Mudflow Research Articles

Origins of complexity in the rheology of Soft Earth suspensions

When wet soil becomes fully saturated by intense rainfall, or is shaken by an earthquake, it may fluidize catastrophically. Sand-rich slurries are treated as granular suspensions, where the failure is related to an unjamming transition, and friction is controlled by particle concentration and pore pressure. Mud flows are modeled as gels, where yielding and shear-thinning behaviors arise from inter-particle attraction and clustering. Here we show that the full range of complex flow behaviors previously reported for natural debris flows can be reproduced with three ingredients: water, silica sand, and kaolin clay. Going from sand-rich to clay-rich suspensions, we observe continuous transition from brittle (Coulomb-like) to ductile (plastic) yielding. We propose a general constitutive relation for soil suspensions, with a particle rearrangement time that is controlled by yield stress and jamming distance. Our experimental results are supported by models for amorphous solids, suggesting that the paradigm of non-equilibrium phase transitions can help us understand and predict the complex behaviors of Soft Earth suspensions.

Mathematical model for the capacity of the mud flow with wave regime taking into account its rheological properties

The paper presents particular issues of mudflow dynamics, one of the hazardous natural disasters, namely the theoretical study of the flow power during mudflow movement in the wave regime taking into account its rheological properties. The paper discusses the physical process of mudflow mass impetus accumulated in erosion banks, taking into account the impact of the tense state of the eroded mass, in particular, similar to soil mechanics problems, the density of the mudflow-forming mass (ρ), the free fall acceleration (g), angle of internal friction (φ), the adhesive force (Pe), the height equivalent to pressure (h′), the height of the mudflow-forming mass (H), the intensity of transverse pressure (P), and the value of the active pressure of the inertial mass cohesion (C) on the deformation mode of the mudflow mass. On the basis of the basic equations of mudflow dynamics and theoretical studies, an equation is obtained to calculate the values of flow power when mudflows move in the wave mode, taking into account the main rheological properties of a mudflow mass.

Derivation and numerical resolution of 2D shallow water equations for multi-regime flows of Herschel–Bulkley fluids

This paper presents mathematical modelling and simulation of thin free-surface flows of viscoplastic fluids with a Herschel–Bulkley rheology over complex topographies with basal perturbations. Using the asymptotic expansion method, depth-averaged models (lubrication and shallow water type models) are derived for 3D (three-dimensional) multi-regime flows on non-flat inclined topographies with varying basal slipperiness. Starting from the Navier–Stokes equations, two flow regimes corresponding to different balances between shear and pressure forces are presented. Flow models corresponding to these regimes are calculated as perturbations of the zeroth-order solutions. The classical reference models in the literature are recovered by considering their respective cases on a flat-inclined surface. In the second regime case, a pressure term is non-negligible. Mathematically, it leads to a corrective term to the classical regime equations. Flow solutions of the two regimes are compared; the difference appears in particular in the vicinity of sharp changes of slopes. Nonetheless, both regime models are compared with experiments and are found to be in good agreement. Furthermore, numerical examples are shown to illustrate the robustness of the present shallow water models to simulate viscoplastic flows in 3D and over an inclined topography with local perturbations in basal elevation and basal slipperiness. The derived models are adequate for direct (engineering and geophysical) applications to real-world flow problems presenting Herschel–Bulkley rheology like lava and mud flows.

Geomorphology of subaerial mud volcanoes in Azerbaijan: Issues about edifice construction and degradation

Mud volcanoes in Azerbaijan present some of the largest and most well-preserved edifices among all the onshore examples. We examined their morphology based on remote sensing and field observations. We classify the general shapes of the edifices into Type 1 (conical edifice), Type 2 (shield-like edifice), Type 3 (domed edifice) and Irregular (or compound). The associated landforms of the examined mud volcanoes are wide-ranging: mud flows, summit mud pies, summit craters/areas, gryphons and mud cones (small- and medium-scale vent structures), and salses (ponds of watery mud). The variety of such constructional landforms testify to the complex processes of mud emplacement modulated by the presence of fluids such as saline/connate waters and hydrocarbons. Degradation features include gullies, aeolian forms, steep slopes at lower flanks and reduced edifice sections due to human exploitation. The steep slopes at lower flanks are interesting since they may represent evidence for wave-cut erosion. The complex interplay of edifice construction and degradation is an important area of future study.

