Eruption Column Research Articles

Tracking Eruption Column Thermal Evolution and Source Unsteadiness in Ground‐Based Thermal Imagery Using Spectral‐Clustering

AbstractVolcanic eruption columns typically have unsteady source conditions, where mass and heat fluxes from the vent evolve or fluctuate on time scales from seconds to hours. However, integral plume models routinely assume source conditions that are statistically stationary, and the degree to which source unsteadiness influences the mechanics of column rise and air entrainment has not been established with quantitative predictions. We address this knowledge gap by examining eruptions with varying unsteady character at Sabancaya Volcano, Peru. Using a novel tracking algorithm based on spectral clustering, we track the spatiotemporal evolution of coherent turbulent structures in columns using ground‐based, thermal infrared imagery. For turbulent structures tracked in time and space, we calculate the power law decay exponent of excess temperature with height. In general, the starting pulses of transient events are characterized by power law exponents matching theoretical predictions for an instantaneous point release of buoyancy (i.e., a thermal), which evolve with sustained emissions to values consistent with steady plumes. Our results support previous findings from field evidence and laboratory experiments that entrainment and gravitational stability in unsteady volcanic columns are inadequately captured by time‐averaging or constant entrainment coefficients. We propose a quantitative definition for column source unsteadiness which captures the timing and magnitude of source fluctuations on time scales that influence entrainment mechanics, and which provisionally predicts our observed differences in power law behavior. We argue for systematic experimental and numerical studies of the relationship between source unsteadiness and entrainment to implement unsteady entrainment parameterizations for integral plume models.

Ash Deposition Triggers Phytoplankton Blooms at Nishinoshima Volcano, Japan

AbstractVolcanoes that deposit eruptive products into the ocean can trigger phytoplankton blooms near the deposition area. Phytoplankton blooms impact the global carbon cycle, but the specific conditions and mechanisms that facilitate volcanically triggered blooms are not well understood, especially in low nutrient ocean regions. We use satellite remote sensing to analyze the chlorophyll response to an 8‐month period of explosive and effusive activity from Nishinoshima volcano, Japan. Nishinoshima is an ocean island volcano in a low nutrient low chlorophyll region of the Northern Pacific Ocean. From June to August 2020, during explosive activity, satellite‐derived chlorophyll‐a was detectable with amplitudes significantly above the long‐term climatological value. After the explosive activity ceased in mid‐August 2020, these areas of heightened chlorophyll concentration decreased as well. In addition, we used aerial observations and satellite imagery to demonstrate a spatial correlation between blooms and ash plume direction. Using a sun‐induced chlorophyll‐a fluorescence satellite product, we confirmed that the observed chlorophyll blooms are phytoplankton blooms. Based on an understanding of the nutrients needed to supply blooms, we hypothesize that blooms of nitrogen‐fixing phytoplankton led to a 1010–1012 g drawdown of carbon. Thus, the bloom could have significantly mediated the output of carbon from the explosive phase of the eruption but is a small fraction of anthropogenic CO2 stored in the ocean or the global biological pump. Overall, we provide a case study of fertilization of a nutrient‐poor ocean with volcanic ash and demonstrate a scenario where multi‐month scale deposition triggers continuous phytoplankton blooms across 1,000s of km2.

Application of Cross model for granular flow and impact analysis using three-dimensional B-spline material point method

Granular flow and impact, such as landslides and debris flows, are typical problems involving large deformations of non-Newtonian free surfaces, which are of great interest in geological engineering and also pose challenges for traditional mesh-based numerical methods. As an enhancement of the traditional Material Point Method (MPM), the B-Spline Material Point Method (BSMPM) can not only effectively reduce mesh-crossing and quadrature errors, but also facilitate the tracking and capturing of free surfaces and contact interfaces. In this paper, the non-Newtonian general Cross model, the rheological parameters of which are determined by the Bingham model and the Mohr-Coulomb yield criterion, is introduced into the three-dimensional BSMPM (3D BSMPM) for simulating granular flow and impact problems. Interparticle effects of granular materials are represented by artificial damping forces. Dynamic simulations are carried out on the collapse of sand column and glass beads, the flow of bentonite suspensions, and the impact between granular mass and elastic obstacles. The overall evolution of granular flow and impact behavior are presented and compared with existing experimental and/or original MPM results. It is found that the proposed method well reproduces the overall process of granular flow and impact behavior, including its various stages of formation, acceleration, deceleration, and deposition, as well as the impact pressure. The results show that the granular flow and impact behavior can be well represented by the proposed 3D BSMPM with the Cross rheological model, demonstrating the effectiveness of the proposed method in simulating complicated environmental fluid dynamics.

