The session General Contributions on Earthquakes, Earth Structure, Seismology features a wide range of presentations on recent earthquakes and earthquake sequences of local, regional, and global significance, as well as recent advances in characterization of Earth structure using a variety of methods.

On New Year’s Day 2024, a shallow Mw 7.5 earthquake hit the Noto Peninsula on the back-arc side of Central Japan. Very intense shaking caused more than 200 casualties and widespread damage to the built infrastructure. The quake triggered a tsunami, numerous landslides, rockfall, and widespread liquefaction. The north of the Peninsula moved by several meters during the rupture. This earthquake is the largest event of a sustained seismic swarm that started in 2020. In this late special session, we will review early analysis of the earthquake, the associated tsunami, its effect on surface processes, and the consequences on the population, infrastructure, and emergency response.

Computational earth science often relies on modelling to understand complex physical systems which cannot be directly observed. Over the last years, numerical modeling of earthquakes provides new approaches to apprehend the physics of earthquake rupture and the seismic cycle, seismic wave propagation, fault zone evolution and seismic hazard assessment. Recent advances in numerical algorithms and increasing computational power enable unforeseen precision and multi-physics components in physics-based simulations of earthquake rupture and seismic wave propagation but also pose challenges in terms of fully exploiting modern supercomputing infrastructure, realistic parameterization of simulation ingredients and the analysis of large synthetic datasets while advances in laboratory experiments link earthquake source processes to rock mechanics. This session aims to bring together modelers and data analysts interested in the physics and computational aspects of earthquake phenomena and earthquake engineering. We welcome studies focusing on all aspects of seismic hazard assessment and the physics of earthquakes — from slow slip events, fault mechanics and rupture dynamics, to wave propagation and ground motion analysis, to the seismic cycle and inter seismic deformation — and studies which further the state-of-the art in the related computational and numerical aspects.

Observational seismology is rapidly changing, influenced by new types of instruments and automated processing paradigms. Among the main reasons for this shift is the constant and exponential increase in the volume of available seismic data produced, for example, by Distributed Acoustic Sensing (DAS) and Large-N nodal arrays.

Big datasets, new monitoring instrumentation, and novel processing methods, combined with rapid communication of scientific results, are instigating breakthroughs in many fields of seismology. However, these advances pose new questions and highlight the limits of current seismic data handling for standard routine seismic analysis, often performed manually by seismologists.

Indeed, novel machine-learning-based methods for seismic data analysis are now able to detect more earthquakes as current operational best practice, greatly reducing the magnitude of completeness, and even revealing hidden patterns associated with earthquake nucleation. Full-data-driven and waveform-based methods have also grown and advanced our resolution capability of crustal imaging.

Nevertheless, automated processing approaches can be error- or bias-prone without careful quantification of uncertainties, making uncertainty assessment another important future research direction. This session aims to promote new methods that can be applied to large data sets, either retroactively or in (near) real-time, for seismicity analysis at a range of length scales and in different tectonic environments. We welcome contributions on methods spanning classical seismicity analysis, such as event detection, location, magnitude, and source-mechanism estimation. We also welcome contributions on novel instrumental and theoretical applications and processing advances that can advance our understanding of earthquake processes and seismic monitoring approaches. We seek methodological studies including -but not limited to- geothermal exploitation, EGS monitoring, seismic observatory automatized routine pipelines, and laboratory- to regional-scale studies.

Within the last decade, machine learning has established itself as an indispensable tool across many disciplines of solid earth geophysics. Remote sensing, seismic data exploration, and laboratory data analysis are only a few fields in which novel machine learning tools have already enabled substantially improved workflows and new discoveries. At the same time, it has become apparent that machine learning is not a silver bullet. While machine learning has illuminated new directions and deeper understanding in several areas, some studies applying machine learning have not achieved improvements over classical workflows, suggesting some problems might not be accessible with current machine learning methods.

In this session, we want to trace out the frontiers of machine learning in geophysics. What is the state of the art and what are the obstacles preventing application of machine learning or further improvements of existing methods? At the same time, we want to discuss how the novel machine learning methods impact scientific progress. Which discoveries have already been enabled by the current state of the art and what would be required to further advance science? To answer these questions, we aim to bring together machine learning experts and practitioners with an interest in machine learning from all disciplines of solid earth geophysics.

Fibre optic based techniques allow probing highly precise direct point and distributed sensing of the full ground motion wave-field including translation, rotation and strain, and environmental parameters such as temperature and even chemicals at a scale and to an extent previously unattainable with conventional geophysical methods. Considerable improvements in optical and atom interferometry enable new concepts for inertial rotation, translational displacement and acceleration sensing. Laser reflectometry using both fit-to-purpose and commercial fibre optic cables have successfully detected a variety of signals including microseism, local and teleseismic earthquakes, volcanic events, ocean dynamics, etc. Significant breakthrough in the use of fibre optic sensing techniques came from the new ability to interrogate telecommunication cables at high precision both on land and at sea, as well as in boreholes and at the surface. Applications of the resulting new type of data are manifold: they include seismic source and wave-field characterization with single point observations in harsh environments like active volcanoes, the ocean bottom, the correction of tilt effects, e.g. for high performance seismic isolation facilities, as well as seismic ambient noise interferometry and seismic building monitoring.

We welcome contributions on developments in instrumental and theoretical advances, applications and processing with fibre optic point and/or distributed multi-sensing techniques, light polarization and transmission analyses, using standard telecommunication and/or engineered fibre cables. We seek studies on theoretical, observation and advanced processing in fields, including seismology, volcanology, glaciology, geodesy, geophysics, natural hazards, oceanography, urban environment, geothermal applications, laboratory studies, large-scale field tests, planetary exploration, gravitational wave detection, fundamental physics. We encourage contributions on data analysis techniques, machine learning, data management, instrumental performance and comparison as well as new experimental, field, laboratory, modeling studies in fibre optic sensing studies.

