Low Density Contrast Research Articles

Partial crystallization in Pd-BMG systems: From understanding structure towards influencing functionality through temperature-time series

Small quantities of crystalline domains created in an amorphous matrix are seen as an active driver for enhanced properties in bulk metallic glasses (BMGs). We investigated partial crystallization and phase transformations through a series of isotherms at 370°C performed on amorphous Pd-based BMG samples with the nominal composition of Pd43Cu27Ni10P20 (Pd-BMG) and a density of 9.425 g/cm3. X-ray based methods such as X-ray diffraction (XRD) and phase enhanced micro-computed tomography (μ-CT) have been pushed to their limits for studying atomic structure and morphology, while time available before crystallization has additionally been investigated via differential scanning calorimetry (DSC), and are combined with optical microscopy (OM), scanning electron microscopy (SEM), and hardness measurements for their mechanical properties. We reveal that Pd-based BMG samples isothermally treated at 370 °C start to crystallize after 20 min and still undergo phase transformations and recrystallization even after being fully crystalline after 60 min of the isothermal treatment. Interestingly, 3D phase enhanced micro-computed tomography shows a clear separation of two domains of slightly different densities. We highlight X-ray tomographic scans, allowing the 3D spatial visualization of extremely low-density contrast in different material domains, thus providing a multi-scale physical description of the Pd-BMG system. Interesting is the fact, that the re-crystallization is not homogenous and the crystalline domains can reach large size of (100–200 μm) in an amorphous matrix.

Antibubble column: A mean to measure and enhance liquid–gas mass transfer through surfactant-laden interfaces

Antibubbles are ephemeral objects composed of a liquid core encapsulated by a thin gas shell immersed in a liquid bulk. The gas shell thickness evolves in time, driven by two contributions: gravitational drainage and gas–liquid mass transfer. The low density contrast between the antibubble and the bulk, as well as its weak deformability constitute advantages that are used to measure the mass transfer coefficient (MTC) in a so-called antibubble column, in a time-resolved fashion. Shells made with pure air give low data reproducibility. Consequently, perfluorohexane, a low-solubility gas, was mixed to air to enforce gas desorption from the bulk and obtain reliable data. MTC obtained with various surfactants and concentrations are found to deviate from the Frössling correlation built for fully rigid interfaces: higher MTC are consistent with partially rigid interfaces due to a partial coverage of surfactants along a so-called spherical cap, while lower MTC are consistent with an additional resistance to the transfer of mass due to the presence of surfactants forming a monolayer at high concentration. Finally, the advantages in terms of control and compactness of an antibubble column as compared to a bubble column for liquid–gas mass transfer are demonstrated. Specifically, an antibubble is shown to transfer dozens of times more mass than a bubble that would initially carry the same amount of gas. Antibubbles are therefore shown to provide a new, time-resolved, way to measure MTC, as well as promising route to enhance liquid–gas transfers in multiphase reactors.

Efficacy and safety of 128 slice CT low-dose scanning technique combined with low-density contrast agent in computed tomography angiography of diabetic foot and lower limb

Efficacy and safety of 128 slice CT low-dose scanning technique combined with low-density contrast agent in computed tomography angiography of diabetic foot and lower limb

Utilization and modeling of satellite gravity data for geohazard assessment in the Yogyakarta area of Java Island, Indonesia

A geohazard assessment was conducted in the Aerotropolis area of the new Yogyakarta international airport, located in the Yogyakarta special region province, Indonesia. The study involved the analysis and modeling of 3-D inversions of earth gravity anomaly data obtained from the high-resolution of Global Gravity Model (GGM). The main objective of the study was to identify subsurface geological structures such as faults, active volcanoes, and sedimentary layers that may pose potential hazards to the Yogyakarta aerotropolis area. The complete Bouguer anomaly in the study region was calculated using modern terrain correction methods that relied on full-scale topography gravity data from the SRTM2gravity model. A 2-D radial spectrum analysis was then performed on this anomaly data, which revealed that the average thickness of sedimentary layers was estimated to be more than 100 ​m. The rock density contrast was determined using the residual gravity anomaly inversion, which showed a range of −0.086 ​g/cm3 to 0.043 ​g/cm3. The analysis of gravity anomalies and rock density contrast provided results that aligned with the regional geological conditions of the Yogyakarta region, including the pattern of igneous rock intrusion with high density contrast, the presence of the Merapi magma chambers associated with low negative density contrast, and the Opak normal fault path at low and high contrast boundaries, which could lead to natural hazards in the region.