Alternating Subplinian and phreatomagmatic phases during the construction of a phonolitic maar-diatreme volcano (Caldera del Rey, Tenerife, Canary Islands)

The Early Pleistocene, well exposed, Caldera del Rey maar-diatreme volcano, Tenerife, Canary Islands was constructed during a ∼ VEI 4 phonolitic eruption that involved two cycles of magmatic-to-phreatomagmatic activity and resulted in two overlapping craters aligned NE-SW. Magmatic phases fed unsteady Subplinian eruption columns that reached 8–12 km altitude and dispersed tephra to the west and southwest of the volcano and shed pyroclastic density currents. Phreatomagmatic phases, driven by explosive interactions between magma and groundwater, constructed an extensive tephra ring via deposition from ballistic curtains, pyroclastic density currents, and tephra fall. Near-optimal-scaled depth phreatomagmatic explosions (strong and/or shallow) excavated a substantial diatreme beneath the north crater and constructed a substantial tephra ring. This abruptly transitioned to deeper-than-optimal scaled depth explosions (weak and/or deep) that erupted mostly fine ash which was dispersed by dilute pyroclastic density currents and fallout and filled the south crater. At distances of >4 km from the volcano, over a metre of ash and pumice accumulated during the phreatomagmatic phases. The Caldera del Rey volcano provides an instructive study on how interaction between ascending felsic magma and groundwater can modify Subplinian eruptions.

Influence of Retrograde Intramedullary Beam Position Within Talar Body on Radiographic Failure of Medial Column Fusion

Category: Midfoot/Forefoot; Diabetes Introduction/Purpose: Intramedullary fixation in the form of retrograde beam or bolt has developed as an intriguing treatment option for unstable midfoot collapse. This is particularly true when it is desired to minimize the length of incision or to avoid surface implants in a compromised soft tissue envelope. However, prior studies have demonstrated high rates of complications associated with intramedullary midfoot fusion constructs (Ford et al., Butt et al). The goal of this study was to create a reproducible convention of classifying position of the terminal implant within the talar body and to uncover an association of relative position of the implant at the time of surgery with an increased risk of failure. Methods: Consecutive patients treated surgically from January 2017 to September 2022 with retrograde intramedullary fusion beam were identified; 44 were included in the final analysis. Average age was 62.7 years and mean radiographic follow up measured 12.86 months. Figure 1 demonstrates our classification of relative talar position. First, a line was drawn along the axis of the talar neck and carried posteriorly dividing the talar body into dorsal and plantar hemispheres. Then, a line was drawn from the anterior articular margin of the talar body to the lateral talar process. Parallel lines were then created in an equidistant fashion to divide the talar body into equal relative quartiles. At the time of surgery, the tip of the intramedullary beam was classified into relative axial and coronal position by a single observer. Our primary outcomes were hardware failure defined by implant fracture or cutout from the bone or additional surgery. Results: Successful midfoot fusion with intramedullary beam was achieved in 77% of our cases. 10 cases demonstrated hardware failure or the need for additional surgery. Relative implant position was classified as dorsal in 43% of cases and plantar in 57% of cases. Talar quartile depth was classified as 1st in 6% cases, 2nd in 32% of cases, 3rd in 30% of cases, and 4th in 32% of cases. There was no clinical or statistically significant difference between rates of failure based on relative implant position. Conclusion: Retrograde intramedullary fusion for medial column collapse remains a viable treatment option and our data supports successful fusion in most patients but a risk of failure remains significant. In this study, the relative position of the terminal implant within the talar body did not correlate with an increased risk of failure. There are likely other patient specific, or biomechanical factors leading to hardware fracture, cut out, or return of deformity. Continued analysis as sample size increases remains paramount to forming additional conclusions.

The Estimated Climate Impact of the Hunga Tonga‐Hunga Ha'apai Eruption Plume

AbstractOn 15 January 2022, the Hunga Tonga‐Hunga Ha'apai (HT) eruption injected SO2 and water into the middle stratosphere. The SO2 is rapidly converted to sulfate aerosols. The aerosol and water vapor anomalies have persisted in the Southern Hemisphere throughout 2022. The water vapor anomaly increases the net downward IR radiative flux whereas the aerosol layer reduces the direct solar forcing. The direct solar flux reduction is larger than the increased IR flux. Thus, the net tropospheric forcing will be negative. The changes in radiative forcing peak in July and August and diminish thereafter. Scaling to the observed cooling after the 1991 Pinatubo eruption, HT would cool the 2022 Southern Hemisphere's average surface temperatures by less than 0.037°C.

