowunmi M A (Botany Dep, Lagos Univ, Lagos, Nigeria) : Age of niger delta sediments inferred from palynological evidence. Bull pure appl Sci-Sect B 2006, 25(2), 87-94.

Sixty-six ditch cutting samples selected from interval 1060-10380feet of a western off shore Niger Delta well were investigated for palynomorphs with specific objectives of palynological zonations and age dating. The samples were largely selected within shale horizons at 60ft intervals within the paralic section of sand and shale intercalations. The selected samples were subjected to standard palynological sample preparation. Two alphanumeric palynozones (P800, P900) and three subzones (P880, P870, and P860) of Evamy et al. (1978) were recognized. They are dated Upper Miocene to Recent based on the stratigraphic appearance and disappearance of identified marker species such as Gemmamonoporites sp., Peregrinipollis nigericus, Cyperus type pollen, Podocarpus milanjianus, Echitriletes pliocenicus. Stereiosporites sp, Retisptephanocolpites gracillis and Mulliareolites formosus.

2 illus, 1 table, 13 ref

001238   Vaz G G;Hariprasad M;Rao B R;Subha Rao V (NO, , West Coast-II, Marine Wing, GSI, Kurekal Buildings, Edappally, Cochin-682 024, Email: ggaitanvaz@rediffmail.com) : Subsidence of southern part of erstwhile Dhanushkodi township, Tamil Nadu- evidences from Bathymetry, side scan and underwater videography. Curr Sci 2007, 92(5), 671-5.

Southern part of erstwhile Dhanushkodi township, Tamil Nadu, experienced subsidence and submergence during AD 1948-49. Shallow bathymetric and side-scan surveys together with sampling and underwater videography confirm the extent and quantum of subsidence. The studies reveal that a vertical tectonic movement (fault) parallel to the coastline with a displacement of ~ 5 m led to the subsidence of the southern part of the township. This fault movement has occurred 57 years ago and hence could be the latest neo-tectonic movement ever recorded along the east coast of India.

6 illus, 6 ref

001237   Tripati S;Godfrey I (Marine Archaeology Centre, National Institute of Oceanography, Dona Paula, Goa-403 004, Email: sila@nio.org) : Elephant tusks and hippopotamus teeth collected from the early 17th century portuguese shipwreck off Goa, West coast of India: evidence of maritime trade between Goa, Portugal and African countries. Curr Sci 2007, 92(3), 332-9.

Shipwreck findings are indicators of the provenance of artefacts and trade routes. Many shipwrecks datable from the Bronze Age to the modern period have been excavated to yield numerous varieties of artefacts, including cargo, personal belongings of the crew, arms and ammunition, treasure, royal belongings, etc. Similarly, exploration of a Portuguese shipwreck in Goa waters has led to the recovery of a variety of artefacts, including elephant tusks, hippopotamus teeth, the barrel of a handgun, Chinese ceramics, stoneware (Mart-aban pottery), iron guns, an iron anchor, bases of glass bottles, pieces of lead sheets, copper vessel and strap, stone and clay bricks and dressed granite blocks. A comparative study of the findings and the thermolumi-nescence date of excavated stoneware dated the wreck to the early 17th century AD. The ¹⁴C date of ivory is 740 ±130 yrs; with a calibrated age range of 740 to 560 yrs BP. The elephant tusks are highly degraded, discoloured and soft to the touch, whereas the hippopotamus teeth are still very hard. Maritime trade records suggest that these tusks are likely to have been brought from African countries to India to make dif-ferent types of finished artefacts before being, sent back to Portugal and her colonies. This article high-lights the state and analysis of elephant tusks and hip-popotamus teeth recovered from the wreck site with the provenance determined primarily on the basis of maritime trade records that report the importation of these materials from African countries to India.

6 illus, 1 tables, 25 ref

001236   Thigale S S;Umrikar B (Geology Dep, Pune Univ, Pune-411 007) : Disastrous landslide episode of July 2005 in the Konkan plain of Maharashtra, India with special reference to tectonic control and hydrothermal anomaly. Curr Sci 2007, 92(3), 383-6.

Ripented disastrous landslide episode of July 2005 that killed 190 people and gave rise to hydrothermal anomaly. Field investigations were carried out to study the physical framework covering climatic, geologic, geomorphologic and seismologic information of the affected area. Structured interviews through an appropriately designed questionnaire were also conduc-ted to collect first-hand information from the people who had witnessed the events and those who were in-volved in rescue operation to throw light on the causative factors responsible for the landslides and generation of hydrothermal anomaly. A meagre record available at the revenue and the police departments was also re-ferred. It has been observed that all the landslides oc-curred within a short span of 20 h between 8 pm of 25 July and 4 pm of 26 July 2005. Majority of events took place speedily, but a few with a rumbling noise coupled with a phenomenon resembling lightening, releasing of dust and steam in the form of fountain leaving be-hind deep but narrow depressions that ultimately trig-gered the landslides. The temperature of muddy water was appreciably high in such cases. The data revealed that seismicity of the region has been responsible for developing fissures parallel to N-W to NNW-SSE trending fracture-controlled streams along which ma-jority of landslides occurred following incessant rains. The genesis of hydrothermal anomaly developed at six places has been explained using dilatancy-diffusion model. The symptoms of slope instability observed before the episode at ten places indicate that sliding surfaces had already crossed geological threshold; as a result, landslides occurred without development of hydrother-mal anomaly.

2 illus, 20 ref

001235   Thayyen R J;Gergan J T;Dobhal D P (NO, Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun-248 001, Email: renoj@rediffmail.com) : Role of glaciers and snow cover on headwater river hydrology in monsoon regime - micro-scale study of Din gad catchment, Garhwal Himalaya, India. Curr Sci 2007, 92(3), 376-82.

Role of glaciers and snow cover in controlling the headwater river run-off variability of areas under the influence of monsoon is discussed. This work is based on the studies carried out in a micro-scale catchment in the Garhwal Himalaya, covering an area of 77.8 sq. km. Run-off data of summer ablation period of 1998, 1999 and 2000 were collected from three hydrometric stations established at different altitudes in the Din Gad catchment. These data have been analysed along with the winter/summer precipitation, temperature and mass balance variations of the Dokriani glacier. The study shows that the hydrometric station at 2360 m asl (Tela) experienced 45% reduction in summer discharge from 1998 to 2000, which translated into a twofold increase in the percentage glacier contribution ' This paradox resulted from variations in the winter precipitation characteristics masking the run-off variations of the glacial regime. Glacier degraded run-off volume varied from 3.5% of the bulk glacier discharge in 1994 to 7.5% in 1999. This study suggests that the uncertainties in the precipitation characteristics in a changing climate, especially the winter snowfall have pronounced effect on the headwater river run-off variability rather than the run-off variations from a receding glacier. On the other hand, glaciers play an important role in sustaining the river flows during the years of low summer run-off.

