
احمد
زمانی
author
مهرداد
براتى
author
text
article
2002
per
Journal of the Earth and Space Physics
Institute of Geophysics, University of Tehran
2538371X
28
v.
2
no.
2002
https://jesphys.ut.ac.ir/article_10852_426e63517cd3e6fc289e846a28dafc06.pdf

همایون
گرامی
author
حمیدرضا
سیاهکوهی
author
حسن معصوم
زاده
author
text
article
2002
per
One of the exclusive beneficial characteristics of VSP data is the possibility of identifying multiple reflections, which exist in upcoming waves. As shown in this paper, powerful predictive deconvolution operators can be designed from down going waves in order to suppress the abovementioned multiples. In this study VSP data from the south of Iran was used to suppress multiples from nearby surface 2D seismic data.
The designed operators suppressed multiples from surface seismic data properly without creating any destructive side effects on the rest of the record. The results indicate that the application of deconvolution operators not only suppressed the multiples from 2D seismic data but also produced a better correlation between VSP data and the final 2D seismic section. Seismic data and required software packages for this study were provided by the National Iranian Oil Company
Journal of the Earth and Space Physics
Institute of Geophysics, University of Tehran
2538371X
28
v.
2
no.
2002
https://jesphys.ut.ac.ir/article_10853_940253a2537f4ba147555086afff1d77.pdf

ایرج عبدالهی
فرد
author
جاوید حسن زاده
آذز
author
text
article
2002
per
Application of seismic atributes is one of the most common way of study ing srbsurface variation .dip and true thickness as seismic attributes play an important role . for instance ,in detection of structural events like faults and imaging edges of straigraphic.
in this study Isopach and dip maps of the reservoir layer in a 3D seismic profect in northeast iran were calculated . Then the true thickness map of the layer was computed .The true thickness map shows subtle features such as minor faults and alluvial fan in the reservoir layer. also displacement of some faults are deduced from the true thickness map
Journal of the Earth and Space Physics
Institute of Geophysics, University of Tehran
2538371X
28
v.
2
no.
2002
https://jesphys.ut.ac.ir/article_10854_789ece30b2ed892fd30c2b1709d2cad4.pdf

علیرضا گلال
زاده
author
عبدالرحیم
جواهریان
author
text
article
2002
per
Journal of the Earth and Space Physics
Institute of Geophysics, University of Tehran
2538371X
28
v.
2
no.
2002
https://jesphys.ut.ac.ir/article_10855_42b8a711d7e72c1cb7e1852f0e9fe0cc.pdf

سهراب
حجام
author
فاطمه مالکی
فرد
author
text
article
2002
per
A major section of the present research is concerned with the identification of the rainfall temporal patterns of five selected meteorological stations in Khorasan province in the north east of Iran using the Pilgrim and Huff methods. The first section provides a brief review and discussion about the identification methods of rainfall patterns. A comparative analysis is presented whereby the Pilgrim method results are assessed by direct comparison with results from the Huff method. It was found that the Huff method is an appropriate choice. The main result is that the rainfall temporal pattern of Khorasan is more correctly modeled by the Huff method. Although the region is semiarid, the patterns are specific and different from other regions like Illinois, although in the same latitude but with different total rainfall patterns.
Journal of the Earth and Space Physics
Institute of Geophysics, University of Tehran
2538371X
28
v.
2
no.
2002
https://jesphys.ut.ac.ir/article_10856_fe830d19449793103d59f3dae9ed5a9a.pdf

سیدعلیرضا صادقی
حسینی
author
جواد راحلی
سلیمی
author
text
article
2002
per
Journal of the Earth and Space Physics
Institute of Geophysics, University of Tehran
2538371X
28
v.
2
no.
2002
https://jesphys.ut.ac.ir/article_10857_8450fff6338cea1b7a9856f2dd6343bd.pdf

عصمت پورجم
علویجه
author
حمیدرضا
سیاهکوهی
author
عبدالرضا
قدس
author
text
article
2002
per
Our eyes can recognize the arrival of the signal by comparing the recorded amplitude in various seismic traces. In this article we tried to imitate this natural ability to find a mathematical tool instead of the eyes. Fractals are mathematical models, which are able to feel these changes.
An algorithm is introduced for the automatic picking of seismic first arrivals. It detects the presence of a signal by analyzing the variation in fractal dimension along the trace. Among different methods, the “divider method” was found to be the most suitable method for calculating the fractal dimension of a seismic trace. A change in dimension was found to occur close to the transition from the noise part of a trace to the signal plus noise part of it, that is the first arrival. The nature of this change varies from trace to trace, but a detectable change is always found to occur. The algorithm has been written in MATLAB environment and is slower than the other nonfractal methods.
Journal of the Earth and Space Physics
Institute of Geophysics, University of Tehran
2538371X
28
v.
2
no.
2002
https://jesphys.ut.ac.ir/article_10858_d183876bc843fee1bab2b640371fce92.pdf

لطیف
صمدى
author
text
article
2002
per
In this paper the distribution of Pwave velocity in regionally metamorphosed rocks of the Zayandehrud dam has
been investigated. The data collection has been carried out by a 24 channel digital device. Data analysis shows that
Pwave velocity in metamorphic rocks increases with depth continuously following the linear equation v(z) = 3200+6.5 z . The Pwave velocity in accordance with metamorphic grades from slate to schist changes from 3200 m/s at surface up to 5475 m/s at 350 m depth.
High velocity gradient in metamorphic rocks of the study area is a consequence of changes in metamorphic grades from surface to the investigated depth and the effects of surface weathering. The calculation of porosity based on Wyllie (1965) equation indicated that the porosity has changed from 5.5% at the surface to less than 1% at the 350 m depth continuously, which is in agreement with litho logical changes from slate to schist.
Journal of the Earth and Space Physics
Institute of Geophysics, University of Tehran
2538371X
28
v.
2
no.
2002
https://jesphys.ut.ac.ir/article_10859_f86ed99ef05ee994c6ef5d6b0ad5234f.pdf

وحید ابراهیم زاده
اردستانی
author
text
article
2002
per
The effect of topographical masses on geoid height determination is described by three terms : the direct topographical effect on gravity, the primary indirect topographical effect on potential and the secondary indirect topographical effect on gravity. Martinec (1998), Sjoeberg and Nahavandchi (1999) and Nahavandchi (2000a) derived different equations to compute these effects. These different approaches for computing the effects over a rugged terrain area (Rocky Mountains) are compared.
Journal of the Earth and Space Physics
Institute of Geophysics, University of Tehran
2538371X
28
v.
2
no.
2002
https://jesphys.ut.ac.ir/article_10860_03ec6999321b598c0c7057817a651dd8.pdf

نوربخش
میرزایی
author
محمدرضا
قیطانچی
author
text
article
2002
per
Journal of the Earth and Space Physics
Institute of Geophysics, University of Tehran
2538371X
28
v.
2
no.
2002
https://jesphys.ut.ac.ir/article_10861_f07891bd71d9291c556c518d82a37209.pdf