Seismic data processing

Alle ore 23.11 ore locali del 20/09/2025 è stato registrato dalla rete sismica e accelerometrica della Regione Umbria un terremoto di magnitudo 3.8 a 1 chilometro a nord est di Massa Martana con ipocentro alla profondità di 8 chilometri. L'accelerazione maggiore è stata registrata dalla stazione posta nei pressi del centro abitato di Massa Martana (stazione MASM) con un'accelerazione massima di 0.07253g secondo la direzione nord-sud. Alle ore 23.51 locali, si segnalano due repliche di magnitudo 1.1 e 1.3 avvenute nelle vicinanze dell'epicentro del terremoto più forte. Dall'inizio del mese di settembre il numero di eventi che ha preceduto il terremoto in oggetto, non è rilevante e in linea con quanto solitamente si registra dal comune di Massa Martana.

Evaluating soil strength by geophysical methods using P-waves was undertaken in this study to assess the effects of changed binder ratios on stabilization and compression characteristics. The materials included dredged sediments collected in the seabed of Timrå region, north Sweden. The Portland cement (Basement CEM II/A-V, SS EN 197-1) and ground granulated blast furnace slag (GGBFS) were used as stabilizers. The experiments were performed on behalf of the Svenska Cellulosa Aktiebolaget (SCA) Biorefinery Östrand AB pulp mill. Quantity of binder included 150, 120 and 100 kg. The properties of soil were evaluated after 28, 42, 43, 70, 71 and 85 days of curing using applied geophysical methods of measuring the travel time of primary wave propagation. The P-waves were determined to evaluate the strength of stabilized soils. The results demonstrated variation of P-waves velocity depending on stabilizing agent and curing time in various ratios: Low water/High binder (𝐿 𝑊 𝐻 𝐵 ), High water/Low binder (𝐻 𝑊 𝐿 𝐵 ) and percentage of agents (CEM II/A-V/GGBFS) as 30%/70%, 50%/50% and 70%/30%. The compression characteristics of soils were assessed using uniaxial compressive strength (UCS). The P-wave velocities were higher for samples stabilized with 𝐿 𝑊 𝐻 𝐵 compared to those with 𝐻 𝑊 𝐿 𝐵 . The primary wave propagation increased over curing time for all stabilized mixes along with the increased UCS, which proves a tight correlation with the increased strength of soil solidified by the agents. Increased water ratio gives a lower strength by maintained amount of binder and vice versa.

sacudida por un gran terremoto requiere atención urgente. Los tres primeros días son críticos para rescatar con vida a las víctimas. Los alcaldes de las ciudades ahora pueden usar RieSis, un software que recibe por internet peticiones desde los sitios dañados, administra el envío de personal y recursos, e informa al público sobre la condición y ubicación de los damnificados, rescatistas, etcétera. os recientes sismos de septiembre de 2017, que afectaron al Istmo de Tehuantepec, a la Ciudad de México y a varios estados centrales (Puebla, Morelos, entre otros), nos invitan a reflexionar sobre la forma de prevenir estos fenómenos, o al menos evitar o disminuir sus efectos perjudiciales. Los fenómenos geológicos e hidrometeorológicos se rigen por leyes todavía desconocidas en gran parte; éstos afectan mayormente a las poblaciones ubicadas en áreas de peligro, o aquéllas que no consideran las normas de construcción ni las zonas más afectables. Por ejemplo, todos los países con frontera con el Cinturón de Fuego del Pacífico y los del Caribe padecemos de tiempo en tiempo algunos terremotos. El área de riesgo situada en las costas del océano Pacífico se caracteriza por concentrar algunas de las zonas de subducción más importantes del mundo, lo que ocasiona una intensa actividad sísmica y volcánica (60% de la actividad sísmica del planeta). Los principales países afectados son: Chile,

La actual norma peruana de diseño sismo resistente (NPDSR) establece desplazamientos espectrales crecientes con el periodo estructural para estructuras con periodo mayor al de la plataforma. Esto no corresponde a la tendencia natural de los espectros, ya que para periodos largos los desplazamientos deben ser constantes e iguales al desplazamiento máximo del suelo. En la actualidad se están construyendo en nuestro medio, edificios con aislación sísmica cuyos periodos superan los 2.5 segundos y la NPDSR no permite estimar adecuadamente los desplazamientos a los que estarían sometidas. Por esta razón, se hace necesario el ajuste del espectro de la actual norma de diseño sismo resistente. En este trabajo se desarrolló una propuesta para los espectros de diseño en la zona de periodos mayores a 2.5 s. Para construir estos espectros no fue posible emplear el método de Newmark& Hall, ya que actualmente en el país no se cuenta con una estimación apropiada de los valores máximos de aceleración, velocidad y desplazamiento del suelo. El estudio se desarrolló estudiando tendencias y empleando regresiones basadas en promedios espectrales de la zona de periodos largos. Se obtuvieron espectros para los tipos de suelo S1 y S3 de la norma actual, correspondientes a valores medios y promedio más desviación estándar. Del análisis realizado se identificó el periodo a partir de la cual las aceleraciones espectrales se reducen con el cuadrado del periodo. Se espera que con esta propuesta, se logre mejorar la estimación de desplazamientos en las estructuras peruanas de periodos mayores a 2.5 s. Esto contribuirá a mejorar el estudio y diseño de los edificios con aislamiento sísmico en el Perú. Índice Capítulo 1. Introducción 1.1 El diseño sismo resistente y el control de desplazamientos laterales 1.2 Los sistemas de aislamiento sísmico 1.3 Objetivo de la tesis 1.4 Alcance del Trabajo 1.5 Organización del documento Capítulo 2. Espectros de Diseño para fuerzas y Desplazamientos 2.1 Espectros de diseño basados en fuerzas (sa) 2.2 Procedimientos para obtener espectros de diseño 2.3 Espectros de diseño de algunos países sísmicos  Norma Chilena  ASCE  Norma Colombiana Capítulo 3. El espectro de desplazamientos de la actual Norma Peruana de DSR 3.1 Estructura del espectro 3.2 Comparación registros peruanos con la norma 3.3 Espectros de desplazamiento de las normas extranjeras 23 Capítulo 4. Propuesta del espectro de diseño para la zona de desplazamientos. 4.1 Metodología de Trabajo 4.2 Obtención de información 4.3 Procesamiento y Clasificación de Señales 4.4 Obtención de los Espectros de diseño 4.5 Propuesta de espectros de desplazamiento 4.6 Propuesta de espectros de aceleración

