Active
fault traces along Bhuj Fault and Katrol Hill Fault,and trenching survey at
Wandhay,Kachchh, Gujarat,India
Michio Morino 1 , ∗,Javed N Malik 2 ,
∗∗,Prashant Mishra 2 , †,
Chandrashekhar Bhuiyan 2 , ‡and Fumio
Kaneko 1 ,$
1 OYO International
Corporation,Rokubancho Kyodo Bldg.2F,6 Rokubancho,
Chiyoda-ku,Tokyo,Japan 102-0085.
2 Department of Civil
Engineering,Indian Institute of Technology Kanpur,Kanpur 208 016,India.
∗e-mail:morino@oyointer.com
∗∗e-mail:javed@iitk.ac.in
†e-mail:pram@iitk.ac.in
‡e-mail:cbhuiyan@gmail.com
$ e-mail:kaneko@oyointer.com
Abstract: Several new active
fault traces were identi fied along Katrol Hill Fault (KHF).A new fault
(named as Bhuj Fault,BF)that extends into the Bhuj Plain was also
identi fied.These fault traces were identi fied based on satellite photo
interpretation and field survey.Trenches were excavated to identify the
paleoseismic events,pattern of faulting and the nature of
deformation.New active fault traces were recognized about 1 km north of
the topographic boundary between the Katrol Hill and the plain area.The
fault exposure along the left bank of Khari River with 10 m wide shear
zone in the Mesozoic rocks and showing displacement of the overlying
Quaternary deposits is indicative of continued tectonic activity along
the ancient fault.The E-W trending active fault traces along the KHF in
the western part changes to NE-SW or ENE-WSW near Wandhay village.
Trenching survey across a low scarp near
Wandhay village reveals three major fault strands F1, F2,and F3.These
fault strands displaced the older terrace deposits comprising Sand,Silt
and Gravel units along with overlying younger deposits from units 1 to
5 made of gravel,sand and silt. Stratigraphic relationship
indicates at least three large magnitude earthquakes along KHF during
Late Holocene or recent historic past.
Magnetotelluric
investigations for imaging electrical structure of Garhwal Himalayan corridor, Uttarakhand,India
MIsrail ∗,D K Tyagi ,P KGupta and Sri
Niwas
Department of Earth Sciences,Indian
Institute of Technology Roorkee,Roorkee 247 667,India.
∗e-mail:mohdfes@iitr.ernet.in
Abstract: Magnetotelluric
investigations have been carried out in the Garhwal Himalayan corridor
to delineate the electrical structure of the crust along a pro file
extending from Indo-Gangetic Plain to Higher Himalayan region in
Uttarakhand,India.The pro file passing through major Himalayan
thrusts:Himalayan Frontal Thrust (HFF),Main Boundary Thrust (MBT)and
Main Central Thrust (MCT),is nearly perpendicular to the regional
geological strike.Data processing and impedance analysis indicate that
out of 44 stations MT data recorded,only 27 stations data show in
general,the validity of 2D assumption.The average geoelectric
strike,N70 0 W,was estimated for the pro file using tensor
decomposition.2D smooth geoelectrical model has been presented,which
provides the electrical image of the shallow and deeper crustal
structure.The major features of the model are (i)a low resistivity
(<50 Ωm),shallow feature interpreted as sediments of Siwalik and
Indo-Gangetic Plain,(ii)highly resistive (>1000 Ωm)zone below the
sediments at a depth of 6 km,interpreted as the top surface of the
Indian plate,(iii)a low resistivity (<10 Ωm)below the depth of 6 km
near MCT zone coincides with the intense micro-seismic activity in the
region. The zone is interpreted as the partial melting or fluid phase at
mid crustal depth.Sensitivity test indicates that the major features of
the geoelectrical model are relevant and desired by the MT data.
Paleosol at
the Archean –Proterozoic contact in NW India revisited:Evidence for oxidizing conditions
during paleo-weathering?
Manoj K Pandit 1 , ∗,Helga de Wall 2
and Narendra K Chauhan 3
1 Department of Geology,University of
Rajasthan,Jaipur 302 004,India.
2 Institut f ¨ur
Geologie,Julius-Maximilians-Universitat W ¨urzburg,Pleicherwall
1,97070 W ¨urzburg,Germany.
3 Department of Geology,MLS
University,Udaipur 313 001,India.
∗e-mail:mpandit −jp1@sancharnet.in
Abstract: A number of
fine-grained sericite bearing pelitic,schistose lithologies occur along
the Archean (Banded Gneiss Complex)–Proterozoic (Aravalli
Supergroup)contact (APC)in the Udaipur valley in NW Indian craton.These
Al-rich lithologies (subsequently metamorphosed)have been described as
‘paleosols ’,developed over a 3.3 Ga old Archean gneissic basement and
are overlain by Paleopro- terozoic Aravalli quartzite.The paleosol was
developed between 2.5 and 2.1,coincident with the globally recognized
Great Oxidation Event (GOE).In previous studies these paleosol sections
were interpreted to have developed under reducing
environment,however,the finding of a ‘ferricrete ’ zone in the upper
part of Tulsi Namla section (east of Udaipur)during the present study
(in addition to earlier reported lithologies) has led to an
alternative suggestion of oxygen-rich conditions during paleosol
development.The Tulsi Namla paleosol section shows all the features
characteristic of a complete paleosol section described from other
Archean cratons.The paleosol includes sericite schist with kyanite as
the prevalent Al-silicate in the lower part of pro file while chloritoid
and Fe-oxides typify the Fe-rich upper part.Alumina has remained
immobile during the weathering process while Fe and Mn show a decrease
in the lower part of the section and an abrupt rise in the upper
part,in the ferricrete zone.The field and geochemical data indicate that
the Tulsi Namla section is an in situ weathering pro file and at least
the upper part shows evidence of oxidizing conditions.