Dust survival rates in clumps passing through the Cas A reverse shock – II. The impact of magnetic fields

ABSTRACTDust grains form in the clumpy ejecta of core-collapse supernovae where they are subject to the reverse shock, which is able to disrupt the clumps and destroy the grains. Important dust destruction processes include thermal and kinetic sputtering as well as fragmentation and grain vaporization. In the present study, we focus on the effect of magnetic fields on the destruction processes. We have performed magnetohydrodynamical simulations using AstroBEAR to model a shock wave interacting with an ejecta clump. The dust transport and destruction fractions are computed using our post-processing code Paperboats, in which the acceleration of grains due to the magnetic field and a procedure that allows partial grain vaporization have been newly implemented. For the oxygen-rich supernova remnant Cassiopeia A, we found a significantly lower dust survival rate when magnetic fields are aligned perpendicular to the shock direction compared to the non-magnetic case. For a parallel field alignment, the destruction is also enhanced but at a lower level. The survival fractions depend sensitively on the gas density contrast between the clump and the ambient medium and on the grain sizes. For a low-density contrast of 100, e.g. 5 nm silicate grains are completely destroyed while the survival fraction of $1\,\mu{\rm m}$ grains is 86 per cent. For a high-density contrast of 1000, 95 per cent of the 5 nm grains survive while the survival fraction of $1\,\mu{\rm m}$ grains is 26 per cent. Alternative clump sizes or dust materials (carbon) have non-negligible effects on the survival rate but have a lower impact compared to density contrast, magnetic field strength, and grain size.

Analysis of Soil Dynamics and Seismic Vulnerability in Kalibening District, Banjarnegara Using the HVSR Method

On April 18, 2018, an earthquake with a magnitude of 4.4 Mw struck the Kalibening district, Banjarnegara. The observations on the damage distribution caused by the earthquake showed something unique: the areas that suffered severe damage were concentrated in villages on hills. This observation may indicate a site-effect phenomenon due to local geological conditions. In this study, we carry out microtremor measurements at 30 stations. The measurement area includes areas that have suffered damage due to the 2018 earthquake and also with minimum damage. We analyze the microtremor observation to estimate the site’s characteristics and map the seismic vulnerability based on predominant frequency (f0 ) and amplification factor (A0 ) using the Horizontal to vertical spectrum ratio (HVSR) method. The results show that the predominant frequency in the Kalibening district area is 0.4 – 3.7 Hz, while the amplification factor is 2.5 – 10.7. The Kalibening Basin has a low f0 (<2.5 Hz) and A0 (<4), which indicates that the Kalibening Basin has a thick and soft soil type but low-density contrast. Areas with a high degree of damage have dominant frequency values in the range of 1.5 – 2.3 Hz and amplification of 5.1 – 9.2. These results suggest that the location has a high-density contrast and thick sediment, causing significant amplification. The seismic vulnerability index (Kg) values are in the range of 3.6 - 46.74. The area around the Kalibening Basin has a low Kg value, While the damaged areas have a moderate to high seismic vulnerability index.

Joint interpretation of gravity and airborne magnetic data along the Calama-Olacapato-Toro fault system (Central Puna, NW Argentina): Structural and geothermal significance

Here, we present new gravity and airborne magnetic geophysical data from a preliminary exploration along the western sector of the NW-striking Calama-Olacapato-Toro fault system. This area is located in the back-arc region of the Central Andes (NW, Argentina) and is considered as a high potential geothermal area within the Central Puna Energy Hub.The gravity and magnetic modelling was carried out with the aim of delineating geological structures that control the geothermal manifestations and estimate the geothermal field extent. Gravity data were separated into regional and residual components. Then, a 2-D gravity and magnetic modelling was carried out through the 2-D GM-SYS - Oasis Montaj software in order to build an inversion model that adjusts the residual gravimetric and magnetic anomalies observed on the surface. The resultant model was also fitted taking into consideration previous electrical resistivity studies, surface manifestations, geology, and geological structures. Bouguer anomalies are negative in the range of -411 to -304 mGal, while magnetic anomalies have a range of − 127 to 15 nT, in the central part of the study area. Hot springs correlate with low residual Bouguer and magnetic anomalies located on the Calama-Olacapato-Toro lineament, and are related to the alteration zone and the main damage zone. Gravity and magnetic inversion show low density and susceptibility contrast of rocks associated with volcano-sedimentary rocks filling a volcano-tectonic depression, limited by the Antuco and Pompeya N-S thrust faults, westward and eastward respectively. The low density and susceptibility contrast can be related to a combination of high temperatures and steam versus liquid-filled pores and fractures. Hence, this geological conceptual model based on the 2-D forward modelling of geophysical data, allows better knowledge and comprehension of hydrothermal fluids circulation in the middle of the Central Puna, in northwest Argentina.