The oceans cover about 71% of the Earth's surface, yet our current picture of the structure and dynamics of the oceanic crust and mantle is mainly based on seismic data recorded in islands or in the continents.

Detailed seismic observations of the sub-oceanic Earth’s interior require the use of ocean-bottom seismometers (OBS), but large OBS deployments - both in numbers of instruments and area covered - remain a major endeavour due to technical, logistical and financial challenges.

A zoo of OBS arrays and other passive ocean-bottom geophysics (e.g., geodesy, magnetotelluric) has been deployed in the last two decades, which led to fascinating new discoveries about the crust and mantle beneath the seafloor in many regions worldwide. Despite great technological advances and improved data processing procedures, some challenges persist.

OBS deployments and recovery are more demanding than anticipated by (first-time) PIs and consist of many challenges obscured by a lack of communication between scientists. Recurring issues include missing or erroneous response files or the challenge of systematically exploring the wealth of information recorded by the OBS datasets. Most processed data sets are not released for several years (if at all). This stagnates the exploration of OBS datasets in the community and reduces its usage to just a few research groups.

We invite contributions from the global ocean-bottom geophysics community to share knowledge, experience, lessons learned and scientific achievements from OBS experiments. We welcome reflections on all aspects, from early-stage planning, different kinds of OBS or amphibian devices, experiment design, deployment and recovery tactics, pre- and post-data processing and analysis (e.g., software), to publishing data reports and final scientific outputs (e.g., tomography, receiver functions, ambient noise studies, earthquake source analysis, etc). We also encourage contributions beyond seismology, such as from seafloor environmental sensors (e.g., using submarine cables), magnetotellurics, geodesy, ocean acoustics and marine mammals studies.

Seismological infrastructures are evolving according to modern user demands. In addition to providing access to traditional seismometer data and associated products, they now must support frontier datasets, applications and workflows, underwritten by modern data management policies. Providing multidisciplinary and data intensive applications requires complex and integrated use cases that are FAIR, acknowledging all contributions at various stages and scaling up with the increasing numbers of users and volumes of data.
This session welcomes all contributions related to data collection, curation and provision from modern seismic network deployment, operation, management and delivery of downstream waveform data products, at local, regional and global level. This includes: (a) best practice for seismic inventory and data management; (b) integration of new data types and communities (for example DAS systems, large-N instrumentation, OBS, GNSS products, environmental monitoring, gravity, infrasound instruments, rotational sensors); (c) development, testing, and comparison of emerging strategies (e.g. machine learning) and software tools for earthquake monitoring, in particular for real-time applications; (d) delivery of technical and scientific seismological and multidisciplinary data products; (e) integration of recorded seismological data in computational workflows and digital twins. The session aims to provide a forum to present and discuss challenges in all aspects of data management from the perspective of network operators as well as users who focus on leading edge use cases with interdisciplinarity and advanced computing. Contributions about proposed extension of existing formats and services as well as new ones that enable integration of new and exotic data are welcome. Promoted by ORFEUS and Earthscope, this session facilitates seismological data exchange, discovery and usage and fosters open and FAIR data policies.

Time series are a very common type of data sets generated by observational and modeling efforts across all fields of Earth, environmental and space sciences. The characteristics of such time series may however vastly differ from one another between different applications – short vs. long, linear vs. nonlinear, univariate vs. multivariate, single- vs. multi-scale, etc., equally calling for specifically tailored methodologies as well as generalist approaches. Similarly, also the specific task of time series analysis may span a vast body of problems, including
- dimensionality/complexity reduction and identification of statistically and/or dynamically meaningful modes of (co-)variability,
- statistical and/or dynamical modeling of time series using stochastic or deterministic time series models or empirical components derived from the data,
- characterization of variability patterns in time and/or frequency domain,
- quantification various aspects of time series complexity and predictability,
- identification and quantification of different flavors of statistical interdependencies within and between time series, and
- discrimination between mere correlation and true causality among two or more time series.
According to this broad range of potential analysis goals, there exists a continuously expanding plethora of time series analysis concepts, many of which are only known to domain experts and have hardly found applications beyond narrow fields despite being potentially relevant for others, too.

Given the broad relevance and rather heterogeneous application of time series analysis methods across disciplines, this session shall serve as a knowledge incubator fostering cross-disciplinary knowledge transfer and corresponding cross-fertilization among the different disciplines gathering at the EGU General Assembly. We equally solicit contributions on methodological developments and theoretical studies of different methodologies as well as applications and case studies highlighting the potentials as well as limitations of different techniques across all fields of Earth, environmental and space sciences and beyond.

The upscaling of laboratory results to regional geophysical observations is a fundamental question and a current challenge in geosciences. Indeed, earthquakes are non-linear and multi-scale problems, whose dynamics depend strongly on the geometry and the physical properties of the fault and its surrounding medium. To reproduce realistic boundary conditions in the laboratory, fault mechanisms are often scaled down to examine the physical and mechanical characteristics of earthquakes. Small-scale experiments are a powerful tool to study friction and bring to light new insights into weakening or dynamic rupture processes. However, it is not evident how the observed mechanisms can be extrapolated to large-scale observations, and this is where numerical simulations can help to bridge the gap in scale. Laboratory experiments, numerical simulations, and geophysical observations are complementary and necessary to understand fault mechanisms across the different scales. In this session, we aim to convene contributions dealing with multiple aspects of earthquake mechanics, such as:
(i) the thermo-hydro-mechanical processes associated with all the different stages of the seismic cycle, e.g., healing, nucleation, co-seismic fault weakening;
(ii) multidisciplinary studies combining laboratory and numerical experimental results;
(iii) bridging the gap between the different scales of fault deformation mechanisms.

We particularly welcome novel observations and/or innovative approaches to study earthquake faulting. Contributions from early career scientists are highly solicited.

