IRANIAN GEOPHYSICS CONFERENCE | Year:2016 | دوره:17 |Papers Count:36

POLAR MESOSPHERIC SUMMER ECHOES (PMSES) ARE VERY STRONG RADAR ECHOES PRODUCED BY ELECTRON DENSITY FLUCTUATIONS AT HALF THE RADAR WAVELENGHT (BRAGG SCATTER CONDITION) IN THE ALTITUDE RANGE 80-90 KM. THE TEMPORAL BEHAVIOR OF PMSE RESPONSE TO HIGH-FREQUENCY PUMP HEATING CAN BE EMPLOYED TO DIAGNOSE THE CHARGED DUST LAYER. SPECIFICALLY, THE RISE AND FALL TIME OF RADAR ECHOES AS WELL AS RELAXATION AND RECOVERY TIME AFTER HEATER TURN-ON AND OFF ARE DISTINCT PARAMETERS THAT ARE FUNCTIONS OF RADAR FREQUENCY. THE MAIN PURPOSE OF THIS STUDY IS TO USE THE TEMPORAL EVOLUTION OF PMSES DURING ACTIVE MODIFICATION USING HIGH POWER RADIOWAVES TO STUDY THE FUNDAMENTAL PHYSICS OF DUST CHARGING IN SPACE AND TO DEVELOP A NEW REMOTE SENSING TECHNIQUE FOR MEASURING IONOSPHERIC PARAMETERS IN THE NEAR-EARTH SPACE ENVIRONMENT.

IN RECENT YEARS, DUE TO INCREASING IN THE SIZE OF 3D SEISMIC DATA VOLUMES AND THE NUMBER OF SEISMIC ATTRIBUTES, UNSUPERVISED PATTERN RECOGNITION TECHNIQUES AS A FIRST-HAND INTERPRETATION METHOD HAVE BEEN USED TO BOTH ADDRESS THIS PROBLEM AND TO PROVIDE INITIAL GUIDANCE WHEN WORKING ON A NEW SEISMIC DATA WHERE PREVIOUS STUDIES AND DATA ARE LIMITED. THESE UNSUPERVISED PATTERN RECOGNITION TECHNIQUES ARE K-MEANS, SELF-ORGANIZING MAP, GENERATIVE TOPOGRAPHIC MAPPING, AND PRINCIPAL COMPONENT ANALYSIS. IN THIS STUDY, THE K-MEANS AND PCA ARE APPLIED TO A 3D SEISMIC DATA VOLUME ACQUIRED OVER THE STRAIT OF HORMUZ TO DETECT THE BURIED CHANNELS IN THIS AREA. NOT SURPRISINGLY, THE MOST IMPORTANT PARAMETER IN THIS STUDY WAS THE CHOICE OF CORRECT SEISMIC ATTRIBUTES. ALTHOUGH THE PRINCIPAL COMPONENT ANALYSIS METHOD IS NOT A CLUSTERING TECHNIQUE, IT CAN DETECT CHANNELS IN 3D SEISMIC DATA MORE EFFICIENT THAN THE KMEANS CLUSTERING METHOD.

THE SOURCE CHARACTERISTICS AND EARTHQUAKE FOCAL MECHANISMS OF THE 18TH AUGUST 2014 MURMURI EARTHQUAKE, WESTERN IRAN, WITH MW 6.2 HAS BEEN ESTIMATED USING THE WAVEFORM DATA FROM BROADBAND SEISMOLOGICAL NETWORKS OF IRSC, IIEES, AND IRAQI SEISMOLOGICAL NETWORK AS WELL.THE REGION IS LOCATED ON THE ZAGROS FOLD-THRUST BELT BASIN, WHERE IS SIGNIFICANT TO SEISMOLOGISTS IN TERMS OF STRUCTURAL AND SEISMOTECTONICS FEATURES. THE METHOD APPLIED IN THIS STUDY IS BASED ON MT INVERSION USING ISOLA PACKAGE, A PACKAGE TO DETERMINE SEISMIC SOURCE PARAMETERS WHICH HAS BEEN USING SINCE 2006. THE RECORDS FROM EIGHT STATIONS WERE USED IN THE MT INVERSION, PROVIDING FAIRLY GOOD COVERAGE OF THE EVENTS. FOR THE FIRST STEP, THE EVENT WAS RELOCATED TO IMPROVE THE ACCURACY OF THE RESULTS. THEN, VARIOUS TESTS WERE CARRIED OUT TO FIND THE APPROPRIATE CRUSTAL MODEL AND FREQUENCY BAND TO ACHIEVE A PERMISSIBLE WAVEFORM MATCH. THE CRUSTAL MODEL IS USED IN THIS PAPER IS THE ONE INTRODUCED BY THE IRANIAN SEISMOLOGICAL CENTER NAMED IRSC.

SPECTRAL ELEMENT METHOD (SEM) PROVIDES AN INNOVATIVE NUMERICAL APPROACH TO THE CALCULATION OF SYNTHETIC SEISMOGRAMS. DUE TO FLEXIBILITIES IN COMPLEX GEOLOGICAL MODELS HANDLING AND APPLYING BOUNDARY CONDITIONS, WE USE SPECTRAL ELEMENT METHOD FOR ELASTIC WAVE PROPAGATION MODELING.THIS APPROACH IS BASED ON WEAK FORMULATION OF THE EQUATION OF MOTION OF CONTINUUM MEDIA, AND SOLVES THE EQUATION ON A MESH OF ELEMENTS. THE WAVE FIELD IS DISCRETIZED ON THE ELEMENTS USING HIGH-DEGREE LAGRANGE INTERPOLATION AND INTEGRATION OVER AN ELEMENT IS COMPUTED BASED UPON THE GAUSS-LOBATTO-LEGENDRE INTEGRATION RULE. THIS COMBINATION OF DISCRETIZATION AND INTEGRATION LEADS TO DIAGONAL MASS MATRIX, WHICH GREATLY REDUCES COMPUTATIONS.WE APPLIED BOTH THE FIRST-ORDER AND THE SECOND-ORDER ABSORBING BOUNDARY CONDITIONS (ABC) IN THE FREQUENCY-DOMAIN. THE QUALITY OF THE SECOND-ORDER ABC IS BETTER THAN THE FIRST-ORDER ABC WHEN A HIGHER ORDER INTERPOLATION POLYNOMIAL IS USED.

HORMOZGAN PROVINCE (52O 30’- 59 O E, 25 O -29 O N) IS LOCATED IN THE SOUTHERN PART OF IRAN.HISTORICAL EARTHQUAKES SHOW THIS REGION HAS HAD MORE THAN 880 EVENTS WITH MAGNITUDE 3 TO 7 IN THE PERIOD OF 1930– 2007. IN THIS STUDY WE HAVE CALCULATED A RELATIONSHIP BETWEEN RETURN PERIOD (RP) AND MODIFIED MERCALLI INTENSITY (MMI) FOR SOME PARTS OF HORMOZGAN PROVINCE.