7 illus, 3 tables, 24 ref

001234   Teotia S S;Dinesh Kumar (Geophysics Dep, Kurukshetra University, Kurukshetra-136 119, Email: teotia_ss@rediffmail.com) : The great Sumatra-Andaman earthquake of 26 December 2004 was predictable even from seismicity data of m_b<. Indian J Mar Sci 2007, 36(2), 122-7.

Spatial distribution of earthquakes is found to change before and after occurrence of an earthquake of given size. The occurrence of an earthquake of any size may be related with the self-organized criticality behavior of turbulence in solids. This change is reflected in the temporal variation of generalized dimension D_q or D_q spectra. Therefore, the study of temporal variations of D_q and D_q spectra may be used to study the changes in Seismicity structure before the occurrence of earthquakes and hence multifractal study holds promise in forcasting earthquake in the regions having potential to generate great earthquake. The study in this paper deals with multifractal analysis of seismicity data of the region which have resulted in great Sumatra-Andaman earthquake of 26 December 2004. The significant increase in D_-2 and D_q spectra has been observed prior to occurrence of (mb=9, M_w =9.1 to 9.3) great Sumatra-Andaman 26th December 2004 even with seismicity data having completeness of catalogue for m_b⁰ 4.5. The monitoring of USGS global network holds promise to reveal changes in Dq prior to occurrence of great earthquakes even from earthquake catalogue which have their completeness for magnitudes (i.e. m_b⁰ 4.5).

001233   Suresh T;Desa E;Rodrigues A;Ramdasan K (NO, National Institute of Oceanography, Goa, Email: suresh@darya.nio.org) : Turbidity of the atmospheric and water at the major ports of India. Envir Geochem 2005, 8(1-2), 214-8.

Atmospheric and water turbidity observed at nine major ports of India, namely Cochin, Managalore, Mormugao, Mumbai, Jawaharlal Nehru (JNP), Kandla on the west coast and Tuticorin, Chennai and Visakhapatnam on the east coast, using the parameters derived from the ocean color satellite, SeaWiFS for the six years from 1998 to 2003. We have used aerosol optical depth (τ) at 865nm to study the atmospheric turbidity and diffuse attenuation coefficient (Kd) at 490 nm to examine the water clarity. The atmospheric turbidities are found to be high over the ports of Mumbai, Jawaharlal Nehru, and Cochin (τ<62>0.18) while the lowest was observed at Kandla (0.136). Water clarity was found to be the lowest at Mumbai and JNP (Kd<62>0.3), while it was much better at Visakhapatnam and Chennai. (Kd<60>0.13 ). We have looked at the inter-annual variations of the atmospheric and water turbidity at the major ports and have not found any significant variations. Atmospheric turbidity at Kandla was found to be increasing at 2.7 % per year (geometric mean) while at other ports where increases were noticed included Mangalore, Mormugao and Visakhapatnam. (- 2%). Water turbidity at Cochin was found to be increasing at a pace of 6.2% per year, and similar trends have been observed at Chennai. The water clarity at the Visakhapatnam was found to improve noticeably over the years and similar trends were observed at Tuticorin. The seasonal variations of aerosol concentrations were observed at all ports, with relatively higher values being noticed during summer than winter. Water turbidity was found to be relatively lower for the ports on the east coast than those situated on the west coast of India.

4 illus, 11 ref

001232   Srivastava S K;Tiwari S K (NO, , Central Ground Water Board, S.E. Region, Bhubaneswar-751 030) : Distribution of high fluoride in ground water of Orissa. SGAT Bull 2006, 7(1), 18-26.

Occurrence of high Fluoride in ground waters of Orissa is needed to be highlighted, in order to make provisions for supply of safe drinking water to the people of the affected areas. Values of fluoride viz. more than 1.5 mg/L have been observed in both coastal and inland districts of Orissa. In specific areas like Harbhanga Block of Boudh district, Balasinghi area of Khurda district and in parts of Anugul & Puri districts, detailed studies have revealed high fluoride concentrations in ground water there. The adverse health effects, however, have been observed in Balasinghi-Singhipur area where such water is being used for drinking purposes. Conjunctive use of high fluoride waters by blending it with alternate source of safe waler available in the area is one of the cheapest remedial measures suggested.

4 illus, 15 ref

001231   Sri Niwas;Gupta P K;De Lima O A L (Earth Science Dep, IIT, Roorkee-247 667, Email: srsupfes@iitr.ernet.in) : Nonlinear electrical conductivity response of shaly-sand reservior. Curr Sci 2007, 92(5), 612-17.

Brief review of electrical conductivity modelling of the porous medium is presented here to establish that, merely for the sake of applicability, the sound physico-mathematical model of Maxwell has been replaced by Archie's empirical one. The extension of clean sand models to shaly-sand models is discussed emphasizing the inadequacy of the former to represent true physical situations. Since the experimental data show nonlinear dependence of rock conductivity on pore fluid conductivity, three nonlinear model equations of Glover, Mixing and Bussian are studied for a wide range of parameters and the results are analysed in the light of physical expectations. It is concluded that only the Bussian model is able to simulate the behaviour of effective conductivity of saturated shaly-sand reservoir over the complete range of water and matrix conductivity and porosity values.

2 illus, 1 table, 30 ref

001230   Sreenivasa Reddy B;Gopal Reddy C;Yadagiri Reddy P;Rama Reddy K (Physics Dep, Osmania Univ, Hyderabad-500 007, Email: yadagirireddy@yahoo.com) : Indoor radioactivity levels n coal mining environs of Khammam District, Andhra Pradesh. Envir Geochem 2005, 8(1-2), 426-8.

Measurement of indoor radioactivity levels due to radon, thoron and natural background radiations were carried out in the Pranahita-Godavari valley coalfields region of Khammam district of Andhra Pradesh, India. Twin chamber cup dosimeters with solid state nuclear track detectors (LR-115, Type-II) were used to estimate indoor radon and thoron levels. Natural background penetrating radiation  levels were measured by employing thermoluminescent detectors and a G.M. tube based μR survey meter. The concentrations of radon and thoron in the dwellings were found to be 44.7 (GSD 1.4) Bq/m³ and 17.7 (GSD 2.0) Bq/m³, respectively. The average natural background radiation levels in the dwellings is estimated to be 1459±108 ±Gy/y. These concentrations are compared with those in other parts of the district, where there is no coal mining activity.

1 table, 15 ref

001229   Siva Kumar K;Anand K J;Gangaimani T; Jeevanandam S;Kumar V (Geology PG & Research Dep, National College, Thiruchirapalli-620 001) : Foraminifera as a tool for identifying marine pollution and environmental modification. Asian J Microbiol Biotechnol envir Sci 2007, 9(1), 159-64.

Benthic foraminifera traditionally have been used as a stratigraphic tool and as a paleo ecological indicator. The utilization of benthic foraminifera in the modem environment is increasing to investigate their response to pollution and environmental modification for the past few decades. The present article aims to review of the abnormalities noted on the morphology of foraminifera, which are caused by ecology and pollution parameters by several authors in different publication. This article is not including all the works that discuss the morphological deformities carried out so far, but a review of some of those important studies, which will be much helpful for those involved in pollution and environmental modification research.