Open-hole extension limit of offshore extended-reach well considering formation collapse

The current extension limit prediction model for offshore extended-reach well (ERW) in mudstone does not consider the formation collapse, which poses a huge risk to offshore drilling construction. To address this problem, this paper presents new open-hole extension limit prediction model for ERW. By considering formation collapse, rate of penetration (ROP), and annular pressure loss, the extension limit models during normal drilling and tripping were derived. The sensitivity of geological and engineering factors was evaluated by analyzing limits for wells 1H and 2H. The research results showed that: (1) The extension limit increases with the ROP and formation collapse duration, but decreases with the increase in mud weight, plastic viscosity, and flow rate. (2) In ERWs, the mud flow rate has a significant impact on the extension limit than the plastic viscosity of mud fluid. However, mud weight has the least impact compared to the two. (3) Considering various parameters, the predicted extension limit of well 1H, when the mud weight is 1.16 g/cm3 [9.67 ppg], is 1593.28 m [5225.96 ft] less than the limit when the collapse period is not considered.

A combined tectono-climatic control on Holocene sedimentation in Ladakh Himalaya, India: Clues from Anisotropy of Magnetic Susceptibility (AMS) of lake sediments

Anisotropy of Magnetic Susceptibility (AMS) data from a ∼27.8 m thick soft sedimentary mud sequence (∼10.5–3.25 k yrs) from the Spituk Palaeolake Sequence (SPSS) of Holocene age, located in the northern bank of the Indus River in the Leh-Ladakh Himalaya, show effects of tectonic versus climate dynamics responsible for the Himalayan sedimentation. The sedimentary sequence, consisting of alternating of aeolian sand and glacio-fluvial mud flow deposits, has been subdivided into an older Last Glacier Phase I (LGP 1) and a younger Last Glacier Phase II (LGP 2), where the termination of each phase is marked by the occurrence of gravel beds of thickness ≤1 m, which were deposited due to glacial melting. The present AMS data along with previously published information on sedimentology confirm that the mudflow deposits of the LGP 1 and LGP 2 phases were deposited in a lacustrine environment under glacio-fluvial conditions. However, a weak fluvial flow towards NW and NE could have existed for the LGP 1 and LGP 2, respectively. The glacial beds terminating LGP 1 and LGP 2 appear to have formed by climatic warming and tectonic activity, respectively. Hence, the Holocene Himalayan sedimentation was influenced by both climatic and tectonic activities. However, the thickness of the gravel bed (∼0.8 m) terminating LGP 2 occupies only ∼ 2.8 vol % of the total studied thickness ∼28 m, of the SPSS in the present study, which indicated a lesser control of tectonism in the growth of the Himalaya in and around the study area.

Optimisation of the depth range of UIV on cohesive sediment (fluid mud) flows

Ultrasound Image Velocimetry (UIV) is a technique that enables the monitoring of flows in natural high-density cohesive sediments, also known as fluid mud. Using conventional medical ultrasound imaging equipment, the depth range of UIV in mud is however too limited. This manuscript discusses how this depth range can be improved based on the results of experimental UIV measurements in fluid mud. The results show that the depth range limitation is determined by the pixel brightness of the generated speckle pattern images. Since pixel brightness is a measure of the intensity of the backscattered signals, it degrades with increasing depth due to the attenuation of the ultrasound radiation by the mud. The rate at which ultrasound is attenuated by fluid mud is constant and is governed by the density of the mud and the applied ultrasound frequency. A greater depth range can thus be achieved by reducing attenuation and increasing the intensity of the emitted ultrasound. The former was confirmed by the results of experiments with variable mud density and ultrasound frequency. Flexibility of both parameters is however restricted, allowing only a limited increase in depth range. Another experiment confirmed an additional increase in depth range when a higher ultrasound intensity is applied. Patient safety measures of medical ultrasound imaging equipment, however restrict the intensity of the emitted ultrasound. To increase the depth range even further, potential solutions are therefore suggested, such as the use of high-power non-medical ultrasound imaging equipment or a novel procedure for processing the acquired acoustic data.