Intense volcanic activity in the Mount Merapi region necessitates a thorough understanding of its subsurface structure, particularly for eruption hazard mitigation and magmatic system analysis. However, limitations in spatial resolution from previous tomography studies have hindered detailed identification of features such as shallow magma reservoirs, fracture zones, and active faults responsible for magma transport. Therefore, this study aims to identify and spatially characterize the subsurface structure beneath Mount Merapi and its surroundings using seismic tomography based on P-wave velocity (Vp), S-wave velocity (Vs), and Vp/Vs ratio data. Local seismic data were obtained from the DOMERAPI and BMKG broadband networks and processed using the LOTOS-13 software with a non-linear inversion model. The results reveal a low-velocity anomaly zone with a high Vp/Vs ratio at depths of less than 6 km beneath Merapi, interpreted as a shallow, fluid-rich magma reservoir. A transition zone and an intermediate magma reservoir were identified at depths of 6-12 km and 13-16 km, respectively. Beneath Mount Merbabu, weaker velocity anomalies without significant magmatic signals indicate a relatively inactive volcanic system. Additionally, low-velocity and high Vp/ Vs ratio zones at depths of 15-18 km south of Merapi are associated with the Opak Fault. These findings enhance our understanding of magmatic dynamics and seismotectonic potential in the Central Java volcanic region.

This paper describes the development and application of a system for quantitative near-bottom seismic profiling at 4 kHz. Developed as part of the Deep-Tow Instrumentation System of the Marine Physical Laboratory, this system represents a capability which is relatively unique in terms of lateral resolution. This capability was developed in order to observe small-scale horizontal variations in acoustic reflectivity of the sea floor as well as similar properties for shallow, layered structures in bottom sediments. The system provides real-time computer processing and quantitative displays of processed data in several forms. These displays include a high-resolution grey scale display of equivalent plane wave pressure (compensating for Fish altitude), a three-dimensional contourogram display of equivalent intensity, and a plot of integrated equivalent energy for travel time sections (typically corresponding to 0–5 and 5–55 m into the bottom). These quantitative displays provide a real-t...

High-resolution marine seismic data degraded by sea swell can be enhanced by swell correction. To correct for swell, two-way travel times are detected for sea bottom locations in seismic traces; linear predicted values are calculated from the previously detected travel times, and correct static shifts between the detected and calculated values before stacking. To pick sea bottom locations for very large numbers of seismic traces, automatic sea bottom detection (SBD) is normally required. However, sea bottom signal degradation by wave noise causes SBD failure. Our first SBD trial using trace-by-trace (TBT) picking from raw and energy ratio data was unsatisfactory, with many of the detected sea bottom values deviating from the correct values due to noise in the field data. However, we achieved reasonable results by considering source-receiver geometry and previously detected sea bottom values. We picked reliable sea bottom values within an expected hyperbolic range (EHR) calculated from the source-receiver offset and group interval. To prevent excessive correction for swell, we excluded unreliable picks that deviated greatly from the linear trend of previously detected sea bottom values, or from the immediately preceding value. Swell correction within the EHR significantly improved the quality of noisy data. We applied this method to noisy field seismic data acquired offshore Yeosu, Korea, and successfully detected the sea bottom, corrected for swell, and improved seismic section. Thus, high-resolution marine seismic data degraded by sea swell can be enhanced by pre-stack swell correction in shot gathers using a hyperbola calculated based on source-receiver geometry.

Bireysel Emeklilik Sistemi (BES) öncelikli olmak üzere fon yatırımlarının pozitif reel getiri elde edip, etmediklerini ölçebilecek bir araç ihtiyacı vardır. Bu çalışma, Emeklilik Gözetim Merkezi (EGM) tarafından önerilen akademik araştırma konuları arasında da bulunan, fonların karşılaştırılma ölçütü ve eşik değer belirleme uygulaması alanlarındaki boşluğu doldurmayı amaçlamaktadır. Birikimlerin değerlendirilebileceği yatırım araçlarına yönelik finansal performans ölçümlerini yapmak üzere bir eşik değer modülü önerilmiştir. Emeklilik fonları, yatırım fonları ve seçilen alternatif yatırım araçlarının (TL, Avro, ABD Doları mevduatları, gram altın, BİST 100 Endeksi) 5-10-15-20 yıllık getiri performansları 2005-2024 yılları arasını kapsayacak şekilde analiz ederek kıyaslanmıştır. Kıyaslama metodunda alım gücü değişim hesaplaması için eşik değeri belirleyen modül yaratılmıştır. Eşik değer, TL'nin ABD Doları karşısındaki değer kaybı ve ABD Doları tüketici enflasyonunu birlikte kullanan bir yöntem ile hesaplanmıştır. Belirli aylık yatırımların farklı araçlarda değerlendirilmesi sonuçlarının, hesaplanan eşik değerin yüzdesel oran olarak ne kadar altında/üstünde kaldığına göre alım gücü değişimleri analiz edilmiştir. 210 emeklilik fonu ve 463 yatırım fonu analize dahil edilmiştir. Araştırmanın sonucunda alternatif birikim yöntemlerinden sadece altının pozitif alım gücü değişimi verebildiği, yatırım ve emeklilik fonlarından da yüksek risk değeri olanların seçilmesi durumunda altının performansının üzerine çıkılabildiği görülmüştür. Devlet katkısının emeklilik fonlarının alım gücü açısından pozitif katkı sağladığı; 5 yıllık analizde ortalama %26, 10 yıllık analizde ise ortalama %18 pozitif alım gücü değişimi sağladığı hesaplanmıştır. Ancak devlet katkısının pozitif etkilerinin vade uzadıkça azaldığı tespit edilmiştir. Sonuç olarak yüksek risk seviyesinde fon seçimlerinin bilinçli yapılması ve devlet katkı fonlarının içeriğinde yapısal geliştirme yapılması önerilmiştir.