Seasonal
variation in biomass and species composition of seaweeds stranded along Port Okha, northwest coast of India
Mukund C Thakur,C R K Reddy and
Bhavanath Jha ∗
Discipline of Marine Biotechnology
&Ecology,Central Salt &Marine Chemicals Research Institute
(Council of
Scienti fic and Industrial
Research),Gijubhai Badheka Marg,Bhavnagar 364 002,India.
e-mail:bjha@csmcri.org
Abstract: Port Okha
coast,which is known for its luxuriant growth of a diverse assemblage
of seaweeds on Saurashtra coast,is found to have abundant quantities of
seaweeds being drifted and washed ashore every year.Studies conducted
for quantifying the stranded seaweeds from May 2004 to April 2005
showed an average biomass value of 3.10 kg fresh wt/m2/month
with maximum being 6.60 kg fresh wt/m2in April.The stranded
weeds constituted a total of 62 species during the entire study
period.Of this,Rhodophyta ranked high with 26 species followed by
Chlorophyta with 22 species and Phaeophyta with 14 species.The stranded
seaweeds that were washed ashore provide valuable floristic information
about the intertidal and near shore sub-tidal algae of the respective
regions.Although natural senescence of seaweeds is one of the major
factors,strong currents primarily forced by tides,also contribute to
the uprooting and subsequent drifting of seaweeds on to the beach.This
ultimately causes changes in floristic features of the existing algal
beds.
Observations
of unusual whistlers during
daytime at Jammu
K KSingh 1 ,R PPatel 1 , ∗,JSingh 2
,B Kumar 2 ,A KSingh 1 ,R PSingh 1 ,3 ,
BLKoul 4 and Lalmani 4
1 Atmospheric Research
Laboratory,Physics Department,Banaras Hindu University,Varanasi,India.
2 Physics Department,G.G.M.Science
College,Canal Road,Jammu,India.
3
Vice-Chancellor,V.K.S.University,Arrah,Bihar,India.
4 Physics Department,National
Institute of Technology Srinagar,Camp Classes,
Old University Campus,Canal
Road,Jammu,India.
∗e-mail:rppatel12@yahoo.co.in abhay
−s@redi ffmail.com
Abstract: In this paper,we
report observations of unusual whistlers recorded at Jammu
(geomag.lat.= 22 ◦26 N;L =1 .17),India on March 8,1999 during the
daytime.They are interpreted as one-hop ducted whistlers having
propagated along higher L -values in closely spaced narrow ducts from
the opposite hemispheres.After leakage from the duct,the waves might
have propagated in the earthionosphere waveguide towards the equator in
surface mode.Tentative explanation of the dynamic spectra of these
events is brie fly presented.
On the
impact of temperature on tropospheric ozone concentration levels in urban environments
E Stathopoulou 1 ,G Mihalakakou 2 ,M
Santamouris 1 and H S Bagiorgas 2 , ∗
1 University of Athens,Department of
Physics,Division of Applied Physics,Laboratory of Meteorology,
University Campus,Build.Phys.V,157 84
Athens,Greece.
2 University of Ioannina,Department
of Environmental and Natural Resources Management,
2 G.Sepheri Str.,30100 Agrinio,Greece.
∗e-mail:chbagior@cc.uoi.gr
Abstract: The in fluence of
temperature on tropospheric ozone (O 3 )concentrations in urban and
photochemically polluted areas in the greater Athens region are
investigated in the present study.Hourly values of the ambient air
temperature used for studying the urban heat island e ffect in Athens
were recorded at twenty-three experimental stations while ozone
concentration values were measured at three of the above-mentioned
stations and for a period of two years (1996 –1997).The linear
correlation between ozone concentration and air temperature values as
well as the temporal variation of temperature and ozone
concentration,for the above-mentioned experimental stations, were
calculated and analysed.Moreover,a neural network approach was used for
investigating the impact of temperature on the ozone concentration
values over the greater Athens area.The neural network model used
ambient air temperature as one of its input parameters and it was found
that temperature is a predominant parameter,a ffecting considerably the
ozone concentration values.
A note on
India ’s water budget and evapotranspiration
T N Narasimhan
Department of Materials Science and
Engineering,210 Hearst Memorial Mining Building,
University of California,Berkeley,Ca
94720-1760,USA.
e-mail:tnnarasimhan@lbl.gov
Abstract: Some recent
analyses of India ’s water budget are based on information attributed
to the Ministry of Water Resources.An examination of the budget
components indicates that they imply an evapotranspiration estimate
that is signi ficantly lower than what one may expect based on
information from other sources.If such is the case,India ’s water
resources situation may be more dire than is otherwise
perceived.For,higher evapotranspiration implies correspondingly reduced
availability of water for human use.It should be worthwhile to
investigate and reconcile the apparent discrepancy between water budget
and evapotranspiration,considering the importance of water in the
national context.