A global dataset of pitted cones on Mars

Pitted cones are positive-relief features that display prominent central craters, and are common features on the northern lowland plains of Mars. Pitted cones have been proposed to form from different mechanisms, including those producing volcanic cinder cones or sedimentary mud volcanoes. Here, we apply a deep learning model to globally map 65,620 pitted cones on Mars using Context Camera images from the Mars Reconnaissance Orbiter. Using model recall and a hand-mapped dataset, we conjecture there could be up to ∼81,900–162,000 individual pitted cones on Mars. A majority of pitted cones (>97%) occur in three of the northern plains' basins—Utopia, Isidis, and Acidalia Planitiae—and occur within geologic units from the late Hesperian and the early–middle Amazonian. The global dataset shows cone estimated diameter increases moving poleward, but pitted cones largely disappear north of ∼50 N, perhaps due to polar processes that erase or modify the cones. Approximately 94% of cones overlie a single geologic unit, the Vastitas Borealis Formation (VBF), interpreted as sediment from the highland terrains deposited via outflow channels. This global distribution supports sedimentary volcanism following deposition of sediments by the outflow channels. On Earth, rapidly-deposited sediments make an ideal setting for trapping water in the subsurface that is later erupted as mud flows, and this appears to be feasible on Mars.

Numerical simulations of dam-break flows of viscoplastic fluids via shallow water equations

This paper presents simulations of dam-break flows of Herschel–Bulkley viscoplastic fluids over complex topographies using the shallow water equations (SWE). In particular, this study aims to assess the effects of rheological parameters: power-law index (n), consistency index (K), and yield stress (τc\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ au _{c}$$\\end{document}), on flow height and velocity over different topographies. Three practical examples of dam-break flow cases are considered: a dam-break on an inclined flat surface, a dam-break over a non-flat topography, and a dam-break over a wet bed (downstream containing an initial fluid level). The effects of bed slope and depth ratios (the ratio between upstream and downstream fluid levels) on flow behaviour are also analyzed. The numerical results are compared with experimental data from the literature and are found to be in good agreement. Results show that for both dry and wet bed conditions, the fluid front position, peak height, and mean velocity decrease when any of the three rheological parameters are increased. However, based on a parametric sensitivity analysis, the power-law index appears to be the dominant factor in dictating fluid behaviour. Moreover, by increasing the bed slope and/or depth ratio, the wave-frontal position moves further downstream. Furthermore, the presence of an obstacle is observed to cause the formation of an upsurge that moves in the upstream direction, which increases by increasing any of the three rheological parameters. This study is useful for an in-depth understanding of the effects of rheology on catastrophic gravity-driven flows of non-Newtonian fluids (like lava or mud flows) for risk assessment and mitigation.Graphical abstract

Investigation of the Highway Between Isparta-Ağlasun (Burdur) in Terms of Mass Movement Sensitivity

In our country, mass-ground movements such as landslides, rockfalls and avalanches are the most common types of disasters after earthquakes in terms of their destructive effects. The aim of the study is to determine the susceptibility of mass movements on sloping surfaces along the Isparta-Ağlasun road route. The study area includes approximately 41 kilometres of highway route between Isparta city centre and Ağlasun districts and its surroundings. Steep slopes on the road, loose soil properties in places, and torrential rains cause frequent rock falls, slope debris and mud flows on the study area. It is extremely important to identify the areas susceptible to ground movements along the route in order to take necessary precautions and prevent future loss of life and property. For this purpose, the parameters that are thought to cause mass movements along the road route were evaluated together with Geographical Information Systems programme and Analytical Hierarchy Method and the areas sensitive to low-medium-high and very high mass movements along the route were determined. The sensitivity map obtained was supported by field observations. With this study, areas sensitive to mass movements along the route were mapped and a database was created to help local administrators and planners.

