Institute of Geophysics, University of TehranJournal of the Earth and Space Physics2538-371X27120010321--13318FAJournal Article19700101To interpret the gravity anomaly of a Koromite mine in south - west of Iran, we have used the three dimensional inversion problem. The method introduced by Last and Kubik (1983) and improved by Lewi (1997) for high precision gravity data has been tested to determine the 3-dimensional form of the anomaly. The results of the inversion process have been approved by exploration drill holes in the area recently.To interpret the gravity anomaly of a Koromite mine in south - west of Iran, we have used the three dimensional inversion problem. The method introduced by Last and Kubik (1983) and improved by Lewi (1997) for high precision gravity data has been tested to determine the 3-dimensional form of the anomaly. The results of the inversion process have been approved by exploration drill holes in the area recently.https://jesphys.ut.ac.ir/article_13318_fe3226c1d0999d9af475526dda50c2c9.pdfInstitute of Geophysics, University of TehranJournal of the Earth and Space Physics2538-371X27120010321--13319FAJournal Article19700101In this study, turbulent flow around a Guassian hill in a water tunnel is studied.
Using a hot film anemometer, velocity and turbulent qualities (such as turbulence
flux and intensity) is measured at different parts of the model.
To understand these measurements, mean velocity deviation and perturbation
velocity fluctuation contours, also turbulence flux and intensity profiles are presented
and the results are consistent with those obtained by other investigators. Also the
cavities in the downwind of the hill cause intense turbulence its scale being in order
of cavities.
The increase of velocity around the hill especially above the crest is significant.
These studies in the use of optimum wind energy in hilly regions are useful.In this study, turbulent flow around a Guassian hill in a water tunnel is studied.
Using a hot film anemometer, velocity and turbulent qualities (such as turbulence
flux and intensity) is measured at different parts of the model.
To understand these measurements, mean velocity deviation and perturbation
velocity fluctuation contours, also turbulence flux and intensity profiles are presented
and the results are consistent with those obtained by other investigators. Also the
cavities in the downwind of the hill cause intense turbulence its scale being in order
of cavities.
The increase of velocity around the hill especially above the crest is significant.
These studies in the use of optimum wind energy in hilly regions are useful.https://jesphys.ut.ac.ir/article_13319_0a13ecc4697057242ddffe20d39c6d13.pdfInstitute of Geophysics, University of TehranJournal of the Earth and Space Physics2538-371X27120010321--13320FAJournal Article19700101A computer program was developed to predict the dispersion of gaseous pollutant
in the atmosphere. This program relies on puff method, and in order to consider the
wind shear effects, the program has the ability to consider the complete dynamic and
unsteady atmospheric conditions. Plume rise of hot pollutants due to buoyancy
effects was also considered. The program has the ability to perform the real-time
calculations and uses on-line data of atmospheric conditions that are measured
directly. In order to consider the effects of the presence of buildings and other
obstacles or sudden changes in surface roughness by the dispersion of released
materials, a model was added to evaluate the dispersion coefficients in the wake of
obstacles. Using this relatively complete simulation, we analyzed the effects of the
above parameters on the dispersion of gaseous pollutants in the atmosphere.A computer program was developed to predict the dispersion of gaseous pollutant
in the atmosphere. This program relies on puff method, and in order to consider the
wind shear effects, the program has the ability to consider the complete dynamic and
unsteady atmospheric conditions. Plume rise of hot pollutants due to buoyancy
effects was also considered. The program has the ability to perform the real-time
calculations and uses on-line data of atmospheric conditions that are measured
directly. In order to consider the effects of the presence of buildings and other
obstacles or sudden changes in surface roughness by the dispersion of released
materials, a model was added to evaluate the dispersion coefficients in the wake of
obstacles. Using this relatively complete simulation, we analyzed the effects of the
above parameters on the dispersion of gaseous pollutants in the atmosphere.https://jesphys.ut.ac.ir/article_13320_3f08c5743211be193e5abe2ab2940f95.pdfInstitute of Geophysics, University of TehranJournal of the Earth and Space Physics2538-371X27120010321--13321FAJournal Article19700101One of the most important steps in the processing of VSP data is the separation of