Hydrodynamic invalidation of synformal traps for dissolved CO2

Abstract Reservoirs with the geometry of structural lows trap negatively buoyant fluids, mirroring the way structural highs trap positively buoyant fluids. In both scenarios, lateral flow of reservoir water alters the trapping geometry by causing fluid contacts to tilt. Tilt increases in proportion to hydraulic head gradient increases and the density contrast between the flowing and trapped fluids decreases. Positively buoyant, immiscible supercritical CO2 is at least 20% lighter than typical saline formation waters at CO2 subsurface storage pressures and temperatures, and would experience relatively low tilts, &amp;lt;1°, similar to hydrocarbon fields. On the other hand, CO2-saturated brines are within 1% of the density of CO2-free equivalent brine. This relatively low density contrast creates tilted contacts at much higher angles even at the low hydraulic head gradients that typify deep saline aquifers. For example, a fluid contact with 0.5% density contrast exceeds 2° tilt for hydraulic head gradients of only 15 cm/km. Many large and basin-scale synformal traps are formed with structural dips of just a few degrees and therefore cannot trap CO2 solutions under hydrodynamic conditions. This problem could be overcome by utilization of hydrodynamic traps or appropriately configured structural-stratigraphic traps for CO2 sequestration.

Coronal Seismology Using Damping of Propagating Kink Waves

We consider the use of propagating kink waves, such as those observed by the Coronal Multi-channel Polarimeter, as a diagnostic technique. The transverse structuring of the plasma may be inferred by the frequency-dependent wave damping, which is attributed to resonant absorption. We include the effect of reflection of waves at the loop footpoints, which leads to the asymmetry parameter, describing the ratio of driven wave power at the footpoints becoming weakly constrained. The classical model of resonant absorption based on an exponential damping profile significantly overestimates the damping rate in coronal loops with low density contrast ratios. The use of the exponential profile in an analysis of observations therefore leads to underestimates for the density contrast ratio and associated parameters such as the heating rate following phase mixing.

Virgo Filaments. II. Catalog and First Results on the Effect of Filaments on Galaxy Properties

Abstract Virgo is the nearest galaxy cluster; it is thus ideal for studies of galaxy evolution in dense environments in the local universe. It is embedded in a complex filamentary network of galaxies and groups, which represents the skeleton of the large-scale Laniakea supercluster. Here we assemble a comprehensive catalog of galaxies extending up to ∼12 virial radii in projection from Virgo to revisit the cosmic-web structure around it. This work is the foundation of a series of papers that will investigate the multiwavelength properties of galaxies in the cosmic web around Virgo. We match spectroscopically confirmed sources from several databases and surveys including HyperLeda, NASA Sloan Atlas, NASA/IPAC Extragalactic Database, and ALFALFA. The sample consists of ∼7000 galaxies. By exploiting a tomographic approach, we identify 13 filaments, spanning several megaparsecs in length. Long &gt;17 h –1 Mpc filaments, tend to be thin (&lt;1 h –1 Mpc in radius) and with a low-density contrast (&lt;5), while shorter filaments show a larger scatter in their structural properties. Overall, we find that filaments are a transitioning environment between the field and cluster in terms of local densities, galaxy morphologies, and fraction of barred galaxies. Denser filaments have a higher fraction of early-type galaxies, suggesting that the morphology–density relation is already in place in the filaments, before galaxies fall into the cluster itself. We release the full catalog of galaxies around Virgo and their associated properties.