The strength of rocks determines how the lithosphere responds to stresses resulting from geodynamic processes, gravitational forces and anthropogenic activities. A thorough understanding of rock strength and stress is therefore crucial for a wide range of topics, from plate tectonics and geohazards to mass transport and engineering applications. However, rock strength and stress remain difficult to measure and our comprehension of both quantities depends much on our ability to constrain them from observations, experiments and models.
One difficulty in constraining strength and stress is their variability in space and time, also because we do not fully understand the factors causing the variability. Fluids are known to reduce rock strength and trigger seismicity by reducing effective stresses and driving mineral reaction, but their exact role in driving mechanical instabilities needs to be better understood, also with respect to other processes like transformation-driven stress transfers.
The current state of stress is mainly assessed on seismic focal mechanisms, fault monitoring and slip inversion, borehole data, and methods such as hydraulic fracturing to determine the magnitude of the applied stress. In addition, the paleostress (ancient state of stress) can be obtained by different methods such as paleopiezometry and fault slip inversion, which mainly yield the direction of paleo-stress axes and the stress ratio. However, full stress tensor remains difficult to determine and investigations typically cover specific spatial and/or temporal scales, with a limited view on possible heterogeneities in space and time. We have to deal with incomplete datasets, part of which are not openly accessible. We must therefore advance and develop mechanical concepts, experiments, measuring methods and data compilations, to refine the models.
This session is intended to bring together researchers from various fields and to facilitate transdisciplinary discussions. We seek contributions that advance the current understanding of the governing mechanics of seismotectonic processes including fluids, the paleo and current in-situ stress state and estimation methods, as well as the strain field of the Earth’s lithosphere.

Tectonic faults accommodate plate motion through various styles of seismic and aseismic slip spanning a wide range of spatiotemporal scales. Understanding the mechanics and interplay between seismic rupture and aseismic slip is central to seismotectonics as it determines the seismic potential of faults. In particular, unraveling the underlying physics controlling these deformation styles bears a great deal in earthquake hazard mitigation, especially in highly urbanized regions. We invite contributions from observational, experimental, geological, and theoretical studies that explore the diversity and interplay among seismic and aseismic slip phenomena in various tectonic settings, including the following questions: (1) How does the nature of creeping faults change with the style of faulting, fluids, loading rate, and other factors? (2) Are different slip behaviors well separated in space, or can the same fault areas experience different failure modes? (3) Is there a systematic spatial or temporal relation between different types of slip?
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Invited speakers:
- Whitney Behr (ETH, Zurich)
- Quentin Beltery (Geoazur, Nice)
- Harsha S. Bhat (ENS, PSL, Paris) Program says 10' talk, but it will 20' one.

Continental rifting is a complex process spanning from the inception of extension to continental rupture or the formation of a failed rift. This session aims at combining new data, concepts and techniques elucidating the structure and dynamics of rifts and rifted margins. We invite submissions highlighting the time-dependent evolution of processes such as: initiation and growth of faults and ductile shear zones, tectonic and sedimentary history, magma migration, storage and volcanism, lithospheric necking and rift strength loss, influence of the pre-rift lithospheric structure, rift kinematics and plate motion, mantle flow and dynamic topography, as well as break-up and the transition to sea-floor spreading. We encourage contributions using multi-disciplinary and innovative methods from field geology, geochronology, geochemistry, petrology, seismology, geodesy, marine geophysics, plate reconstruction, or numerical or analogue modelling. Special emphasis will be given to presentations that provide an integrated picture by combining results from active rifts, passive margins, failed rift arms or by bridging the temporal and spatial scales associated with rifting.

Across the time scales, from earthquakes to earthquake cycle
The last decade has seen the accumulation of new observations about earthquakes with a level of detail never reach before. In parallel, methods have significantly improved in geophysics, geodesy, and in paleoseismology-geomorphology. Hence, on one hand the number of earthquakes with well-documented rupture process and deformation pattern has increased significantly. On the other hand, the number of studies documenting long time series of past earthquakes, including quantification of past deformation has also increased. In parallel, the modeling community working on rupture dynamics, including earthquake cycle is also making significant progresses. Thus, this session is the opportunity to bring together these different contributions to foster further collaboration between the different groups focusing all on the same objective of integrating earthquake processes into the earthquake cycle framework. In this session we welcome contributions documenting earthquake ruptures and processes, both for ancient events or recent events, such as the Turkey sequence of 2023 for example, from seismological, geodetic, or paleoseismological perspective. Contributions documenting deformation during pre-, post-, or interseismic periods, which are highly relevant to earthquake cycle understanding, are also very welcomed. Finally, we seek for any contribution looking at the earthquake cycle from the modeling perspective, especially including approaches mixing data and modeling.

Even in a recent timeframe, earthquake occurrences like the 6 February 2023, Mw 7.8 and 7.7 Kahramanmaraş (Turkey) and the 8 September 2023, Mw 6.8 (Atlas Mountains, Morocco), put into the spotlight the high seismogenic potential of the Mediterranean regions and, more broadly, delineate a clear reminder for the need to individualise and parametrise the sources of future seismic events.
A key issue for seismic hazard assessment pertains to the identification of active faults as well as the reconstruction, to the best possible extent, of their geometry, kinematics and deformation rates. Such a task can often be challenging, either due to the possible paucity of unambiguous evidence, or quantitative data, both at the near-surface and at seismogenic depths.
Integrating different methodologies, both innovative in their technologies and complementary in their prospecting at different resolution scales, depth- and dimensions (3D to 4D), has become the necessary approach to apply in active fault studies. In this perspective, the multidisciplinary characteristic of seismotectonics integrating structural-geologic, morphologic, seismologic, geophysical, remote-sensing, geodetic data and numerical/analogue modelling methods can help to individualise evidence of active tectonics.
This session is aimed at gathering studies focused on the following topics: i) field-based geological and structural surveys of active faults, including in volcanic areas; ii) classical to innovative multiscale and multidisciplinary geological, seismological and geophysical approaches; iii) new or revised seismological, geophysical, field-and remotely-collected datasets; iv) faults imaging, tectonic-setting definition and 3D seismotectonic models; v) numerical and analogue modelling. In the above framework, we hope to spark major scientific interest and debate on how to advance our understanding of active faulting as well as producing robust seismotectonic models.