Traditional geotechnical and geophysical investigations were conducted to determine the characteristics of a study site proposed for the construction of an electrical power plant in Al-Shamiyah city, Al-Qadisiya Governorate. These assessments are crucial for ensuring the durability of subsurface layers to support the foundations of engineering structures. The geophysical data consisted of twenty-three Ground Penetrating Radar profiles arranged perpendicularly to each other and nine points of Electrical Resistivity Sounding. These data were integrated with three types of samples-Disturbed, Standard Penetration Test, and Undisturbed-which were collected from nineteen geotechnical engineering boreholes. The samples were analyzed for soil classification, strength, consolidation, and chemical properties of both soil and water. The Ground Penetrating Radar profiles revealed several weak zones, while the resistivity survey points showed random values ranging 2-16 Ωm at depths up to 20 m, indicating loose and incohesive soil. The findings from the geophysical data aligned with the geotechnical analysis, which classified the soil profile into seven distinct layers. Soil activity was assessed through the plasticity index and liquid limit, with an average elasticity index to clay content ratio of-0.53, suggesting poor clay activity. The in-situ allowable bearing capacity of the soil at depths ranging from 1.5 to 22 m was found to be between 4.0 and >17.0 T/m² across all boreholes. Sulfate (SO₃) content ranged from 0.112% to 0.527%. Groundwater levels were measured at 1.7 to 1.45 m, exhibiting high alkalinity content and moderate to high salinity.

One of the first operations in a seismic signal processing system applied to earthquake data is to distinguish between valid and invalid records. Since valid signals are characterized by a combination of their time and frequency properties, wavelets are natural candidates for describing seismic features in a compact way. This paper develops a seismic buffer pattern recognition technique, comprising wavelet‐based feature extraction, feature selection based on the mutual information criterion, and neural classification based on feedforward networks. The ability of the wavelet transform to capture discriminating information from seismic data in a small number of features is compared with alternative feature reduction techniques, including statistical moments. Three different variations of the wavelet transform are used to extract features: the discrete wavelet transform, the single wavelet transform and the continuous wavelet transform. The mutual information criterion is employed to s...

Contents of this paper were reviewed by the Technical Committee of the 14 th International Congress of the Brazilian Geophysical Society and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited.

La storia / Le storie Benedetto gravagnuoLo L'interminabilità degli interrogativi e i limiti dell'interpretazione Werner oeChsLin L'architetto moderno e la storia FranCo purini Architettura e storia tra finalismo e casualità andrea Branzi Un Rinascimento inquieto vinCenzo Fontana Per una storia concreta dell'architettura MarCo spesso Le forme e lo spazio geografico. Architetture del dominio genovese in Corsica 1571-1768 CapitoLo iii Le storie speciali giuLio pane La storia dell'architettura "come pensiero e come azione"

The seismic experiment of 3D array of OBS in the southwestern sub-basin of the South China Sea (SCS) is briefly introduced in this paper. The data analysis of broadband OBS shows that totally 93 earthquakes with magnitude of Ms 6.0-6.9 and 10 earthquakes with magnitude above Ms 7.0 were recorded in high quality during this experiment, especially the catastrophic earthquake Ms 9.0 occurred in the east sea area of Japan on March 11, 2011. The anisotropy parameters inversion of ScS wave of four events above Ms 7.0 indicates that the fast direction of shear wave is N58°E parallel to the ceased spreading ridge of the southwestern sub-basin of SCS (the slow direction is S35°E perpendicular to the spreading ridge), which means the spreading ridge is under compressing stress at present and the cessation of seafloor spreading is related to such stress field as well. broadband OBS, southwestern subbasin of SCS, passive seismic experiment, anisotropy, spreading ridge

Crustal structure across the passive continental margin of the northeastern South China Sea (SCS) is presented based on a deep seismic survey cooperated between Taiwan and China in August 2001. Reflection data collected from a 48-hydrophone streamer and the vertical component of refraction/reflection data recorded at 11 ocean-bottom seismometers along a NW-SE profile are integrated to image the upper (1.6-2.4 km/s), lower (2.5-2.9 km/s), and compacted (3-4.5 km/s) sediment, the upper (4.5-5.5 km/ s), middle (5.5-6.5 km/s) and lower (6.5-7.5 km/s) crystalline crust successively. The velocity model shows that the thickness (0.5-3 km) and the basement of the compacted sediment are strongly varied due to intrusion of the magma and igneous rocks after seafloor spreading of the SCS. Furthermore, several volcanoes and igneous rocks in the upper/middle crust (7-10 km thick) and a high velocity layer (0-5 km thick) in the lower crust of the model are identified as the ocean-continent transition (OCT) below the lower slope in the northeastern margin of the SCS. A thin continent NW of the OCT and a thick oceanic crust SE of the OCT in the continental margin of the northeastern SCS are also imaged, but these transitional crusts cannot be classified as the OCT due to their crustal thickness and the limited amount of the volcano, the magma and the high velocity layer. The extended continent, next to the gravity low and a sag zone extended from the SW Taiwan Basin, may have resulted from subduction of the Eurasian Plate beneath the Manila Trench whereas the thick oceanic crust may have been due to the excess volcanism and the late magmatic underplating in the oceanic crust after seafloor spreading of the SCS.

Research of 2009, we investigated data from thirty-seven ocean-bottom seismometers (OBS) and three multi-channel seismic (MCS) profiles across the deformation front in the northernmost South China Sea (SCS) off SW Taiwan. Initial velocity-interface models were built from horizon velocity analysis and pre-stack depth migration of MCS data. Subsequently, we used refracted, head-wave and reflected arrivals from OBS data to forward model and then invert the velocity-interface structures layer-by-layer. Based on OBS velocity models west of the deformation front, possible Mesozoic sedimentary rocks, revealed by large variation of the lateral velocity (3.1-4.8 km/s) and the thickness (5.0-10.0 km), below the rift-onset unconformity and above the continental crust extended southward to the NW limit of the continent-ocean boundary (COB). The interpreted Mesozoic sedimentary rocks NW of the COB and the oceanic layer 2 SE of the COB imaged from OBS and gravity data were incorporated into the overriding wedge below the deformation front because the transitional crust subducted beneath the overriding wedge of the southern Taiwan. East of the deformation front, the thickness of the overriding wedge (1.7-5.0 km/s) from the sea floor to the de ´collement decreases toward the WSW direction from 20.0 km off SW Taiwan to 8.0 km at the deformation front. In particular, near a turn in the orientation of the deformation front, the crustal thickness (7.0-12.0 km) is abruptly thinner and the free-air (-20 to 10 mGal) and Bouguer (30-50 mGal) gravity anomalies are relatively low due to plate warping from an ongoing transition from subduction to collision. West of the deformation front, intra-crustal interfaces dipping landward were observed owing to subduction of the extended continent toward the deformation front. However, the intracrustal interface near the turn in the orientation of the deformation front dipping seaward caused by the transition from subduction to collision. SE of the COB, the oceanic crust, with a crustal thickness of about 10.0-17.0 km, was thickened due to late magmatic underplating or partially serpentinized mantle after SCS seafloor spreading. The thick oceanic crust may have subducted beneath the overriding wedge observed from the low anomalies of the freeair (-50 to -20 mGal) and Bouguer (40-80 mGal) gravi ties across the deformation front.