Mixing-phase model for shear-induced contractive/dilative effects in unsteady water-sediment mixture flows

Among the geophysical surface processes, mud and debris flows show one of the most complex and challenging behaviour for scientists and modellers. These flows consist of highly-unsteady gravity-driven movements of water-sediment mixtures with non-Newtonian rheology where the solid concentration could be about 40%–80% of the flow volume and which occur along steep and irregular terrains. Furthermore, the appearance of dynamic pressures in the fluid filling the intergranular pores increases the complexity and dominates the behaviour of the fluidized water-sediment material, leading to the appearance of significant density gradients during the movement. The dynamic pressure in the pore-fluid changes the effective normal stress within the mobilized material, affecting the frictional shear stress between grains and leading to the solid phase dilation/contraction. This must be properly accounted for when developing realistic models for water-sediment surface flows. In this work, a novel physically-based approach for modelling multi-grain dense-packed water-sediment flows is presented. A novel closure formulation for the pressure distribution within the pore-fluid during the movement of dense-packed water-sediment materials has been derived. This closure allows to relate the appearance of shear-induced dynamic pore pressures to the contractive/dilative behaviour of the solid aggregate. The resultant system of depth-averaged conservation laws includes continuity of the density-variable water-sediment material and the different solid classes transported in the flow, as well as the linear momentum equation for the fluidized bulk material, and it is solved using a well-balanced fully-coupled Finite Volume (FV) method. The resultant simulation tool is faced to synthetic, laboratory and real-scale benchmark cases to test its robustness and accuracy. The presence of dynamic pore pressures within the pore-fluid leads to the appearance of a deviatoric contribution to the solid flux, which causes the shear-induced separation of the solid and liquid phases and sustains the flow mobility for long distances, as it has been observed in real mud and debris events.

A mass transfer-based LES modelling methodology for analyzing the movement of submarine sediment flows with extensive shear behavior

This study employs the large-eddy simulation (LES) method to investigate the interaction of submarine sediment flows with extensive shear behavior and ambient water. This method is validated with good accuracy by simulating the head velocity and evolution geometries of a submarine mud flow with non-Newtonian fluid characteristics and a submarine turbidity current with Newtonian fluid characteristics in inclined and regular lock-exchange flume experiments. This study finds that the violent mass transfer at the interface of the submarine sediment flow and seawater is caused by numerous eddies, which significantly alter the submarine sediment flow's geometry, resulting in varying degrees of undulation, including the deposition pattern of the submarine sediment flow tail. The acceleration zone, where the velocity of the submarine sediment flow increases significantly at this undulation, propels the sediment flow forward, supporting its long-distance transport. Furthermore, the turbulence and mass transport characteristics of submarine turbidity currents with low dynamic viscosity Newtonian fluid characteristics are stronger than those of submarine mud flows with high dynamic viscosity non-Newtonian fluid characteristics. Therefore, when submarine landslides develop into later stages, such as submarine turbidity currents with high velocity, large volume, and long run-out distance characteristics, more attention must be given to the mass transport process.