upcoming and down going waves. It can be performed by applying a velocity filter
either in the f-k or 't-p domain. In the f-k domain, upcoming and down going waves
will be separated into two groups having negative and positive wave numbers,
respectively. A simple way of extracting them is to remove energies with the positive
or negative velocities in the f-k plane. Similarly, by transforming VSP data from t-x
domain to 't-p domain, upcoming and down going wave fields become separable and
they are mapped to different quadrants of a 't-p plane. This allows either upcoming or
down going waves to be reconstructed by the application of inverse Radon transform
to the related quadrant of the 't-p plane. Results obtained by the 't-p method are
similar to those obtained by the f-k velocity filtering. However, by implementing an
amplitude ratio-resting filter in the forward slant stack, the quality of the
reconstructed wave field would be improved. The filter was based on the amplitude
of a slant-stacked event. The event with different amplitudes can be identified and
suppressed when amplitudes are incoherent. In this regared, the efficiency of the f-k
filter and the Radon transform over synthetic and real VSP data are considered. For the real data, we compared the results of our written soft wares with those of the
Prom AX software.One of the most important steps in the processing of VSP data is the separation of
upcoming and down going waves. It can be performed by applying a velocity filter
either in the f-k or 't-p domain. In the f-k domain, upcoming and down going waves
will be separated into two groups having negative and positive wave numbers,
respectively. A simple way of extracting them is to remove energies with the positive
or negative velocities in the f-k plane. Similarly, by transforming VSP data from t-x
domain to 't-p domain, upcoming and down going wave fields become separable and
they are mapped to different quadrants of a 't-p plane. This allows either upcoming or
down going waves to be reconstructed by the application of inverse Radon transform
to the related quadrant of the 't-p plane. Results obtained by the 't-p method are
similar to those obtained by the f-k velocity filtering. However, by implementing an
amplitude ratio-resting filter in the forward slant stack, the quality of the
reconstructed wave field would be improved. The filter was based on the amplitude
of a slant-stacked event. The event with different amplitudes can be identified and
suppressed when amplitudes are incoherent. In this regared, the efficiency of the f-k
filter and the Radon transform over synthetic and real VSP data are considered. For the real data, we compared the results of our written soft wares with those of the
Prom AX software.https://jesphys.ut.ac.ir/article_13321_7f062a7522884cd3aa9eb1c40f755618.pdfInstitute of Geophysics, University of TehranJournal of the Earth and Space Physics2538-371X27120010321--13322FAJournal Article19700101To interpret the gravity anomaly of a Koromite mine in south - west of Iran, we have used the three dimensional inversion problem. The method introduced by Last and Kubik (1983) and improved by Lewi (1997) for high precision gravity data has been tested to determine the 3-dimensional form of the anomaly. The results of the inversion process have been approved by exploration drill holes in the area recently.To interpret the gravity anomaly of a Koromite mine in south - west of Iran, we have used the three dimensional inversion problem. The method introduced by Last and Kubik (1983) and improved by Lewi (1997) for high precision gravity data has been tested to determine the 3-dimensional form of the anomaly. The results of the inversion process have been approved by exploration drill holes in the area recently.https://jesphys.ut.ac.ir/article_13322_e9fb97e90c153fc5b6e6157105ab10fd.pdfInstitute of Geophysics, University of TehranJournal of the Earth and Space Physics2538-371X27120010321--13323FAJournal Article19700101This paper describes a methodology for the integrated interpretation of airborne
magnetic and airborne y-ray spectrometer data. The Darrehzar porphyry copper deposit is
situated in the Uromieh-Dokhtar magmatic assemblage of Central Iran. Phyllic and
propylitic alteration are pervasive in the area but potassic and argillic alterations are not
readily recognized on the surface. The spatial distributions of geophysical data resemble the
lithological and alteration patterns in the area. The Darrehzar porphyry copper deposit is