An automated ash dispersion forecast system: case study Popocatépetl volcano, Mexico

An operational volcanic ash dispersion forecast system was developed for Popocatépetl. It runs automatically every day developing 108 possible scenarios of ash dispersion for the following 36 h. Scenarios are simulated for three eruption column heights: 3 km, 5 km, and 10 km above the volcano’s crater level, every hour for eruptions lasting 1 h. For each hypothetical eruption that starts every hour, the dispersion during the following 8 h is modelled. The system uses the Weather Research and Forecasting (WRF) model for weather data and the Fall3D model. It includes a visualization website that displays, among other products: ground accumulation, deposit load, and concentration at relevant flight levels. Popocatépetl volcano, located ~ 60 km from Mexico Megacity was selected as a case study. A comparison from ash forecast system results and satellite observations is presented. The system developed and tested here can be adapted to be operative at any volcano.

Strong geochemical anomalies following active submarine eruption offshore Mayotte

Submarine volcanic activity releases large amounts of gases and metals in the water column, affecting biogeochemical cycles and ecosystems at a regional and local scale. In 2018, Fani Maoré submarine volcano erupted 50 km offshore Mayotte Island (Comoros Archipelago, Indian Ocean). Active eruptive plumes were observed in May 2019 at and around the summit with acoustic plumes rising 2 km into the water column coupled to strong geochemical anomalies. Between May 2019 and October 2020, three research cruises monitored the eruptive activity. Here, we report spatial and temporal variability of water column chemistry above the volcano, focusing on dissolved gases, trace metal concentrations, and physico-chemical parameters. In May 2019, concentrations above 800 nM in CH4 and H2 were measured throughout the water column, with Total Dissolvable Mn and Total Dissolvable Fe concentrations above 500 nM, and CO2 values of 265 μM. Strong water column acidification was measured (0.6 pH unit) compared to the regional background. From May 2019 to October 2020, we observed a general decrease in gas concentrations, and an evolution of the TDMn/TDFe ratios similar to previously reported values in other submarine volcanic contexts, and consistent with a decrease of the eruptive activity at the volcano. In October 2020, a rebound of high H2 concentrations resulted from new lava flows, which were identified by seafloor observation using deep-towed camera, 5 km further than the volcano summit. During 2 years timespan of our observations (2019–2020), He, CO2 and CH4 concentrations correlate highlighting a magmatic origin of dissolved gases. δ13C-CH4 values of −34‰ vs. vPDB might suggest magma/sediments interaction during the magma ascent, and potential thermal cracking of organic matter, although abiotic methane generation cannot be ruled out given the volcanic context. Weak correlations between H2 and excess of 3He suggest complex processes of H2 from magmatic degassing, lava/seawater interaction, and oxidation processes in the water column. Strong and correlated Fe, Mn and Si water column anomalies are also consistent with fluid-rock reactions induced by acidic fluids rich in magmatic volatiles. Water column acidification appears to be associated with the release of CO2-rich fluids. A year after the main eruptive event, the system seems to be back to steady-state highlighting the buffer capacity and resilience of the seawater column environment.

Restraint System Optimizations Using Diverse Human Body Models in Frontal Crashes

<div><b>Objective:</b> This study aimed to optimize restraint systems and improve safety equity by using parametric human body models (HBMs) and vehicle models accounting for variations in occupant size and shape as well as vehicle type.</div> <div><b>Methodology:</b> A diverse set of finite element (FE) HBMs were developed by morphing the GHBMC midsize male simplified model into statistically predicted skeleton and body shape geometries with varied age, stature, and body mass index (BMI). A parametric vehicle model was equipped with driver, front passenger, knee, and curtain airbags along with seat belts with pretensioner(s) and load limiter and has been validated against US-NCAP results from four vehicles (Corolla, Accord, RAV4, F150). Ten student groups were formed for this study, and each group picked a vehicle model, occupant side (driver vs. passenger), and an occupant model among the 60 HBMs. About 200 frontal crash simulations were performed with 10 combinations of vehicles (n = 4) and occupants (m = 8). The airbag inflation, airbag vent size, seatbelt load limiter, and steering column collapse force were varied to reach better occupant protection. The joint injury probability (Pjoint) combining head, neck, chest, and lower extremity injury risks was used for the design optimization. Injury risk curves were scaled based on the skeleton size and shape of each HBM.</div> <div><b>Results and Conclusions:</b> We observed that tall and heavier male occupants tend to strike through the airbag leading to higher head injury risk; older and female occupants tend to sustain higher chest injury risk, while obese occupants tend to have higher lower extremity injury risk. After design optimizations, the average <i>P</i>joint was reduced from 0.576 ± 0.218 to 0.343 ± 0.044. The airbag inflation and venting were found to be highly effective in head protection, while the belt load limit and steering column force were sensitive to chest injury risks. Conflicting parameter effects were found between head and chest injuries and among different occupants, highlighting the complexity of achieving safety equity across a diverse population. This study demonstrated the benefit of adaptive restraint systems for a diverse population.</div>