^iia71 ref

001228   Sinha D K;Saxena R (Chemistry Dep, K.G.K. (P.G.) College, Moradabad-244 001) : Statistical assessment of underground drinking water contamination and effect of monsoon at Hasanpur, J. P. Nagar (Uttar Pradesh, India). J envir Sci Engng 2006, 48(3), 157-64.

Water Quality Index (WQI) has been calculated for underground drinking water at Hasanpur in J. P. Nagar district, Uttar Pradesh, India at ten different sites in the pre-monsoon season as well as after the onset of monsoon. Water quality parameters were selected as per the WHO guidelines and seventeen water quality physico-chemical parameters were estimated following the standard methods and procedures. Drinking water at almost all the sites was found to be highly contaminated, except a few sites, where it was found moderately contaminated for both the periods during the year 2005. In general, to some extent water quality showed deterioration after the onset of monsoon. It was found that some effective measures are urgently required for water quality management in this region.

1 illus, 5 tables, 13 ref

001227   Shanbhag A A;Sartande S J;Ramachandran T V; Puranik V D (Environmental Assessment Div, Bhabha Atomic Research Center, Mumbai-400 085) : Natural radioactivity content in beach sands of Ratnagiri coast, Maharashtra. Envir Geochem 2005, 8(1-2), 304-8.

Results of the gamma ray spectrometric measurements carried out for natural radioactivity levels due to ²²⁵Ra, ²³²Th and ⁴⁰K in beach sand samples around the coast of Ratnagiri, Maharashtra, India are presented. Measurements were carried out using a HPGe based gamma ray spectrometer. The activities of ²²⁶Ra, ²³²Th and ⁴⁰K in the beach sand samples varied from (7.5 - 70) Bq/kg, (5.5 - 75.5) Bq/kg and (4.0 -34.2) Bq/kg respectively. This paper presents methods of measurement and the results in detail.

2 tables, 26 ref

001226   Shaji T S;Desapati T;Fahmi S;Yadav G S;Pande A K (Aatomic Energy Dep, Atomic Minerals Directorate for Exloration and Research, Jaipur-302 030) : Occurrence of uraninite and brannerite in the Samarkiya area, Bhilwara district, Rajasthan. Curr Sci 2007, 92(5), 592-4.

1 illus, 2 tables, 9 ref

001225   Satyanarayana A;Girdhar Reddy P (Lower Krishna Div, , Central Water Commission, Hyderabad, Email: vivek4348@yahoo.com) : Certain water quality parameters of river krishna at selected points. Envir Geochem 2005, 8(1-2), 419-21.

Certain water quality parameters are measured in river Krishna with respect to its discharge. All the measured parameters are with in the permissible limits for various uses of water, though there are some exceptions and which are attributed to the local activity.

2 tables, 6 ref

001224   Satya Prakash;Ramesh R (Planetry and Geoscience Div, Physical Research laboratory, Ahmedabad-380 009) : Is the arabian sea getting more productive?. Curr Sci 2007, 92(5), 667-71.

Recent observations based on ocean colour show that summer productivity in the western Arabian Sea has been increasing during the last seven years, reportedly due to the warming of the Eurasian land mass. analysis of eight years' record of satellite ocean colour data over northeastern Arabian Sea suggests that chlorophyll concentration has not changed significantly in this region and is thrice that in the southeastern part. Al-though there is some seasonal variations in different parts of the Arabian Sea, a significant secular trend is not discernible. The reported trend in Chla in the western Arabian Sea is not observed in the eastern Arabian Sea. Hence, it is conclude that the increasing trend in the western Arabian Sea may not be entirely attributable to global warming.

6 illus, 21 ref

001223   Rao K S;Neelima Satyam D (Civil Engineering Dep, Indian Institute of Technology Delhi, New Delhi-110 016, Email: raoks@civil.iitd.ernet.in) : Liquefaction study for seimic microzonation of Delhi region. Curr Sci 2007, 92(5), 646-54.

After the devastating 2001 Bhuj earthquake, the national capital region of Delhi has attracted major attention with several scientific studies in recent times. This region, being in zone-IV, has experienced many earthquakes in the past and recent tunes. It also faces the danger of severe seismic threat from the central Himalayan seismic gap. Seismic microzonation, which is a subdivision of an area into micro zones depending upon site-specific seismic response, is an effective mitigation method. During an earthquake, soil can fail due to liquefaction with devastating effects such as land sliding, lateral spreading, or large ground settlement The phenomenon of liquefaction of soil had been observed for many years, but was brought to the attention of engineers after the Niigata (1964) and Alaska (1964) earthquakes. Since Delhi falls in the area with high seismic probability, there is need for the assessment of liquefaction potential. An extensive geotechnical borehole database has been prepared after compiling more than 1200 boreholes at various locations of Delhi, along with geological and seismological details. In this article, with the collected borehole data an attempt is made to assess in detail the liquefaction potential of soils using SPT-based methods and also to present a liquefaction hazard map.

11 illus, 1 table, 26 ref

001222   Ramakrishnan P S (School of Environmental Sciences, Jawaharlal Nehru Univ, New Delhi-110 067, Email: psr@mail.jnu.ac.in) : Sustainable mountain development: the Himalayan tragedy. Curr Sci 2007, 92(3), 308-16.

Mountain systems in India, including the Himalayan region are characterized by highly complex socio-ecological systems, with rich cultural diversity linked with equally rich species of biological diversity. With a large number of ethnic societies having their own social, economic and cultural attributes placed in a highly heterogeneous mountain environment, any conservation-linked developmental initiative has to be based upon a value system that they understand, appreciate and therefore can participate. While textbook-based 'formal knowledge' has its value in this effort, the rich traditional ecological knowledge (TEK) derived through an experiential process and available with local communities forms a powerful connecting link between ecological and social systems. Converting TEK, often seen as location-specific into broad generalizations that are applicable across socio-ecological systems was the major step that was undertaken by this author to convert research results into policy formulations and developmental initiatives, as illustrated here. In the ultimate analysis, developmental initiatives that link cultural diversity with biological diversity are seen as the basis for ensuring human security in these socio-ecologically fragile mountain systems.

5 illus, 43 ref

001221   Ramachandran A;Jaykumar S;Haroon R M; Bhaskaran A;Arockiasamy D I (Tamil Nadu Forest Dep, , Tiruchirappalli-620 005, Email: a_ramachandran7@rediffmail.com) : Carbon sequestration: estimation of carbon stock in natural forests using geospatial technology in the eastern ghats of Tamil Nadu, India. Curr Sci 2007, 92(3), 323-31.

