Geophysical imaging techniques such as seismic, (complex) electrical resistivity, electromagnetic, and ground-penetrating radar methods are widely used to characterize structures and processes in the shallow subsurface. Advances in experimental design, instrumentation, data acquisition, data processing, numerical modeling, and inversion constantly push the limits of spatial and temporal resolution. Despite these advances, 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, appropriate spatial and temporal regularization of model parameters, integration of non-geophysical measurements and geological realism into the imaging process, 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 methods 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.

Invited speaker: Andreas Fichtner (ETH Zurich)

This session will cover applied and theoretical aspects of geophysical imaging, modelling and inversion using active- and passive-source seismic measurements as well as other geophysical techniques (e.g., gravity, magnetic and electromagnetic) to investigate properties of the Earth’s crust and uppermost mantle, 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 using body- and surface-waves;
- Full waveform inversion developments and applications;
- Advancements and case studies in 2D and 3D 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;
- Applications of new acquisition systems.

Seismic data analysis and interpretation is the key tool enabling the unravelling of the geometry and evolution of subsurface geology.
In the last decades, significant improvements in the acquisition and processing techniques have been combined with a growing coverage of high-resolution and broadband frequency seismic data, including the public release of large volumes of 2D-3D hydrocarbon industry-sourced data. This led to shedding genuine new light on the subsurface geology of large portions of the Earth’s continental margins, and enabled improved quantitative rock property parametrization.
In addition, seismic reflection data have recently appealed to an ever-growing scientific audience, including exploration geoscientists, marine geologists, seismic geomorphologists, stratigraphers and structural geologists. This growing community has been collectively working towards the integrated application of seismic interpretation techniques, including seismic attribute analysis, for industrial purposes as well as for environmental and academic research studies.
In this fast-developing context, it is fundamental to share the knowledge between different research and application approaches. Therefore, the aim of this session is to provide the state-of-the-art and new prospective in seismic data analysis and quantitative subsurface characterization for structural geology and tectonics, but also for exploration seismology, marine geology, seismic geomorphology, stratigraphy, etc.
We thus invite submissions that aim to present new insights in the seismic interpretation of: i) shallow high-resolution seismic data; ii) deep industrial subsurface data (e.g., for hydrocarbon exploration); and iii) ultra-deep lithospheric seismic data. Studies integrating different approaches and disciplines are particularly welcomed.

International Lithosphere Program (ILP) has since 1980 been initiating major international, multidisciplinary research programmes to elucidate the nature, dynamics, origin and evolution of the lithosphere. ILP has taken initiative to more than 70 programmes within its four research themes: (1) Geoscience of Global Change, (2) Contemporary Dynamics and Deep Processes, (3) Continental Lithosphere and (4) Oceanic Lithosphere. Example programmes initiated by ILP include World Stress Map, Global Strain Rate Map, Global Seismic Hazard Assessment Map, Seismic Hazards and Megacities, Global Impact project, International Continental Drilling Program (ICDP), and a series of Global Geoscience Transects and programmes. Present programmes focus on integrated mapping of lithosphere physical parameters, lithosphere dynamics including the fate of subducted lithosphere and deformation of continental lithosphere, response of the lithosphere to surface processes including changes in climate and erosion/deposition dynamics, mineral resources, and seismic risk. ILP promotes high class science in combination with community services through the Evgueni Burov medal for mid-career scientists and the Flinn-Hart Award for outstanding early-career scientists, which are awarded during the UGU annual meeting. The activities of ILP seeks to achieve a balance between: "addressing societal needs" in regard to e.g. natural catastrophes, resource exploration and environmental protection; and "satisfying scientific curiosity" in regard to global and regional processes affecting the lithosphere. This symposium presents some of the ILP activities.
In particular, we invite, in particular multidisciplinary, contributions which focus on the structure 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 within interdisciplinary approaches. Papers with focus on the structure of the crust and the nature of the Moho are also welcome. Methodologically, the contributions will include studies based on seismic, thermal, gravity, petrological, and/or electro-magnetic data interpretations.

Confirmed invited speakers: Sierd Cloetingh, Harsh Gupta, Sergei Lebedev and Taras Gerya.