Temporal change in eruption style during the basaltic explosive An’ei eruption of the Izu-Oshima volcano, Japan: insights from stratigraphy and chemical composition analyses

Basaltic eruptions sometimes show an explosive and complex nature; thus, clarifying the sequence and controlling parameters is essential for understanding their causes. The An’ei eruption of the Izu-Oshima volcano during 1777–1792 was a complex basaltic eruption producing lava flows, pyroclastic falls, and ash plumes. We reconstructed the transition of the eruption style based on geological data combined with comparisons with data from historical documents and used chemical analyses to develop a magma plumbing model. The An’ei eruption started in August 1777 with scoria ejection. The scoria deposit was classified into Units A–C. Unit A scoria was produced by early weak explosions and more intense subsequent explosions. Unit B scoria marked a return to weak plumes before the summit eruption reached its climactic phase in November 1778 and explosively ejected Unit C scoria. Several lava flows were also effused from the foot of the scoria cone during these periods of scoria ejection. After a 5-year hiatus, the eruption ultimately shifted to persistent, weak ash ejection and pyroclastic surges. The tephra volumes of Units A, B, and C were estimated at 1.9–4.3 × 107, 0.6–4.5 × 106, and 1.3–3.2 × 107 m3, respectively. Associated column heights of 8–11, 3–10, and 9–12 km were obtained for Units A, B, and C, respectively, resulting in sub-Plinian classification. Chemical analyses have shown that the plagioclase phenocryst content increased as the eruption progressed. The transition from relatively weak activity with Strombolian and sub-Plinian explosions, caused by aphyric magma, to short-period activity with more intense sub-Plinian explosions, caused by porphyritic magma, can be explained by evacuation of magma from multiple reservoirs with different contents of plagioclase phenocrysts. Simultaneous lava flows that have different petrological features from those of the scoria eruptions also suggest multiple magma reservoirs and pathways. This view of the temporal change in eruptive style, corresponding to change in magma type, is essential for understanding the eruptive processes of large-scale basaltic eruptions of the Izu-Oshima volcano and contributes to clarifying the nature and hazards of basaltic eruptions which turn into explosive activities in general.

Effects of debris entrainment and recycling on explosive volcanic eruption jets and columns

Effects of debris entrainment and recycling on explosive volcanic eruption jets and columns

Atmosphere injection of sea salts during large explosive submarine volcanic eruptions

The 15 January 2022 submarine eruption at Hunga volcano was the most explosive volcanic eruption in 140 years. It involved exceptional magma and seawater interaction throughout the entire submarine caldera collapse. The submarine volcanic jet breached the sea surface and formed a subaerial eruptive plume that transported volcanic ash, gas, sea salts and seawater up to ~ 57 km, reaching into the mesosphere. We document high concentrations of sea salts in tephra (volcanic ash) collected shortly after deposition. We also discuss the potential climatic consequences of large-scale injection of salts into the upper atmosphere during submarine eruptions. Sodium chloride in these volcanic plumes can reach extreme concentrations, and dehalogenation of chlorides and bromides poses the risk of long-term atmospheric and weather impact. Salt content in rapidly collected tephra samples may also be used as a proxy to estimate the water:magma ratio during eruption, with implications for quantification of fragmentation efficiency in submarine breaching events. The balance between salt loading into the atmosphere versus deposition in ash aggregates is a key factor in understanding the atmospheric and climatic consequences of submarine eruptions.