Geologic processes are generally too slow, too rare, or too deep to be observed in-situ and to be monitored with a resolution high enough to understand their dynamics. Analogue experiments and numerical simulation have thus become an integral part of the Earth explorer's toolbox to select, formulate, and test hypotheses on the origin and evolution of geological phenomena.

To foster synergy between the rather independently evolving experimentalists and modellers we provide a multi-disciplinary platform to discuss research on tectonics, structural geology, rock mechanics, geodynamics, volcanology, geomorphology, and sedimentology.

We therefore invite contributions demonstrating the state-of-the-art in analogue and numerical / analytical modelling on a variety of spatial and temporal scales, varying from earthquakes, landslides and volcanic eruptions to sedimentary processes, plate tectonics and landscape evolution. We especially welcome those presentations that discuss model strengths and weaknesses, challenge the existing limits, or compare/combine the different modelling techniques to realistically simulate and better understand the Earth's behaviour.

Subduction drives plate tectonics, generating the major proportion of subaerial volcanism, releasing >90% seismic moment magnitude, forming continents, and recycling lithosphere. Numerical and laboratory modelling studies have successfully built our understanding of many aspects of the geodynamics of subduction zones. Detailed geochemical studies, investigating compositional variation within and between volcanic arcs, provide further insights into systematic chemical processes at the slab surface and within the mantle wedge, providing constraints on thermal structures and material transport within subduction zones. However, with different technical and methodological approaches, model set-ups, inputs, and material properties, and in some cases conflicting conclusions between chemical and physical models, a consistent picture of the controlling parameters of subduction-zone processes has so far not emerged.

This session aims to follow subducting lithosphere on its journey from the surface down into the Earth's mantle and to understand the driving processes for deformation and magmatism in the over-riding plate. We aim to address topics such as: subduction initiation and dynamics; changes in mineral breakdown processes at the slab surface; the formation and migration of fluids and melts at the slab surface; primary melt generation in the wedge; subduction-related magmatism; controls on the position and width of the volcanic arc; subduction-induced seismicity; mantle wedge processes; the fate of subducted crust, sediments and volatiles; the importance of subducting seamounts, LIPs, and ridges; links between near-surface processes and slab dynamics and with regional tectonic evolution; slab delamination and break-off; the effect of subduction on mantle flow; and imaging subduction zone processes.

With this session, we aim to form an integrated picture of the subduction process and invite contributions from a wide range of disciplines, such as geodynamics, modelling, geochemistry, petrology, volcanology, and seismology, to discuss subduction zone dynamics at all scales from the surface to the lower mantle, or in applications to natural laboratories.

The western South American subduction zone is among the largest subduction systems on the planet and stands out as the archetype of ocean-continent convergent margins. Compared to other subduction zones, the region is notable because it is associated with the largest accretionary orogen of the world (The Andes cordillera), it shows several regions of flat slab subduction, and it hosted some of the largest instrumentally recorded earthquakes. Over the last years and decades, significant progress has been achieved in characterizing and imaging the constituent parts of the South American subduction zone (downgoing oceanic plates, South American upper plate, plate interface between them, mantle wedge beneath the upper plate) as well in the understanding of geodynamic and seismotectonic processes shaping the convergent margin.

In this session, we aim to bring together scientists and contributions from a wide variety of disciplines that try to constrain and understand past and ongoing processes in this subduction zone. These can include, but are not limited to: seismo-geodetic studies of slow and fast deformation along the plate interface; geophysical studies of subduction zone structure, geometry and fluid processes; analog and numerical modeling studies of this subduction zone; studies on faulting or fluid processes in the upper plate; offshore studies on bathymetry and structure of the downgoing plate or the outer forearc; studies of Andean magmatism, volcanic processes and their link to tectonics.

The Tethyan Belt is the most prominent collisional zone on Earth, covering the vast area between far eastern Asia and Europe. The geological-tectonic evolution of the belt shows along-strike heterogeneity between its various regions, including the Indo-Burman Range, the Tibetan-Himalayan region, the Iranian Plateau, Anatolia and the Alps. The Tethyan Belt is the result of the subduction of the Tethyan Oceans, including significant terrane amalgamation, and collisional tectonics along the whole belt. The belt is today strongly affected by the ongoing convergence and collision between the Eurasian, African, Arabian and Indian plates. The long formation history and the variability of tectonic characteristics and deep structures of the belt make it a natural laboratory for understanding the accretion processes that have shaped the Earth through its history and have led to the formation of vast resources in the crust.

We invite contributions based on geological, tectonic, geophysical and geodynamic studies of the Tethyan Belt. We particularly invite interdisciplinary studies, which integrate observational data and interpretations based on a variety of methods. This session will include contributions on the whole suite of studies of the Tethyan Belt with the aim of providing a comprehensive overview of its formation and evolution.

This session will focus on investigations about the physics of earthquakes – fast and slow. On the one hand contributions deal with imaging and numerical simulations of earthquake physics. On the other hand we solicit studies towards a comprehensive understanding of slow earthquakes.

We invite abstracts on works to image rupture kinematics and simulate earthquake dynamics using numerical method to improve understanding of the physics of earthquakes. In particular, these are works that aim to develop a deeper understanding of earthquake source physics by linking novel laboratory experiments to earthquake dynamics, and studies on earthquake scaling properties. For instance assessing the roles fluids and heterogeneities play in influencing, directing, or obstructing the behavior of slow earthquakes and how they impact rupture mechanics. Other works show progress in imaging earthquake sources using seismic data and surface deformation measurements (e.g. GNSS and InSAR) to estimate rupture properties on faults and fault systems. Especially for slow earthquakes we look for technological innovations, showcasing cutting-edge tools and methodologies that boost our proficiency in detecting, analyzing, and understanding slow earthquakes.

