Salt Movement Research Articles

Prediction of salt transport in different soil textures under drip irrigation in an arid zone using the SWAGMAN Destiny model

In recent years, Xinjiang Oasis has faced a major challenge of increasing risk of secondary salinization caused by drip irrigation under plastic mulch. Predicting the salt balance is therefore essential for understanding how to sustain the use of salinized land in this arid area. This research validated the SWAGMAN (Salt, Water And Groundwater MANagement) Destiny model to simulate and forecast the movement of salt in different soil textures based on field experiments. The results were verified with extensive field work in Shihutan, Xinjiang, China. They show that soil salinity decreases in the upper layers and increases in the bottom layers of the investigated soil profile. The desalinization rate in sand, which shows an overall steady trend throughout the soil profile, is generally higher than that in loam and clay. The depth of 60cm is critical for loam and clay; soil salinity decreases above it but increases below it. Model sensitivity analysis reveals the variation of soil salinity is independent of the initial electrical conductivity setting of SWAGMAN Destiny simulations. This study indicates that numerical modelling is a useful approach for efficiently estimating the salt balance under drip irrigation. The result provides a scientific basis for making adaptive strategies to manage salinised farmlands in arid zones.

Paleogeographic Reconstitution and Tangential Tectonic in the Backland of Tunisian Dorsal (Fahs Area: J. Rouas and Ruissate)

The Tunisian Dorsal backland is the Eastern Atlas side of maghrebides. Field data of Fahs area allowed us to develop new interpretations and to characterize the main structural features of the studied devices (Jebel Rouas and Ruissate). Heritage of Zaghouan accident, Triassic salt movements and strike-direction of major synsedimentary faults are the principal causes and results of the skinned and superimposed geometric architecture, generated by the reversed extensional (Jurassic-Cretaceous) tectonics. The actual geometry of Jebel Rouas and Ruissate represents a fault propagation fold, affecting Jurassic and Cretaceous sets. The backland of this thrust fault defines an imbrications structures of Barremian series. Tectonic records activities show the existence of angular unconformities (Oligocene and Eocene series on the Cretaceous sets considered as bedrock), slumps, tectonic breccias and synsedimentary faults are all of them controlled by a deep major accident; N-S to NE-SW and NW-SE. Features of the study area are probably related first; to the blockage of Zaghouan thrust oriented NE-SW in the foreland; then, to the intense halokinetic activity, which facilitates the layers displacement acting as decollment level. The detailed structural and stratigraphic study of Fahs area and its neighbors shows the presence of an intense tangential tectonic during upper Miocene, affecting Meso-Cenozoic sets, because all the structures involved are sealed by Oligocene and Miocene thinned series. This is accentuated by the existence of different sets of decollment at different depths, which are represented by a displacement to the SE through the backland of the Tunisian Dorsal. We define these features as an imbrication and thrusting Out of sequence system.

Study on Movement of Water and Salt through Soil Column and Utilization of Hydrus-1D Program to Simulate Five Scenarios of Crop Production in Salt Affected Paddy Soil