Need for a carbon databank is addressed in the context of mitigating climatic changes. As a pilot study, carbon stock in a natural forest area of Kolli hills, part of the Eastern Ghats of Tamil Nadu, India has been estimated using geospatial technology. The total biomass, both above and below ground, is calculated and the total carbon stock estimated. Like-wise, the sequestered soil organic carbon is also esti-mated. The biomass carbon estimated is 2.74 Tg and the soil carbon is 3.48 Tg. The lesser soil organic car-bon indicates that the forest area is severely affected by degradation due to various need-based forestry prac-tices and anthropogenic disturbances. A national-level carbon databank is envisaged for all types of forest in India to study the temporal change and carbon seques-tration potential for better management of forests.

4 tables, 50 ref

001220   Pilkington M (NO, Geological Survey of Canada, 615 Booth Street, Ottawa, K1A 0E9, Canada, Email: mpilking@nrcan.gc.ca) : Fractal character of oceanic crustal magnetism determined from drill hole measurements. Indian J Mar Sci 2007, 36(2), 97-104.

Wide range of geophysical processes and rock properties has been described in fractal or scaling terms. For continental crust, well log susceptibilities, surface susceptibilities and aeromagnetic fields all tend to support a model for a 3-D magnetization distribution having a radially-averaged power spectrum proportional to some power of the spatial frequency. This simple model of the scale-invariant behaviour of crustal magnetization and the magnetic fields it produces can be exploited by several applications which require information on such spatial variation. A more realistic power spectrum, and equivalently, covariance model for continental crustal magnetization offers many advantages over the geologically incorrect assumption of a white power spectrum (equivalent to an uncorrelated distribution). Well log susceptibilities and natural remanent magnetization intensities measured for oceanic crust are shown here to exhibit scaling behaviour. Measurements from Ocean Drilling Program holes 504B, 735B, 801C and holes CY1, CY4 in the Troodos ophiolite sequence in Cyprus show overall values for the scaling exponent, ", between -1.36 and -0.68 for susceptibilities and between -1.52 and -0.54 for natural remanent magnetization intensities. Based on this small number of samples, scaling exponents determined for basalt, sheeted dyke and gabbro sequences within these logs show wide variation, indicating no apparent correlation between rock type and scaling behaviour.

001219   Ojha N K;Pandey M K (NO, I.C.AR. Project Centre, Lokmahavidyalya, Hafizpur, Baniapur, Saran (Bihar)) : Fertilizer (urea) effect on the pila in rural Chapra affecting the pila activities with special reference to their morphology and mortality. Acta Cienc Indica-Chem 2006, 32(3), 215-16.

Shells of pila (pila globossa) are made of calcium carbonate, which treated by urea used by farmers, shows marked changes in the Morphology and activity in the species (pila globossa) 1 this assay shows a curve between the pila mortality and doses applied on the species.

1 illus, 6 ref

001218   Nainwal H C;Chaudhary M;Rana N;Negi B D S; Negi R S;Juyal N;Singhvi A K (Geology Dep, HNB Garhwal Univ, Srinagar (Garhwal)-246 174) : Chronology of the late quaternary glaciation around Badrinath (upper Alaknanda basin): preliminary observations. Curr Sci 2007, 93(1), 90-6.

Reconstruction based on the presence of lateral moraines and other relict periglacial features in Upper Alak-nanda basin indicates three phases of glaciation during the Late Quaternary. From oldest to youngest, they are named as Alaknanda (Stage-I), Alkapuri (Stage-II) and Satopanth (Stage-Ill) glacial advances. The oldest Stage-I was the most extensive glaciation in the basin that reached south of Badrinath (2604 m asl). Compared to this, the other two glaciations were terminated around 3550 and 3700 m asl respectively, in the N-S trending Upper Alaknanda basin. Preliminary estimate based on limited optical dating suggests the Stage-I predates the Last Glacial Maximum (LGM). An indirect age estimate based on the chronology of recessional moraine dated to 12 ka suggests that Stage-II was deposited during the LGM whereas Stage-Ill is dated to 4.5 ka. Conical heaps in the vicinity of the present-day snout are attributed to the recent recession probably associated with the Little Ice Age.

6 illus, 2 tables, 61 ref

001217   Nagaraja P N;Suresh T S;Nagesh P C (Geology Dep, Bangalore Univ, Bangalore-56) : Quality of groundwater in relation to agricultural practices in Chinna hagari basin, Karnataka, India. SGAT Bull 2006, 7(1), 10-17.

Chinna Hagari basin, a sub-basin of river Vedavathi occupies a drainage area of 3461 sq.kms. It is a typical hard rock terrain and chronically drought prone region. The major part of the basin. lies in Chitradurga, Bellary districts of Karnataka and a small portion in Anantapur district of Andhra pradesh. The evaluation of chemical quality of ground water is essential in order to utilize the available resources for agricultural purposes SAR, RSC, % Na, chloride, sulphate, permeability index and corrosivity ratio are used to evaluate the interpretations, based on the data of 204 water samples collected from bore wells from different aquifers in the study area. The study indicated that the quality of water is suitable for agricultural practices except for few pockets.

2 illus, 6 ref

001216   Murari M K;Achyuthan H;Singhvi A K (Planetary and Geosciences Div, , Physical Research Laboratory, Ahmedabad-380 009, Email: singhvi@prl.res.in) : Luminescence studies on the sediments laid down by the December 2004 tsunami event: prospects for the dating of palaeo tsunamis dating and for the estimation of sediment fluxes.. Curr Sci 2007, 92(3), 367-71.

Tsunami of 26 December 2004 was associated with an Mw 9.3 earthquake. This was the second largest earthquake ever recorded. Geodynamic processes leading to such earthquakes suggest that these are repetitive. It is therefore desirable to obtain their recurrence interval. Earlier attempts to date palaeo-tsunami sediments have assumed that the basic premises for the use of optically stimulated luminescence (OSL) are adequately met. The sediments transported by the 2004 tsunami provided a maiden opportunity to verify the basic premises of the zeroing of the luminescence at the time of deposition. Results on eight of the nine samples using the conventional single aliquot regeneration (SAR) method provided OSL palaeodoses in the range 0.5 to 0.7 Gy. The recently developed component-specific SAR (CS-SAR) consistently provided OSL palaeodoses in the range 0.5-0.7 Gy. Further, CS-SAR consistently provided evidence that in eight of the nine samples, a fraction of the sample did experience daylight bleaching during transport with the tsunami. This was suggested by the fast-component OSL palaeodose of -0.2 Gy. This implies a maximum age offset of ± 50 yrs and suggests that despite its energy and wave amplitude, only the top -20-50 cm layer of the sediment in the intertidal zone was mobilized. This inference can be used for sediment influx calculations and hence for regional disaster management.

5 illus, 1 table, 15 ref

001215   Mohanty W K;Routray A;Nath S K (Geology and Geophysics Dep, Indian Institute of Technology, Kharagpur-721 302) : New strategy for phase detection in seismic signals using an adaptive markov amplitude model. Curr Sci 2007, 93(1), 54-60.