The seismic experiment of 3D array of OBS in the southwestern sub-basin of the South China Sea (SCS) is briefly introduced in this paper. The data analysis of broadband OBS shows that totally 93 earthquakes with magnitude of Ms 6.0-6.9 and 10 earthquakes with magnitude above Ms 7.0 were recorded in high quality during this experiment, especially the catastrophic earthquake Ms 9.0 occurred in the east sea area of Japan on March 11, 2011. The anisotropy parameters inversion of ScS wave of four events above Ms 7.0 indicates that the fast direction of shear wave is N58°E parallel to the ceased spreading ridge of the southwestern sub-basin of SCS (the slow direction is S35°E perpendicular to the spreading ridge), which means the spreading ridge is under compressing stress at present and the cessation of seafloor spreading is related to such stress field as well. broadband OBS, southwestern subbasin of SCS, passive seismic experiment, anisotropy, spreading ridge

Seismic inversion has become almost routine in quantitative 3D seismic interpretation. To ensure the quality of the seismic inversion, the input seismic data need to have a high signal-to-noise ratio. With the current low oil price environment, seismic reprocessing is often preferred over reacquisition to improve data quality. Common filter pairs include forward and inverse [Formula: see text]-[Formula: see text] and Radon transforms. Forward and inverse migrations (i.e., migration and demigration) are a more recently introduced transform pair that, when used together in an iterative workflow, results in a least-squares migration algorithm. Least-squares migration compensates for surface variation in data density and, when combined with a filter applied to prestack migrated images, suppresses the operator and data aliasing. We apply a least-squares migration workflow to a fractured-basement data set from the Texas Panhandle to demonstrate the enhancement in signal-to-noise ratio, th...

Lithology basically refers to the type of rock in the Earth crust. Different kinds of rocks exist in the subsurface but not all are conducive for hydrocarbon accumulation. For a subsurface rock to be a good hydrocarbon storage, the rock should be sedimentary with pore spaces. These pore spaces can be filled with hydrocarbons . Knowledge obtained about the lithology of a well can be used to determine a range of parameters including the much-needed pore fluid content. Lithology and pore fluid prediction are vital for reservoir characterization. Lithology and pore fluid prediction are very important aspects of exploration and production such as geological studies, reservoir modeling, formation evaluation, enhanced oil recovery processes, and well planning including drilling and well completion management. Accurate determination and understanding of lithology, pore fluid, pore shapes, and sizes are fundamental to other petrophysical analysis. Determining lithology and pore fluid are key for effective exploration and production of hydrocarbon. However, accurate prediction of lithology and pore fluid is, and will continue to be, a key challenge for hydrocarbon exploration and development . The accurate determination of lithology and pore fluid aids in the accurate determination of porosity, saturation, and permeability. The economic viability of a hydrocarbon field is also reliant on the quality and accuracy of lithology and pore fluid . The growing difficulty in convention (reservoir that uses the natural pressure gradient for hydrocarbon extraction) and unconventional (reservoir that requires special recovery operations outside the conventional operating practices) reservoir has made precise lithology and pore fluid prediction very essential . The accurate determination of lithology and pore fluid also aid petroleum engineering decisions making. Lithology and pore fluid can be unambiguously determined using core samples obtained from underground formation.

Daerah studi yang di daratan daerah Sumatra bagian utara pada daerah seluas kurang lebih 2,946 km2. Cekungan Sumatera Utara adalah salah satu dari tiga cekungan busur belakang yang terbentuk selama Tersier (Oligosen Awal), pada Lempeng Eurasia atau Paparan Sunda (Sastromihardjo, 1988). area studi sebelumnya sudah pernah dilakukan kegiatan eksplorasi dan eskploitasi sejak jaman sebelum kemerdekaan. Berdasarkan informasi terdahulu hidrokarbon wilayah studi didominasi oleh gas dengan beberapa kemungkinan prospek minyak yang dibuktikan dari beberapa rembesan di daerah ini. Studi dilakukan adalah salah satunya dengan melakukan evaluasi dan interpretasi terhadap data-data sumur dan line seismik 2D.

Using wave-equation migration and demigration in the extended subsurface domain, we introduce a practical leastsquares migration for the inversion of angle-domain common-image gathers. Through synthetic and field data examples, we demonstrate that least-squares migration provides high-resolution angle-domain common-image gathers with extended angle range, enhanced illumination, and balanced amplitudes. Similarly, the stacked images show better structural fidelity, improved resolution, balanced illumination, and reduced artifacts.

There are many factors which affect the quality of a subsurface image: acquisition geometry, data quality, accuracy of the subsurface model, imaging algorithm, image post-processing steps, etc. Despite improvements in seismic acquisition, such as full azimuth (FAZ) surveys, and advanced imaging algorithms such as reverse time migration (RTM), focusing energy beneath a complex salt overburden remains a challenging problem. We propose a post-imaging workflow to mitigate migration artefacts, limited illumination problems, and velocity model inaccuracies that cause image distortion. RTM images derived with an inverse scattering imaging condition are decomposed into angle/azimuth domain gathers. The angles and azimuths which constructively interfere at each image point to produce the best image are chosen so as to remove both coherent and incoherent noise and produce an optimal stack. Finally, structure-conformable filtering is applied. We apply this workflow to an RTM image from Garden Banks in the Gulf of Mexico.

Geological storage is one of the solutions to avoid the emission of carbon dioxide to the atmosphere. This process requires a careful monitoring of the CO 2 bubble, which can be performed by means of seismic and electromagnetic (EM) methods, on the basis of seismic velocity, attenuation and electrical conductivity contrasts before and after the injection. A successful monitoring depends on many factors, for instance the depth and properties of the reservoir. To test the feasibility of detecting the gas, we have performed cross-well seismic and EM tomographic inversions on a synthetic data set generated from a realistic aquifer partially saturated with CO 2 . We use two different algorithms based on traveltime picks. The method is novel regarding the EM inversion. Besides seismic velocity and conductivity, we have also obtained the seismic quality factor by performing attenuation tomography based on the frequency-shift approach. The RMS differences between the inverted and true initial models show that the methodology (and the adopted acquisition geometry) allows us to obtain reliable results which agree well with the true petrophysical model. Moreover, we have used a forward optimisation method to recover saturation, porosity and clay content from the tomographic seismic velocities, Q values and electric conductivity, with errors less than 15%.