We want to highlight strengths and limitations of each data set and method in the context of the source-inversion problem, accounting for uncertainties and robustness of the source models and imaging or simulation methods. Contributions are welcome that make use of modern computing paradigms and infrastructure to tackle large-scale forward simulation of earthquake process, but also inverse modeling to retrieve the rupture process with proper uncertainty quantification. We also welcome seismic studies using data from natural faults, lab results and numerical approaches to understand earthquake physics.

Interferometric techniques turn seismic networks into continuous observation devices for (time-varying) Earth structure, volcanic and hydrologic processes, ocean - solid Earth interactions and many other phenomena. The application of this technique has expanded to signals beyond ocean microseismic noise, capturing anthropogenic seismic signals as well.

Great strides have been taken in obtaining high-resolution images of seismic velocity and other properties, in observing and quantifying the sources of various ambient noise wave types, and in interpreting seismic property variations. Current challenges include the interpretation of signals from less-than-ideally situated sources, such as those in the context of traffic noise interferometry or ambient noise body waves from localized storms; the interpretation of ambient noise amplitudes for elastic effects and anelastic attenuation; the localization of seismic property changes; the implementation of spatial wavefield gradient measurements from fiber optic or rotational sensors.

This session offers a broad space for discussing recent advances in ambient noise seismology and seismic interferometry. We invite abstracts on theoretical and numerical developments as well as novel applications. Topics may include, but are not limited to, studies of ambient seismic sources; ocean wave quantification through ambient noise; urban seismic noise; interferometric imaging; monitoring subsurface properties and quantifying the response of seismic velocity to various stresses and strains; studies of the spatial sensitivity for imaging and monitoring under diverse source conditions; quantification of site effects, amplification and attenuation; improvements in processing and retrieval of high-quality interferometry observations, and interdisciplinary applications of seismic interferometry.

Our planet is shaped by a multitude of physical, chemical and biological processes. Most of these processes and their effect on the ground’s properties can be sensed by seismic instruments – as discrete events or continuous signatures. Seismic methods have been developed, adopted, and advanced to study those dynamics at or near the surface of the earth, with unprecedented detail, completeness, and resolution. The community of geophysicists interested in Earth surface dynamics and geomorphologists, glaciologists, hydrologists, volcanologists, geochemists, biologists or engineering geologists interested in using arising geophysical tools and techniques is progressively growing and collaboratively advancing the emerging scientific discipline Environmental Seismology.

If you are interested in contributing to or getting to know the latest methodological and theoretical developments, field and lab scale experimental outcomes, and the broad range of applications in geomorphology, glaciology, hydrology, meteorology, engineering geology, volcanology and natural hazards, then this session would be your choice. We anticipate a lively discussion about standing questions in Earth surface dynamics research and how seismic methods could help solving them. We will debate about community based research opportunities and are looking forward to bringing together transdisciplinary knowledge and mutual curiosity.

Topical keywords: erosion, transient, landslide, rockfall, debris flow, fracturing, stress, granular flow, rock mechanics, snow avalanche, calving, icequake, basal motion, subglacial, karst, bedload, flood, GLOF, early warning, coast, tsunami, eruption, tremor, turbidity current, groundwater, soil moisture, noise, dv/v, HVSR, fundamental frequency, polarization, array, DAS, infrasound, machine learning, classification, experiment, signal processing.

We are happy to announce our solicited speakers Emma Pearce and Florent Gimbert!

This session will cover applied and theoretical aspects of geophysical imaging, modeling and inversion using active- and
passive-source seismic measurements as well as other geophysical techniques (e.g., gravity, magnetic, electromagnetic) to investigate properties of the Earth’s lithosphere and asthenosphere, and explore the processes involved. We invite contributions focused on methodological developments, theoretical aspects, and applications. Studies across the scales and disciplines are particularly welcome.

Among others, the session may cover the following topics:
- Active- and passive-source imaging
- Full waveform inversion developments and applications
- Advancements and case studies in 2D and 3D imaging
- DAS imaging
- Interferometry and Marchenko imaging
- Seismic attenuation and anisotropy
- Developments and applications of multi-scale and multi-parameter inversion
- Joint inversion of seismic and complementary geophysical data

Carbon capture and storage, hydrogen storage, geothermal energy and mining of critical minerals all have a key role in the energy transition in Europe and worldwide. Innovation in efficient low-cost exploration methods is critically needed to characterize and image sedimentary basins and other geological environments that present challenges due to, for example, deeper targets, remoteness, difficult terrain, high population density, or high lateral medium property contrasts.
In recent decades, passive-source methods have progressively emerged as powerful and versatile alternatives to conventional active-source methods, offering non-invasive and cost-effective insights into the geometry and properties of subsurface reservoirs and large-scale structures relevant to seismic hazard analysis. Numerous methodologies such as ambient noise tomography, seismic interferometry, horizontal-to-vertical spectral ratio and high-frequency receiver function analysis have been developed or adapted for exploration and monitoring applications. Meanwhile, the growth of large nodal networks and Distributed Acoustic Sensing (DAS) offers the potential to study the shallow upper crust in new ways.
In this session, we welcome contributions showing advancements in acquisition, methodology and modelling for imaging of the upper crust at different scales (from a few meters to a few kilometres) and case studies demonstrating the performance and benefit of passive seismic imaging and how it can be integrated into the industry exploration workflow. We invite contributions from all passive seismic disciplines, including ambient-noise and earthquake-based approaches. Contributions that take a multidisciplinary approach are particularly welcome.