VARIOUS APPLICATIONS IN EARTHQUAKE ENGINEERING REQUIRE TIME-HISTORY RECORDS OF STRONG GROUND MOTION AS THE EXCITATION SOURCE. TUNING PROPER GROUND MOTION FACTORS HAS A GREAT ROLE IN THE CONSEQUENT ANALYSIS RESULTS. A WELL-ACCEPTED SOLUTION IS TO SEARCH FOR SUITABLE RECORDS’ SCALING IN ORDER TO ACHIEVE MAXIMAL COMPATIBILITY WITH A TARGET DESIGN-CODE SPECTRUM. THE PRESENT PAPER FORMULATES SUCH AN OPTIMIZATION PROBLEM WITH THE SCALE FACTORS BEING TREATED AS DESIGN VARIABLES. IN THIS PROCEDURE, PROPER FACTORS FOR A SET OF PREDEFINED EARTHQUAKES ARE CHOSEN SO THAT THE COMPATIBILITY ERROR IS MINIMIZED FOR THE MEAN RESPONSE SPECTRUM WITH RESPECT TO THE TARGET. A NOVEL HYBRIDIZATION OF EVOLUTIONARY COMPUTING WITH RECENTLY DEVELOPED TEACHING-LEARNING BASED OPTIMIZATION IS PRESENTED AS THE SOLUTION ALGORITHM. NUMERICAL RESULTS SHOW CONSIDERABLE PERFORMANCE ENHANCEMENT IN THE PROPOSED METHOD FOR THE TREATED SCALING PROBLEM.

THERE ARE DIFFERENT OBJECTIVES IN PERFORMING SEISMIC RESERVOIR CHARACTERIZATION STUDIES BUT AMONG ALL OF THEM LITHOLOGY AND PORE FLUID PREDICTION ARE TWO OF THE MOST IMPORTANT ONES. IN SEISMIC RESERVOIR CHARACTERIZATION, DIFFERENT TECHNIQUES ARE APPLIED TO EXTRACT THE MOST VALUABLE RESULTS FROM THE AVAILABLE SEISMIC DATA, ESPECIALLY IN PLACES WITH LIMITED WELL CONTROL AND LOW QUALITY SEISMIC DATA. EXTENDED ELASTIC IMPEDANCE (EEI) INVERSION IS A TECHNIQUE THAT PROVIDES A SIMPLE ROBUST MEANS OF DERIVING LITHOLOGICAL AND FLUID SENSITIVE SEISMIC IMPEDANCE VOLUMES BY DEFINING AN ANGLE CALLED CHI ANGLE (Χ) AND USING THIS ANGLE AS A ROTATION IN INTERCEPT-GRADIENT SPACE, TO COMPUTE THE VOLUME TO BE INVERTED. EEI AT VARIOUS CHI ANGLES IS PROVED TO BE PROPORTIONAL TO NUMEROUS ELASTIC AND PETRO-PHYSICAL PROPERTIES SUCH AS DENSITY, S-IMPEDANCE, VP/VS RATIO, SHEAR MODULUS, CLAY VOLUME, POROSITY AND WATER SATURATION. IN THIS CASE STUDY EEI ANALYSIS IS PERFORMED TO ESTIMATE VP/VS RATIO AND WATER SATURATION CUBES TO EVALUATE AN OIL PRODUCING RESERVOIR. AFTER DETERMINATION OF THE PROPER CHI ANGLES, THE EEI REFLECTIVITY DATA WERE GENERATED BY INTEGRATION OF A (INTERCEPT) AND B (GRADIENT) VOLUMES (ESTIMATED FROM AVO ANALYSIS). THEN LP SPARSE SPIKE INVERSION PROCEDURE WAS PERFORMED TO GENERATE DESIRED CUBES.GENERATED VP/VS RATIO CUBE IN ADDITION TO WELL LOG DATA, WAS COMPARED WITH THE CORRESPONDING VP/VS RATIO CUBE ACQUIRED FROM PRE-STACK SEISMIC INVERSION. THE RESULTS REVEALED A PROPER MATCH AT WELL LOCATION AND ALSO AT PLACES FAR FROM THE WELL CONTROL. GENERATED WATER SATURATION RESULTS WERE ALSO COMPARED WITH AVAILABLE LOG DATA THAT AGAIN GOOD MATCH WAS OBSERVED. THE OUTCOMES OF THIS FAST SEISMIC RESERVOIR CHARACTERIZATION METHOD CAN HELP TO RANK PREVIOUSLY DEFINED DRILLING LOCATIONS AND ALSO DETERMINE NEW POTENTIAL LOCATIONS.

A HUGE AND HIGH RESOLUTION MAGNETOTELLURIC (MT) INVESTIGATION WAS CONDUCTED ON SEHQANAT OIL FIELD (SOF), SW OF IRAN, IN 2013, TO MAP THE GEOELECTRICAL STRUCTURES OF THE REGION FROM SURFACE DOWN TO SEVERAL KILOMETERS. THE SEHQANAT OIL FIELD IS A PART OF SEDIMENTARY ZAGROS ZONE COMPRISING RANGES OF THE BIGGEST OIL FIELDS IN IRAN. THE MOST INTERESTING TARGET IN THIS SURVEY IS THE GEOLOGICAL CONTACT BETWEEN GACHSARAN (THE CAP ROCK) AND ASMARI (THE RESERVOIR) FORMATIONS.ACCORDING TO THE INFROMATION FROM ELECTRICAL LOGS, LARGE RESISTIVITY CONTRAST EXISTS AT THE BOUNDARY OF THE TWO ABOVE MENTIONED FORMATIONS. THE GACHSARAN FORMATION IS FORMED BY A SUCCESSION OF TENS TO HUNDREDS M OF HIGHLY CONDUCTIVE (CA.1-10 OHMM) EVAPORITES AND THE ASMARI FORMATION CONSISTS OF RELATIVELY RESISTIVE (MORE THAN 100 OHMM) DENSE CARBONATES. ON THE CONTRARY. BROADBAND MAGNETOTELLURIC DATA WERE COLLECTED IN A REGULAR GRID AT MORE THAN 500 STATIONS ALONG FIVE PARALLEL SW-NE PROFILES CROSSING THE MAIN GEOLOGICAL TREND OF THE STUDY AREA.IN ORDER TO IMAGE A COMPREHENSIVE SUBSURFACE RESISTIVITY MAP THROUGHOUT THE SEHQANAT OIL FIELD, TWO-DIMENSIONAL (2D) AND THREE-DIMENSIONAL (3D) INVERSION CODES WERE PERFORMED ON THE MT DATA. THE 2D INVERSION RESULTS DEPICTED THE MAIN RESISTIVITY STRUCTURES WHILE THE 3D INVERTED MODEL SHOWS SIGNIFICANTLY MORE DETAILS AND RELIABILITY.