Reviewing the characteristics of slip behaviour for megathrust earthquake at Sumatera using vertical derivative of GOCE satellite gravity field

The review of the seismogenic zone characteristics associated with the earthquake rupture process in the Sumatra Subduction Zone has been carried out by various methods. This zone has experienced several major earthquakes; Aceh 2004 Mw=9,1, Nias-Simeulue 2005 Mw=8,6, Bengkulu 2007 Mw=8,5, and Enggano 2000 Mw=7,9. This study focuses on the relationship between density contrast analysis based on gravity data from the GOCE satellite and the slip distribution in four major earthquake rupture zones. Satellite gravity data processing is carried out to obtain data for Gravity disturbance (Gd) and vertical gravity derivatives (Tzz), corrected by topography and sediment effects with different spectrum decomposition to get gravity maps with different depths. Based on the Tzz analysis, the maximum slip of the earthquake rupture is correlated with the minimum Tzz pattern and low-density contrast. In contrast, the rupture ends at the maximum Tzz pattern and high-density contrast. Tzz pattern and Gravity disturbance can describe the barrier and asperity of the Sumatra subduction zone. The schematic maps portray the seismic segmentation of Sumatra Subduction, which have asperities zone along the subduction strike associated with the minimum Tzz and associated with the forearc zone, as well as the barrier related to the maximum Tzz, which is a manifestation of structures (fracture zone and seamount) that are subducted to the oceanic plate.

Measurement of Particle Concentration by Multifrequency Ultrasound Attenuation in Liquid-Solid Dispersion.

In mineral transportations, it is essential to measure the gas hydrate particle concentration to manage the risk of flowline blockage. Traditional single-frequency ultrasonic methods measure the particle concentration by treating the mixtures with an average particle size, which ignores the influence of the particle size distribution, and thus, measurement accuracy is limited. Therefore, this research studies the multifrequency ultrasound attenuation method to measure the particle concentration through the prior estimate of particle size distribution. First, considering the large particle size and low-density contrast characteristics of the hydrate-water dispersion, the influence of multiple scattering among particles cannot be ignored apart from the scattering attenuation caused by each particle, so the ultrasonic scattering attenuation mechanism considering multiple scattering effects is established to solve the attenuation prediction problem of the hydrate-water dispersion. Since the solution of the equation obtained by the ultrasonic attenuation model produces a Fredholm integral equation of the first kind, an inversion algorithm combining simulated annealing with genetic algorithm based on ultrasonic attenuation mechanism is proposed to solve the ill-posed problem in the inversion calculation of particle concentration. Finally, considering the characteristics of hydrate-water dispersion, the experiments were carried out with millimeter-sized acrylic spheres and saltwater as substitute materials of the hydrate-water dispersion. The results show that the method based on the multifrequency attenuation of ultrasound in the range 1-5 MHz has a good discrimination for the particle size, and the measurement error of particle concentration is less than 3% under different particle size distributions.

Numerical simulation of Rayleigh-Bénard convection and three-phase Rayleigh-Taylor instability using a modified MPS method

The main objective of the current work is to enhance consistency and capabilities of Moving Particle Semi-implicit (MPS) method for simulating a wide range of free-surface flows and convection heat transfer. For this purpose, two novel high-order gradient and Laplacian operators are derived from the Taylor series expansion and are applied for the discretization of governing equations. Furthermore, the combination of the explicit Third-order TVD Runge-Kutta scheme and two-step projection algorithm is employed to approximate transient terms in the Navier-stokes and energy equations. To further improve the accuracy and performance of the method, a new kernel function is constructed by a combination of the Gaussian and cosine functions and then implemented for modeling the 1D Sod shock tube problem. Validation and verification of the proposed model are conducted through the simulations of several canonical test cases such as: dam break, rotation of a square patch of fluid, two-phase Rayleigh-Taylor instability, oscillating concentric circular drop and good agreement are achieved. The proposed model is then employed to simulate three-phase Rayleigh-Taylor instability and entropy generation due to natural convection heat transfer (Differentially Heated Cavity and Rayleigh-Bénard convection). The obtained results reveal that, the newly constructed kernel function provides more reliable results in comparison with two frequently used kernel functions namely; quartic spline and Wendland. Furthermore, it is found that, the enhanced MPS model is capable of handling multiphase flow problems with low and high density contrast.