Great Sumatra earthquake (26 December 2004, Mw 9.3) and the resulting tsunami have generated considerable interest amongst scientists and engineers to develop algorithms for phase detection in order to subsequently assess the seismic moment, radiated energy, source mechanism and rupture propagation to decide the possibility of developing an early tsunami warning system. In this article, changes in the parameters of a seismic signal model have been used to detect the various phases of the seismic event on the tsunami-causing earthquake as well as a local earthquake of M 5 that occurred on 12 December 2000 in the border regions of Idukki and Kottayam districts, Kerala. An adaptive Markov model has been used for this purpose. A modified least mean square algorithm with an adjustable learning rate has been proposed to adap-tively and accurately estimate the parameters of the model. The model order has been determined by applying multiple signal classification algorithm that estimates the dominant frequencies of the signal. Subsequently, the cumulative SUM algorithm has been used to detect the significant changes in the model parameters, which are indicative of the changes in phases of the seismic signal.

13 illus, 22 ref

001214   Mitra A;Das I M L (K. Banerjee Centre of Atmospheric and Ocean Studies, Nehru Science Cen, Allahabad Univ, Allhabad-211 002, Email: drimldas@yahoo.com) : Simulation of Antarctic sea ice. Curr Sci 2007, 92(3), 345-50.

Semtner's three-layer sea ice model and Winton's refor-mulated three-layer sea ice model have been applied to the Antarctic region (where there are chances of sea ice disappearing in the summer leading to open water) for simulating some features of sea ice using the ECMWF re-analysis data. The results of the simulation have been compared with the observation.

2 illus, 1 table, 9 ref

001213   Mathew J;Jha V K;Rawat G S (NO, Regional Remote Sensing Service Centre (ISRO), Dehradun-248 001) : Weights of evidence modelling for landslide hazard zonation mapping in part of Bhagirathi valley, Uttarakhand. Curr Sci 2007, 92(5), 628-38.

Weights of evidence method, which is basically the Bayes-ian approach in a log-linear form, using the prior probability of occurrence of an event like landslide, helps to find out its posterior probability based on the relative contributions of evidential themes which are influential in creating slope instability. In the present study, this method has been used to find out the probability of occurrence of landslides for unique combinations of evidential themes and to prepare a landslide hazard zonation map of part of Bhagirathi valley, Uttarakhand, within a Geographic Information System environment. Lithology, structure, slope, slope aspect, land use/land cover, drainage and distance to road are the evidential themes considered in the study. The model has been further validated using receiver operator characteristic curve analysis, which shows an accuracy of 84.6%.

9 illus, 12 tables, 22 ref

001212   Mahalik N K;Maejima W (Utkal Univ, , Bhubaneswar, Orissa) : Kuturia boulder bed and provenance characteristics of the Talchir formation at the eastern closure of the Talcher Gondwana basin. SGAT Bull 2006, 7(1), 47-52.

Recent geological investigation at the eastern closure of Talcher Gondwana basin has shown an important boulder horizon, forming the base of the Talchir Formation. The basal boulder bed is well developed south of Kuturia village and named as Kutria Boulder Bed. It forms hills and consists of large rounded boulders measuring maximum of one metre to smaller sizes. The boulders are of variable lithology such as specularite quartzite, very coarse granular quartzite and muscovite-bearing quartzite etc. The parent source rocks of these boulders are found forming hill ranges to the north (e.g. Petraparbat, Petraghati) within the Iron Ore Province and belong to BIF I Formation. The boulder bed is succeeded to the south by green shales and Talchir sandstones observed along the left bank irrigation canal which is under construction. From the similarity of boulders with source rocks to the north, it is believed that the paleoslope and sediment supply directions were from the Iron Ore craton on the north to the Gondwana basin on the south.

2 illus, 2 tables, 6 ref

001211   Madhnure P;Sirsikar D Y;Tiwari A N;Ranjan B; Malpe D B (NO, , Central Ground Water Board, Central Region, N. S. Building, Civil Lines, Nagpur-440 0016, Email: pandith_m@rediffmail.com) : Occurrence of fluoride in the groundwaters of Pandharkawada area, Yavatmal district, Maharashtra, India. Curr Sci 2007, 92(5), 675-9.

Hydrogeological investigations have been carried out in the rural parts of Yavatmal district, Maharashtra, where agriculture is the main occupation. The area is mainly occupied by Deccan basalts, except in the southern part, where limestone and shale belonging to the Penganga Group occur. Groundwater occurs under unconfined conditions in the weathered and fractured portions of rocks, and semi-confined to confined conditions in fractured rocks. The groundwater of the area is of bicarbonate (HCO₃)-type and high fluoride (F^-) concentration is observed in deeper aquifers compared to shallow aquifers. Physicochemical conditions like decomposition, dissociation and subsequent dissolution along with long residence tune might be responsible for leaching of F^- into the groundwater.

2 illus, 1 table, 30 ref

001210   Janardhana Raju N (Geology Dep, Banaras Hindu Univ, Varanasi-221 005, Email: rajunj7@yahoo.com) : Season-wise estimation of total dissolved solids from electrical conductance and silica in ground waters of upper Gunjanaeru River basin, Kadapa District, Andhra Pradesh. Curr Sci 2007, 92(3), 371-6.

In order to establish season-wise relationship between total dissolved solids (TDS), electrical conductance (EC) and silica (SiO₂) in upper Gunjaneru River basin, Kadapa district, Andhra Pradesh, a study has been made by collecting 51 and 46 groundwater samples during post-monsoon and pre-monsoon season, respectively. TDS, EC and silica are some of the groundwater quality parameters measured in a laboratory generally. EC and silica measurements are made quickly and are less costly than TDS measurement. The results indicate that 99.7% and 99.8% of the variability in TDS could be ascribed to the variable EC and SiO₂ concentrations and the rest by some other unaccounted variables in the post-monsoon and pre-monsoon sea son, respectively. Inclusion of SiO₂ concentration in the regression models produces, for individual samples, a lower per cent difference between measured and estimated TDS for both seasons. However, on the average ' the inclusion of SiO₂ in regression models reduced the mean difference 0.09% for the post-monsoon season and 0.11% for the pre-monsoon. From regression analysis it is found that the multiple regression model did not improve the predictability of TDS values over the linear regression model for both post-monsoon and pre-monsoon seasons. TDS can be estimated from either EC or EC and SiO₂ by these regression models within the acceptable limit of error. This is due to the low content of SiO₂ in the groundwater samples in shale aquifers of the study area.

3 illus, 4 tables, 13 ref

001209   Jaiswal K;Sinha R (Civil Engineering Dep, IIT, Bombay, Mumbai- 400 076, Email: rsinha@civil.iitb.ac.in) : Spatial variation of maximum considered and design basis earthquakes in peninsular India. Curr Sci 2007, 92(5), 639-45.