THE FEASIBILITY TEST FOR APPLICATION OF EARTHQUAKE EARLY WARNING SYSTEMS (EEWS) IN THE TEHRAN METROPOLIS IS INVESTIGATED IN THIS PAPER. ONE OF THE PIONEER COUNTRIES IN THE EEWS IS ITALY AND RECENTLY THE PROBABILISTIC AND EVOLUTIONARY EARLY WARNING SYSTEM (PRESTO) WAS DEVELOPED BY THE SEISMOLOGICAL LAB AT THEUNIVERSITA DI NAPOLI FEDERICO II‖, NAPLES, ITALY. USING REGIONAL APPROACH IMPLEMENTED IN PRESTO, THE EARTHQUAKE OF SHARIF-ABAD, 2011 FEBRUARY 20, MN 4.0 THAT OCCURRED NEAR THE PARCHIN (EYVANAKI) FAULT IN THE SOUTH-EAST OF THE TEHRAN REGION, WAS RE-EVALUATED USING TWO DIFFERENT VELOCITY MODELS AVAILABLE FOR THE STUDY AREA. USING THE VELOCITY MODEL DEVELOPED BY ABBASSI ET AL, 2010 THE ESTIMATED MAGNITUDE FOR THE EARTHQUAKE WAS 3.7 BASED ON ONLY THE VERTICAL COMPONENTS OF ACCELERATION WAVEFORMS FROM THE TDMMO NETWORK. THE RESULTS ALSO INDICATE THAT THE OBTAINED LOCATION OF THE EPICENTER IN COMPARISON WITH THE REPORTED LOCATION BY IRANIAN SEISMOLOGICAL CENTRE (IRSC) HAVE A DIFFERENCE AS SMALL AS 0.3O AND 0.1 O FOR LATITUDE AND LONGITUDE RESPECTIVELY.

IN THIS PAPER WE DEAL WITH TIKHONOV REGULARIZATION OF 1D WAVEFORM INVERSION IN FREQUENCYDOMAIN.WAVEFORM INVERSION FACES DIFFICULTIES WHEN APPLIED TO FIELD SEISMIC DATA CONTAMINATED WITH NOISE. REGULARIZATION IS NECESSARY FOR REDUCTION OF NON-UNIQUENESS AND TACKLE THE ILLPOSEDNESS ISSUE OF THE PROBLEM. ONE OF THE MOST POPULAR ALGORITHMS FOR REGULARIZATION IS BASED ON TIKHONOV APPROACH THAT IS THE SUBJECT OF THIS PAPER. FIRST WE EMPLOY FINITE-DIFFERENCE MODELING IN THE FREQUENCY-DOMAIN FOR GENERATING 1D DATA (FORWARD STEP); IN THE SECOND STEP WE DEFINE TIKHONOV FUNCTION AS AN OBJECTIVE FUNCTION FOR INVERSION. WE USE MULTI-SCALE STRATEGY FOR INVERSION, AND BACK PROPAGATION ALGORITHM IS USED FOR GRADIENT CALCULATION. WE APPLY WAVEFORM INVERSION ON SYNTHETIC DATA CONTAMINATED WITH NOISE; THE RESULTS SHOWS THAT BY PROPER SELECTION OF THE FREQUENCIES, TIKHONOV REGULARIZATION CAN LEAD TO ACCEPTABLE RESULTS.

SEISMIC INVERSION PLAYS AN IMPORTANT ROLE IN RESERVOIR CHARACTERIZATION. SIMULTANEOUS INVERSION OF PRE-STACK SEISMIC DATA PRODUCES ELASTIC PROPERTIES THAT CAN BE RELATED TO RESERVOIR PROPERTIES SUCH AS POROSITY AND WATER SATURATION. IN THIS STUDY WELL LOGS AND PRE-STACK TIME MIGRATED SEISMIC DATA WERE USED TO CHARACTERIZE THIN CARBONATE RESERVOIR LAYERS OF ARAB FORMATION IN AN OIL FIELD LOCATED IN PERSIAN GULF. FIRST, A DETERMINISTIC SIMULTANEOUS INVERSION WAS CONDUCTED, BUT THESE THIN LAYERS WERE NOT DISTINGUISHABLE IN THE RESULTS. THEREFORE, GEOSTATISTICAL INVERSION WAS USED TO ACHIEVE HIGHER VERTICAL RESOLUTION. AFTERWARDS, THE WATER SATURATION AND POROSITY OF RESERVOIR LAYERS WERE ESTIMATED BY COSIMULATION OF GEOSTATISTICALLY INVERTED P IMPEDANCE AND VP/VS. FINALLY, UNCERTAINTY OF RESULTS WAS QUANTIFIED AND HIGH RESERVOIR QUALITY BODIES WERE CAPTURED. SIMULTANEOUS GEOSTATISTICAL INVERSION OF PRE-STACK SEISMIC DATA LEADS TO DELINEATION OF THIN LAYERS OF ARAB FORMATION. IN ADDITION, THIS INVERSION METHOD PROVIDES POSSIBILITY OF RESERVOIR PROPERTIES ESTIMATION AND RESERVOIR GEO-BODIES EXTRACTION IN THIS OIL FIELD.

THIS PAPER DESCRIBES THE APPLICATION OF INTEGRATED GEOELECTRICAL METHODS INCLUDING INDUCED POLARIZATION (IP) AND RESISTIVITY (RS) FOR EXPLORATION AND EVALUATION OF THE BAHARIEH COPPER DEPOSIT. FOR THE CONDUCT OF RS AND IP, AT FIRST RECTANGULAR ARRAY IS USED TO OBTAIN AN OVERALL VIEW FROM THE AREA BY DESIGNING TWO BOXES NEXT TO EACH OTHER THAT MADE IT POSSIBLE TO COVER ALL THE INVESTIGATION AREA AND PRODUCE IP& RS PSEUDO-SECTIONS. SOME ANOMALIES WERE DETECTED BY MEANS OF IP AND RS PSEUDO-SECTIONS, AND THERE WAS GOOD CONSISTENCY BETWEEN ANOMALIES DETECTED BY IP AND RS METHODS. THEN, 5 PROFILES WITH THE DIPOLE–DIPOLE ARRAY WERE DESIGNED AND SURVEYED IN LOCATIONS WHERE THE RECTANGULAR ARRAY SHOWS A GOOD ANOMALY. FINALLY, BY INTEGRATION OF THE RESULTS FROM INDUCED POLARIZATION AND RESISTIVITY AND METAL FACTOR SECTIONS, SOME LOCATIONS WERE SUGGESTED FOR BOREHOLE DRILLING. THE RESULTS OBTAINED BY THE TWO RECTANGULAR AND DIPOLEDIPOLE ARRAYS HAVE A GOOD MATCH WITH THE DRILLING RESULTS.