considered as a control site for determination of the degree that the geophysical data is correlated with the mineralization zone. Airborne magnetic/radiometric, geochemical
/alteration and ground geophysical data sets have been integrated and analyzed using
canonical correlation method. This technique is found to be useful for the delineation of
hydrothermally altered areas and data compression.This paper describes a methodology for the integrated interpretation of airborne
magnetic and airborne y-ray spectrometer data. The Darrehzar porphyry copper deposit is
situated in the Uromieh-Dokhtar magmatic assemblage of Central Iran. Phyllic and
propylitic alteration are pervasive in the area but potassic and argillic alterations are not
readily recognized on the surface. The spatial distributions of geophysical data resemble the
lithological and alteration patterns in the area. The Darrehzar porphyry copper deposit is
considered as a control site for determination of the degree that the geophysical data is correlated with the mineralization zone. Airborne magnetic/radiometric, geochemical
/alteration and ground geophysical data sets have been integrated and analyzed using
canonical correlation method. This technique is found to be useful for the delineation of
hydrothermally altered areas and data compression.https://jesphys.ut.ac.ir/article_13323_2ac05eeb337b40a140bfb98e13dc1eaf.pdfInstitute of Geophysics, University of TehranJournal of the Earth and Space Physics2538-371X27120010321--13324FAJournal Article19700101https://jesphys.ut.ac.ir/article_13324_49f5585076624910c4128360cc847740.pdfInstitute of Geophysics, University of TehranJournal of the Earth and Space Physics2538-371X27120010321--13325FAJournal Article19700101We analyzed the International Seismological Center (ISC) catalogue of seismological
publications from 1980 to 1995 to investigate to what extent the information provided by an
earthquake has been utilized to obtain a better understanding of earthquakes and seismic
disaster. We select the ISC bulletin which has a wider coverage of seismological journals
and languages than the Scientific Citation Index (SCI), so that there is less regional or
language bias in the analysis. The earthquakes in the catalogue spans the period from 1975
to 1990. Papers which have direct relations with an earthquake as defined by the ISC
catalogue ranges from 1 to 102 in order of magnitudes. The logarithm of the maximum number of papers on an earthquake is shown to be proportional to the magnitude of the
earthquake, which provides a possibility to define a 'normalized impact factor' of an
earthquake, so that earthquakes with different magnitudes can be compared with each other.
The magnitude span of earthquakes with a certain 'impact factor' and the 'impact factor'
itself can be used in the regional comparisons. The analysis shows a regional difference that
the academic impact strength' of the earthquakes occurring in Asian developing countries
are not comparable to the societal effects of these earthquakes, implying that one of the
future directions of the development of Asian seismology is to have more observations and
more researches on the earthquakes occurred 'at home.We analyzed the International Seismological Center (ISC) catalogue of seismological
publications from 1980 to 1995 to investigate to what extent the information provided by an
earthquake has been utilized to obtain a better understanding of earthquakes and seismic
disaster. We select the ISC bulletin which has a wider coverage of seismological journals
and languages than the Scientific Citation Index (SCI), so that there is less regional or
language bias in the analysis. The earthquakes in the catalogue spans the period from 1975
to 1990. Papers which have direct relations with an earthquake as defined by the ISC
catalogue ranges from 1 to 102 in order of magnitudes. The logarithm of the maximum number of papers on an earthquake is shown to be proportional to the magnitude of the
earthquake, which provides a possibility to define a 'normalized impact factor' of an
earthquake, so that earthquakes with different magnitudes can be compared with each other.
The magnitude span of earthquakes with a certain 'impact factor' and the 'impact factor'
itself can be used in the regional comparisons. The analysis shows a regional difference that
the academic impact strength' of the earthquakes occurring in Asian developing countries
are not comparable to the societal effects of these earthquakes, implying that one of the
future directions of the development of Asian seismology is to have more observations and
more researches on the earthquakes occurred 'at home.https://jesphys.ut.ac.ir/article_13325_4a341acf6b2bdb94e71cd7b99235f1ea.pdf