PICO
Analogue modeling for Earth Sciences started over two centuries ago as an explorative technique that allowed for the first time unfolding and visualizing a wide range of tectonic processes. While this character remains a compelling feature of analogue models, this experimental methodology has evolved over the last few decades into a quantitative, reproducible and reliable method. Most recent developments aredispersed across scientific journal articles, many behind pay-walls and sometimes hidden in appendices, but no open-access overview exists that brings all this knowledge together.
In the context of the EU research infrastructure EPOS, we are preparing the first comprehensive guide (SPRINGER will publish that as open access) on the state-of-the-art in analogue modeling of geologic processes. This community-built book will be organized into three sections. The first section will serve as a “cookbook” for building analogue models, offering up-to-date guide on scaling down models, selecting suitable analog materials, collecting experimental data, and interpreting those results. The second section will focus on a variety of tectonic processes that can be reproduced in the lab and analyzed using analogue modelling. The final section will emphasize the importance of sharing experimental research data through Open Access data publications and illustrate how analogue models can enhance the Earth Science teaching experience in classrooms. This book will fill a significant gap in the scholarly literature and will serve as a reference and guide for both early-career and experienced researchers as well as reaching out to a broader community of educational and academic teachers. In this presentation, we will share our journey toward this community-effort and give examples of the different sections of the book.
How to cite: Funiciello, F., Buiter, S., Corbi, F., Reitano, R., Rosenau, M., Rudolf, M., Willingshofer, E., and Zwaan, F. and the Authors of the book: Analogue modelling in Geosciences uncovered: a textbook for modern minds, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7471, https://doi.org/10.5194/egusphere-egu25-7471, 2025.
The Central Mediterranean is a great natural laboratory for many processes related to subduction. Along the Dinaric-Hellenic margin, the rigid Adria microplate indents the Eastern Alps and Dinarides in the north, while the southern part subducts beneath the advancing Hellenides. The Kefalonia Transform Fault System (KTFS) marks the current position of this unique transition between subduction of more buoyant continental lithosphere and less buoyant oceanic lithosphere. The resulting differential convergence is thought to have caused vertical tearing or bending of the subducting slab, although the lack of detailed seismological investigations leaves an open question concerning this geometry.
Slab tears have a significant role in surface evolution around subduction zones. They affect mantle flow, stress propagation within the subducting plate, as well as dynamic topography and volcanism on the surface. However, most models of slab tears investigate their evolution by pre-cutting the subducting lithosphere. We investigated the mechanisms underlying the dynamic formation of a vertical slab tear to interpret geodetic, tomographic, and tectonic observations from around the KTFS. To achieve this, we built a setup with a geometry inspired by the natural subduction system, varied the continental domain's rheology, and introduced an ocean-continent transition zone composed of non-Newtonian analogue materials that allow for strain localisation and slab detachment.
In particular, we wanted to: i) explore how the subducting plate deforms when a tear is forming; ii) observe how the mantle flow reacts to such changes in subduction dynamics; iii) estimate what are the resulting effects on the stress distribution and surface strain on the overriding plate.
We analysed two experimental end-members (i.e., model (A) ocean and continent in lateral contact Vs model (B) separated by non-Newtonian, transitional material) and compared them with the natural observations and the geometry of the subduction system. In both models the rigidity of the continental segment has a critical role in the type of deformation we observe during continental subduction, and controls the amount of stretching, rotation, and continental subduction. The transition zone in model (B) localises deformation, minimising shear and extensional deformation of the continent.
At the end of the experiment, the subduction front geometry of model (B) better reproduces the actual eastern Adriatic margin in correspondence of the KTFS, and the deformation observed on the continental plate is consistent with the structures observed on the field, indicating a certain level of coupling between slab and overriding plate. This similarity without achieving slab tearing suggests that a slab bend may be sufficient to reach the present natural configuration. Consequently, a slab tear may be absent or its extent be limited to a deeper section of the slab.
How to cite: Crosetto, S., Király, Á., Brizzi, S., Funiciello, F., and Faccenna, C.: To tear or not to tear? A comparison between analogue modelling and field observations along the Kefalonia Transform Fault System, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16959, https://doi.org/10.5194/egusphere-egu25-16959, 2025.