MANY ENVIRONMENTAL FACTORS, BASED ON DYNAMIC OR THERMODYNAMIC COMPONENTS, HAVE BEEN DEFINED TO INTERPRET TROPICAL CYCLONE (TC) BEHAVIOR DURING ITS FORMATION, INTENSIFICATION AND DISSIPATION STAGES. HENCE ONE OF THE CONSIDERED ASPECTS IN TC RESEARCH STUDIES IS TO IDENTIFY THE CONTRIBUTION OF THESE BASIC OR COMPLEX FACTORS.IN THE CURRENT MANUSCRIPT, MOIST ENTROPY HAS BEEN CALCULATED FOR TC HAIYAN, AS ONE OF THE STRONGEST TC FORMED OVER LARGE BODIES OF RELATIVELY WARM WATER OF WESTERN NORTH PACIFIC OCEAN. ENTROPY VALUES AT THREE VARIOUS DOMAINS HAVE BEEN COMPUTED AND AVERAGED. THE SELECTED DOMAIN AREAS HAVE BEEN CHOSEN TO INVOLVE INNER CORE, RAINBAND AND EYEWALL STRUCTURE AND ENVIRONMENT OF TCH, RESPECTIVELY. FOR THIS AIM DATA PRODUCED BY (1) NATIONAL CENTERS FOR ENVIRONMENTAL PREDICTION (NCEP) GLOBAL FORECAST SYSTEM (GFS) AND JAPAN METEOROLOGY AGENCY (JMA) HAVE BEEN USED. THE OBTAINED RESULTS INDICATE THAT ENTROPY VARIATIONS AT THE MEAN SURFACE LEVEL PRESSURE NOT ONLY IN THE RANGE OF MESOSCALE-ALPHA AND -BETA, BUT ALSO IN THE LARGE SCALE RANGE AFFECT TC STRENGTHENING AND WEAKENING PROCESSES. SO ENVIRONMENTAL MOIST ENTROPY, COMPUTED USING GLOBAL DATA, CAN BE USED AS A PREDICATOR DURING TC LIFE TIME.

THE BEAMING ANGLE OF NON THERMAL RADIATIONS AS A PREDICTION OF LMCT IS IMPORTANT, BUT THIS PREDICTION IS NOT ALWAYS CONSISTENT WITH OBSERVATION. FROM THE BEAMING ANGLE THEORY THIS ANGLE OBTAINED FROM THE FORMULA THAT SO CALL JONES’ FORMULA.THE JONES RELATION ONLY WORKS FOR A CASE THAT THE MAGNETIC FIELD DIRECTION IS PERPENDICULAR TO THE NORMAL BOUNDARY. FOR NON PERPENDICULAR CASES THE BEAMING ANGLE RELATION SHOULD BE MODIFIED. IN THIS STUDY, WE INVESTIGATE THIS EFFECT AND PRESENT A NEW FORMULA THAT CAN BE WIDELY USED IN THE PLASMASPHERE.

A NEW, ABSOLUTE VELOCITY SENSOR, GEOPHONE, IS DESIGNED AND MANUFACTURED AS A HIGH QUALITY PRODUCT WHICH IS THE MOST IMPORTANT EQUIPMENT FREQUENTLY USED IN MANY VIBRATION MONITORING STUDIES SUCH AS EARTH EXPLORATION SCIENCES, EARTHQUAKE MONITORING, AND MANY OTHER ENGINEERING APPLICATIONS. MANUFACTURING AND ANALYSIS STEPS ARE CONCISELY PRESENTED. GEOPHONE KEY FEATURES SUCH AS RESONANT FREQUENCY, MAGNETIC FLUX OF PERMANENT MAGNET AND PHYSICAL DIMENSIONS ARE CONSIDERED AS INPUTS FOR PROCESS, THEN, PROOF MASS, SPRING DIMENSIONS AND STIFFNESS, SPURIOUS FREQUENCY AND GENERATOR CONSTANT ARE OBTAINED AS OUTPUTS THROUGH AN ANALYTICAL PROCEDURE FOR EACH PARAMETER. EVALUATING AND OPTIMIZING PROOF MASS, SPRING DESIGN, DAMPING CONSTANT OF COILS ON GEOPHONE STEP RESPONSE, RANDOM VIBRATION AND STATIC STRESS ANALYSIS OF SPRINGS BOTH IN HORIZONTAL AND VERTICAL DIRECTIONS, THE ANSYS PROGRAM IS USED. TAKING ALL PARAMETERS INTO ACCOUNT, THE GEOPHONE HAS A 10 HZ FUNDAMENTAL FREQUENCY AND PROOF MASS OF 11 GRAMS WITH SENSITIVITY OF 30 V/M/S. THE DISTINCTIVE CHARACTERISTIC OF GEOPHONE IS TO HAVE HIGH SPURIOUS FREQUENCY OF 460 HZ IN COMPARISON WITH CURRENTLY EXISTING SIMILAR TYPES. TO ADDRESS THE SUITABLE QUALITY, FUNCTIONALITY OF THE GEOPHONE IS COMPARED WITH A FAMOUS GENERAL SAMPLE AND THE RESULTS ARE PRESENTED.

PLATE TECTONICS STUDIES USING GPS REQUIRE PROPER ANALYSIS OF TIME SERIES, IN WHICH ALL FUNCTIONAL EFFECTS ARE UNDERSTOOD AND ALL STOCHASTIC EFFECTS ARE CAPTURED USING AN APPROPRIATE NOISE ASSESSMENT TECHNIQUE.BOTH ISSUES ARE ADDRESSED IN THIS CONTRIBUTION. AFTER APPLICATION OF A MULTIVARIATE OFFSET DETECTION METHOD, THE RESULTS OF TIME CORRELATED NOISE FOR A LARGE NUMBER OF CGPS STATIONS ARE PRESENTED. IT IS SHOWN THAT THE UNDETECTED OFFSETS CAN MIMIC RANDOM WALK NOISE, IN AGREEMENT WITH THE PREVIOUS WORK. RANDOM WALK NOISE WHICH WAS NOT CORRECTLY DETECTED IN CASE OF AN INEFFECTIVE OFFSET DETECTION METHOD RESULTED IN OBTAINING INCORRECT RATE UNCERTAINTIES. THIS ISSUE, IF NOT IMPLEMENTED CORRECTLY, WILL BIAS BOTH THE RATES AND THEIR UNCERTAINTIES. FURTHERMORE, APPLYING A NOISE ASSESSMENT METHOD INDICATES THAT FLICKER NOISE HAS THE LARGEST CONTRIBUTION TO THE TOTAL NOISE STRUCTURE OF THE SERIES. THE NOISE AMPLITUDES OF THE UP COMPONENT ARE LARGER THAN THOSE OF THE NORTH AND EAST COMPONENTS BY A FACTOR OF 2.5. IN ADDITION, IN ORDER TO OBTAIN CORRECT RATES, THE ANNUAL AND SEMI-ANNUAL SIGNALS ARE TO BE TAKEN INTO CONSIDERATION IN THE FUNCTIONAL MODEL. THIS COULD ALSO HOLD TO A LESSER EXTENT FOR THE GPS DRACONITIC HARMONICS, ESPECIALLY FOR SHORT TIME SERIES.