<p class="zhengwen"><span lang="EN-GB">An experiment was conducted on the purpose to study movement of water and salt through soil column. Salt-affected paddy soil was assessed for its relevant transport parameters consisting of the hydraulic and the solute transport parameters. The hydraulic parameters included soil hydraulic conductivity (K<sub>s</sub>) and the van Genuchten’s parameters (θ<sub>s</sub>, θ<sub>r</sub>, α, and n). In this experiment the solute transport parameters was referred to the coefficient of Langmuir’s isotherm which consisted of k<sub>d</sub> and η. Experience showed that hydraulic parameters were sensitive to changes of soil bulk density (ρ<sub>b</sub>). Therefore pedotransfer functions describing the relations between these parameters with ρ<sub>b</sub> were established. Straight line functions were found for θ<sub>s</sub> and n, exponential functions were found for α and K<sub>s</sub>, and logarithmic function was found for θ<sub>r</sub>. Packing the soil in the physical column inevitably caused horizontal differentiation of different ρ<sub>b</sub>. Bulk density of each layer was estimated by analysis of water flow through soil column at steady-state. Then ρ<sub>b</sub> of each layer was calculated from the relation K<sub>s</sub> (ρ<sub>b</sub>). After the ρ<sub>b</sub> was known the van Genuchten’s parameters were calculated from the pedotransfer functions. A physical column of 4 inches diameter and 50 cm length was constructed. Sodium chloride solution EC 6 dS/m was fed on soil surface during the process of salinization and the feeding solution was changed to fresh water during the process of desalinization. Breakthrough solution was analyzed for Na concentration and the breakthrough curves were constructed. The relevant parameters as well as initial and boundary conditions were fed into Hydrus-1D on the purpose to simulate the breakthrough curves. Statistical comparison results using t-test and RMSE suggested that Hydrus-1D could be used successfully to monitor transport of water and salt through soil column.</span></p><p class="zhengwen"><span lang="EN-GB">Five scenarios concerning water and solute transport through soil profile under rice and mung bean cropping were simulated using Hydrus-1D. Simulation results suggested that continuous flooding was the most efficient way to leach soluble salts down to ground water. Wet/dry irrigation scheme for rice production could drain salts only when rice crop was in the first period of growth where crop water uptake was small. During later stages of growth concentration profile of Na remained almost unchange indicating negligible downward movement of salts. Leaving the soil to dry naturally during the dry season caused upward accumulation of salt to the degree smaller than cultivating mung bean since water content and hence the diffusion coefficient of the soil were higher and more favorable for upward salt diffusion than in the former case. Inserting the capillary rise hindering soil layer underneath mung bean root zone was found to retard upward diffusion of salt to the degree comparable to leaving the soil to dry naturally.</span></p>

Modeling and assessing field irrigation water use in a canal system of Hetao, upper Yellow River basin: Application to maize, sunflower and watermelon

Water saving in irrigation is a key issue in the upper Yellow River basin. Excessive irrigation leads to water waste, water table rising and increased salinity. Land fragmentation associated with a large dispersion of crops adds to the agro-hydrological complexity of the irrigation system. The model HYDRUS-1D, coupled with the FAO-56 dual crop coefficient approach (dualKc), was applied to simulate the water and salt movement processes. Field experiments were conducted for maize, sunflower and watermelon crops in the command area of a typical irrigation canal system in Hetao Irrigation District during 2012 and 2013. The model was calibrated and validated in three crop fields using two-year experimental data. Simulations of soil moisture, salinity concentration and crop yield fitted well with the observations. The irrigation water use was then evaluated and results showed that large amounts of irrigation water percolated due to over-irrigation but their reuse through capillary rise was also quite large. That reuse was facilitated by the dispersion of crops throughout largely fragmented field, thus with fields reusing water percolated from nearby areas due to the rapid lateral migration of groundwater. Beneficial water use could be improved when taking this aspect into account, which was not considered in previous researches. The non-beneficial evaporation and salt accumulation into the root zone were found to significantly increase during non-growth periods due to the shallow water tables. It could be concluded that when applying water saving measures, close attention should be paid to cropping pattern distribution and groundwater control in association with irrigation scheduling and technique improvement.

Evidence of early halokinesis in the Zechstein Group suggests the formation of Permian-Triassic carbonates build-ups offshore UK (Quad. 20-21)