Structure and dynamics of the lithosphere-asthenosphere system is one of the key questions for understanding geological processes. Constraining the styles, mechanisms and fabrics evolution in the crust and the upper mantle come from both direct and indirect observations with the use of variety of methods. Seismological studies focusing on anisotropy have successfully improved our knowledge of deformation patterns, acting both at present as well as in the past. When combined with tomographic models, velocity anisotropy can shed light on the geometry, structure, and dynamics of deformation in the lithosphere and the asthenosphere. Sophisticated geodynamic modelling and laboratory experiments enhance our understanding of flow patterns in the upper mantle and their effects on vertical motions of the crust and the lithosphere. Combining with inferences from seismic anisotropy, these methods have the potential to reveal mechanisms that create deformation-induced features such as shape preferred orientation (SPO) and lattice-preferred orientation (LPO), which created in the past or during the last deforming processes. Structural and kinematic characterization of deformation events by geometric and kinematic analyses infer the direction and magnitude of the tectonic forces involved in driving deformation within crust and upper mantle. Additionally, both physical analogue and numerical modelling foster our understanding of complex 3D-plate interaction on various timescales, controlled through the degree of plate coupling and the rheology of the lithosphere.
However, additional work is required to better integrate various experimental and modelling techniques, and to link them with multi-scale observations. The session aims at bringing together inferences from different disciplines that focus on structure and deformation of the lithosphere and the sub-lithospheric upper mantle as well as on the dynamics and nature of the lithosphere-asthenosphere system. The main goal is to demonstrate the potential of different methods, and to share ideas of how we can collaboratively study lithosphere structure, and how the present-day fabrics of the lithosphere relates to the contemporary deformation processes and ongoing dynamics within the asthenospheric mantle. Contributions from studies employing seismic anisotropy observation, geodynamical modelling (analogue and numerical), structural geology, and mineral and rock physics are welcome.

Invited Speakers:
Eric Debayle (Laboratoire de Geologie de Lyon-Terre, Planètes, Environnement, CNRS, France)
Christof Völksen (Bayerische Akademie der Wissenschaften, Germany)

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.

Dynamic processes shape the Earth and other planets throughout their history. Geochemical observations place major constraints on dynamical processes that operated throughout Earth’s history while seismic imaging gives a snapshot of today’s mantle. Knowledge of physical properties and rheology from mineral physics is key to quantify processes in the mantle, and is undergoing constant advances (e.g. related to the iron spin transition or the thermal conductivity of the core). Magma ocean crystallisation established the initial conditions for subsequent long-term Earth evolution but is not well understood and typically not considered in models of long-term evolution. Modern-day plate tectonics may not have operated in the past; there is active debate about what tectonic mode(s) may have preceded it and their geological and geochemical signatures.

This session aims to provide a multidisciplinary view of the dynamics and evolution of the Earth, including its mantle, lithosphere, core and atmosphere. We welcome contributions that address aspects of this problem including geochemical observations and their interpretation, new mineral physics findings, geodynamical modelling, and seismological observations, on temporal scales ranging from the present day to billions of years, and on spatial scales ranging from microscopic mineralogical samples to global models. Contributions that take a multidisciplinary approach are particularly welcome.

Invited speaker: Matthew Jackson, Saskia Goes, Lorenzo Colli, Paula Koelemeijer

The Alps have been intensively studied by geologists for more than a century, providing a unique natural laboratory to deepen our understanding of orogenic processes and their relationship to mantle dynamics. Although most concepts that underlie current studies of mountain belts and convergence dynamics were born in the Alps, the belt is now being examined with renewed vigour in the AlpArray project. This project involves a large number of European institutions, with efforts focused on the AlpArray Seismic Network to provide homogeneous seismological coverage of the greater Alpine area at unprecedented aperture and station density, both on land and sea. New data is being recorded in a multidisciplinary research effort, and other projects are being planned in the immediate and mid-term future.
Within this context, we invite contributions from the Earth Science community that highlight new results in AlpArray and that identify and solve key open questions of the present and past structure and dynamics of the Alps and neighbouring orogens. Both disciplinary and multi-disciplinary contributions are welcome from geophysical imaging, (seismo)tectonics, structural geology, gravimetry, geodesy, geodynamics, petrology, geochronology and other allied fields, combined with various modelling approaches. Scales of interest range from crustal to upper mantle, in the Alps and neighbouring mountain belts such as the Apennines, the Carpathians and the Dinarides.