SURFACE-NMR SIGNAL IS STRONGLY AFFECTED BY THE PRESENCE OF AMBIENT ELECTROMAGNETIC INTERFERENCES, I.E., POWER-LINE HARMONICS, SO THAT ESTIMATION OF THE SIGNAL PARAMETERS PRIOR TO THE NOISE REMOVAL PROCESS MAY LEAD TO INACCURATE CALCULATION OF THE PETRO-PHYSICAL PARAMETERS OF THE AQUIFER. HENCE, WE DISCUSS TWO ALGORITHMS FOR ISOLATION AND THEN SUBTRACTION OF HARMONIC INTERFERING NOISE. THIS STUDY FIRST TACKLES THE USE OF A MODIFIED FREQUENCY-ESTIMATION APPROACH STEMMING FROM THE ESTIMATOR PROPOSED BY NYMAN-GAISER. THE REMOVAL OF POWER-LINE HARMONICS IS ALSO IMPLEMENTED THROUGH THE RESIDUAL SIGNAL POWER TECHNIQUE. THEN, THE RESULTS OBTAINED FROM THE PROPOSED ALGORITHMS ARE COMPARED THROUGH THE MODELING OF SOME SYNTHETIC SIGNALS EMBEDDED IN NOISE-ONLY RECORDINGS DERIVED FROM SURFACE-NMR FIELD MEASUREMENTS. THE RESULTS FROM THE NUMERICAL EXPERIMENTS REVEAL AN OUTPUT SIGNAL-TO-NOISE RATIO INCREASE WITH AN ACCOMPANYING ENHANCEMENT IN RECOVERY OF THE SURFACE-NMR SIGNAL PARAMETERS.

BALAL IS AN OIL FIELD IN THE MIDDLE OF PERSIAN GULF; IT HAS THREE MAIN RESERVOIRS: SARVAK, DARIYAN AND ARAB FORMATIONS. WE USED GEOSTATISTICAL METHODS TO CHARACTERIZE RESERVOIR ARAB. SEQUENTIAL GAUSSIAN SIMULATION HELPED US INTEGRATE THE WELL LOG AND SEISMIC DATA TO MAKE POROSITY MAP OF THE RESERVOIR. WE FIRST INVERTED THE SEISMIC CUBE USING THE INITIAL MODEL, RE-SAMPLING IT INTO THE RESERVOIR GRID. FOLLOWING THIS, WE MADE VELOCITY MODEL AND THEN DEPTH CONVERTING THE CUBE. WE USED ACOUSTIC IMPEDANCE AS THE SECONDARY VARIABLE IN SGS METHOD. FOR THIS, AFTER REMOVING TRENDS FROM POROSITY AND ACOUSTIC IMPEDANCE DATA, WE NORMALIZED THE DATA SO THEY COULD BE USED BY THE SGS METHOD. SINCE STOCHASTIC METHODS SHOULD BE USED CAREFULLY, WE CROSS-VALIDATED THE RESULTING MAPS, BY REMOVING INDIVIDUAL WELL DATA ONE AT A TIME FROM THE DATA SET AND CHECKING THE RESULTS AND REPEATING THIS PROCEDURE FOR ALL OTHER WELLS. WE SUBSEQUENTLY CHOSE THE BEST FITTING MODEL AMONG THEM. THE RESULTS WERE REPRESENTATIVE OF THE STRENGTH OF GEOSTATISTICAL METHODS IN CHARACTERIZING RESERVOIRS.

THIS PAPER PRESENTS A METHOD FOR THE ESTIMATION OF PARAMETERS ASSOCIATED WITH A 2D SOURCE, BASED ON CURVATURE OF THE SPECIAL FUNCTIONS. THESE SPECIAL FUNCTIONS, WHICH ARE FORMED BY CONVERTING THE GRAVITY ANOMALIES, HAVE PEAKS OVER ISOLATED SOURCES. FIRST, A QUADRATIC CURVE IS FITTED TO THE SPECIAL FUNCTION IN A WINDOW COMPRISED OF THREE OR FIVE SUCCESSIVE DATA POINTS IN THE VICINITY OF PEAK LOCATION WITH THE ORIGIN BEING LOCATED IN THE CENTER. THEN, THE CURVATURE OF THE FITTED CURVE IS CALCULATED FOR THE CENTRAL POINT, AND THE DEPTH OF THE SOURCE IS CALCULATED USING THE VALUES OF THE SPECIAL FUNCTION AND CURVATURE AT THE POSITION OF THE PEAK. THE TYPE OF THE SOURCE ALONG WITH AN INITIAL ESTIMATE OF ITS DEPTH COULD BE FOUND BY LOCAL WAVENUMBER SPECIAL FUNCTION.HAVING THE SOURCE TYPE (OR ASSUMING A PARTICULAR SOURCE TYPE), THE GEOMETRY FACTOR AND THE DEPTH OF THE SOURCE ARE CALCULATED USING THE MODEL-SPECIFIC SPECIAL FUNCTION. AN ADDITIONAL ESTIMATE OF THE DEPTH OF SOURCE IS ALSO DERIVED USING THE ANALYTICAL SIGNAL AMPLITUDE. ONE MEASURE FOR THE RELIABILITY OF THE ESTIMATED DEPTH OF SOURCE IS THE DEGREE TO WHICH THESE THREE INDEPENDENTLY ESTIMATED DEPTHS AGREE WITH EACH OTHER. IN THIS STUDY, THE PROPOSED METHOD IS APPLIED ON NOISY DATA.

IN THIS PAPER WE INVESTIGATE NUMERICAL CHARACTERISTICS OF DIFFERENT FINITE-DIFFERENCE SCHEMES USED FOR 2D ACOUSTIC WAVE PROPAGATION SIMULATION. NUMERICAL DISPERSION IS ANALYZED AS A FUNCTION OF TEMPORAL FREQUENCY TO DEMONSTRATE DIRECTIONAL PROPAGATION DEPENDENCY OF DIFFERENT SCHEMES.5-POINT, 7-POINT AND 9-POINT EXPLICIT SCHEMES ARE COMPARED USING METRICS RELEVANT TO ACOUSTIC WAVE SIMULATION. IT IS SHOWN THAT THE 7-POINT HEXAGONAL SCHEME HAS BETTER ISOTROPIC CHARACTERISTICS THAN CONVENTIONAL 5-POINT AND 9-POINT RECTANGULAR SCHEMES.

PROBABILITY DISTRIBUTION OF EARTHQUAKE SIZE IS NEEDED AS INPUT DATA FOR SOME EARTHQUAKE ANALYSES .IN THIS STUDY, WE PROPOSE A NEW PROBABILITY DISTRIBUTION WITH ONE SCALE AND ONE SHAPE PARAMETERS DENOTED BY. SEVERAL STATISTICAL PROPERTIES OF THIS NEW CLASS OF DISTRIBUTION ARE OBTAINED. ESTIMATION AND INFERENCE PROCEDURE FOR DISTRIBUTION PARAMETERS ARE INVESTIGATED.FINALLY, THE NEW MODEL IS UTILIZED TO MODEL THE EARTHQUAKE-SIZE DATA IN KERMAN PROVINCE IN 1393.