Experimental and numerical investigation on the collapse of annular columns of dry granular matter

The collapse of a granular column confined in a vertical annulus is investigated through both experiments and DEM. During the collapse of column, an outward-moving avalanche and a unique shape of final deposit are commonly observed. In contrast, the present problem involves an inward granular avalanche towards the center of the annulus along with an outward avalanche. The final deposit profile has been categorized into four different cases involving single or double peaks and valley in between based on the aspect ratio. Apart from the mild effect of the coefficient of friction, no other particle properties influence the shape of the deposit. Removal speed of the confining walls strongly affects the speed of the avalanche but not the deposit shape. Scaling analyses show a power law dependence of runout distance on aspect ratio and a linear dependence of event duration on the free fall time of a grain.

NUMERICAL SIMULATION OF TSUNAMI IMPACT FROM THE 1/15/22 ERUPTION OF THE HUNGA TONGA - HUNGA HA’APAI VOLCANO

Tsunamis from volcanic ‘explosive’ eruptions are rare, with the last catastrophic event being Krakatau in 1883 (Verbeek, 1885), during which, tsunamis were generated in the far-field by pressure shock-waves and in the nearfield of the volcano, in the Sunda Straits, by several potential geological mechanisms including pyroclastic flows, ash column, and/or caldera collapse. On 1/22/55, at about 4:15 UTC, a one in 1,000 year eruption of the Hunga Tonga-Hunga Ha’a-pai Volcano (HTHHV), that had started on12/20/21, reached its paroxysm with a series of large underwater explosions, releasing enormous energy (4-18 Mt of TNT), and ejecting a large ash plume 58 km into the stratosphere. We simulate both the near- and far-field tsunami generation from the eruption, but in this paper we focus on analyzing and validating the near-field impact against field data.

Volcanology and facies analysis of the youngest phreatomagmatic deposits on O'ahu, Hawai'i

The area known as the Lānaʻi Lookout has Oʻahu's youngest and best exposures of deposits from pyroclastic density currents (PDCs), generated by explosions involving magma-water interaction. This work presents the first detailed facies analysis of the deposits at the Lānaʻi Lookout, fundamental to understanding the explosion dynamics, post-fragmentation transport and depositional processes, and to unravel the eruptive history. The lithofacies identified include planar-bedded, low-angle, and megaripple, cross-bedded ash to lapilli, accretionary lapilli-rich falls and isolated ballistic blocks and bombs. These features are interpreted as generated by mostly dilute PDCs, co-PDC fall and sedimentation from eruptive clouds and ballistic-charged jets. Overall, at least four eruptive stages formed the pyroclastic succession: (i) frequent, brief explosions from Kahauloa and Koko craters, producing fallout deposits and ballistics; (ii) a dominant stage of sustained passing to short-lived production of PDCs from Kahauloa crater, followed by a short break in volcanic activity; (iii) return of explosive activity dominated by fallout deposits likely sourced at Kahauloa; (iv) intermittent PDCs from Kahauloa alternating with debris flows coming down Koko Crater flanks. This stage is followed by lava flow emplacement that marked the end of the explosive eruptions at the Koko Rift system. In summary, the lithofacies analysis and stratigraphic relations of this complex multi-vent system informs on the dynamics, eruptive style, and frequency of eruptions of the late-stage volcanism on Oʻahu.

Optimizing mass eruption rate estimates by combining simple plume models

Tephra injected into the atmosphere by volcanic ash plumes poses one of the key hazards in explosive eruptions. Forecasting the atmospheric dispersal of volcanic ash requires good knowledge of the current eruption source parameters, in particular of the mass eruption rate (MER), which quantifies the mass flow rate of gas and tephra at the vent. Since this parameter cannot be directly measured in real-time, monitoring efforts aim to assess the MER indirectly, for example, by applying plume models that link the (relatively easily detectable) plume height with the mass flux at the vent. By comparing the model estimates with independently acquired fallout measurements from the 130 eruptions listed in the Independent Volcanic Eruption Source Parameter Archive (Aubry et al., J. Volcanol. Geotherm. Res., 2021, 417), we tested the success rates of six 0D plume models along with four different modelling approaches with the aim to optimize MER prediction. According to our findings, instead of simply relying on the application of one plume model for all situations, the accuracy of MER forecast can be increased by mixing the plume models via model weight factors when these factors are appropriately selected. The optimal choice of model weight factors depends on the availability and type of volcanological and meteorological information for the eruption monitored. A decision tree is presented that assists the reader in finding the optimal modelling strategy to ascertain highest MER forecast accuracy.