Rock physics modelling has been employed in studying the elastic behaviors of reservoir SAND_K2 in the 'KUTI' Field, Niger Delta under a plausible production scenario of increasing water saturation. The study aimed to investigate how variation in reservoir fluid saturation will influence seismic attributes and determine the characteristics of expected time-lapsed (4-D) seismic signals that may be generated due to the effects of production. Multivariate cross-plot analyses of petro-elastic parameters were carried out to establish the seismic characteristics of the target reservoir with different pore fluids in its natural state before production. Fluid replacement modelling was applied to calculate measurable changes in the reservoir's seismic characters by steadily increasing the water saturation from its initial value to 100%. Synthetic logs of petro-elastic parameters were created for different values of water saturation and combined into property cross-plots to predict the dynamic seismic response of the reservoir as brine gradually replaced hydrocarbon. Results showed that fluid changes from hydrocarbon to brine produced significant and quantifiable seismic signatures for timelapse monitoring investigation. At some future points in the production history of the field under increasing water saturation conditions, the density, P-wave velocity and acoustic impedance of SAND_K2 increase and produce a negative seismic difference data of P-wave amplitude. Based on the responses of reservoir SAND_K2 under modelled production conditions, the study concluded that rock physics analysis can help to optimize and enhance the success of time-lapse monitoring of the KUTI Field.

Deep neural networks (DNNs) can learn accurately from large quantities of labeled input data, but often fail to do so when labelled data are scarce. DNNs sometimes fail to generalize ontest data sampled from different input distributions. Unsupervised Deep Domain Adaptation (DDA) techniques have been proven useful when no labels are available, and when distribution shifts are observed in the target domain (TD). In the present study, experiments are performed on seismic images of the F3 block 3D dataset from offshore Netherlands (source domain; SD) and Penobscot 3D survey data from Canada (target domain; TD). Three geological classes from SD and TD that have similar reflection patterns are considered. A deep neural network architecture named EarthAdaptNet (EAN) is proposed to semantically segment the seismic images when few classes have data scarcity, and we use a transposed residual unit to replace the traditional dilated convolution in the decoder block. The EAN achieved a pixel-level accuracy >84% and an accuracy of ~70% for the minority classes, showing improved performance compared to existing architectures. In addition, we introduce the CORAL (Correlation Alignment) method to the EAN to create an unsupervised deep domain adaptation network (EAN-DDA) for the classification of seismic reflections from F3 and Penobscot, to demonstrate possible approaches when labelled data are unavailable. Maximum class accuracy achieved was ~99% for class 2 of Penobscot, with an overall accuracy>50%. Taken together, the EAN-DDA has the potential to classify target domain seismic facies classes with high accuracy.

Image segmentation (Shi and Malik, 2000; Hale and Emanuel, 2 003, 2002) for tracking salt boundaries (Lomask and Biondi, 2003; Lomask et al., 2004) is extremely memory intensive. Memory saving measures must be implemented in order to consi der applying this technique to 3D seismic cubes. If coarse bounds can be picked, either ma nually or using another automatic algorithm, this image segmentation algorithm can t hen be used to partition between the bounds. Unfortunately, the quality of the segmentation result is strongly affected by the shape of the image. For example, elongated images are more li kely to be partitioned along their shortest dimension.

Image segmentation can be used to track salt boundaries when the salt boundary amplitude is greater than any other local reflections. We apply a modified version of the normalized cut image segmentation method to partition seismic images along salt boundaries. In principle our method should work even when the boundaries are not continuous, and conventional horizon tracking algorithms may fail. Our implementation of this method calculates a weight connecting each pixel in the image to each pixel in a local neighborhood. The weight is made weak where the negative amplitude of the complex trace along the shortest path between the two pixels has a minimum and is less than a threshold value. This method is demonstrated to be effective on synthetic 2D seismic sections and can easily be modified to be applied to 3D data. To overcome the formidable computational expense and storage requirements, three cost saving approaches are proposed. Firstly, pixels are sampled from windows centered at powers of 2, this greatly increases the sparseness of the weight matrix. Secondly, initial solutions are provided to subsequent segmentations for multiple segmentation passes in iterative velocity analysis. Thirdly, an iterative multiscale approach should allow the tracking of the bright salt events in large 3D cubes.

Analysis on Pre - Stack Depth Migration ( PSDM ) has been applied in the data field " X " on line 11 and 48.  Pre - Stack Time Migration ( PSTM ) often get  discontinuity of reflector caused by lateral velocity variations and complex geological structure . It can be overcome by processing the data using an accurate velocity model . Pre- Stack Depth Migration has done by using the velocity model obtained from a tomography velocity models that reflect the actual state of the earth . PSDM able to show better results compared with the results of PSTM , which is able to confirm the continuity of reflectors and more coherent resolution. Keyword:  PSDM, PSTM, lateral velocity variation

Multiple caused by waves that trapped in a layer of sea water or rock layers. The effect information propagation time longer effect as if there is a new layer, thus looping wave reflection. The existence of multiple noise is disruptive and even damaging that complicates intrepetasi in interpreting seismik that have focused so that multiple seismik cross sections obtained free of multiple. Methods in multiple energi weaken, one of them by using the filtering radon method which, in principle, filtering radon, radon transform of the data pre-stack time-offset domain (t-x) in the domain of p-tau (τ-p). In τ-p domain and the expected multiple primary signal can be distinguished by the speed difference moveoutnya. This study aims to evaluate the response of radon filtering is applied to the conventional method for multiple mengatenuasi. The results obtained from the radon showed multiple filtering methods reduced from previous conventional methods which showed multiple. It shows good effe...