THE STUDY OF EARTHQUAKE PRECURSORS CAN LEAD TO DELIVER AN ENTIRELY MEASURABLE, TIME VARYING ESTIMATION OF THE COMING EVENTS WHICH IS STRONGLY BASED ON PHYSICAL AND GEOLOGICAL PRINCIPALS AND FULLY RESPONSIVE TO ANY FUTURE EXAMINATION. THE TEMPORAL VARIATION OF THE SEISMIC PARAMETERS SUCH AS “A” AND “B” VALUES, IN THE GUTENBERG–RICHTER FORMULA LOGN=A - BM, AS WELL AS SOME DETAILS OF THE PRE-SHOCK ACCELERATING MOMENT RELEASE (AMR) IS INVESTIGATED IN THE VICINITY OF THE TEHRAN CITY. SOME PRESHOCK ACCELERATING MOMENT RELEASE (AMR) CAN BE OBSERVED BEFORE THE BIGGER EVENTS IN THE REGION WHICH CAN BE AGGREGATED WITH THE SIGNALS OF TIME VARIATION OF THE GR B-VALUE.THE RESULTS SUGGEST THAT A COMBINATION OF THESE PHYSICAL PRECURSORS HAS A POTENTIAL WHICH COULD BE EMPLOYED IN A MEDIUM TERM EARTHQUAKE WARNINGS.

WE HAVE MEASURED INTERSEISMIC DEFORMATION ACROSS THE NORTH TABRIZ FAULT (NTF) USING 17 ASAR/ENVISAT ACQUISITIONS ON A SINGLE TRACK FOR THE PERIOD 2003-2010. THE MAIN LIMITING FACTOR ON THE ACCURACY OF INTERFEROMETRIC SYNTHETIC APERTURE RADAR (INSAR) MEASUREMENTS COMES FROM PHASE PROPAGATION DELAYS THROUGH THE TROPOSPHERE. IN ORDER TO RETRIEVE THE PATTERN OF STRAIN ACCUMULATION, WE SHOW IT IS NECESSARY TO USE DATA FROM THE EUROPEAN CENTRE FOR MEDIUM RANGE WEATHER FORECASTS (ECMWF), TO CORRECT INTERFEROGRAMS FOR DIFFERENCES IN WATER VAPOR AND PRESSURE. THIS HAS ENABLED US TO ROBUSTLY ESTIMATE THE SLIP RATE AND LOCKING DEPTH FOR THE NTF USING A SIMPLE ELASTIC DISLOCATION MODEL. OUR DATA ARE CONSISTENT WITH A SLIP RATE OF 3–6 MM/YR BELOW A LOCKING DEPTH OF 9-12 KM FOR THE NTF IN AGREEMENT WITH PREVIOUS GEODETIC ESTIMATES BASED ON RECENT GPS MEASUREMENTS.

IN THE CURRENT STUDY THE EARTHQUAKE (MW 6.2) OCCURRED IN 18TH AUGUST 2014 IN MURMURI, ILAM (IRAN) WAS ANALYZED IN ORDER TO DETERMINE THE RESPECTIVE FAULT PLANE. THE EVENT WAS RELOCATED TO ASSESS PHYSICAL INSIGHT INTO THE HYPOCENTER UNCERTAINTY. TO IDENTIFY EARTHQUAKE SOURCE PARAMETERS, THREE COMPONENTS LOCAL WAVEFORMS REPORTED BY THE BROADBAND SEISMOLOGICAL NETWORKS OF IRSC, IIEES, AND IRAQI SEISMOLOGICAL NETWORK WERE USED AND EXAMINATION WAS DONE BY ISOLA PACKAGE, WHICH IS BASED ON MULTIPLE POINT SOURCE REPRESENTATION AND ITERATIVE DECONVOLUTION METHOD. THE STATIONS HAVE PROVIDED A FULL COVERAGE OF THE EVENT TO THE EXTENT THAT THE ACCURACY OF THE RESULTS CAN BE SAID TO BE HIGHLY RELIABLE. THE METHOD APPLIED IN THIS PAPER IS H-C METHOD, A SIMPLE, IMMEDIATELY APPLICABLE APPROACH WHEN THERE IS RELIABLE INFORMATION ON THE EVENT LOCATION AND ITS CENTROID MOMENT TENSOR SOLUTION (CMT). THE RESULTS SHOW THAT THE MOUNTAIN FRONT FAULT CAN BE INTRODUCED AS THE CAUSATIVE FAULT PLANE FOR THE EVENT.

SHEAR AND COMPRESSIONAL WAVE VELOCITIES COUPLED WITH OTHER PETROPHYSICAL DATA, ARE VERY IMPORTANT FOR HYDROCARBON RESERVOIR CHARACTERIZATION. IN SITU SHEAR WAVE VELOCITY (VS) IS MEASURED BY SOME SONIC LOGGING TOOLS. SHEAR VELOCITY COUPLED WITH COMPRESSIONAL VELOCITY IS VITALLY IMPORTANT IN DETERMINING GEOMECHANICAL PARAMETERS, IDENTIFYING THE LITHOLOGY, MUD WEIGHT DESIGN, HYDRAULIC FRACTURING, GEOPHYSICAL STUDIES SUCH AS VSP, ETC. IN THIS PAPER, A CORRELATION BETWEEN COMPRESSIONAL AND SHEAR WAVE VELOCITY IS OBTAINED FOR AGHAJARI FORMATION IN MAROON OIL FIELD. REAL DATA WERE USED TO EXAMINE THE ACCURACY OF THE PREDICTION EQUATION.MOREOVER, THE GENETIC ALGORITHM WAS USED TO OBTAIN THE OPTIMAL VALUE FOR CONSTANTS OF THE SUGGESTED EQUATION.

WE HAVE DEVELOPED A METHOD TO ESTIMATE THE GEOMETRY, LOCATION AND DENSITIES OF ANOMALIES COMING FROM GRAVITY DATA. THE METHOD IS BASED ON COMPACT GRAVITY INVERSION TECHNIQUE.COMPACT GRAVITY INVERSION IS SIMPLE, FAST AND USER FRIENDLY BUT SEVERELY DEPEND ON THE NUMBER OF MODEL PARAMETER, I.E. BY INCREASING THE MODEL PARAMETER, AND THE ANOMALIES TEND TO CONCENTRATE NEAR THE SURFACE. TO OVERCOME THIS AMBIGUITY THE NEW WEIGHTING FUNCTIONS HAVE INTRODUCED HERE WHICH THEIR ELEMENTS ARE THE DENSITY, DEPTH, AND KERNEL FUNCTION OF THE MODEL TO PRODUCE COMPACTNESS, DEPTH AND KERNEL WEIGHTING MATRICES RESPECTIVELY. TEST WITH A 3D MODEL OBTAINED FROM GRAV3D SOFTWARE 2005 SHOW THAT THE METHOD CAN BE PERFORMED SUCCESSFULLY IN DEEP GRAVITY SOURCES AND THE ANOMALIES LAID CLOSE TOGETHER.

WE CONSIDER THE CRRES OBSERVATIONS OF NON THERMAL EMISSIONS ON 19 AUGUST 1990, WITH THE RANGE OF PLASMA FREQUENCY FROM 100 TO 300 KHZ. A COMPARISON OF THE RESULTS OF THEORY WITH THE RESULTS OF THE BEAMING ANGLE OBSERVATION, SHOW THAT IF WE ACCEPT THAT THE SOURCE OF RADIATIONS LOCATED IN THE PLASMAPAUSE AT 3.9 RE, IT NEEDS TO A SMALL ANGLE BETWEEN THE BOUNDARY AND THE MAGNETIC FIELD SO THAT THE BEAMING ANGLE BECOMES AGREEABLE TO OBSERVATIONS.