Geophysical imaging techniques are widely used to characterize and monitor structures and processes in the shallow subsurface. Methods include active imaging using seismic, (complex) electrical resistivity, electromagnetic, and ground-penetrating radar methods, as well as passive monitoring based on ambient noise or electrical self-potentials. Advances in experimental design, instrumentation, data acquisition, data processing, numerical modeling, open hardware and software, and inversion push the limits of spatial and temporal resolution. Nonetheless, the interpretation of geophysical images often remains ambiguous. Persistent challenges addressed in this session include optimal data acquisition strategies, (automated) data processing and error quantification, spatial and temporal regularization of model parameters, integration of non-geophysical measurements and geological/process realism into the imaging procedure, joint inversion, as well as the quantitative interpretation of tomograms through suitable petrophysical relations.

In light of these topics, we invite submissions concerning a broad spectrum of near-surface geophysical imaging developments and applications at different spatial and temporal scales. Novel developments in the combination of complementary measurement methods, machine learning, and process monitoring applications are particularly welcome.

Volcanic hazards and risk mitigation lie at the core of global geoscience. Volcanoes impact humans and the environment on global scales, as recently demonstrated by the Hunga Tonga Ha'apai eruption in early 2022. However, since volcanic systems are among the most complex and inaccessible systems on Earth, our knowledge about their plumbing systems and spatiotemporal history, as well as volumes and reoccurrence rates of eruptions or collapse events, is limited. In recent years, seismic imaging has emerged as a versatile tool for studying volcanic systems by providing constraints on volcanic plumbing systems, their eruptive products, and related mass-wasting deposits on a wide range of spatial and temporal scales. Recent advances in seismic tomography have enabled detailed imaging of volcanic plumbing systems at crustal scales revealing trans-crustal mush zones or shallow, melt-dominated magma reservoirs. Furthermore, modern high-resolution reflection seismic surveys have provided images of the shallow part of volcanic systems, offering the unique opportunity to study the internal architecture of volcanic edifices, reveal the geometry of dyke and sill intrusions, and map out pyroclastic flow deposits and related mass-wasting events. In addition, seismic imaging can provide valuable insights into past collapse events as well as the present-day stability of volcanic edifices. Thus, the combination of seismic imaging methods on different scales offers a unique opportunity for the holistic understanding of volcanic systems, which is crucial for a more reliable risk assessment.
In this session, we welcome contributions using earthquake and controlled-source seismic (land and marine) data in concert with different techniques to image active or ancient volcanic systems. Contributions from volcanic arcs, mid-ocean ridges/rifts, or intra-plate volcanoes are equally encouraged.

The imaging of Earth’s crustal structure is a challenging task in seismology and seismic, due to strong lateral discontinuities, heterogeneities and presence of fluids. Active and passive seismic methods are widely used to characterize tectonic structures and geological processes ranging from large to very shallow scale.
Active seismic methods using reflected and refracted waves have shown to be particularly useful in providing images and seismic velocity variations of the subsurface. Recently, important developments in the frame of data instrumentation, data acquisition and inversion methods have pushed the limits of spatial resolution, like the utilization of shear-wave and multi-component reflection seismic for shallow investigations. Despite these significant improvements, the interpretation of geophysical images and properties still remains ambiguous and shows several limitations, mainly due to the cost and availability of the instruments and the difficulties in exploring remote but also urban areas, as well as the loss of resolution with depth.
To overcome this obstacle, it can be useful to combine active and passive seismic methods. Furthermore, the number of high-quality seismic catalogs is increasing, thanks to new denser seismic networks and the use of artificial intelligence, improving knowledge of tectonic structures. This session shall promote the exchange of experience using cutting-edge active and passive seismic techniques with the aim of imaging and characterizing deep and shallow geological structures, in particular active and ancient faults in tectonic or volcanic settings but also intraplate regions.
We welcome contributions to technical developments, data analysis, seismic processing from both active methods like seismic reflection (P- and S- wave reflection seismic, multi-component methods, Vp/Vs analysis, traveltime tomography or full waveform inversion), seismic refraction and integrated drilling data, seismic attributes analysis, and passive techniques including seismic tomography (based on local earthquakes, ambient noise or converted waves), attenuation tomography, receiver functions, source imaging characterization also based on a data-driven approach and high-quality seismic catalogs, which reveal new insights about tectonic and volcanic structures.
We also encourage contributions using novel techniques based on complementary methods, such as data mining and machine learning.

In this session we want to celebrate the scientific achievements of W. Jason Morgan, the discoverer of Plate Tectonics and Mantle Plumes, while looking into the future developments of the scientific revolution that he helped to ignite. Fifty years after their discovery, we still have basic questions in our understanding of how Plate Tectonics and Mantle Plumes are linked to the flow structure of the mantle, heat loss from Earth's core, and Earth's evolution from its accretion to the present day. Inspired by these concepts, the modern subdisciplines of Tectonics, Geodynamics, Seismology, Geochemistry, and Earth Magnetism/Rock Physics continue to grapple with gaining a deeper understanding of our planet. Here we welcome contributions that highlight recent progress and problems in this endeavor.

The session topic is interpretation and modelling of the geodynamic processes in the lithosphere-asthenosphere system and the interaction between crust and lithospheric mantle, as well as the importance of these processes for the formation of the discontinuities that we today observe in the crust and mantle. We aim at establishing links between seismological observations and process-oriented modelling studies to better understand the relation between present-day fabrics of the lithosphere and contemporary deformation and ongoing dynamics within the asthenospheric mantle. Methodologically, the contributions will include studies based on application of geochemical, petrological, tectonic and geophysical (seismic, thermal, gravity, electro-magnetic) methods with emphasis on integrated interpretations.

We invite, in particular multidisciplinary, contributions which focus on the structure, deformation and evolution of the continental crust and upper mantle and on the nature of mantle discontinuities. The latter include, but are not limited to, the mid-lithosphere discontinuity (MLD), the lithosphere-asthenosphere boundary (LAB), and the mantle transition zone, as imaged by various seismological techniques and interpreted with interdisciplinary approaches. Papers with focus on the structure of the crust and the nature of the Moho are also welcome.