Strike-slip faults are subvertical faults with horizontal movement. They are a fundamental expression of plate tectonics and play a fundamental role in the dynamics of our planet. Transform faults are one of the three types of terrestrial plate boundaries and transcurrent faults occur almost in all tectonic environments on Earth. Understanding their kinematics and dynamics is, therefore, essential for advancing knowledge of plate’s deformation and their seismicity. However, the kinematics and dynamics of the different types of strike-slip faults are still not fully understood. In this study, we use analogue models to investigate four distinct types of strike-slip movement. The strike-slip systems are simulated by deforming a sand-cake on top of two rigid basal acrylic plates. We impose four movements to these plates: 1) two plates moving in opposite directions; 2) one plate stopped and another moving; 3) two plates moving in the same direction but at different velocities and 4) two plates moving in alternating manner in the same direction. The results show some unexpected and insightful outcomes that shed new lights on how some of these systems work. These experiments can be used to gain knowledge on natural prototypes and have implications for our understanding of how strike slip faults operate in different tectonics environments, with important implications for seismic hazards.
How to cite: A. Reis, C., C. Duarte, J., M. Rosas, F., João, M., and Gomes, A.: Analogue modeling of strike-slip faults: a new insight from different kinematic constrains, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10756, https://doi.org/10.5194/egusphere-egu25-10756, 2025.
The Huoerguosi-Manasi-Tugulu (HMT) fold-and-thrust belt, which is located in the southern Junggar Basin, has formed in response to contraction during Late Cenozoic. However, the tectonic environment for its formation before Late Cenozoic is still controversial. In this paper, we conducted geometric and kinematic analysis of seismic profiles and outcrop data to reveal the Late Jurassic deformation characteristics in this area. Angular unconformity between Cretaceous and Jurassic is well preserved in Qigu anticline belt south to the HMT fold-and-thrust belt. This unconformity also exists in the HMT fold-and-thrust belt, indicating that HMT fold-and-thrust belt started to active during Late Jurassic. We use surface data, recently collected and processed subsurface seismic refection data, isopach map of Lower Jurassic and balanced sections to propose pre-existing half-graben system developed in the Lower Jurassic with this fold-and-thrust belt. We also use results of a series of scaled sandbox analogue models, where industrial CT apparatus was used to monitor deformation, to simulate the evolution of this fold and thrust belt. We suggest that the segmented shape of the HMT fold-and-thrust belt is a response to the presence of thrust ramps, which were formed during early Jurassic. During late Jurassic and Cenozoic shortening, the Lower Jurassic syn-rift sediments served as major detachment horizon, making a pre-existing normal fault act as a stress concentration zone leading to steeping of a thrust-ramp over the normal fault and cover detachment overstep the underlying half-grabens. Modeling results reveal that the presented structural framework has close resemblance with paleostructures especially in the intracontinental environment, which underwent a complex multicycle evolution process, and provide a new prospective for the interpretation of natural examples.
How to cite: Ma, D., Koyi, H., He, D., Sun, Y., Pan, S., Qu, Y., Wang, H., Wang, Y., Cui, J., and Yang, S.: Modelling inversion of two stages shortening overprinted pre-existing grabens: A case study of Huoerguosi-Manasi-Tugulu fold-and-thrust belt, northern Tian Shan, China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14708, https://doi.org/10.5194/egusphere-egu25-14708, 2025.
Volcano deformation can be a key signal of volcanic unrest and often precedes an eruption. Understanding the relationship between magmatic intrusions and subsequent deformation is crucial for predicting temporal and spatial eruption patterns and thus reducing the impacts of volcanic hazards by enhancing preparedness.
Laboratory analogue models enable the direct study of model volcano subsurface changes. A 2D experimental approach enables subsurface intrusions to be tracked through time and directly compared to the surface displacements. In this study, golden syrup, a viscous fluid, was injected as a magma analogue into a cone-shaped granular material representing an analogue edifice. Images were taken to capture the time-series evolution of the intrusions and associated deformation. The relationship between subsurface intrusions and subsequent surface deformation was investigated by analysing the frame-by-frame pixel displacements using Particle Image Velocimetry (PIV).
Initial findings indicated that the internal compaction of granular material accommodated the radial deformation resulting from the intrusions. Transitions to surface displacement correlated with increased strain rate from the intrusions. Material cohesion influenced material compaction; injections into high cohesion material produced surface deformation when the intrusion approached near-surface regions, compared to injections into low cohesion material (that produced surface deformation when the intrusion was deeper). These findings highlight the role of material (host rock) strength in accommodating deformation via compaction.