CARBONATE SEDIMENTS ARE PRONE TO RAPID AND PERVASIVE DIAGENETIC ALTERATIONS THAT CHANGE THE PORE STRUCTURE WITHIN CARBONATE ROCKS. ROCK PHYSICS PLAYS AN IMPORTANT ROLE IN LINKING ELASTIC PROPERTIES OF ROCK TO PETROPHYSICAL PROPERTIES, SO A ROCK PHYSICS MODEL WHICH MIGHT BE CAPABLE TO MODEL PORE STRUCTURE OF CARBONATE ROCKS CAN BE VERY BENEFICIAL FOR CHARACTERIZATION OF THESE RESERVOIRS. IN THIS STUDY WELL LOGS AND SEISMIC DATA OF AN OIL FIELD LOCATED IN IRAN ARE USED FOR CHARACTERIZATION OF A CARBONATE RESERVOIR. THE ARAB FORMATION, WHICH CONSISTS OF DOLOMITE, CALCITE AND ANHYDRITE IS STUDIED IN ORDER TO EXAMINE EFFICIENCY OF AN INCLUSION ROCK PHYSICS MODEL IN S-WAVE VELOCITY ESTIMATION AND LITHO-FLUIDS DISCRIMINATION.THE ROCK PHYSICS MODEL IS OPTIMIZED BY CALIBRATING THE ESTIMATED PROPERTIES WITH THE MEASURED LOG DATA, AND THEN THE MODEL IS USED FOR GENERATING A ROCK PHYSIC TEMPLATE. THEN, THE LITHO-FLUIDS DISTINGUISHED BASED ON THIS TEMPLATE AND THE RESULTS OF SIMULTANEOUS PRE-STACK SEISMIC INVERSION ARE CLASSIFIED BY USING BAYES’ RULE. THE RESULTS SHOW THAT PRESENTED ROCK PHYSICS MODEL HELPS TO ESTIMATE S-WAVE VELOCITY MORE ACCURATE AND IMPROVES LITHO-FLUIDS CLASSIFICATION OF ARAB FORMATION IN THE STUDIED FIELD.

ONE OF THE RECENTLY USED METHODS TO IMAGE THE SOURCE AND RUPTURE DETAILS INCLUDING VELOCITY, EXTENSION, DIRECTION AND DURATION IS BACK-PROJECTION (REVERSE TIME MIGRATION). BACK-PROJECTION METHOD HAS SOME ADVANTAGES COMPARING TO TRADITIONAL METHODS SUCH AS FINITE-FAULT SOURCE INVERSION; SINCE IT IS MUCH FASTER (THE COMPUTATION IS RELATIVELY EASIER THAN INVERSION) AND IT CAN BE APPLIED TO DIFFERENT FREQUENCY BANDS, EVEN HIGH FREQUENCIES. IN THIS METHOD, SEISMIC ARRAYS AT TELESEISMIC DISTANCES ARE USED TO IMAGE DETAIL OF RUPTURE. TO INVESTIGATE THE RUPTURE PROPAGATION AND ENERGY RELEASE OF 2007/06/18 MW 5.5, KAHAK EARTHQUAKE A BACK-PROJECTION OF TELESEISMIC P WAVE WITH X4 (CHINA) SEISMIC NETWORK ARRAY, VERTICAL COMPONENT DATA HIGH-PASS FILTERED AT 1.0 HZ IS USED. ACCORDING TO OUR RESULTS BY CONSIDERING THE TIME SHIFT, WHICH OBTAINED FROM CROSS CORRELATING 4 SECONDS OF INITIAL P WAVE, THE RUPTURE VELOCITY IS IN ORDER OF 1.9 ± 0.01 KMS-1 AND THE RUPTURE FRONT PROPAGATES SOUTHWEST TO NORTHEAST ABOUT 8.0 ± 1.0 SECONDS. THE BACK-PROJECTION METHOD USUALLY IS USED FOR LARGE EARTHQUAKES AND USING A VERY DENSE ARRAY, HOWEVER THIS EARTHQUAKE IS MODERATE SIZE AND SEISMIC ARRAY USED IN THE PROCESSING IS NOT DENSE BUT THE RESULTS ARE ACCEPTABLE.

IN THIS PAPER THE ROBUSTNESS OF HUBER FUNCTION IN 1D FULL WAVEFORM INVERSION (FWI) IS STUDIED.BECAUSE OF HIGH ILL-POSEDNESS OF THE FWI PROBLEM IN ERRONEOUS DATA, USE OF SOME FUNCTIONS WHICH ARE LESS SENSITIVE TO THE ERRORS IS NECESSARY. ONE OF THE POWERFUL ALGORITHMS WHICH CAN BE USED AS AN OBJECTIVE FUNCTION IN THE INVERSE PROBLEMS IS THE HUBER FUNCTION. IN THIS PAPER WE USE THIS FUNCTION FOR 1D FWI PROBLEM AND APPLY IT FOR TWO DIFFERENT VELOCITY MODELS; THE FIRST MODEL HAS SMOOTH FEATURES AND THE SECOND ONE HAS A COMBINATION OF SMOOTH AND BLOCKY PARTS. ALL THE IMPLEMENTATION IS DONE IN THE FREQUENCY-DOMAIN. THE STUDY FOR NOISE-CONTAMINATED DATA SHOWS THAT THE HUBER FUNCTION HAS A GOOD PERFORMANCE IN RECONSTRUCTING DIFFERENT PARTS OF THE MODEL.

FROM HYDROCARBON EXPLORATION POINT OF VIEW, CHANNELS ARE AMONG THE IMPORTANT GEOLOGICAL PHENOMENA. IT IS POSSIBLE TO IMAGE CHANNELS IN TIME SLICES AFTER THE ADVENT OF 3D SEISMIC TECHNOLOGY. HOWEVER, MOST OF THE TIME, CHANNELS CANNOT BE EASILY DETECTED FROM ORIGINAL SEISMIC DATA BECAUSE OF STRUCTURAL COMPLEXITIES. IN THIS STUDY, CLASSIC OPERATORS OF IMAGE PROCESSING INCLUDING SOBEL AND CANNY ARE APPLIED TO A SYNTHETIC TIME SECTION OF A CHANNEL MODEL WITH AND WITHOUT ADDITIVE RANDOM NOISE TO DETECT CHANNEL BOUNDARIES. MOREOVER, LAPLACIAN PYRAMID AS A MULTI-SCALE DECOMPOSITION ALGORITHM IS USED TO DETECT CHANNEL BOUNDARIES AT DIFFERENT SCALES. SOBEL OPERATOR FAILS TO DETECT CHANNEL BOUNDARIES IN THE PRESENCE OF RANDOM NOISE. APPLYING CANNY OPERATOR WITH ITS DEFAULT PARAMETERS DETECT HIGH FREQUENCY RANDOM NOISE AS EDGES. LAPLACIAN PYRAMID AT THE FINEST DECOMPOSITION SCALE PROVIDES SUFFICIENT RESOLUTION FOR CHANNEL BOUNDARY DETECTION EVEN IN THE PRESENCE OF ADDITIVE RANDOM NOISE.