The Upper Permian Zechstein Group comprises sequences of carbonate and evaporites, which extend over most of the onshore areas in North- West Europe, from Britain to Poland, and across the central and southern North Sea, bringing important economic value to hydrocarbon exploration. The nature and distribution of the evaporitic facies are key factors influencing the deposition, thermal evolution and the trap¬ping mechanism in the overburden section, as well as the sealing of the Early Permian-Carboniferous units under¬neath. The Zechstein Group includes source rocks from anoxic shale and microbialites, reservoirs from shallow water carbonate and several levels of seals from anhydrites and halite (Karnin et al., 1992; Cooke-Yarborough 1994; Slowakiewicz et al., 2013). The early salt movements have been tracked back to the Triassic and Jurassic (Glennie and Higham, 2003 and references therein), under different tectonic regimes between the Jurassic-Cretaceous rifting, to the Paleogene inversion, active in the remote foreland of the Alpine Orogeny. The lateral facies distribution has been largely described as a result of different subsidence rates and climatic fluctuation in the Zechstein Basin (Figure 1). Well data confirms the complex architecture of this basin at different scales (Geluk, 2000).

Salt removal from soil using the argil porous ceramic

In this study, porous ceramic columns formed by argil of traditional pottery were used to remove salt from the saline soils. Experiences were conducted in a laboratory prototype to determine the salinity variation in different soil depths and locations as well as the salt germination and deposal on the porous ceramic. The obtained experimental results showed that this technique has effectively reduced the soil salt's concentration by 95%.Moreover, samples from the porous ceramic material were analyzed before and after application for the salt extraction from the soil. The analyses using the scanning electron microscopy (SEM) had showed the importance of the pore's dimensions and structures on the solution movement and salt deposal. In addition, the possible mechanisms of salt movement and deposal such as evaporation, interaction between saline solution and porous ceramic and salt ionic germination were discussed. Even a comparison with the Electrokinetic (EK) desalination method was performed to reveal the importance of using the porous ceramic column that constitutes a simple, cheap, preferment and appropriate environmental process.

Modelling the coupling between salt kinematics and subsidence evolution: Inferences for the Miocene evolution of the Transylvanian Basin

Large-scale diapiric salt movements affect the architecture of sedimentary basins and often prevent the understanding of their mechanics by hiding or distorting subsidence patterns. One good example is the evolution of the Transylvanian Basin, which formed during Miocene times in an area located in between the rapid slab rollback and continental collision recorded at the exterior of the Carpathians and the extension of the neighbouring Pannonian Basin. In the absence of major genetic fault systems, quantifying these external tectonic forcing factors requires an accurate reconstruction of subsidence evolution. Having the advent of a detailed 3D geometrical model of the Transylvanian Basin, we apply a 3D numerical modelling technique that couples salt re-distribution and subsidence evolution to quantify and understand the basin kinematics and vertical motions. Two techniques, backward and forward modelling are coupled in order to discriminate between salt migration driven by overburden and the influence of external tectonic forcing factors. The results show that salt kinematics was more complex than simple unidirectional migration, suggesting the existence of areas with significant subsidence hidden by the inward salt migration and areas with apparent large subsidence that are in reality artefacts of outwards salt migration. Additionally, the results suggest that parts of the basin have been successively affected by in- and out-ward salt migration events, an effect of localising subsidence and overburden. Furthermore, accelerated moments of salt migration took place during the main Miocene contraction events recorded at the exterior of the Carpathians, demonstrating that salt migration is enhanced by intraplate stresses. Our study also infers that the subsidence of the Transylvanian Basin is the result of the superposition of the contraction at the exterior of the orogenic chain and the back-arc extension.

Dual-well 3D vertical seismic profile enabled by distributed acoustic sensing in deepwater Gulf of Mexico