Abstract: There has been much discussion in the scientific literature about potential correlation between solar weather and seismic activity, most especially the seminal paper by Marchitelli et al., 2020 (e.g., Marchitelli, V., Harabaglia, P., Troise, C. et al. On the correlation between solar activity and large earthquakes worldwide. Sci Rep 10, 11495 (2020). https://doi.org/10.1038/s41598-020-67860-3). Although the USGS, and the scientific community at large, have not supported the theory of such a correlation, research and discussion is ongoing on this controversial topic. While X-class flares have been mentioned in connection with a possible effect on seismic activity, anecdotal mention of solar proton density appears – at least to this undersigned researcher – to show a stronger promise of possible correlation to seismic activity than solar flares: this researcher recalls recent discussion of that, and the Marchitelli paper focuses on “20 years of proton density and velocity data, as recorded by the SOHO satellite” (brief quote from abstract), so, in beginning our analysis, this researcher decided to pull raw data for solar photon density and USGS earthquake datasets and do a more comprehensive and robust statistical analysis de novo – afresh and anew. The results – in short – show that, while individual analyses seem to usually find no statistically-significant correlation, except in rare cases where I suspect Gemini got suspiciously low p-Values due to math errors – nonetheless, the meta-analysis of individual – mostly independent – analyses seems to find a weak, but persistent, pattern of >= 1.0 Odds ratios and positive R-values – which is very unlikely by chance. Thus, while there are certainly much greater factors elsewhere (inferred from very low R-values) and not much effect on the seismic activity – if at all (inferred from the close-to-one Odds Ratios), nonetheless, there may be a super weak – but statistically-significant – correlation that lies “just under the surface” of an individual analysis – implying the need for “further research.” Whatever effects solar proton density may (or may not) have on telluric seismic activity, the effect (if any) is very small, and generally not of scientific significance. However, the meta-analysis method employed here may prove useful for other researchers who are seeking to find a pattern that lies “just beneath” traditional statistical analysis inquiry. In this context, several theories have been bandied about as to a possible cause-and-effect relationship, chiefly the reverse piezoelectric effect where Maxwell currents induced by photons – either directly in telluric ground near fault lines, or indirectly, via disturbance of the geomagnetic field which would could, in turn, induce currents as it fluctuates. Also, the Schumann Resonance effect from inductive and capacities properties of telluric material, has been discussed in this context. But these details are beyond the limited scope of this paper, and such matters, as to a possible mechanism of “cause and effect,” are left for other researchers to study – again – implying the need for “further research” on these controversial and unsettled areas of space weather, earth science, and meta-analysis of individual analyses. ADDENDUM: After initial publication, we sent this paper (Version 1.0, pub. 5-19-2025) out to fellow-researchers in the Solar Weather community, and and one colleague asked if there was any difference in our findings based on “time-shift,” that is, “same day” versus what was observed 1-day (or more) after a “high” proton density day. Additionally, we shall look for other metrics that are readily found in our analyses, focusing on “apples-to-apples” comparison within each individual analysis—to make things more easily understood. Thus, we append our initial paper with additional summary findings – Time-shift SUMMARY: A meta-analysis of these analyses finds that Marchitelli was correct in claiming the 1-day shift had the highest correlation. The “same day” correlation was came in a “distant second” place, followed by a “very distant” 3rd-place and 4th-place (Last Place) finish for 2-day and 3-day times shifts, respectively. While our paper is primarily looking at “what” happened (data analysis), nonetheless, the overwhelming results found beg the question as to possible mechanism, which (on merely a 1st-order estimation by the undersigned author) seems to be possibly either the need for a small “time frame” for the earth's geomagnetic field to bounce around and induce currents after being hit by solar photon and/or the possibility that and reverse piezoelectric effects would cause weakening in the ground and/or molten core, and need time to stabilize and move around before an effect is had. These are just theories to pique interest and invite further research—no more – but beg the question of whether Schumann Resonance is set up or some other “long duration” phenomenon that delays the observed effects. Quake Magnitude SUMMARY: M5+ versus M6+ quakes – Thirty-nine (39) total head-to-head comparisons: M6+ won in 26 comparisons. // M5+ won in 13 comparisons. Total adds up to 39 (checks), so the anecdotal evidence I recall about larger magnitude quakes having stronger correlation to solar weather holds up 26-to-13 in a head-to-head comparison. “High” density threshold SUMMARY: Per above, the 99TH percentile shows a stronger correlation between seismic activity and solar proton density at the 99TH percentile (top 1%) than the 95TH percentile (top 5%) – even if only “by a hair.”

While slant stacking or plane wave decomposition is common in seismic data processing [1, 2], spherical wave decomposition (SWD) of the source wavefield has not been extensively used. We explore SWD for a point source under radial symmetry and demonstrate its application to multiple suppression using synthetic data with three primaries and their multiples. We show that SWD via hyperbolic τ-p transform allows cleaner separation of events and compare two inversion approaches: direct hyperbolic spreading and inverse linear τ-p with r 0 (τ) correction. The methodology demonstrates superior primary recovery and multiple attenuation.

Seismographs have recorded ground motion since the end of the 19th century until digital recordings became available in the 1970s. Pre-digital seismic records were typically created by using ink on white paper, scratching black-smoked paper, or by using light on photographic paper. With most of these legacy seismic data now stored in archives and exposed to physical decay, several projects in the last 20 years started to dedicate resources to digitising them to preserve and exploit the unexplored scientific wealth they contain and, in turn, introduce them into the age of modern seismology. This effort has become increasingly important due to the increasing risk of permanently losing those ageing paper seismograms combined with their recently found exclusive potential in recovering the global oceanic climate for the last century. The Royal Observatory of Belgium (ROB) possesses a vast archive of legacy seismic data, some of which has recently been scanned. Our project used computer vision and recently developed machine learning approaches to digitise waveform data extracted from these scanned images. This process results in the creation of calibrated and time-coded seismic time series, which can subsequently be disseminated to the scientific community via international web services following seismic community-defined standards. By providing access to continuous seismic data spanning the past century following the FAIR principles (findability, accessibility, interoperability, and reusability), the project aims to facilitate the investigation of historical oceanic climates using seismic data and to improve the accessibility to tools necessary for the digitization efforts across various institutes, observatories, and universities. Furthermore, the broad availability of quantitative observational data from around the world will significantly enhance existing oceanic wave models of the 20th century, contributing to climate research. We meticulously compiled all the information on the seismic archive of the ROB, along with its metadata. Our decision to concentrate on Galitzin data was informed by the instruments' high response in the microseismic frequency band, rendering them ideal proxies for sea state analysis. We developed an algorithm to vectorize and extract digital seismic waveforms from scanned seismograms using traditional computer vision techniques, supplemented by a distinct module leveraging deep neural networks to address more complex scenarios, such as line inter-crossing induced by high-amplitude events like earthquakes. We also developed a tool to compare vectorized waveforms with theoretical microseismic ground motions derived from the WaveWatch III oceanic models, facilitating initial validation of the time series. The work conducted within this project is continually evolving to ensure its enduring utility for the widest possible audience. Furthermore, the project has made significant contributions to the broader scientific community through the establishment of working groups, participation in international initiatives, provision of training courses, and ongoing contributions to a book chapter.