The largest earthquakes globally occur along plate boundaries, producing intense shaking and associated secondary hazards over broad regions. In the past few years, there have been significant improvements in the quantity and quality of geodetic, seismological, and geological observations of the slow accumulation and rapid release of strain at these plate boundaries. At the same time, improvements in modeling techniques are providing new insights into the geodynamic processes controlling the occurrence of major earthquakes. With these advances, it is now becoming possible to address outstanding issues about both seismic and aseismic deformation at plate boundaries, such as time-variable locking and unlocking of the plate interface, the extent and role of slow slip events, the links between earthquake cycles and permanent deformation, and the behavior of complete cycles revealed by paleo-seismic and paleo-geodetic observations.

We invite contributions that investigate the spectrum of deformation occurring throughout the earthquake cycle at plate boundaries, from aseismic to seismic and across a variety of spatial and temporal scales. Submissions that utilize improved remote and field observational capabilities, developments in data analysis, or innovations in analog and numerical modeling to advance the understanding of the underlying physical processes are encouraged.

Public information:
----------

We will begin our session by allowing 5-10 minutes for participants to look through the displays and prepare some discussion points. After this, we will go through all of the presenting author, and have each author briefly introduce their research. Audience participants will then have a few minutes to ask questions and make comments. Depending on the number of displays, we will be more or less strict on timing, but we are aiming for 5-10 minutes per author. Finally, after all authors have presented, we will turn the comments to open discussion. Talk to you soon!

The separation of the African and Arabian plates is responsible for the opening of the Red Sea and Gulf of Aden that meet the East African Rift at the Afar triple junction. Moreover, the strike-slip movement between the African and the Arabian plates is accommodated in the northernmost part of the rift system by the Dead Sea fault and its marine extension in the Gulf of Aqaba. High volcanic and seismic activity in and around the three arms of the divergence highlights some of the key aspects of this opening system.

This complex geodynamic system is currently investigated by multiple geoscientific approaches including e.g., tectonics, volcanology, stratigraphy, geodynamics, geodesy as well as active and passive geophysical methods.

In this session, we welcome contributions that are based on (but not limited to) such methods and investigate the basins of the Gulf of Suez, Gulf of Aqaba, Red Sea, Gulf of Aden, Afar depression and their surrounding regions, from the mantle to the crust.

Geophysical measurements offer important baseline datasets as well as validation for modelling and remote sensing products for cryospheric sciences. Applications include the dynamics of ice-sheets, alpine glaciers and sea ice, changes in snow cover properties of seasonal and permanent snow, snow/ice-atmosphere-ocean interactions, permafrost degradation, geomorphic processes and changes in subsurface materials.

In this session we welcome contributions related to a wide spectrum of geophysical- and in-situ methods, including advances in diverse techniques such as radioglaciology, active and passive seismology, acoustic sounding, GPS/GNSS reflectometry or time delay techniques, cosmic ray neutron sensing, drone applications, geoelectrics and NMR. Contributions may concern field applications as well as new approaches in geophysical/in-situ survey techniques or theoretical advances in the field of data analysis, processing or inversion. Case studies from all parts of the cryosphere such as snow, alpine glaciers, ice sheets, glacial and periglacial environments and sea ice are highly welcome. The focus of the session is to compare experiences in the application, processing, analysis and interpretation of different geophysical and in-situ techniques in these highly complex environments.

This session is offered as a PICO: an engaging presentation format that has been successfully tested for this session during the last three years at EGU. All selected contributions will present their research orally, and then further present their research using interactive screens. This results in rich scientific feedback and is an effective tool for communicating science with high visibility.

This is a joined session - we merged with the former session SM5.5 'Active and passive seismic methods for imaging and monitoring the cryosphere'.