We have acquired and processed 3D vertical seismic profile (VSP) data recorded simultaneously in two wells using distributed acoustic sensing (DAS) during the acquisition of the 2012 Mars 4D ocean-bottom seismic survey in the deepwater Gulf of Mexico. The objectives of the project were to assess the quality of DAS data recorded in fiber-optic cables from the surface to the total depth, to demonstrate the efficacy of the DAS VSP technology in a deepwater environment, to derisk the use of the technology for future water injection or production monitoring without intervention, and to exploit the velocity information that 3D VSP data provide for evaluating and updating the velocity model. We evaluated the advantages of DAS VSP to reduce costs and intrusiveness, and we determined that high-quality images can be obtained from relatively noisy raw 3D DAS VSP data, as evidenced by the well 1 image, probably the best 3D VSP image we have ever seen. Our results also revealed that the direct arrival traveltimes can be used to assess the quality of an existing velocity model and to invert for an improved velocity model. We identified issues with the DAS acquisition and the processing steps to mitigate them and to handle problems specific to DAS VSP data. We described the steps for conditioning the data before migration, reverse time migration, and postmigration processing to reduce noise artifacts. We outlined a novel first-break picking procedure that works even in the absence of a strong first arrival and a velocity diagnosis method to assess and validate velocity models and velocity updates. Finally, we determined potential applications to 4D monitoring of fluid movement around producer or injector wells, identification of active salt movements, and more accurate imaging and monitoring of complex structures around the wells.

Transport of solutes under transient flow conditions – A case study – Yamuna river sub basin (Kosi Kalan to Agra)

The imbalance between incoming and outgoing salt causes salinization of soils and sub-soils that result in increasing the salinity of stream-flows and agriculture land. This salinization is a serious environmental hazard particularly in semi-arid and arid lands. In order to estimate the magnitude of the hazard posed by salinity, it is important to understand and identify the processes that control salt movement from the soil surface through the root zone to the ground water and stream flows. In the present study, Yamuna sub-basin (both sides of Gokul dam site) has been selected which has two distinct climatic zones, sub-humid (upstream of Mathura) and semi-arid region (downstream of Mathura). In the upstream, both surface and ground waters are used for irrigation, whereas in the downstream mostly groundwater is used. Both soils and ground waters are more saline in downstream parts of the study area. In this study we characterized the soil salinity and groundwater quality in both areas. An attempt is also made to model the distribution of potassium concentration in the soil profile in response to varying irrigation conditions using the Soil-Water Infiltration and Movement (SWIM) model. Fair agreement was obtained between predicted and measured results indicating the applicability of the model.

Evolution of a highly dilatant fault zone in the grabens of Canyonlands National Park, Utah, USA – integrating fieldwork, ground-penetrating radar and airborne imagery analysis

Abstract. The grabens of Canyonlands National Park are a young and active system of sub-parallel, arcuate grabens, whose evolution is the result of salt movement in the subsurface and a slight regional tilt of the faulted strata. We present results of ground-penetrating radar (GPR) surveys in combination with field observations and analysis of high-resolution airborne imagery. GPR data show intense faulting of the Quaternary sediments at the flat graben floors, implying a more complex fault structure than visible at the surface. Direct measurements of heave and throw at several locations to infer fault dips at depth, combined with observations of primary joint surfaces in the upper 100 m, suggest a highly dilatant fault geometry. Sinkholes observed in the field as well as in airborne imagery give insights in local dilatancy and show where water and sediments are transported underground. Based on correlations of paleosols observed in outcrops and GPR profiles, we argue that either the grabens in Canyonlands National Park are older than previously assumed or that sedimentation rates were much higher in the Pleistocene.

Mass-transport deposits and reservoir quality of Upper Cretaceous Chalk within the German Central Graben, North Sea

The architecture of intra-chalk deposits in the ‘Entenschnabel’ area of the German North Sea is studied based on 3D seismic data. Adapted from seismic reflection characteristics, four types of mass-transport deposits (MTDs) are distinguished, i.e. slumps, slides, channels and frontal splay deposits. The development of these systems can be linked to inversion tectonics and halotectonic movements of Zechstein salt. Tectonic uplift is interpreted to have caused repeated tilting of the sea floor. This triggered large-scale slump deposition during Turonian–Santonian times. Slump deposits are characterised by chaotic reflection patterns interpreted to result from significant stratal distortion. The south-eastern study area is characterised by a large-scale frontal splay complex. This comprises a network of shallow channel systems arranged in a distributive pattern. Several slide complexes are observed near the Top Chalk in Maastrichtian and Danian sediments. These slides are commonly associated with large incisions into the sediments below. Best reservoir properties with high producible porosities are found in the reworked chalk strata, e.g. Danish North Sea, therefore MTDs detected in the study area are regarded as potential hydrocarbon reservoirs and considered as exploration targets.