In the experiments, an “eruption” occurred when the golden syrup breached the surface of the analogue edifice, and this terminated the experiment. The extrusion location was consistent for each experiment and occurred along the edges of the deforming section at the surface. This finding may improve our ability to locate eruption locations based on surface deformation patterns, enhancing preparedness for deforming volcanoes and their potential eruption location.
How to cite: Mitchell, A., Lane, S., Gilbert, J., Tuffen, H., and James, M.: Analogue Modelling of Intrusion Dynamics in Relation to Internal and Surface Deformation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10571, https://doi.org/10.5194/egusphere-egu25-10571, 2025.
Title:
Insights into plume-ridge-transform fault interactions as derived from 3D numerical geodynamic modelling of the Azores Triple Junction
Authors: J. Almeida; J. Duarte; F. Rosas; R. Fernandes; R. Ramalho
The Azores archipelago is located at the centre of the Northern Atlantic Ocean and is characterized by a large bathymetric plateau bisected by the Mid Atlantic Ridge (MAR). Over the last 10 Myr, the interaction between the Azores plume, the MAR, and the Gloria Fault zone has led to a complex tectonic history, namely the transition from a R-R-T to a diffuse R-R-R triple junction. The implied tectonic stresses are presently accommodated along several right-lateral oblique extensional structures, which includes the Terceira intra-oceanic rift. To this day, a full understanding of the geodynamic mechanisms behind this change in triple junction configuration is still lacking.
With the present work, we explore how the Azores system was shaped by the complex plume-ridge-transform-fault interactions by conducting 3D viscoelastoplastic geodynamic models. Prior publications concerning this region argued that most NW-SE oriented features – such as the Terceira Rift – form due to the onset of the right-lateral motion between Eurasia and Nubia during the Early Miocene. We thus designed an initial model setup which follows plate reconstructions for Azores and implemented a complying shift from extensional to right-lateral shear tectonic conditions. We further assessed the role of the Azores plume by imposing a thermal anomaly close to the MAR to gain additional insight on the main geodynamic processes which govern this system.
Our results suggest that the primary controlling mechanism behind the formation of the Terceira Rift is the change in tectonic forcing imposed by the change in motion between Eurasia and Nubia during the Early Miocene, acting in tandem with the strain localization effects of the Azores Plateau. The shift towards a relative right-lateral motion between these plates induces a rotation of the local stress field, promoting the localization of transtensional shear along the NE edge of the plateau, closely mirroring the present-day location of the Terceira Rift.
This work was funded by the Portuguese Fundação para a Ciência e a Tecnologia (FCT) I.P./MCTES through projects GEMMA (https://doi.org/10.54499/PTDC/CTA-GEO/2083/2021) and through national funds (PIDDAC) – UID/50019/2025 and LA/P/0068/2020 (https://doi.org/10.54499/LA/P/0068/2020).
How to cite: Almeida, J., Duarte, J., Rosas, F., Fernandes, R., and Ramalho, R.: Insights into plume-ridge-transform fault interactions as derived from 3D numerical geodynamic modelling of the Azores Triple Junction, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18844, https://doi.org/10.5194/egusphere-egu25-18844, 2025.
The linearity of current-day ocean floor fracture zones demonstrates the longevity of periods of relatively steady plate motion, characterized by little to very slow movement of the associated Euler poles that describe the motion of the plates on a spherical surface. However, the geologic record also holds evidence that periods of nearly steady plate motion have been interrupted by comparatively rapid plate reorganization events, occurring in less than 10 Myr, that are well described by considering the associated change in the history of the Euler vector directions and/or magnitudes of the affected plates. One category of proposals for the driving mechanism for plate reorganization events makes a case for deeper mantle derived forces instigating surface motion change. A key factor in starting the initiation of mantle driven plate reorganization events may be the mantle’s radiogenically derived internal heating, which acts to form unstable reservoirs of buoyancy below the oldest sections of a plate, adjacent to mature slabs. The potential for internal heating to produce focused hot parcels in the mantle, capable of disrupting the steadiness of convection patterns, was described in previous numerical studies of thermal convection in momentum free fluids. Determination of the degree of success of plate generation is dependent on identifying all potential plate boundaries and inverting the implied intra-plate velocities to test their agreement on a common rotation axis (i.e., the plate’s Euler pole). Here, we utilize an iterative method for implementing a previously described tool for identifying potential plate boundaries in the output of a 3D numerical model of mantle convection. Post-processing model output for a period simulating nearly 150 Myr of evolution we track the history of several neighbouring plates and find that they maintain rigidity well demonstrated by Euler vector fitting of the intra-plate velocities. We find that generally, as their sizes and position change, the plates exhibit motion that changes direction and magnitude slowly. However, we also find that steady evolution can be punctuated by major but relatively short duration reorganization events, that we identify as being driven by the impact of mantle internal heating on the loss of slab-pull at a mature convergent plate boundary.