The Milky Way’s bar structural properties from gravitational waves

ABSTRACT The Laser Interferometer Space Antenna (LISA) will enable Galactic gravitational wave (GW) astronomy by individually resolving &amp;gt;104 signals from double white dwarf (DWD) binaries throughout the Milky Way. Since GWs are unaffected by stellar crowding and dust extinction unlike optical observations of the Galactic plane, in this work, we assess for the first time the potential of LISA to map the Galactic stellar bar and spiral arms. To achieve this goal, we combine a realistic population of Galactic DWDs with a high-resolution N-body Galactic simulation in good agreement with current observations of the Milky Way. We then model GW signals from our synthetic DWD population and reconstruct the structure of the simulated Galaxy from mock LISA observations. Our results show that while the low-density contrast between the background disc and the spiral arms hampers our ability to characterize the spiral structure, the stellar bar will clearly appear in the GW map of the bulge. The axial ratio derived from the synthetic observations agrees within 1σ with the reference value, although the scale lengths are underestimated. We also recover the bar viewing angle to within 1° and the bar’s physical length to within 0.2 kpc. This shows that LISA can provide independent constraints on the bar’s structural parameter, competitive compared to those from electromagnetic tracers. We therefore foresee that synergistic use of GWs and electromagnetic tracers will be a powerful strategy to map the Milky Way’s bar and bulge.

Alfa Laval AB, Sweden

The tomographic reconstruction of biological specimens requires robust algorithms, able to deal with low density contrast and low element concentrations. At the IST/ITN microprobe facility new GPU-accelerated reconstruction software, JPIXET, has been developed, which can significantly increase the speed of quantitative reconstruction of Proton Induced X-ray Emission Tomography (PIXE-T) data. It has a user-friendly graphical user interface for pre-processing, data analysis and reconstruction of PIXE-T and Scanning Transmission Ion Microscopy Tomography (STIM-T). The reconstruction of PIXE-T data is performed using either an algorithm based on a GPU-accelerated version of the Maximum Likelihood Expectation Maximisation (MLEM) method or a GPU-accelerated version of the Discrete Image Space Reconstruction Algorithm (DISRA) (Sakellariou (2001) [2]). The original DISRA, its accelerated version, and the MLEM algorithm, were compared for the reconstruction of a biological sample of Caenorhabditis elegans – a small worm. This sample was analysed at the microbeam line of the AIFIRA facility of CENBG, Bordeaux. A qualitative PIXE-T reconstruction was obtained using the CENBG software package TomoRebuild (Habchi et al. (2013) [6]). The effects of pre-processing and experimental conditions on the elemental concentrations are discussed.

CroSSED sequence, a new tool for 3D processing in geosciences using the free software 3DSlicer

The scientific application of 3D imaging has evolved significantly over recent years. These techniques make it possible to study internal features by non-destructive analysis. Despite its potential, the development of 3D imaging in the Geosciences is behind other fields due to the high cost of commercial software and the scarce free alternatives. Most free software was designed for the Health Sciences, and the pre-settled workflows are not suited to geoscientific materials. Thus, an outstanding challenge in the Geosciences is to define workflows using free alternatives for Computed Tomography (CT) data processing, promoting data sharing, reproducibility, and the development of specific extensions. We present CroSSED, a processing sequence for 3D reconstructions of CT data, using 3DSlicer, a popular application in medical imaging. Its usefulness is exemplified in the study of burrows that have low-density contrast with respect to the host sediment. For geoscientists who have access to CT data and wish to reconstruct 3D structures, this method offers a wide range of possibilities and contributes to open-science and applied CT studies.

Integration of gravity and magnetic inversion for geothermal system evaluation in Suli and Tulehu, Ambon, eastern Indonesia

The geothermal field of Suli and Tulehu is located in the eastern part of the Ambon Island, administratively situated in central Maluku regency, Maluku province, Indonesia. In the year 2017, the measurement of the Earth’s gravity and magnetic field has been done to evaluate the geothermal system in Suli and Tulehu. The application of gravity and magnetic methods was applied to determine the subsurface geological model describing geothermal sources, reservoirs, and faulting as a fluid conduit in the study area. Bouguer anomalies are positive in the range from 93 to 105 mGal, while magnetic anomalies are negative to positive in the range from − 656 to 310 nT, generally southwest to northeast. Geothermal manifestations in the form of hot springs associated with low residual Bouguer and magnetic anomalies positioned on the Banda-Hatuasa, Banda, and Huwe fault lines related to the alteration zone. Euler deconvolution analysis of the complete Bouguer anomaly data shows the maximum depth of fault detected at 1200 m. Gravity and magnetic inversion show high density and susceptibility contrast of rocks associated with Eriwakang and Simalopu pyroclastic rocks as geothermal sources. Low density and susceptibility contrast is estimated to be geothermal reservoirs due to interactions with geothermal source rocks below. A geological conceptual model based on the inversion modeling of gravity and magnetic data provides clear and comprehensive information on the geothermal systems in Suli and Tulehu, Ambon, the eastern part of Indonesia.