Many regions of the Earth, from crust to core, exhibit anisotropic fabrics which can reveal much about geodynamic processes in the subsurface. These fabrics can exist at a variety of scales, from crystallographic orientations to regional structure alignments. In the past few decades, a tremendous body of multidisciplinary research has been dedicated to characterizing anisotropy in the solid Earth and understanding its geodynamical implications. This has included work in fields such as: (1) geophysics, to make in situ observations and construct models of anisotropic properties at a range of depths; (2) mineral physics, to explain the cause of some of these observations; and (3) numerical modelling, to relate the inferred fabrics to regional stress and flow regimes and, thus, geodynamic processes in the Earth. The study of anisotropy in the Solid Earth encompasses topics so diverse that it often appears fragmented according to regions of interest, e.g., the upper or lower crust, oceanic lithosphere, continental lithosphere, cratons, subduction zones, D'', or the inner core. The aim of this session is to bring together scientists working on different aspects of anisotropy to provide a comprehensive overview of the field. We encourage contributions from all disciplines of the earth sciences (including mineral physics, seismology, magnetotellurics, geodynamic modelling) focused on anisotropy at all scales and depths within the Earth.

Mantle circulation simulations are now capable of a high level of precision and complexity that allows the creation of numerous "Earth-like" models. Likewise, advances in observation resources and methods have improved the quantity and quality of data on the Earth's interior. Combining these developments presents a unique opportunity to enhance our understanding of mantle dynamics and evolution over geological time scales. However, the exact physics leading to Earth-like simulations remains debated (e.g. the existence of a primordial layer, the core-mantle-boundary temperature, etc...). Furthermore, constraining geodynamical simulations or assessing their predictions with observational data can be challenging, for example, due to data noise, issues related to inverse methods, or uncertainty propagation.

This session aims to explore how observational data can be used to constrain or assess geodynamical simulations and advance our knowledge of the physical processes that govern the Earth's mantle. We invite submissions from various fields, including seismology, geochemistry, mineral physics or geomagnetism where observations have the potential to constrain geodynamical simulations or assess their predictions. The nature of these studies can be purely observational, exploring the inversion of data to possible Earth models or proposing metrics to assess how Earth-like a model is.

This session also aims to compare these observations and address their potential to constrain or assess geodynamical simulations, with the ultimate goal of better understanding which parameters may cause models to be more or less Earth-like.

Earth’s cryosphere demonstrates itself in many shapes and forms, but we use similar geophysical and in-situ methods to study its wide spectrum: from ice-sheets and glaciers, to firn and snow, sea ice, permafrost, and en-glacial and subglacial environments.

In this session, we welcome contributions related to all methods in cryospheric measurements, including: advances in radioglaciology, active and passive seismology, geoelectrics, acoustic sounding, fibre-optic sensing, GNSS reflectometry, signal attenuation, and time delay techniques, cosmic ray neutron sensing, ROV and drone applications, and electromagnetic methods. Contributions can include field applications, new approaches in geophysical or in-situ survey techniques, or theoretical advances in data analysis processing or inversion. Case studies from all parts of the cryosphere, including snow and firn, alpine glaciers, ice sheets, glacial and periglacial environments, alpine and arctic permafrost as well as rock glaciers, or sea ice, are highly welcome.

This session will give you an opportunity to step out of your research focus of a single cryosphere type and to share experiences in the application, processing, analysis, and interpretation of different geophysical and in-situ techniques in these highly complex environments. This session has been running for over a decade and always produces lively and informative discussion. We have a successful history of PICO and other short-style presentations - submit here if you want a guaranteed short oral!

Seismicity often exhibits complex spatio-temporal and moment release patterns that deviate from the traditional occurrence of isolated mainshock-aftershocks sequences. Earthquake swarms, intense foreshock activity, and sequences of doublets or triplets of comparable large magnitude earthquakes are observable across all tectonic settings, albeit more frequently in volcanic regions. These sequences exemplify complex seismic processes that do not conform with the conventional laws of earthquake occurrence, such as Båth, Omori-Utsu, and Gutenberg-Richter laws. The absence of definitive laws governing these sequences highlights the challenge faced by the geophysical community in understanding the underlying physical processes. Potential triggering mechanisms could include local increases of the pore-pressure, loading/stressing rate due to aseismic rupture processes (like creep and, slow slip events), magma-induced stress changes, earthquake-earthquake interaction or a combination of those. New generation of enhanced high-resolution earthquake catalogs obtained through the application of machine learning, template matching, and double difference techniques, now enable us to investigate complex sequences and their triggering mechanisms with unprecedented resolution. Furthermore, local or global studies of earthquake swarms and complex sequences, ideally approached through a multidisciplinary perspective that involves deformation, geophysical imaging of the crust, geology, and fluid geochemistry, are crucial for advancing our insights on the physics of triggering mechanisms.

This session aims at bringing together studies of earthquake swarms and complex seismic sequences across tectonic settings and scales. We welcome contributions that focus on the characterization of earthquake swarms and complex seismic sequences in terms of spatio-temporal evolution, frequency-magnitude analysis, scaling properties, aseismic transients, as well as laboratory and numerical modeling simulating the mechanical condition yielding to swarm-like and complex seismic sequences. The overarching objective is to bring together studies from different tectonic settings in order to acquire and share knowledge concerning the physical processes that contribute to the occurrence of such complex seismic sequences.

Volcanic seismicity is fundamental for monitoring and investigating volcanic systems, their structure and their underlying processes. Volcanoes are very complex objects, where both the pronounced heterogeneity and topography can strongly modify the recorded signals for a wide variety of source types. In source inversion work, one of the challenges is to capture the effect of small-scale heterogeneities in order to remove complex path effects from seismic data. This requires high-resolution imagery, which is a significant challenge in heterogeneous volcanoes. In addition, the link between the variety of physical processes beneath volcanoes and their seismic response (or lack of) is often not well known, leading to large uncertainties in the interpretation of volcano dynamics based on the seismic observations. Taking into account all of these complexities, many standard techniques for seismic analysis may fail to produce breakthrough results.