Realistic seismic hazard assessment is essential for carrying out safe and economic design of structures. The zone factors corresponding to seismic hazard in different parts of India that has been specified in the IS code (IS 1893:2002) does not fully consider the recent advances in understanding of seismic hazard in peninsular India. The recent damaging earthquakes in this region have indicated that the seismic zonation may not be accurate. The MCE-level peak horizontal accelerations may also be underestimated, considering the damage caused by moderate to large earthquakes in the past. The IS code also assumes a uniform ratio of maximum considered earthquake (MCE) to design basis earthquake (DBE) as 2, which may result in non-uniform margin of safety at MCE level ground motions. These issues have been discussed in this article based on probabilistic seismic hazard assessment of peninsular India. It is shown that uniform level of safety against MCE cannot be achieved in both peninsular India as well as the seismically active regions. It is also shown that the MCE-level ground motion earthquake is significantly underestimated in large parts of peninsular India.

6 illus, 2 table, 20 ref

001208   Hoda S Q (NO, , Atomic Minerals Directorate for Exploration and Research North Eastern Region, Shillong-793 001) : Ground water resources of Northeast India : emerging scenario and environmental viewpoint. Envir Geochem 2005, 8(1-2), 80-3.

5 tables, 6 ref

001207   Gupta H;Chakrapani G J (Earth Science Dep, Indian Institute of Technology Rorrkee, Roorkee-247 667) : Temporal and spatial variations in water flow and sediment load in the Narmada river. Curr Sci 2007, 92(5), 679-84.

Rivers are an integral part of the hydrologic cycle and are the major geologic agents which erode the continents and transport water and sediments to the oceans. Thus rivers constitute an important link between continents and oceans. A number of natural and anthropogenic factors influence the water and suspended sediment flux of a river basin along its pathway. Some important key factors are: area of drainage basin, relief, geology of basin, climate including rainfall and its intensity, run-off, vegetation, tectonics, land-use patterns and presence of reservoirs/dams. Any or all of these factors can be important in a particular river system. We recognize three key factors that influence water and suspended sediment load of the Narmada river, namely basin geology, rainfall and presence of reservoirs/dams. In the present study, water flow and suspended sedi-ment load data in the Narmada river have been assessed based on 20 years of monitoring at various gauging stations. Most of the water flow in the river is during the monsoon season, except in some tributaries, where groundwater flow to the river during non-monsoon is significant. The suspended sediment flux is significantly lowered by the construction of dams and reservoirs along the river course.

6 illus, 2 tables, 18 ref

001206   Goswami P K;Pant C C (Geology Dep, Kumaun Univ, Nainital-263 002, Email: drpgoswami@yahoo.com) : Geomorphology and tectonics of Kota-Pawalgarh Duns, central Kumaaun sub-Himalaya. Curr Sci 2007, 92(5), 685-90.

Interpretation of IRS LISS III satellite data and analysis of digital terrain models in GIS, together with field studies have made it possible to delineate and map geomorphic and tectonic features in Kota-Pawal-garh Duns within the Kumaun Sub-Himalaya. The present study highlights the disposition and characteristics of major geomorphic units within the Duns. The Duns are made up of sediments deposited in different small piedmont fans having modified shapes and distinct surfaces formed in response to various longitudinal and transverse faults. The geomorphic evidences have enabled us to understand the active tectonic activities in the area.

10 illus, 15 ref

001205   Geetha K A;Josphin M;Maiti S (NO, National Research Centre for Medicinal and Aromatic Plants, Boriavi, Anand-387 310) : Gender instabity in Tinospora cordifola - an immunomodulator. Curr Sci 2007, 92(5), 591-1.

1 illus, 9 ref

001204   Freeda D;Gnana Rani (NO, Government Arts College, Ariyalur, Tamil Nadu) : Hydrochemistry of groundwater of Thirumanur area, Tamil Nadu (India). J envir Sci Engng 2006, 48(3), 199-202.

Perambalur is the most backward district in the state of Tamil Nadu (India). It has ten unions, of which Thirumanur union has historical importance and is blessed with fertile lands. Thirumanur union has Kollidam river and Pullambadi canal as rich sources of water for irrigation. Thirumanur union has large number of Chozha temples at various places like Thirumalapadi, Periyamanai, Kamarasavalli, Thoothur, Senapathimudikondan, Kandaradhitham, Keelapalur and Melapalur. Thirumanur union being the south end union of Perambalur district, has Trichy district and Tanjore district as its neighbours. Thirumanur union has an area of 64 hectare, of which 48 hectare is under cultivating land. This union has maximum number of thirty-six villages. Though most of the villages use river water as their major source of drinking, they also use groundwater as their other source. Lot of work has been done and published already on the groundwater quality of many villages in other different unions of the Perambalur district. But in the Thirumanur union, there was need to undertake the study to assess the drinking water quality in the region. Hence, ten villages of Thirumanur union were selected, where the people use groundwater for drinking, and the water samples were subjected to systematic analysis. The depth of the bore wells varied from 100-200 feet. The values obtained for different parameters were compared with the standard values given by ISI / ICMR / WHO and the variations were notable for the parameters like nitrate and total hardness for few samples. Therefore, a medical survey was carried out to study the harmful effects on the society due to these two parameters at the villages-Keelapazhur, Palanganatham and Venganur.

4 tables, 9 ref

001203   Diwan H D;Kuity D P (NO, Pt. R.S.S.U., Raipur, Chattisgarh) : "Geomorphic evaluation of kurung watershed using remote sensing techniques, Arpa valley, C.G.". SGAT Bull 2006, 7(1), 5-9.

Integrated development of any area depends largely on total natural resources available within a watershed. Geomorphic units of Kurung watershed, district Bilaspur, Mahanadi system have been evaluated using remote sensing techniques with limited field checks. Kurung stream watershed posses a variety of land forms including hills, ridges, buried pediplains and undulating plains etc. The sub tropical climate is prevailing in the region and watershed receives 1290 mm mean rainfall annually. The average density of water bodies (5.5 ponds / km²) around Ratanpur indicates high surface water potentiality. The Kurung watershed consists of rocks ranging from Archean to Recent in age. It includes Granitoids, Chlorite Schists, Lameta beds, Deccan lavas, Gondwana Sandstone, Shale Chhattishgarh limestone and dolomite. The landforms of watershed are found useful in landuse practice. Geomorphic mapping indicate that 45% of the land area (buried pediplains) is suitable for cultivation in the watershed. Geomorphic features control the 'water conservation measures in the watershed. Erosional landforms are dominant in the area, largely influenced by fluvial processes and lithological variations of the terrain. Development of Gullies in upper reaches, deteriorating the fertile land, needs conservation measures. Pediments and undulating plains are favourable units for construction of check dams and underground dykes respectively.Integrated development of any area depends largely on total natural resources available within a watershed. Geomorphic units of Kurung watershed, * district Bilaspur, Mahanadi system have been evaluated using remote sensing techniques with limited field checks. Kurung stream watershed posses a variety of land forms including hills, ridges, buried pediplains and undulating plains etc. The sub tropical climate is prevailing in the region and watershed receives 1290 mm mean rainfall annually. The a

1 table, 2 ref

001202   Dimri V P;Srivastava K (NO, National Geophysical Research Institute, Hyderabad-500 007, Email: director@ngri.res.in) : Tsunami propagation of the 2004 Sumatra earthquake and the fractal analysis of the aftershock activity. Indian J Mar Sci 2007, 36(2), 128-35.