REMOVING NOISE FROM SEISMIC DATA IS A CHALLENGING RESEARCH FIELD IN SEISMIC DATA PROCESSING.THE QUALITY OF SEISMIC IMAGES WILL BE IMPROVED BY RANDOM NOISE ATTENUATION; HENCE, INTERPRETATION OF SEISMIC EVENTS WILL BE MUCH FACILITATED AND ALSO THE PERFORMANCE OF AUTOMATIC HORIZON PICKING WILL BE IMPROVED. IN THIS PAPER, IT IS PROPOSED TO USE A DECISION METHOD (DM) TO DETECT NOISE PRIOR TO APPLICATION OF THE MEDIAN FILTER WHICH CALLED DECISION BASED MEDIAN (DBM) FILTER. THIS METHOD IS ABLE TO DIMINISH THE RANDOM NOISE WHILE PRESERVING THE SIGNAL SAMPLES.DM IS A SIMPLE AND EFFECTIVE MEDIAN FILTER AND COULD EASILY BE IMPLEMENTED. THE RESULTS OF OPERATING THE SUGGESTED TECHNIQUE ON OBSERVED PRE/POST STACK SEISMIC RECORDS SHOWS THE PERFORMANCE OF IT FOR IMPROVING THE QUALITY AND INTERPRETABILITY OF SEISMIC RECORDS.

THE APPLICABILITY OF H/V METHOD FOR DELINEATION OF SALT IN MARUN OIL FIELD IS STUDIED. THREE DIFFERENT WINDOWS FOR EACH STATION IS STUDIED FOR COMPARING H/V RATIO. THE DROPS IN VALUES OF H/V IS CONSISTENT WITH FREQUENCY DISTORTION IN SEISMIC REFLECTION SECTIONS. IT IS CONCLUDED THAT FOR DIFFERENT USED BROADBAND STATIONS, THE VALUES OF H/V IS CONSISTENT TO STRUCTURAL FOLDS AND SEISMIC SIGNATURE.

THE S-WAVE VELOCITY MODEL, TO THE DEPTH OF 350 KM FOR THE NW OF IRAN IS OBTAINED USING NONLINEAR INVERSION OF RAYLEIGH WAVE TOMOGRAPHIC DATA IN THE PERIOD RANGE FROM 10 TO 150 S. THE THREE-DIMENSIONAL SHEAR VELOCITY MODEL OF THE REGION IS CREATED BY 32 JUXTAPOSED ONEDIMENSIONAL CELLULAR STRUCTURES, SIZED 1O BY 1O. OUR VS. MODELS SHOW THAT HE THICKNESS OF THE CRUST AND LITHOSPHERE VARIES BETWEEN 40-50 KM AND 60-100 KM, RESPECTIVELY. THE SHALLOWEST LITHOSPHERE IS LOCATED BENEATH SABALAN VOLCANO, PROBABLY DUE TO SOME MAGMATIC ACTIVITIES. IN MOST PART OF THE CELLS THE CONTRAST OF VELOCITY ABOVE AND BELOW MOHO DISCONTINUITY IS HIGH.BASED ON THE AVERAGE VALUE OF MOHO AND LITHOSPHERE DEPTH, WE CONCLUDED THAT THE APPROXIMATELY HIGH TOPOGRAPHY OF THE REGION IS SUPPORTED BY A WARM AND UPWELLING MANTLE, RATHER THAN BY A THICK CRUST.

THIS STUDY WE USED THE STRONG MOTION DATA TO OBTAIN SHEAR WAVE QUALITY FACTOR AND SOURCE PARAMETERS IN THE NEAR FIELD. IN THIS APPROACH THE THEORETICAL S WAVE DISPLACEMENT SPECTRA CONDITIONED BY FREQUENCY INDEPENDENT Q, WAS FITTED WITH THE OBSERVED DISPLACEMENT SPECTRA.THUS CORNER FREQUENCY, MOMENT MAGNITUDE, AND FREQUENCY INDEPENDENT Q FOR EACH RECORDED WERE COMPUTED AT THE SAME TIME AND THE ESTIMATE OF ERROR IS GIVEN IN THE ROOT-MEAN-SQUARE SENS OVER ALL FREQUENCIES. THE EARTHQUAKE IN KAKI, 9 APRIL 2013 AT (11: 52: 50) MW=6.3 WAS THE LARGEST EARTHQUAKE IN THE ZAGROS SINCE THE NOVEMBER 1990 MW=6.4 FURG (HORMOZGAN) REVERSE FAULTING EVENT [WALKER ET AL, 2005]. THE DATA REPRESENTED BY 16 ACCELEROGRAM RECORDED FROM KAKI-BUSHEHR EARTHQUAKE IN THE HYPOCENTRAL DISTANCE RANG FROM 32 TO 160 KM. THE SOURCE TERM OBTAINED FROM INVERSION WAS ANALYZED TO ESTIMATE, VARIOUS SOURCE PARAMETERS. THEREBY, WE ESTIMATED SEISMIC MOMENT (1.21E+26 DYNE-CM), CORNER FREQUENCY (0.29 HZ), FAULT SLIP (107.54 CM), STRESS DROP (11.3 BARS), SOURCE DURATION (5.3 SEC) AND MOMENT MAGNITUDE (6.3). THE PATH AVERAGE VALUE Q IS THE RANGE Q=186 TO 1599.

JET GROUTING IS A GEOTECHNICAL METHOD OF GROUND IMPROVEMENT TO INCREASE SHEAR STRENGTH AND STIFFNESS OF SOILS BY MEANS OF IN-SITU GEOMETRIES OF GROUTED SOIL, SUCH AS PANELS OR COLUMNS.SOME OF THE MOST COMMON JET GROUTING APPLICATIONS ARE FOUNDATION RESTORATION, EXCAVATION SUPPORT AND SEALING. IT IS ONLY VAGUELY POSSIBLE TO CONTROL THE COLUMN DIAMETER DURING THE GROUTING PROCESS. THEREFORE, AN EXCAVATION OF A TEST COLUMN AND A VISUAL EXAMINATION IS A GENERAL PRACTICE AFTER INSTALLATION. EXCAVATION IS OFTEN IMPOSSIBLE, ESPECIALLY UNDER COMPLEX SITE CONDITIONS, SUCH AS A HIGH GROUND WATER TABLE. AS PART OF A RESEARCH PROJECT, BOREHOLE SEISMIC MEASUREMENTS (CROSSHOLE, DOWNHOLE AND TOMOGRAPHY) WERE PROPOSED AS A NEW QUALITY CONTROL OF THE COLUMN’S DIAMETER IN-SITU AND TO MONITOR THE TIME DEPENDENT EFFECTS OF THE JET GROUT INJECTION. THE TECHNIQUE WAS TESTED AT A TESTING SITE IN BERLIN (GERMANY) AND IN THE FRAMEWORK OF AN ONGOING GROUTING PROJECT IN PASSAU (GERMANY).