++++++++++++++++++++++++++++ Invited Speaker ++++++++++++++++++++++++++++++++++++

Dustin Schroeder: Observing Evolving Subglacial Conditions with Muti-Temporal Radar Sounding

Public information:
Session topics:
A) Glaciers, Englacial and Subglacial: Schroeder (invited), Rix & Mulvaney et al., Yushkova et al., Jansen et al., Delf et al., Church et al., Pettinelli et al., Kufner et al., Mordret et al., Brisbourne et al., Jones et al., Stevens et al.
B) Sea Ice & Ocean Floors: Jakovlev et al., Schlindwein et al.
C) Ice Rheology: Hellmann et al., Booth et al., Ershadi et al., Martin et al.
D) Snow & Firn: Case et al., Pearce et al., Priestley, Capelli et al., Henkel et al.
E) Permafrost: Maierhofer et al., Limbrock et al., Boaga et al., Lyu et al., Valois et al., Majdanski et al.

Besides our EGU2020: Sharing Geoscience Online text-based chat on Mon, 04 May, 08:30–10:15, we are planning an additional video conference (outside the EGU programme) at the same day starting at 18:00/06:00p.m. In this video conference, our invited speaker Dustin Schroeder will give his talk on ‘Observing Evolving Subglacial Conditions with Mutitemporal Radar Sounding’. We will then open a broader discussion on all different topics and methods of our session.
Time: Mon, 04 May, start: 18:00/06:00p.m. Vienna time (CEST) (= 12:00 New York time)
Place/Link: https://rutgers.webex.com/rutgers/k2/j.php?MTID=tc085b8a9bc24b1c04784c81584672fc4
Session password: YvBGu8jV773 (Global call-in numbers: https://rutgers.webex.com/rutgers/globalcallin.php?MTID=t7ddb8d0ab92b0bd317c7e36862494393 Access code: 192 664 533)

@all authors of this session: It would be great if you can help us a bit in our session planning. Therefore, we would like to ask you to complete the following Doodle survey asap: https://doodle.com/poll/sese8bcs57dcfye5
In this survey we would like to know, if you will be able to
a) upload a display until Thu, 30 April
b) participate during our official EGU2020: Sharing Geoscience Online text-based chat on Mon, 04 May, 08:30–10:15 am
c) participate during our additional video conference on Mon, 04 May, 18:00/6p.m. (please pay attention, time was updated!)
Thank you very much for your help.

The Arctic realm hosts vast extended continental shelves bordering old land masses, one of the largest submarine Large Igneous Provinces (LIPs) -the Alpha-Mendeleev Ridge - of Mesozoic age, and the slowest mid-ocean spreading ridge (the Gakkel Ridge) on the globe. Extreme variations in the evolution of landscapes and geology reflect the tug-of-war between the formation of new oceans, like the North Atlantic, and the destruction of older oceans: the South Anyui, Angayucham and North Pacific, which were accompanied by rifting, collision, uplift and subsidence. The causal relationships between the deep-mantle and surface processes in the Circum-Arcic region remain unclear. Geoscientific information on the relationship between the onshore geology and offshore ridges and basins in combination with variations in the mantle is the key for any deeper understanding of the entire Arctic Ocean.
This session provides a forum for discussions of a variety of problems linked to the Circum-Arctic geodynamics and aims to bring together a diversity of sub-disciplines including plate tectonics, mantle tomography, seismology, geodynamic modelling, igneous and structural geology, geophysical imaging, sedimentology, and geochemistry. Particularly encouraged are papers that address lithospheric-mantle interactions in the North Atlantic, the Arctic and North Pacific regions, mantle dynamics and vertical and horizontal motion of crustal blocks and consequences for paleogeography. As geologic and tectonic models are inherently tied with changes in the oceanographic and climatic development of the Arctic, we also invite studies that focus on the interplay between these processes and across timescales. Lastly, we would like to invite contributions from studies concerning the implications of how the Arctic’s geography and geology are portrayed by modern data and issues related to jurisdiction and sovereign rights with particular focus on the UN Convention on the Law of the Sea.