From the Other Side

In the last FTOS (April TLE), I had a nice chat with Alistair Brown on the subject of interpretation. One of my points suggested that the result greatly hinges on whether your objective is “what” or “why” it's there. My issue with salt domes and salt movement is on the “why” side rather than “what.” The geophysical industry, which includes smart and experienced people, has done a marvelous job of analyzing and displaying the seismic data associated with salt bodies. We know with a fair amount of certainty “what” is there. Someone needs to come up with the “why” answer (how it got there).

Hydrocarbon source rock generative potential of the Sudanese Red Sea basin

To date, the Sudanese Red Sea like the Red Sea as a whole, represents a grossly under-explored basin. Recently, the basin has seen increased exploration interest, with more than 15 wells being drilled, some of which have been petroleum discoveries (gas and condensate with oil shows). A similar exploration trend has been seen in the Saudi, Eriteria and Egyptian sectors of the Red Sea. The Red Sea rift marks the break-up of the Afro-Arabian plate in Eocene–Oligocene time. The tectonostratigraphic evolution can be subdivided into three major phases: Pre-rift, Syn-rift and Post-rift phase. Generally, terrestrials and marginal to deep marine sediments were deposited with both good reservoir quality and potential source rocks being present. The pre-Salt Rudeis/Kareem shales are expected to be good petroleum source rocks for the basin. Moreover, shales of base Zeit (post-Salt) are considered the main source of the known accumulated hydrocarbon (gas and condensate) in the shallow targets with the condensate charge also expected from intra-evaporites shales and pre-salt sources along the salt windows. The measured amount of TOC, HI, and hydrocarbon generation from pyrolysis of kerogen of the examined samples indicate source rock generative potential of these intervals. The TOC contents for base Zeit, and interbeded shales of Dungnab Formations, range from 0.60& to 5.40 wt. %, while the hydrogen index (HI) values are in the range of 50-600mg HC/gTOC suggesting dominantly type III-II kerogen. The high TOC (>1.5) and HI (>300) values of base Zeit and Dungnab Formations are limited to some intervals within these formations. Consequently, the base Zeit source rocks are considered very good for condensate and gas generation. In comparison to their equivalents Burqan and Maqna Group sources (HI = 350–600 mg HC/gTOC) on the Saudi Red Sea sector, Rudeis/Kareem shales could perhaps possess good quality type-II kerogen. The Red Sea’s high pressure and temperature regimes have a significant impact on hydrocarbon maturation, generation and the quality of the preserved accumlations. Presently, the Zeit source varies in maturity across the basin and within the oil window in the Suakin and Bashayer areas and at gas window elsewhere to the east towards offshore. On the other hand, the pre-salt Rudies/Kareem Formations are currently in the late oil to wet gas zone and probably out of gas phase distally offshore. However, the salt tectonics makes for challenging exploration. The salt movement is considered recent as it is only the recent sediments that appear to be controlled by salt movement.

Numerical modeling of the effect of composite rheology on internal deformation in down-built diapirs