Liquefaction potential identification in the Central Sulawesi using gravity inversion model

Liquefaction is one of the effects following an earthquake, it is the soil strength loss due to the vibration of an earthquake. The earthquake which struck with a 7.7 magnitude on September 28th 2018 in Donggala and Palu, Sulawesi caused a series of disastrous events including a tsunami and aftershock liquefaction in Balaroa and Petobo, causing many casualties. The liquefaction can be investigated and possibly predicted by identifying and interpreting the subsurface structures. This paper identifies the geological structures in the subsurface using the gravity method. The study was carried out by 3D inversion modelling at locations 119.6–120.2 BT and 0.6–1.2 LS based on gravity data. The gravity data was gained from Global Gravity Model plus (GGMplus). The study from satellite and the Bouguer anomaly in the Central Sulawesi shows that it has gravity of -50 to 130 mGal. The 3D inversion model of the subsurface shows low density contrast around the areas of Palu, Balaroa, and Petobo with values of -0.055 to -0.05 gram/cm3 where these low density depths have been identified from 0–125 meters below the surface and even deeper to the southern part of the study area. This low density contrast is in accordance with the geological conditions of the Palu which is dominated by porous sediment layers which are capable of storing fluids that are the main factor in causing the liquefaction.

3-D inversion of gravity data to determine the Tulehu geothermal prospect zone, Maluku

The Gravity method is a geophysical method that is widely used for geothermal exploration. The use of gravity data is commonly limited to interpretation of geological structure using 2-D modeling. In this study, 3-D inversion of gravity data conducted to improve 3-D conceptual model of geothermal system. This method was applied in Tulehu geothermal prospect area, which is located in Maluku Province. In 2019, gravity survey was conducted for geothermal exploration in Tulehu by gridding measurement of 130 stations with 500 m spacing. The geological condition of the area is dominated by quaternary volcanic rocks, limestone, alluvial, and metamorphic rocks. The result of CBA and residual gravity indicate the existence of medium gravity anomaly at the Mt. Eriwakang, the high gravity anomalies are found around several structures obtained from Remote Sensing. In the section of gravity 3-D inversion, it shows that the low-density contrast can be seen at 2000–3500 meter and 4500–7000 meter, while high density contrast can be seen at 0–5000 meters and 6500–8000 meters. The low and high-density contrast is associated with the presence of Huwe Fault, Banda Fault, and Banda Hatuasa Fault in the prospect area which is correlated to the geological condition. 2-D forward modeling has a good correlation to confirm the results of 3-D inversion of gravity data.

Exploring computed tomography in ichnological analysis of cores from modern marine sediments

Ichnological analysis is considered a very useful tool in several disciplines of Earth Sciences, including palaeoenvironmental studies and hydrocarbon exploration. Sediment cores provide excellent records, despite difficulties encountered during study runs due to specific core features. Previous studies using 2D images have proven the benefits of high-resolution image treatment in improving the visibility of ichnological features, but with limitations. 3D computed tomography (CT) techniques were applied to palaeoichnological studies in lithified cores and other disciplines of palaeontology to solve these limitations, but not used for ichnological studies in unconsolidated sediments due to the low density contrast between host sediment and trace fossils. In this study, a CT processing technique, previously tested in coral research, is applied to facilitate the characterisation of the ichnological signature of cores from modern marine soft sediments. This technique allows for the first time the isolation of burrows within these kinds of sediments and the differentiation of intervals based on burrow orientation. Data obtained from the technique are complemented with the ichnological information from conventional core description, thus providing a more complete characterisation of the trace fossil assemblage with additional ichnological properties such as burrow orientation and branching. This will improve palaeoenvironmental interpretations related to changes in energy or oxygenation, and the analysis of reservoir quality given the impact of burrows on porosity and permeability. Therefore, adopting CT to complement visual core description in the ichnological analysis of soft modern marine cores is a very informative approach.