The 26 December 2004, earthquake of magnitude Mw<126>9.3 had generated large tsunami waves that traveled large distances lying along the rim of the Indian Ocean, Bay of Bengal and Arabian Sea and as far as the west coast of Americas causing large scale devastation. The seismicity pattern of the fault zone has been modeled by several authors, and it is seen that the fault rupture can be divided into three segments. The aftershock sequences have been analyzed, using the fractal approach, for three segments independently. The first segment of 500 km long is the zone of the fastest rupture and has the largest fractal dimension of about 2.10 implying that the fault rupture is two dimensional. This region has a lower b value indicative of high stress regime. The fastest rupture zone has been considered for the generation and propagation of the tsunami waves. The tsunami wave propagation has been modeled using the nonlinear form of long wave equations. The governing equations are expressed as the partial differential equations which have been solved numerically using the finite differences and the tsunami wave heights have been computed at two Gauge locations i.e at Chennai and Visakhapatnam. The wave heights at Chennai and Visakhapatnam have been compared with the tidal data observed at two of these locations. Results show that the arrival times and the magnitude of the wave heights are seen to be in agreement.

001201   Chu P C;Hsieh C P (Naval Ocean Analysis and Prediction Laboratory, Oceanography Dep, Naval Postgraduate School, Monterey, California 93943, USA, Email: pcchu@nps.edu) : Multifractal thermal characteristics of the western Philippine Sea upper layer. Indian J Mar Sci 2007, 36(2), 141-51.

Multifractal characteristics of the upper layer (above 140 m depth) thermal structure in the western Philippine Sea near Taiwan are analyzed using high-resolution, digital thermistor chain data. The power spectra at all the depths have multi-scale characteristics with the spectral exponent b in the range of (1, 2), which indicates nonstationary with stationary increments. The graph dimension varies from higher values such as 1.71 (in sublayer: 60 m), to lower values such as 1.59 (in second thermocline: 120 m). However, the information dimension varies slightly from 0.929 to 0.941. The multi-dimensional structure is stronger in nonstationarity (graph dimension) than in intermittency (information dimension). These results provide useful information for investigating turbulence structure in the upper layer of the western Philippine Sea.

001200   Chattopadhyay S;Suresh Kumar S (NO, Centre for Earth Science Studies, Trivandrum-695 031, Email: radresource@vsnl.com) : Fractal dimensions of selected coastal water bodies in Kerala, SW coast of India - a case study. Indian J Mar Sci 2007, 36(2), 162-6.

Fractal dimension (D) of shorelines of four coastal water bodies, namely Paravoor, Ashtamudi, Kayamkulam and Vembanad have been worked out applying three methods. The D values ranged from 1.09 to 1.40. Edge of Ashtamudi, which is genetically different from the rest, is rougher compared to other water bodies as is evident from the higher D values recorded by this water body. The method of log N-log G plots appeared to be the most suitable for this study. Coast perpendicular water body surrounded by laterites like Asthamudi estuary could be well separated from the rest based on fractal dimension. It is suggested that fractal dimensions may be used for classifying coastal water bodies as linked to their genesis.

001199   Chatterjee R S;Roy P S;Dadhwal V K;Lakhera R C;Quang T X;Saha R (NO, Indian Institute of Remote Sensing, National Remote Sensing Agency, Dehradun-248 001) : Assessment of land subsidence phenomenon in Kolkata city, India using satellite-based D-InSAR technique. Curr Sci 2007, 93(1), 85-90.

One of the latest space-based techniques for measuring sub-centimetric ground displacement, Differential Synthetic Aperture Radar Interferometry (D-InSAR) has been used to assess the potential land subsidence phenomenon of Kolkata city, India. The occurrence of a thick surface clay layer with an average thickness of -40 m and above, raises a question on the land subsidence phenomenon in Kolkata city. At this juncture, the D-InSAR-based study will help to ascertain the actual land subsidence scenario of Kolkata city. Authors have identified an area in Kolkata city in and around Machhua Bazar, Calcutta University and Raja Bazar Science College, which had been undergoing subsidence during the period of observation, i.e. 1992-98 with an estimated rate of 5 to 6.5 mm/yr.

4 illus, 1 table, 11 ref

001198   Chamoli A;Dimri V P (NO, National Geophysical Research Institute, Hyderabad-500 007, Email: chamoli_jp@rediffmail.com) : Evidence of continental crust in Laxmi Basin (Arabian Sea) using wavelet analysis. Indian J Mar Sci 2007, 36(2), 117-21.

Spectral analysis of bathymetry along 17° 12'N latitude between the longitude <126>60° E and 73° E has been done using wavelet transform. The profile covers all the major features of the region including Western Basin, Laxmi Ridge, Laxmi Basin, Panikkar Ridge, continental slope and continental shelf. The wavelet coefficients at different scales a = 1, 2, 4, 8, 16, 32 showed that the signatures are different on the left and right regions of the Laxmi Ridge. On the basis of these signatures, the profile has been divided into different sections and wavelet variance analysis for these sections has been done. The calculated exponent β has the value <126>2.0771 for whole data set and <126>1.9367, 2.838, 2.9911 and 2.8750 corresponding to Western Basin, Laxmi Basin, region from Laxmi Basin up to continental shelf and region covering continental slope and continental shelf respectively. The fractal dimension corresponding to these values are 1.53, 1.1, 1.0 and 1.06 respectively. The values of β and fractal dimension show that the spectral behaviour of crust of Laxmi Basin is near to continental shelf and slope, which indicates the nature of crust of Laxmi Basin as continental.

001197   Chakraborty B;Mahale V;Shashikumar K;Srinivas K (NO, National Institute of Oceanography, Dona Paula, Goa-403 004, Email: bishwajt@nio.org) : Quantitative characteristics of the Indian Ocean seafloor relief using fractal dimension. Indian J Mar Sci 2007, 36(2), 152-61.