A two-dimensional finite difference code (FDCON) is used to estimate the progressive deformation and the effect of a composite rheology, i.e., Newtonian combined with non-Newtonian, on finite deformation patterns within a down-built diapir. The geometry of the diapir is fixed using two rigid rectangular overburden units which sink into a source layer of a certain viscosity. We have analyzed the progressive deformation within the entire salt layer for a composite rheology and compared them to a standard model with Newtonian rheology (ηs=1018Pas). The composite rheology models show a more complex deformation patterns in comparison to the standard model. Deformation is more localized within the source layer, leaving a broader less deformed zone within the middle of the source layer. In comparison to the standard model, ellipticity (R) of the strain ellipse is amplified by a factor of up to three in high deformation regions with a finite deformation f larger than two (f=log10(R)). Initially vertical and horizontal passive marker-lines within the salt layer, are folded during salt movement. Initially horizontally-oriented marker-lines in the source layer show upright folds within the middle of the stem. Within the source layer, initially vertical marker-lines form recumbent folds, which are refolded during their flow from the source layer into the stem. During their refolding, the hinge of the fold migrates outward towards the flank of the diapir. A temporal and spatial hinge migration is observed for sub-horizontal folds that originated in the source layer as they are refolded. We have also studied both the effect of curved versus sharp corners between the source layer and the stem on strain evolution within both the feeding source layer and the down-built diapir. Strain evolution and hinge migration are strongly influenced by the geometry of the corner between the source layer and the stem.

Salt water dynamics under point source of drip irrigation-A Review

The shrinking fresh water resources have motivated many researchers to investigate and evaluate the use of poor quality saline water using improved irrigation techniques such as drip irrigation. Saline water application through a point drip source in the root zone adversely impact the crop due to accumulated salts. The shape of wetted soil volume has remained of great interest since the advent of drip irrigation. The accumulation of the salts is mostly found towards the outer wetted zone, the knowledge of the actual shape and size in case of a point source of drip irrigation has remained a matter of concern to researchers for the purpose of design and operation of this irrigation system could be further refined. An attempt has been made in this paper to review the works conducted and reported worldwide and specially in India to monitor and evaluate the wetting front and salt movement within it under a point source of drip irrigation. This review can guide a definite methodology to evaluate salt accumulation and its impact on crop growth as well as its mathematical modelling.

不同隔盐措施对滨海盐碱地土壤水盐运移及刺槐光合特性的影响

Soil salinization is a major obstacle to the optimal utilization of land resources. Salt-affected soils are widely distributed throughout the world. The present extent of salt-affected soils substantially restricts plant growth in these areas. It has been demonstrated that leaching with water,chemical amendment,surface mulching with straw and phytoremediation are the most often used approaches to ameliorate saline soils. Engineering measures are also an effective solution to control salt movement in the saline soil. Establishing salt-isolation interlayers beneath the surface of saline soil is one of the most widely used engineering measures. Even though there are many studies dealing with salt-isolation interlayers establishment,very little is known about their effects on saline soil. Here,we used three salt-isolation materials to restrict the water andsalt movements in saline soil: zeolite,ceramsite and river sand. The aim of this study was to assess the effects of saltisolation interlayers application on soil water and salt movements in saline soil and on the photosynthetic characteristics of Robinia pseudoacacia in the coastal regions of Tianjin city. We also anticipate that the outcome of the study could form part of the basis for selection of salt-isolation materials in improving coastal saline soil with consideration of their costs. The research was conducted from April 2010 to August 2013 at the Coastal Salt-tolerant Plant Science and Technology Park,Dagang,Tianjin,China. An experiment was conducted with four treatments:( 1) No addition of slat-isolation interlayer( CK);( 2) Addition of zeolite( FS) at the bottom and side walls of the planting sites;( 3) Addition of ceramsite( TL) at the bottom and side walls of the planting sites;( 4) Addition of river sand( HS) at the bottom and side walls of the planting sites. All treatments were arranged in a randomized complete block design with four blocks. Each block was again divided into four plots. The four treatments were randomly assigned to each plot within the individual blocks with a separate randomization for each block. The salt-isolation materials were added to nine planting sites in each plot. The nine sites were evenly distributed based on a planting spacing of 3 m× 3 m. Each planting site was 1 m× 1 m× 1 m. The results indicated:( 1) Salt-isolation interlayers could significantly increase soil water content of tree planting site. FS treatment performed best and had the lowest salt content and salt solute concentration,followed by TL. Relative to the CK,HS had no significant effects on salt content and salt solute concentration.( 2) FS treatment significantly increased the leaf photosynthetic rate( Pn),transpiration rate( Tr),stomata conductance( Gs) and leaf water use efficiency( LWUE),and reduced intercellular CO2concentration( Ci). TL treatment can also significantly enhance Pn、Tr,but it had no significant effects on Gs、Ci and LWUE. HS treatment had significantly increased Pn and Tr,and reduced LWUE. We concluded that the zeolite was an optimal salt-isolation material in controlling salt movement in saline soil and improving tree growth in the coastal regions.