To address one of the central questions of plate tectonics-How do large transform systems work and what are their typical features?-seismic investigations across the Dead Sea Transform (DST), the boundary between the African and Arabian plates in the Middle East, were conducted for the first time. A major component of these investigations was a combined reflection/refraction survey across the territories of Palestine, Israel and Jordan. The main results of this study are: (1) The seismic basement is offset by 3-5 km under the DST, (2) The DST cuts through the entire crust, broadening in the lower crust, (3) Strong lower crustal reflectors are imaged only on one side of the DST, (4) The seismic velocity sections show a steady increase in the depth of the crust-mantle transition (Moho) from ∼26 km at the Mediterranean to ∼39 km under the Jordan highlands, with only a small but visible, asymmetric topography of the Moho under the DST. These observations can be linked to the left-lateral movement of 105 km of the two plates in the last 17 Myr, accompanied by strong deformation within a narrow zone cutting through the entire crust. Comparing the DST and the San Andreas Fault (SAF) system, a strong asymmetry in subhorizontal lower crustal reflectors and a deep reaching deformation zone both occur around the DST and the SAF. The fact that such lower crustal reflectors and deep deformation zones are observed in such different transform systems suggests that these structures are possibly fundamental features of large transform plate boundaries.

The study area lies within latitude N 07 to N 07 and longitude E 006’20” to E 006’45” on Ankpa Topographic Map Sheet 248NW. Biostratigraphic investigation was carried out by subjecting outcrop samples to palynological studies with view of determining the relative geologic age and paleoenvironment of deposition of the sediments. Thirty two outcrop samples from Odagbo Coal Mine were analyzed for both lithologic and palynomorph contents. Palynologic sample preparation went through sample digestion, floatation and mounting on glass slides in order to determine palynomorph contents such as pollen, spore, dinoflagellate, foraminifera lining and algae present. The samples were subjected to lithologic description through the observation of textural parameters and other important features to determine type of lithology and various units present in the sequence. Result of this study shows that the lithologic unit comprises of coal, dark to grey shale, sandstone, siltstone and mudstone. The heterolithic shales and siltstones yielded some well preserved palynomorphs consisting of angiospermous pollen and pteridophytic spores. Recovered angiosperms include among others Monocolpites, Echitriporites, and Psilatricolpites while Laevigatosporites, Longapertites and Funga spores constitute the spores. Also from Micropaleontological analysis, Ammobaculites spp., Saccammina spp., and Arenaceous indeterminate were recovered. The abundant occurrence of land derived palynomorphs suggest deposition of these sediments in a predominantly marine environment. Based on the recovered marker species and palynomorph assemblage, a Campanian to Maastrichtian age is suggested for these sediments.
Keywords: Biostratigraphic; Paleoenvironment; Marker Species; Odagbo; Anambra Basin

The stiffness of the base layer is an important parameter for designing the pavement thickness needed to support traffic loadings. It is normally related to the California bearing ratio (CBR). Currently, the CBR could be obtained from laboratory and field testing using Dynamic Cone Penetrometer (DCP). These methods are time consuming, destructive and costly. The spectral analysis of surface waves (SASW) method is hereby introduced as an in situ non destructive seismic technique to obtain the CBR and DCP values from the measurement and correlation of the dynamic properties of the pavement system. The relationship between the shear wave velocity and dynamic stiffness of the SASW were found to correlate well with DCP and CBR. The empirical correlations of CBR to dynamic stiffness in terms of elastic modulus were found to be similar to the correlation suggested by Shell (1978). Preliminary analysis also indicated that the empirical model was useful for predicting pavement base layer mod...

In this work, we develop a multidisciplinary approach to investigate a geothermal system located at the volcanic arc of a subduction-related orogen and highlight the interplay between active tectonism, stress field and fluid migration. By using results of field investigations from the Tinguiririca geothermal field in the High Andes of Chile (35 S), empirical analysis, and numerical models of static stress variations, we proposed a geomechanical model for evaluating the distribution of hydrothermal manifestations in a seismically-active region. The present geomechanical model follows four major steps: (1) development of the 3D structural model of fault pattern; (2) estimation of the in-situ stress field; (3) calculation of the resolved-shear-to-normal-stress ratio (slip tendency) on each fault with varying geomechanical parameters (coefficient of friction, pore pressure and cohesion) as inputs; and (4) estimation of Coulomb static stress changes as a consequence of failure in a nearby fault. Through combination of all these analyses, we characterize in detail both the active deformation in the geothermal field and its relationship with hot fluid migration.

Si bien en el noroeste argentino existen numerosos sitios de interés para la explotación del recurso geotérmico, la mayoría de ellos sólo cuenta con estudios de reconocimiento. En esta contribución se presentan los resultados del estudio geoquímico de los fluidos relacionados al sistema geotermal El Sauce utilizados para construir un modelo conceptual preliminar, donde se describe el origen de los compuestos y las condiciones de P-T de los fluidos dentro del reservorio. La caracterización geoquímica se realizó mediante el muestreo directo de aguas y gases, y el posterior análisis de su composición química e isotópica. El reservorio geotermal, alojado en la Formación Yacoraite, adquiere una composición HCO3¯-Na+ por interacción agua-roca, favorecida por el aporte de CO2 cortical. Los gases atmosféricos disueltos en las aguas meteóricas que recargan el acuífero dominan la composición de la fase gaseosa. El acuífero profundo se mezcla con acuíferos salinos de composición Cl¯(SO42-)-Na+...