Application of Ultrasound Image Velocimetry (UIV) to cohesive sediment (fluid mud) flows

Ultrasound image velocimetry (UIV) is a technique that enables non-intrusive whole-flow field velocimetry measurements in opaque fluids. It gained interest in experimental fluid dynamics to study the flow mechanics of, amongst others, sediment-laden fluids. Further customisation of this technique is required to make it a reliable asset for experimental research involving high density cohesive sediments (fluid mud). Potential applications include rheological or settling experiments or experiments serving nautical research on the interaction between a ship, water and fluid mud forming the bottom of the navigation channel. This study presents experiments to validate the applicability of UIV in such dense cohesive sediments exhibiting non-Newtonian and thixotropic behaviour. During these experiments, an ultrasound transducer was moved through stationary mud at known velocities. Due to the viscosity of the mud, the zone of influence of the moving transducer is limited in depth. This enables the recording of the relative velocity between moving transducer and the undisturbed mud at greater depths. Medical ultrasound imaging equipment was used, as such equipment allows ultrasound imaging in the required frequency range and frame rate. A good correlation (accuracy >95\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$>95$$\\end{document} %) was found between the imposed motion velocity of the transducer and the output of UIV. However, limitations were found in both depth and velocity, caused by the equipment, settings and mud properties.

Modelling of fluid mud flow based on a three-dimensional hydrodynamic model : incorporating a 3D rheological model

Modeling fluid mud in estuaries and coastal areas is a complicated task due to its non-Newtonian characteristics. A continuous modeling approach was adopted to investigate the laminar flow of fluid mud, with a three-dimensional (3D) form of the Herschel–Bulkley rheological model introduced into the finite volume coastal ocean model (FVCOM) to calculate the apparent viscosity of fluid mud. The model was validated against two flume experiments for the laminar flow of fluid mud. The results showed that the developed model was capable of accurately reflecting the continuous distribution of velocity and density from the near-bottom to the upper water column. Based on the validated model, the difference between the 3D rheological model and a 1DV rheological model on the simulation results was assessed. The study found the results of the 1DV model and the 3D model show obvious differences. This illustrates the significant effect of apparent viscosity in horizontal direction taken into account by the 3D rheological model.

Decreasing the stick-slip vibration during drilling wells using water and polymer drilling mud modified with NanoSiO2 particles

Stick-slip in drilling happens when the drill bit and assembly repeatedly stop and slide due to factors like friction and torque. Using better lubricants in the drilling mud can help reduce friction, lessening stick-slip issues. Nanotechnology has improved drilling mud, making it more resistant to heat and enhancing its viscosity and friction properties. This research extensively investigates the use of nanofluids in drilling processes through thorough lab tests. It examines the impact of introducing NanoSiO2 into two types of drilling mud—freshwater bentonite (FWB) and polymer-based mud—at concentrations of 0.04%, 0.08%, 0.15%, and 0.31% under higher temperatures. The study also explores two methods of dispersing NPs using ultrasonic and solvent techniques. The results show that SiO2 nanoparticles notably improve the flow and filtering abilities of FWB mud but have negative effects on polymer-based mud. A 0.05% addition of NanoSiO2 significantly reduces friction by 52% in FWB mud. In FWB mud, all NanoSiO2 concentrations lead to a 25% decrease in mud cake thickness. Furthermore, adding NanoSiO2 to FWB mud decreases torque, with the most substantial reduction of 40% observed at 0.09% concentration (0.35 gm). On the contrary, incorporating NanoSiO2 into polymer-based mud increases fluid loss volume for all concentrations, reaching up to 36% compared to the base mud. Additionally, filter cake thickness increases eightfold, while lubricity factor doubles. This study offers insights into the advantages of using SiO2 nanoparticles in drilling mud and their impact on the fluid properties during drilling.