How to cite: Lowman, J., Guerrero, J., Fairservice, C., Javaheri, P., and Tackley, P.: A rapid tectonic plate reorganization event dynamically modelled by subduction cessation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14030, https://doi.org/10.5194/egusphere-egu25-14030, 2025.
Diapiric intrusions induce significant thermal and mechanical changes in the surrounding host rock, including heating and deformation. While previous studies have focused on intrusion formation, few models detail the thermal field evolution during progressive pluton boundary migration, even less, with the associated host-rock deformation. This study aims to simulate the Flamanville granitic diapir's growth and cooling processes to investigate the coupling between thermal evolution and deformation in the aureole during contact metamorphism. The Flamanville intrusion, located in Normandy, northwest France, is a homogeneous, coarse-grained granodioritic diapir with an elliptical geometry, measuring 7.4 km (E-W) by 4.5 km (N-S), and a maximum depth of over 3 km. The pluton intruded Cambrian to Devonian meta-sediments around 318 ± 1.5 Ma. The contact metamorphic aureole extends up to 1 km from the pluton boundary, where intense deformation is characterized by radial shortening, concentric stretching, boudinage, and shear structures. A thermal model is constructed using OpenFOAM 11, an open-source computational fluid dynamics (CFD) platform. To accurately capture the dynamic emplacement of the Flamanville pluton, a custom solver is developed to incorporate an adequate advection term into the thermal diffusion equation, representing the gradual migration of the Flamanville pluton boundary during its emplacement. The solver accounts for the spatial variation in deformation intensity within the aureole, where deformation decreases systematically with increasing distance from the diapir, reflecting observed field patterns of shortening, stretching, and shear structures. Approximately 90 host-rock samples were collected across the aureole to determine maximum metamorphic temperatures using the Laser Raman Spectroscopy Carbon Geothermometer (RSCM) method. The temperatures, ranging from 250°C to 650°C, provide a robust dataset for validating the thermal model and defining the thermal variation in the aureole. This numerical model will simulate the thermal evolution of the host rock during diapiric growth and cooling. By comparing the results with Raman-derived temperature profiles, it is expected to facilitate a quantitative analysis of the evolution of the thermal field within the aureole, offering advanced insights into the thermal regimes governing aureole deformation and contact metamorphism processes.
Key words: Numerical modeling; thermal evolution; aureole deformation; Flamanville granitic diapir; contact metamorphism; Raman Spectroscopy Carbon Geothermometer (RSCM)
How to cite: Chen, Y., Wang, B., Richard, G., Liu, J., Augier, R., Raimbourg, H., Guillou-Frottier, L., Canizares, A., and Chen, Y.: A Thermal Model of the Flamanville Granitic Diapir Deforming Aureole, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3129, https://doi.org/10.5194/egusphere-egu25-3129, 2025.
Ischia Island, Italy, is a densely populated, active resurgent volcanic caldera that has undergone rapid deformation during the Holocene. The northern sector of the island, particularly the Casamicciola area, is notable for destructive shallow earthquakes, among the most severe in the Italian seismic catalog; for instance, the 1883 event claimed more than 2300 lives.
Dense vegetation has historically hindered detailed mapping efforts, but the application of drone-based LiDAR has facilitated us a high-resolution neotectonic mapping. Previously, we investigated the fault geometries along the Casamicciola Holocene Graben fault by integrating high-resolution remote sensing data with field-based mapping techniques in the epicentral area of the 1883, Mw 5.0, and 2017, Md 4.0, earthquakes.