N. Favretto-Cristinia, P. Cristinia, A. Tantserevab, B. Ursinb, D. Komatitscha et A.M. Aizenbergc aCNRS, Laboratoire de Mécanique et d’Acoustique UPR 7051, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France bNTNU -Department of Petroleum Engineering and Applied Geophysics, S.P. Andersens vei 15A, N-7491 Trondheim, Norvège cInstitute of Petroleum Geology and Geophysics SB RAS, Pr.Ac.Koptyug 3, 630090 Novosibirsk, Fédération de Russie favretto@lma.cnrs-mrs.fr CFA 2014 Poitiers 22-25 Avril 2014, Poitiers

To address one of the central questions of plate tectonics-How do large transform systems work and what are their typical features?-seismic investigations across the Dead Sea Transform (DST), the boundary between the African and Arabian plates in the Middle East, were conducted for the first time. A major component of these investigations was a combined reflection/refraction survey across the territories of Palestine, Israel and Jordan. The main results of this study are: (1) The seismic basement is offset by 3-5 km under the DST, (2) The DST cuts through the entire crust, broadening in the lower crust, (3) Strong lower crustal reflectors are imaged only on one side of the DST, (4) The seismic velocity sections show a steady increase in the depth of the crust-mantle transition (Moho) from ∼26 km at the Mediterranean to ∼39 km under the Jordan highlands, with only a small but visible, asymmetric topography of the Moho under the DST. These observations can be linked to the left-lateral movement of 105 km of the two plates in the last 17 Myr, accompanied by strong deformation within a narrow zone cutting through the entire crust. Comparing the DST and the San Andreas Fault (SAF) system, a strong asymmetry in subhorizontal lower crustal reflectors and a deep reaching deformation zone both occur around the DST and the SAF. The fact that such lower crustal reflectors and deep deformation zones are observed in such different transform systems suggests that these structures are possibly fundamental features of large transform plate boundaries.

To address one of the central questions of plate tectonics-How do large transform systems work and what are their typical features?-seismic investigations across the Dead Sea Transform (DST), the boundary between the African and Arabian plates in the Middle East, were conducted for the first time. A major component of these investigations was a combined reflection/refraction survey across the territories of Palestine, Israel and Jordan. The main results of this study are: (1) The seismic basement is offset by 3-5 km under the DST, (2) The DST cuts through the entire crust, broadening in the lower crust, (3) Strong lower crustal reflectors are imaged only on one side of the DST, (4) The seismic velocity sections show a steady increase in the depth of the crust-mantle transition (Moho) from ∼26 km at the Mediterranean to ∼39 km under the Jordan highlands, with only a small but visible, asymmetric topography of the Moho under the DST. These observations can be linked to the left-lateral movement of 105 km of the two plates in the last 17 Myr, accompanied by strong deformation within a narrow zone cutting through the entire crust. Comparing the DST and the San Andreas Fault (SAF) system, a strong asymmetry in subhorizontal lower crustal reflectors and a deep reaching deformation zone both occur around the DST and the SAF. The fact that such lower crustal reflectors and deep deformation zones are observed in such different transform systems suggests that these structures are possibly fundamental features of large transform plate boundaries.

Seismic data contains reflections along with diffractions. Diffractions in seismic data are related to different features like faults, fractures, pinchouts and rough edges of salt bodies. It follows that suppression of reflections and enhancement of diffractions can be very useful for seismic interpretation of various subsurface features that cause diffractions. During the last years, different techniques have been proposed to separate reflections from diffractions. In this study both simple synthetic test data and complex synthetic data (Sigsbee2a) have been used to investigate the modified version of the Common Reflection Surface (CRS) technique. The simple synthetic data were sorted into different domains to investigate the difference in signature of reflections and diffractions. A two-step procedure based on CMPsorting followed by zero-offset (eventually constant-offset) sorting seemed to give a good diffraction separation. Optimal parameters were determined based on Semblance as a coherency measure. This separation scheme was applied to a complex controlled data set (Sigsbee2a) and diffractions were successfully separated from reflections. Acknowledgements .

The paper proposes the results of a research industry project concerning predictive maintenance process optimization, applied to a machine cutting polyurethane. A company producing cutting machines, has been provided with an online control system able to detect blade status of a machine supplied to a customer producing polyurethane components. A software platform has been developed for the real time monitoring of the blade status and for the prediction of the break up conditions adopting a multi-parametric data analysis approach, based on the simultaneous use of unsupervised and supervised machine learning algorithms. Specifically, the proposed method adopts a k-Means algorithm to classify bidimensional risk maps, and a Long Short Term Memory (LSTM) one to predict the alerting levels based on the analysis of the last values for some process variables. The analysed algorithms are applied to an experimental dataset.

To address one of the central questions of plate tectonics-How do large transform systems work and what are their typical features?-seismic investigations across the Dead Sea Transform (DST), the boundary between the African and Arabian plates in the Middle East, were conducted for the first time. A major component of these investigations was a combined reflection/refraction survey across the territories of Palestine, Israel and Jordan. The main results of this study are: (1) The seismic basement is offset by 3-5 km under the DST, (2) The DST cuts through the entire crust, broadening in the lower crust, (3) Strong lower crustal reflectors are imaged only on one side of the DST, (4) The seismic velocity sections show a steady increase in the depth of the crust-mantle transition (Moho) from ∼26 km at the Mediterranean to ∼39 km under the Jordan highlands, with only a small but visible, asymmetric topography of the Moho under the DST. These observations can be linked to the left-lateral movement of 105 km of the two plates in the last 17 Myr, accompanied by strong deformation within a narrow zone cutting through the entire crust. Comparing the DST and the San Andreas Fault (SAF) system, a strong asymmetry in subhorizontal lower crustal reflectors and a deep reaching deformation zone both occur around the DST and the SAF. The fact that such lower crustal reflectors and deep deformation zones are observed in such different transform systems suggests that these structures are possibly fundamental features of large transform plate boundaries.

In this study we focused on seismic attenuation (1/ Q c ) tomography in Northern Morocco. For this purpose, two different models are employed: The Single Backscattering model hypothesis of to calculate values of Coda Q (Q c ) and the Back-projection technique of to estimate lateral variation in Q c via a tomographic inversion. For this investigation, the Coda Q method is applied to a number of 94 local earthquakes with a magnitude between Ml=0.7 and Ml=4. The digital seismograms of these earthquakes were recorded during the year 2008 by both local temporary and permanent broadband seismic station network deployed in Northern of Morocco. The Q c quality factor values have been computed at central frequencies 0.75, 1.5, 3, 6 and 12 Hz. The lapse time windows are restricted to 30s in order to sample the earth's crust only. The Q c results indicate that strong frequency dependence follow a power law for the entire area. The preliminary results of seismic Coda Q c attenuation tomography shows a dependence at each frequency band, between seismic attenuation and the geology structure units in the study area, especially in the region of Al Hoceima and the eastern part of the Rif which are characterized by high attenuation values due to active faults area, while low attenuation values are seen in the west and the south of the Rif in high frequencies.