Determination of the thermal state of a block gravel filter during its transportation along the borehole

Purpose. Development of a methodology for determining the thermal state of block inverse gravel filters manufactured using low-temperature technology during their transportation in a well based on computer and mathematical modeling. Methods. The study of hydrodynamic processes occurring during the transportation of the filter in the borehole, as well as the calculation of thermal fields in the filter body, was performed using the Ansys Fluent software package. To determine the effective thermophysical characteristics of the filter, the approaches of the heat transfer theory in porous media were applied. To investigate the thermal conditions of the filter at heat exchange with well fluid, the use of analytical solution of the heat conduction problem in a cylindrical shell, taking into account the properties of porous dispersed water-saturated medium, is proposed. Findings. The methodology for calculating the thermal state of a gravel filter during its operation in a well has been developed. For estimation of the filter surface temperature, the expression obtained on the basis of the analytical solution of the heat conduction equation, taking into account the characteristics of the porous filter medium, is proposed. Hydrodynamic and thermal fields in the borehole and the filter body during the filter transportation process in the borehole have been obtained. Originality. For the first time, the problem of heat exchange of a gravel inversion filter, manufactured by low-temperature technology in a well is considered. The influence of hydrothermal conditions in the well on the process of filter heating during its transportation in the well is shown. The hydrodynamic fields during the flow of the drilling mud around the inverse gravel filter are determined. Practical implications. The proposed approaches and results of the study allow to determine and can be used in the development of technological regulations for the use of block gravel filters produced by low-temperature technology for the equipment of hydrogeological wells. The methodology for modelling the process of two-phase inversion transition of aggregate state of the binding agent during transportation of inverted block-type gravel filter during well construction has been developed.

Los Enebrales rock-shelter (Tamajón, Guadalajara, Spain): First Gravettian site in central Iberia

The stratigraphy and materials from a survey carried out in 1994 and 1995 in a rock-shelter in Tamajón (southwestern Iberian Central Range) are studied here. The Pleistocene deposits were generated by high-energy channelled fluvial flows and dense currents of debris flow and mud flow type. The recovered lithic industry, created mainly in low-quality local materials, can be associated with Gravettian technocomplexes. Three radiocarbon dates obtained from the stratigraphic sequence are located in a temperate interstadial of OIS 3a and in a cold episode at the beginning of OIS 2. The faunal remains, which come from human consumption, display cut and percussion marks. They reveal a predominance of equines, followed by deer, in a mosaic environment. A shale plaque-pendant, worked and decorated, was found outside the stratigraphy. The human occupations of the shelter must have been sporadic, but reflect, with the growing evidence nearby, a thriving population in this area of anatomically modern humans. The association of pre-Solutrean archaeological materials, together with the dates obtained, establishes the human occupation of the Los Enebrales shelter as the oldest evidence of the Upper Palaeolithic in the inner Iberian Plateau.

Research on the effects of slurry uniformity and mixing power of continuous cementing slurry mixers based on statistical and CFD methods

To enhance the efficiency of continuous cement mixing in well cementing, a Computational Fluid Dynamics (CFD) approach was employed to investigate the mud flow and mixing processes within the continuous mixing system. This study aims to analyze the influence of various design factors and their interactions on the mixing of different slurries in the well cementing slurry continuous mixer. Using the Response Surface Methodology (RSM) with a Box-Behnken model, this work combines the Euler-Euler multiphase flow model, k-turbulence model, and the Multiple Reference Frame (MRF) method to simulate two-phase fluid flow and agitator rotation, establishing the CFD model of the mixing system. The CFD model, coupled with the RSM method, analyzed four design factors: impeller diameter (400–800 mm), design density (1.4–2.6 g/cm³), impeller speed (100–300 rpm), and particle size (20–500 μm), studying their impact on two response variables, slurry mixing uniformity, and total power consumption. Through RSM and multiple regression analyses, predictive models for slurry mixing uniformity and corresponding power consumption were established under different design factors. Data comparison analysis revealed excellent agreement between predicted and actual results. Findings indicate that, when using uniformity or power as evaluation criteria, the P-value is smallest for impeller speed and largest for particle size. Hence, the impeller speed exhibited the strongest correlation with both, followed by impeller diameter, and lastly, design density and particle size. Only the interaction between impeller diameter and impeller speed (P-value <0.0001) significantly influenced both power and mixing uniformity, with its significance ranking just below the linear effects of impeller speed and diameter. Slurry uniformity decreased with increased design density and particle size, while power consumption exhibited the opposite trend. Uniformity increased with increasing impeller speed, but when the uniformity reached its maximum, further speed increments led to a slight decrease in uniformity, accompanied by a sharp increase in power. This was significantly influenced by the quadratic effect of impeller speed (P-value <0.0001), with its significance weaker than the linear effects. The proposed predictive model accurately forecasts response values for any given design parameter, providing a research direction for optimizing mixer design and selecting corresponding design parameters. This approach streamlines the study of mud mixing systems, reducing research time and costs. Moreover, it offers scientific guidance for optimizing operational parameters corresponding to well cementing conditions.