Spectral technique has been applied for seafloor topographic data analyses from three seafloor provinces of the Indian Ocean. Study sites include West of the Andaman Island (WAI), Western Continental Margins of India (WCMI) and Central Indian Ocean Basin (CIOB). The analyses involved application of suitable gridding techniques to bathymetric data of the multi-beam-Hydrosweep from these sites. Total eleven profiles i.e., three from two sites (A and B) and five from site C were used from varying physiographic provinces. Segmentation method is employed to non-stationary profile into homogenous or stationary segments. Thereafter, estimation of spectral parameters (β) is carried out for thirty-five segmented profiles and amplitude parameter (S) is computed. Also, computation of Fractal Dimension (D) using spectral exponent parameter was carried out and analyses is presented. Current investigation also includes presentation of scatter plot between the β and S value for each site. The computed Fractal Dimension (D) from sedimentary area of the trench side of WAI site revealed very high D values i.e., higher roughness, whereas varying fractal dimension values from remaining areas of this site are indicative of moderate to lower seafloor roughness. Similarly, results form WCMI (site B) area showed variable physiographic provinces from shelf (higher D) to slope morphology which appears to have modified by presence of physiographic highs and slump related features. Highest 'D' values for summit of the highs indicate sub-aerial erosion and lower 'D' values for flanks across the highs were also observed. Fractal Dimension (D) values from site C (CIOB) also indicated moderate 'D' values for E-W and N-S profiles. However, scatter plot between the á and S values for E-W and N-S profiles show interesting demarcation in terms of clustering. In this work, application of Fractal Dimension is demonstrated for quantitative characterization of the Indian Ocean seafloor roughness.

001196   Bhattacharya S;Sarkar S;Gwal A K;Parrot M (Space Science Laboratory, Physics Dep, Barkatullah Univ, Bhopal-462 026, Email: shourabhbhattacharya@rediffmail.com) : Satellite and ground-based ULF/ELF emissions observed before Gujarat earthquake in March 2006. Curr Sci 2007, 93(1), 41-5.

Recent years have evidenced observations pertaining to electromagnetic emissions that are detected during the course of a seismic event. Study has been carried out related to seismo-electromagnetic emissions that were detected as perturbations in the ionosphere before the Gujarat earthquake which occurred on 7 March 2006, of magnitude 5.5 on the Richter scale. The epicentre of this activity was in the remote Rann of Kutch area near the border with Pakistan (M = 5.5, lat. 23.78°N, long. 70.90°E, 18:20:46 h UT, d - 10 km). Strong electromagnetic emissions have been observed with the help of the DEMETER satellite in the ELF (extremely low frequency) electric and magnetic components pertaining to the seismic activity. Ground-based data of ULF (ultra low frequency) magnetic field was studied and found significant enhancement of polarization ratio employing the LEMI-30i search coil magnetometer at the Department of Physics, Barkatullah University, Bhopal. The analysis of satellite as well as ground-based data suggests significant emissions that were ovserved before the Gujrat earthquake.

8 illus, 1 table, 30 ref

001195   Bhattacharya P M;Kayal J R (Geophysics Div, Geological Survey of India, 27 J.N Road, Kolkata-700 016, Email: pankajmala2006@yahoo.com) : Application of fractal in marine sciences: study of the 2004 Sumatra earthquake (Mw 9.3) sequence in Andaman-Nicobar islands. Indian J Mar Sci 2007, 36(2), 136-40.

Aftershock sequence of the 26 December 2004, Sumatra-Andaman mega thrust event (Mw 9.3) that resulted a rupture of about 1300 km in the ocean floor, Sumatra to Andaman-Nicobar islands, is studied to evaluate the fractal dimension of the oceanic tectonic features. A large number of aftershocks (Mw³ 3.0) are recorded by temporary network that was established by the Geological Survey of India (GSI) in the Indian state of Andaman-Nicobar islands. The complex geological structures that include the Andaman trench, West Andaman fault and the backarc spreading zone , Andaman spreading Ridge (ASR), in the region generated a rupture area 800 ' 300 km² below the Andaman - Nicobar islands. The Fractal dimension was estimated using correlation dimension method and the box counting method. Epicenters of 1100 well located earthquakes were considered for the analysis. A prominent N-S trending contour with fractal dimension between 0.90 - 1.30 indicates that the epicenters are linear, or almost one dimensional that correlates with the West Andaman fault. The box counting method estimated the fractal dimension 1.17 for this linear fault that lie between the trench and the back arc spreading zone in the ocean basin. The higher fractal dimension (<62>1.5) contours on both sides of the West Andaman fault indicate the extent of 2D heterogeneity of the Andaman Trench and the ASR. The fractal dimension values for the entire region suggests that the faults are spatially distributed in the whole region, and the whole region is seismically active.

001194   Bhatt P N;Mehta J P;Jani H J;Kurup S (Chemistry Dep, Bhavnagar Univ, Bhavnagar-364 002, Email: pnbchem@yahoo.com) : Ingress of Bhavnagar city (India). J envir Sci Engng 2006, 48(3), 165-8.

Prelirninary survey of the coastal city-Bhavnagar was undertaken to assess salinity ingress probed through groundwater quality. Water samples from the wells and bores located in the study area were collected and analyzed. Bhavnagar City is found significantly affected by the seawater intrusion. The ground water showed very high values of SO₄^-2, Cl^-1 , PO₄^-3 and, Na⁺¹, K⁺¹ compared to the permissible limits for drinking purposes. The quality of ground water in some of the areas was found highly saline and can not be used even for irrigation purpose. The results also indicated a gradual encroachment of seawater into the native ground water.

1 illus, 3 tables, 5 ref

001193   Beura D;Singh P (Geology P.G. Dep, Utkal Univ, Bhubaneswar, Email: debanandabeura@rediffmail.com) : Disaster management in Orissa coast - an information technology vision. SGAT Bull 2006, 7(1), 27-36.

Disasters are unforeseen and unpredictable phenomena that can be mitigated by proper management taking the advantages of information technology. Management focuses on certain principles, practices and techniques. The principle incorporates Pre-disaster preparedness including DPS, DWS, PCS; Post-disaster settlement and environmental restructuring. Satellite points, remote sensing and radars are the significant sources for data acquisition. GIS, AI (fuzzy logic) programming, online transaction processes (OLTP) and online analytic process (OLAP) are the useful software in appraisal of data processing and interpretation. Communication techniques are facilitated through advanced electronic media.

5 illus, 6 ref

001192   Bansal A R (NO, National Geophysical Research Institute, Uppal Road, Hyderabad-500 007) : Power law relation of bathymetry and gravity roughness with age of oceanic crust below Ninety East Ridge. Indian J Mar Sci 2007, 36(2), 105-9.

Altimeter gravity and ship track bathymetry data from National Geophysical Data Center (NGDC) is explored to investigate the relation between roughness of gravity and bathymetry data to the age of oceanic crust over 90° E Ridge. The gravity and bathymetry profiles are selected over the ridge at places of known ages from Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP). The gravity and bathymetry data are gridded at sampling interval of 1' 12'' and profiles are extracted on the DSDP and ODP sites. The roughness of gravity and bathymetry data is computed as the square root of the average squared deviation about a linear trend. The roughness varies as a power -1.31 and -1.59 of age for bathymetry and gravity data. The mean fractal dimension is found to be 1.54 and 1.46 for bathymetry and gravity data. The roughness of bathymetry and gravity data varies with age with different power law. It is also interesting to note that the roughness of bathymetry decreased with age, which indicates modification of bathymetry data in the older (northern) portion of the ridge with continuous depositions of Bengal fan sediments.