Eruption, transport mechanisms and deposition of Paleogene ignimbrites, southwestern North Patagonian Massif, Argentina

The Paleocene-Eocene Catán Lil Ignimbrite (CLI) is one of the few occurrences within the explosive acid volcanism of this age in the extra-Andean region of the North Patagonian Massif. It represents a small-scale explosive eruption covering an area of 214 km2, with an estimated volume of 1.27 km3 and consisting of three weakly-to densely welded cooling units. The maximum thickness of this sequence is 90 m. Its basal unit is the best preserved, and has allowed a lithofacial analysis that reveals different aspects of the eruption and the emplacement mode of the Catán Lil pyroclastic flows. The CLI ignimbrites are generally massive, poorly sorted, matrix-supported deposits (tuff and lapilli tuff) resulting from dense pyroclastic currents (PDCs). They are composed mainly of juvenile fragments, scarce lithoclasts and crystalloclasts, being a product of a purely magmatic fragmentation occurred at a shallow level. A pyroclastic fountaining eruptive model is interpreted, resulting from the collapse of a low eruptive column, and a rapid and high-temperature emplacement. The CLI PDCs generally respond to slow moving pyroclastic flows with low erosive energy. The morphology and stratigraphy indicate radial emissions with thicknesses decreasing towards the periphery that become evident in Central-South ignimbrites. These PDCs flowed over a planar terrain, giving rise to most of the CLI deposits (South-Central area and North- East). The Northwestern ignimbrites are deposits in the interior (south and middle part) of the Catán Lil creek, forming thick deposits within the latter valley and thin, veneer-like deposits over the flanking Lipetrén granitoids. In the North- East region, the ignimbrites show stratigraphic relationships that suggest that the PDCs would slightly postdate those of the South-Central area. The Catán Lil Ignimbrites represent the most eastern exposures of the Paleocene-Eocene Pilcaniyeu Belt, differing from the latter in that it lacks a conspicuous lava facies, and by the unimodal character and the tectonic signature of the Catán Lil sequence.

A mesh-free particle method for continuum modelling of granular flow

Based on the continuum model for granular media developed in Dunatunga et al. we propose a mesh-free generalized finite difference method for the simulation of granular flows. The model is given by an elasto-viscoplastic model with a yield criterion using the μ(I) rheology from Jop et al. The numerical procedure is based on a mesh-free particle method with a least squares approximation of the derivatives in the balance equations combined with the numerical algorithm developed in Dunatunga et al. to compute the plastic stresses. The method is numerically tested and verified for several numerical experiments including granular column collapse and rigid body motion in granular materials. For comparison a nonlinear microscopic model from Lacaze et al. is implemented and results are compared to the those obtained from the continuum model for granular column collapse and rigid body coupling to granular flow.

An efficient material point method framework based on the affine matrix

The material point method (MPM) has proven to be an effective numerical approach for simulating extreme events involving large deformations. Although numerous MPM variants have been proposed to enhance the capability of MPM, its application is currently limited by issues of computational efficiency and stability. This study presents an innovative affine matrix-based MPM scheme (AM-MPM) that can substantially promote the computational efficiency of MPM while maintaining exceptional stability. The proposed scheme is featured by its use of the affine matrix as a first-order approximation of the velocity gradient in the subsequent step and the direct computation of associated strain/stress for particles. This approach reduces the information interpolation between particles and grid nodes from two times to a single time, significantly leveraging computational efficiency. The proposed MPM scheme is firstly validated by the quasi-static compaction under self-weight and then applied to various classical problems involving large deformations, including biaxial compression test, column collapse, the impact of two rings, and the twisting of a 3D elastic column. The performance of the proposed scheme in terms of accuracy and efficiency is also discussed in detail.

A material point/finite volume method for coupled shallow water flows and large dynamic deformations in seabeds

A hybrid material point/finite volume method for the numerical simulation of shallow water waves caused by large dynamic deformations in the bathymetry is presented. The proposed model consists of coupling the nonlinear shallow water equations for the water flow and a dynamic elastoplastic system for the seabed deformation. As a constitutive law, we consider a linear elastic-non-associative plastic model with the Drucker-Prager yield criterion allowing for large deformations under undrained cases. The transfer conditions between these models are achieved by using forces sampled from the hydraulic pressure and the friction terms along the interface between the seabed soil and shallow water. A detailed description regarding the coupled algorithm for the hybrid material point/finite volume method is presented. Several numerical examples are investigated to demonstrate the performance of the finite volume method for simulations of shallow water flow and the material point method for capturing the large deformation process of the solid phase. We also present numerical simulations of an undrained clay column collapse that induced shallow water waves and a dam-break problem to demonstrate the excellent performance of the proposed hybrid material point/finite volume method.