Volumetric Changes of Mud on Mars: Evidence From Laboratory Simulations

AbstractSubtle mounds have been discovered in the source areas of Martian kilometer‐sized flows and on top of summit areas of domes. These features have been suggested to be related to subsurface sediment mobilization, opening questions regarding their formation mechanisms. Previous studies hypothesized that they mark the position of feeder vents through which mud was brought to the surface. Two theories have been proposed: (a) ascent of more viscous mud during the late stage of eruption and (b) expansion of mud within the conduit due to the instability of water under Martian conditions. Here, we present experiments performed inside a low‐pressure chamber designed to investigate whether the volume of mud changes when exposed to a Martian atmospheric pressure. Depending on the mud viscosity, we observe a volumetric increase of up to 30% at the Martian average pressure of ∼6 mbar. The reason is that the low pressure causes instability of the water within the mud, leading to the bubble formation that increases the volume of the mixture. This mechanism bears resemblance to the volumetric changes associated with the degassing of terrestrial lava or mud volcano eruptions caused by a rapid pressure drop. We conclude that the mounds associated with putative Martian sedimentary volcanoes might indeed be explained by volumetric changes in the mud. We also show that mud flows on Mars and elsewhere in the Solar System could behave differently to those found on Earth because mud dynamics are affected by the formation of bubbles in response to the different atmospheric pressures.

Volume Calculation of Sidoarjo Mud Using TLS Data and Numerical Methods

Sidoarjo Mud is one of the phenomena of mud volcanoes located in the northern part of Java Island. A mud volcano is a phenomenon where mud material is released from the earth due to pressure (eruption). The mud continuously flows and accumulates around the central embankments. This phenomenon has caused the embankments to break several times due to the uncontainable mud volume. Observing the volume of Sidoarjo Mud is expected to help mitigate this problem. The Sidoarjo Mud volume was calculated using point cloud data obtained from Terrestrial Laser Scanner (TLS). Numerical methods such as the Trapezoidal and Simpson rules were employed to determine the mud volume. These numerical methods involve approximating the volume of irregularly shaped earthwork surfaces using mathematical techniques. The numerical method approximates the area under a trapezoid or curve representing the cross-section of the earthwork. In this study, kriging interpolation was conducted with a grid size of five meters. The relative difference between the numerical methods was found to be within acceptable limits, not exceeding 2.78% based on the American Society for Testing and Materials (ASTM) 2002 and not exceeding 2% based on ASTM 1998 as an industry acceptance error. Considering the relative difference results and the institutional report, the Trapezoidal method with a 5-meter grid size was considered the accurate volume calculation method. Based on the processed data, the total volume of Sidoarjo Mud within the embankment was 32,793,917.171 m3 in February 2022, 32,889,012.793 m3 in April 2022, and 33,390,051.407 m3 in June 2022. The volume calculation results show a difference of 95,095.622 m3 between February-April and a difference of 501,038.613 m3 between April-June. The mud flow rate for the February-April period was calculated as 1,872.114 m3/day, while for the April-June period was determined as 9,278.492 m3/day.