In order to address the outlined challenges, this session aims to bring together seismologists, volcano and geothermal seismologists, wave propagation and source modellers, working on different aspects of volcano seismology including: (i) seismicity catalogues, statistics and spatio-temporal evolution of seismicity, (ii) seismic wave propagation and scattering, (iii) new developments in volcano imagery, (iii) seismic source inversions, and (iv) seismic time-lapse monitoring. Contribution on controlled geothermal systems in volcanic environments are also welcome. Contributions on developments in instrumentation and new methodologies (e.g. Machine Learning) are particularly welcome.
By considering interrelationships in these complementary seismological areas, we aim to build up a coherent picture of the latest advances and outstanding challenges in volcano seismology.

Numerous cases of induced/triggered seismicity resulting either directly or indirectly from injection/extraction associated with anthropogenic activity related to geo-resources exploration have been reported in the last decades. Induced earthquakes felt by the general public can often negatively affect public perception of geo-energies and may lead to the cancellation of important projects. Furthermore, large earthquakes may jeopardize wellbore stability and damage surface infrastructure. Thus, monitoring and modeling processes leading to fault slip, either seismic or aseismic, are critical to developing effective and reliable forecasting methodologies during deep underground exploitation. The complex interaction between injected fluids, subsurface geology, stress interactions, and resulting fault slip requires an interdisciplinary approach to understand the triggering mechanisms, and may require taking coupled thermo-hydro-mechanical-chemical processes into account.
In this session, we invite contributions from research aimed at investigating the interaction of the above processes during exploitation of underground resources, including hydrocarbon extraction, wastewater disposal, geothermal energy exploitation, hydraulic fracturing, gas storage and production, mining, and reservoir impoundment for hydro-energy. We particularly encourage novel contributions based on laboratory and underground near-fault experiments, numerical modeling, the spatio-temporal relationship between seismic properties, injection/extraction parameters, and/or geology, and fieldwork. Contributions covering both theoretical and experimental aspects of induced and triggered seismicity at multiple spatial and temporal scales are welcome.

Earthquakes are one of the most impactful natural phenomena responsible of many losses of life and resources. To minimize their effects, it is important to characterize the seismic hazard of the different areas understanding the variables involved. To better estimate the seismic hazard, earthquake source(s) and seismicity need to be better understood. Moreover, local site conditions have to be characterized to produce a reliable model of the ground shaking in the sites of interest. The goal of this session is to understand what are the cutting-edge studies about the topics of seismic hazard, site effect and microzonation.
In this session, studies related to the following topics, but not limited to, are welcome:
● Seismic hazard analysis
● Seismic source characterization
● Characterization of seismicity in seismic hazard analysis
● Ground motion prediction analysis
● Site effect and microzonation
● Earthquake-induced effects (eg. Liquefaction and landslide)
● Numerical site effect modelling in 1D, 2D, and/or 3D medium
● Soil-structure interaction and analysis
● New approaches in seismic hazard characterization
● Machine learning for seismic hazard, site effect, and microzonation

New physical and statistical models based on observed seismicity patterns shed light on the preparation process of large earthquakes and on the temporal and spatial evolution of seismicity clusters.

As a result of technological improvements in seismic monitoring, seismic data is nowadays gathered with ever-increasing quality and quantity. As a result, models can benefit from large and accurate seismic catalogues. Indeed, accuracy of hypocenter locations and coherence in magnitude determination are fundamental for reliable analyses. And physics-based earthquake simulators can produce large synthetic catalogues that can be used to improve the models.

Multidisciplinary data recorded by both ground and satellite instruments, such as geodetic deformation, geological and geochemical data, fluid content analyses and laboratory experiments, can better constrain the models, in addition to available seismological results such as source parameters and tomographic information.

Statistical approaches and machine learning techniques of big data analysis are required to benefit from this wealth of information, and unveiling complex and nonlinear relationships in the data. This allows a deeper understanding of earthquake occurrence and its statistical forecasting.

In this session, we invite researchers to present their latest results and findings in physical and statistical models and machine learning approaches for space, time, and magnitude evolution of earthquake sequences. Emphasis will be given to the following topics:

• Physical and statistical models of earthquake occurrence.
• Analysis of earthquake clustering.
• Spatial, temporal and magnitude properties of earthquake statistics.
• Quantitative testing of earthquake occurrence models.
• Reliability of earthquake catalogues.
• Time-dependent hazard assessment.
• Methods and software for earthquake forecasting.
• Data analyses and requirements for model testing.
• Machine learning applied to seismic data.
• Methods for quantifying uncertainty in pattern recognition and machine learning.

The purpose of this session is to: (1) showcase the current state-of-the-art in global and continental scale natural hazard risk science, assessment, and application; (2) foster broader exchange of knowledge, datasets, methods, models, and good practice between scientists and practitioners working on different natural hazards and across disciplines globally; and (3) collaboratively identify future research avenues.
Reducing natural hazard risk is high on the global political agenda. For example, it is at the heart of the Sendai Framework for Disaster Risk Reduction and the Paris Agreement. In response, the last decade has seen an explosion in the number of scientific datasets, methods, and models for assessing risk at the global and continental scale. More and more, these datasets, methods and models are being applied together with stakeholders in the decision decision-making process.
We invite contributions related to all aspects of natural hazard risk assessment at the continental to global scale, including contributions focusing on single hazards, multiple hazards, or a combination or cascade of hazards. We also encourage contributions examining the use of scientific methods in practice, and the appropriate use of continental to global risk assessment data in efforts to reduce risks. Furthermore, we encourage contributions focusing on globally applicable methods, such as novel methods for using globally available datasets and models to force more local models or inform more local risk assessment.