The identified fault structures served as initial conditions for numerical simulations using the mantle convection and lithospheric dynamics code ASPECT. The simulations incorporated the effects of fault strength variations, high geothermal gradients, and contrasts in viscosity and mechanical properties on Holocene deformation distribution. Three primary scenarios were tested: (1) deformation driven by regional NE-SW extensional tectonic stress, (2) deformation caused by pressurization of a magmatic intrusion driving resurgence, and (3) deformation resulting from magma depressurization associated with subsidence.
Results reveal that the high deformation rates are primarily driven by shallow magmatic intrusions (~2 km depth) that induce resurgence of the caldera floor, with minimal contribution from regional tectonic stress. Modelled cumulative slip rates during the Holocene, range from 5.0 mm/yr to 31.12 mm/yr, closely matching rates derived from geological data. Additionally, velocity profiles simulating magma intrusion elucidate how the geometry, pressure, and volume of magma govern the asymmetric uplift of the caldera floor. These findings provide insights into the relationship between magmatic processes and earthquake occurrences in the Casamicciola Holocene Graben.
How to cite: Silva Fragoso, A., Naliboff, J., Norini, G., Douglas, D., Nappi, R., Groppelli, G., and Michetti, A.: Exploring the resurgence stage of Ischia caldera by coupling 2D numerical modelling and high-resolution remote sensing, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1092, https://doi.org/10.5194/egusphere-egu25-1092, 2025.
Mountain regions are globally recognized as biodiversity hotspots. Taiwan is a vivid example, offering an ideal landscape to study the interplay between mountain building and biodiversity. The island resulted from an active arc-continent collision that created a high-relief landscape. The high rates of tectonic uplift, shortening, and extension together with its location in the typhoon belt with high rates of precipitation and erosion results in some of the highest rates of landscape change globally. The short tectonic history and extensive tectonic and geomorphic research provide an opportunity for exploring how mountain building has influenced the island's biodiversity. In this study, we use the landscape evolution model ‘Divide and Capture’ (DAC) to simulate Taiwan’s topography from the onset of uplift to the present day. Landscape evolution modeling predicts the river network patterns, erosion rates, and physical geography in response to tectonic and climatic forcing. We subdivide Taiwan into four major geological domains (Western Foothills, Hsuehshan Range, Central Range, and the extensional Ilan back-arc) and apply horizontal and vertical velocities to each domain subject to a sea level boundary condition that changes in time to simulate the island shape. The resulting model is constrained to fit the exhumation history estimated from low-temperature thermochronometry. Cooling ages from apatite and zircon fission track and helium dating are converted to erosion rates using a thermal model (GLIDE), and used for calibration of the landscape evolution model. The model improves our understanding of Taiwan’s geomorphic history and lays the groundwork for future studies on the interconnection between tectonics, landscape evolution, physical geography, and biodiversity.
How to cite: Krug, C. and Willett, S. D.: Modeling Taiwan’s landscape evolution, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3159, https://doi.org/10.5194/egusphere-egu25-3159, 2025.
Madagascar’s topography is defined by three distinct features: the western remnant escarpment, a central dissected plateau, and the eastern great escarpment. The modern landscape reflects a complex geological history shaped by multiple phases of rifting. The western escarpment dates back approximately 170 Myr, coinciding with Madagascar’s initial separation from Africa. A second phase of rifting, around 90 Myr ago, marked Madagascar’s separation from the Seychelles-India block, leading to the formation of the eastern escarpment. A final phase of landscape evolution resulted from Late Cenozoic volcanic and tectonic extension of Madagascar’s interior, which led to the westward migration of the water divide away from the escarpment.
Building on this geological context, we constructed a landscape evolution model to understand how these rifting phases and subsequent processes influence Madagascar's topography using the Divide and Capture (DAC) code. We test the first-order topography by generating two phases of rifting, including the formation of rift escarpments and flexural tilting. We assume that rifting thinned the crust, inducing unloading at each margin with flexural uplift and tilting in response. We find that each rifting phase results in the formation of an escarpment with divide-type river profiles, but that westward flexural tilting during the second phase shifts the main divide eastward, accelerating the disintegration of the western escarpment and creating detached landforms and knickzone-type river profiles.