Imaging the Evolution of Brine Transport in Experimentally Grown Quasi-two-dimensional Sea Ice

Anthropogenic climate change is affecting the extent and composition of sea ice,modifying the movement of salt, gases and nutrients in the ocean-ice-atmosphere system. In order to understand how these changes will feedback into the climate system, it is necessary to understand how brine and fresher water are transported during the phase changes as sea ice grows and melts. We present here the methodology and preliminary results of an experimental approach visualizing the convective movements of brine and fresher water as sea ice grows in a quasi-two-dimensional set-up, using Schlieren imaging techniques.

The Biggest Salt-Tongue Canopy of Central Iran

One of the most interesting salt structures is salt-tongue canopy. The Central Iran basin has a few salt provinces and in this paper, morphotectonic concept of the salt-tongue canopy on the west of Garmsar city has been investigated. In this study, field data coupling with the salt tectonic-related factors to provide a position for salt rocks in the west Garmsar. Firstly, various geological factors such as faults, folds and roads were extracted and compiled. This is because the factors mentioned above play important role in the instability of the region. The results of this study showed that the salt extrusion from the Lower Red formation is severe. Further, it is evident that the shortening of main structures has had a great impact on it whilst the salt movements have occurred within Garmsar Syncline. Finally, the paper concluded that the salt-tongue canopy in the region has increased the rates of salt extrusion.

CFTR: a missing link between exocrine and endocrine pancreas?

CFTR: a missing link between exocrine and endocrine pancreas?

Analysis of Oil-Volume Fluxes of Hydrocarbon-Seep Formations on the Green Canyon and Mississippi Canyon: A Study With 3D-Seismic Attributes in Combination With Satellite and Acoustic Data

Summary Natural hydrocarbon seeps have an important role in the carbon cycle and in the Gulf of Mexico (GOM) ecosystem. The magnitude of these natural oil seeps was analyzed with 3D-seismic attributes in combination with satellite and acoustic data. Hydrocarbon seepage in the deep water of the GOM is associated with deep cutting faults, generated by vertical salt movement, that provide conduits for the upward migration of oil and gas. Seeps transform surface geology and generate prominent geophysical targets that can be identified in 3D-seismic data. Seafloor-amplitude anomalies in plain view correlate with the underlying fault systems. On the basis of 3D-seismic data, detailed mapping of the northern GOM has identified more than 24,000 geophysical anomalies across the basin. In addition to seismic data, synthetic-aperture-radar (SAR) images have proved to be a reliable tool for localizing natural seepage of oil. We used a texture-classifier neural-network algorithm (TCNNA) to process more than 1,200 SAR images collected over the GOM. We quantified more than 1,000 individual seep formations distributed along the outer continental shelf and in deep water. Comparison of the geophysical anomalies with the SAR oil-slick targets shows good general agreement between the distributions of the two indicators. However, there are far fewer active oil seeps than geophysical anomalies, probably because of timing constraints during the basin evolution. Studying the size of the oil slicks on the surface (normalized to weather conditions), we found that the average flux rate of oil (per seep) may be affected by the local change in the baroclinic and barotrophic pressures [e.g., warm core eddies (WCEs) and storms]. We found that oil slicks in the Mississippi Canyon (MC) protraction area tend to be more sensitive to pressure changes than Green Canyon (GC) protraction-area seeps.