Next, we investigate how second-order topographic features can be explained by volcanic activity, intraplate extension, and rock erodibility contrasts. In our model, volcanic activity affects the landscape by steadily building up less erosive topographic edifices. This feature is located on the plateau closer to the eastern escarpment, simulating the real-world scenario. The volcanic topographic highs can locally deflect the topographic gradient such that the major divide “jumps” from its original location and becomes locally pinned to the top of the volcanic edifices. We also explored the influence of surface subsidence in the graben due to intraplate extension on the landscape. We kinematically lowered the plateau surface in the specified rectangular “graben” area by assuming the graben’s longitudinal axis is parallel to the major divide. We find that the progressive retreat of the escarpment erodes the nearest flank of the graben, capturing the enclosed basin of the graben and causing the divide to jump to the furthest flank. These processes reshape the escarpment river morphology but remain confined locally to the graben-affected area. Rock erodibility contrast in the plateau basement is modeled by specifying various shapes of vertical blocks composed of more erosion-resistant rock. These blocks are assumed to have the same initial height as their surroundings and are applied at model initialization. During plateau incision, these blocks erode at a slower rate, causing the escarpment retreat to slow down upon encountering them. As a result, they are left behind as remnant escarpments detached from the plateau.
How to cite: Uchusov, E., Clementucci, R., Wang, Y., and Willett, S.: Rifting, Cenozoic volcanic and tectonic processes control the landscape of Madagascar , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19272, https://doi.org/10.5194/egusphere-egu25-19272, 2025.
Longitudinal river profiles record the uplift history of any tectonically active area. The tectonic forcing causes variation in the topography in the form of channel slope adjustments. The change in the gradient tends to migrate along the river profile at a definite rate. Thus, linear inverse modelling of the river profile can decrypt the spatiotemporal variability of the tectonic uplift rate. This approach relies on the analytical solution of the linear stream incision model. The inversion scheme is applied to the Siang Basin, a sub-basin of the tectonically active Brahmaputra river system, to provide insight into the uplift history and paleo topography of the basin. The V-shaped Siang valley, located south of the Eastern Himalayan Syntaxis, undergoes a sudden change in slope descending from the Tsangpo gorge. The inversion is performed in the Siang Basin, assuming that the uniform tectonic uplift rate is time-independent but space-invariant. Inversion results reveal a temporal pattern of uplift acceleration between 1-2 Myr ago towards the present. The elevation profile indicates the occurrence of some prominent features that have rejuvenated the topography and increased erosion rates in the past. The base level plot also revealed a drastic fall in the base level since the past 2 Myrs. These results provide insights into the evolutionary history of the Siang Basin.
How to cite: Narayan M, U., Bharti, R., and M Nair, A.: Linear Inversion of Fluvial Long Profiles to deduct the Upliftmet history:A case study of Siang Basin, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-758, https://doi.org/10.5194/egusphere-egu25-758, 2025.
, Are the Vibrationand Equation and Wave Equation of Tidal Forc. These Physicale Equations are the basis for further study of the Wave theory of the Earth. Due to a combination of the Earth Rotation and Tidal Forces, the Earth to Wave constantly. The Wave of the Earth produce many Physical Effect, such as: Harmonic Motion of the Earth, Ocean Tides, and so on. Harmonic Dynamics of the Earth (D) studies only two Physical Effects of crustal Wave Processes: Fatigue Effect and Surge Effect. The Fatigue Fracture of Continents forms Peninsulas or Islands, such as: Madagascar and the Malay Peninsula. Continental Surge Effects create Plateaus and Mountain Ranges, such as the Andes and the Brazilian Highlands.
The Topography of the Ocean Floor records the Move Trackway of the Continents. Reconstructing Continents along their Move Trackway on the Ocean Floor is not the same as " fitting " two Continent Masses into one. For the Reconstruction of the Antarctic Continent and South America: Where the two Continents were connected earlier, they have been pulled in two tails by the Ocean Floor of the Drake Passage. The Continent connecting North and South America has also been severely deformed. The Ocean Floor and the Continents all are constantly contraction and deformation. This contraction makes room for the New Ocean Floor. The area where the two Continents joined before 250Ma is already con not fully " fitting " now. For example, the Continent Side of the Mariana Trench cannot accommodate the Continent of the middle and lower Yangtze River plain and Wuyi Mountain. The Side of Gulf of Mexico of the North American Continent cannot accommodate the Northern tip of South America. Ocean Ridges often develop from Early Rifts in Continents. Therefore, the Ocean Ridge can be used as evidence that the Continent Mass was connected ever to the Continent: The Indian Ocean Ridge at 90° E is the evidence of Australia and Asia once connected. The Southwest Indian Ocean Ridge is the evidence of Antarctica and Africa once connected. The Mid-Atlantic Ridge is evidence that the Americas were once connected to Asia and Africa.
The Reconstruction of Ancient Continent needs to follow three basic constraints: (1) Regression point by point based on time. It follows the Calculation Results of the Harmonic Dynamics of the Earth. Because every centimeter of Continental Drift requires a huge Driving Force. (2) Pay attention to the correspondence between the Topography of the Ocean Floor and the location of the Continent. (3) To consider the " fitting " of the Shape, Geological Structure, Paleomagnetism, and Ancient Plant and Animal communities between Continent Masses. This Reconstruction Method is beneficial for determining the Paleogeographic Location of each City. Provide clearer information on Continental Drift.
How to cite: xin, X.: Harmonic dynamic of the Earth （D）, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4, https://doi.org/10.5194/egusphere-egu25-4, 2025.
We conducted a series of numerical modelling experiments to investigate the mechanism of slab breakoff beneath the Java Trench. The subduction of seamounts, which are characterized by overthickened and buoyant crust, can be a key factor conducive to slab detachment. The modeling experiments explored a range of variable parameters, including whether seamount is involved in the subduction process, the geometry and rheological properties of the seamount, the convergence rate, and the age of subducting oceanic lithosphere. The modelling results demonstrate that the presence of seamount significantly affects the slab breakoff process. Slab breakoff typically occurs at the edges of the subducting seamount. The specific geometry and rheological strength of the seamount emerges as the internal factors in determining whether the slab breakoff will occur. Additionally, the slab age and convergence rate are the external effective controlling factors on the timing and depth of slab breakoff. The evolution of surface elevation caused by seamount subduction differs from that of general oceanic lithosphere subduction, featuring an additional uplift event related to the slab breakoff. Based on our findings, we infer that the participation of seamounts in the subduction process beneath the Java Trench (110°E) has led to the development of low-velocity zone in the mantle wedge and high potassium volcanoes in the Java Island, which has further resulted in a compressional tectonic region in the overriding continental crust.
How to cite: Ding, W., Liang, D., and Niu, X.: 2-D Numerical modelling Experements on slab breakoff mechanism beneath the Java Trench , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1865, https://doi.org/10.5194/egusphere-egu25-1865, 2025.
The structural deformation of foreland thrust zones is notably complex and remains a central focus in structural geology. This study investigates the deformation characteristics and formation mechanisms of the Hutubi anticline, located in the southern margin of the Junggar Basin, through numerical simulations using Underworld software. By designing three experimental setups, we analyzed the key controlling factors of the anticline's development.
The primary findings are as follows: (1) the simulation results of Experiment 1 exhibit a high degree of similarity to seismic profile characteristics, indicating that the high brittleness of the stratigraphy, pre-existing paleo-uplifts, and faults are the primary controlling factors for the formation of the Hutubi anticline. Furthermore, the localized depression above the paleo-uplift is attributed to lateral adjustments within the plastic layer, which provides a significant structural indicator for identifying paleo-uplifts; (2)Experiment 2 shows that under high-brittleness stratigraphic conditions, pre-existing faults do not play a dominant role in controlling paleo-uplift formation, highlighting other key mechanisms in such settings; (3)Experiment 3 indicates that in high-plasticity stratigraphic environments, multiple uplifts are prone to formation, with pre-existing faults influencing the specific locations of individual uplifts.
Overall, these results provide critical insights into the formation mechanisms of the Hutubi anticline and underscore the value of numerical simulations in experimental design. The findings not only advance the understanding of thrust tectonics in the southern Junggar Basin but also provide a solid foundation for further detailed studies of regional structural evolution.
How to cite: Cui, L., Chen, Y., Huang, Y., Niu, Y., Tao, Y., Liu, Y., and Chen, Z.: Numerical Simulation of the Deformation of the Hutubi Anticline in the Southern Margin of the Junggar Basin, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4669, https://doi.org/10.5194/egusphere-egu25-4669, 2025.
