TS13.1 | Planetary Volcanism, Tectonics, and Seismology
EDI
Planetary Volcanism, Tectonics, and Seismology
Co-organized by GMPV3/PS4
Convener: Matteo Massironi | Co-conveners: Iris van Zelst, Géraldine Zenhäusern, Costanza Rossi, Anna Horleston, Valentina Galluzzi, Daniel Mege
Orals
| Tue, 25 Apr, 08:30–10:15 (CEST)
 
Room D1
Posters on site
| Attendance Tue, 25 Apr, 16:15–18:00 (CEST)
 
Hall X2
Posters virtual
| Attendance Tue, 25 Apr, 16:15–18:00 (CEST)
 
vHall TS/EMRP
Orals |
Tue, 08:30
Tue, 16:15
Tue, 16:15
Tectonics, volcanism, and seismicity are the main constructive agents in shaping planetary surfaces and provide precious information on planetary interiors and evolution. They are driven by both endogenous processes and external triggers such as impact events and tidal forces and are associated with an enormous variety of landforms and structures. Even small bodies such as asteroids and comets, where volcanism and tectonics do not play a dominant role, are still affected by fracturing and faulting as a result of other processes like tides, dynamic loading, and gravitational collapse. The study of such geological processes involves many scientific disciplines including remote sensing observation, experimental modelling, geological mapping, rheological and geomechanical studies, field analogue investigations and geophysics. In particular, seismology is one of the most powerful tools to study the interior of planetary bodies and their tectonic regime. Recently, InSight has provided a wealth of seismological data from Mars. Similarly, the selection of Dragonfly by NASA promises a wealth of seismological observations of Titan. It is also expected that seismology will return to the Moon with the selection of the Farside Seismic Suite to fly to the farside of the Moon on a commercial lander in the next few years, and the Lunar Geophysical Network remaining an encouraged mission concept for a future NASA New Frontiers call. In addition to these mission-driven insights, modelling presents an increasingly powerful tool that can help to estimate the expected tectonics and seismicity of different planetary bodies.

This session aims to look at the broad range of tectonics, seismicity, and volcanism and their interactions on Solar System bodies and explore how we could improve our understanding through comparable processes on Earth.

Hence, we welcome contributions on observations from space missions, as well as theoretical estimates and modelling efforts on volcanism, tectonics, and seismicity occurring on all planetary bodies.

Orals: Tue, 25 Apr | Room D1

Chairpersons: Iris van Zelst, Matteo Massironi
08:30–08:35
08:35–08:45
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EGU23-11631
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Highlight
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On-site presentation
Thomas Kenkmann

Many scientists who study the tectonic inventory of planetary bodies were initially trained as Earth-based structural geologists. In this context, a comparative approach of methodology in planetary and terrestrial tectonics is helpful with regards to what works and what does not. The methodological approaches are subdivided into (i) nature, (ii) experiment, (iii) modeling.

(i) Acquisition of data in the field, which provides the ground truth for the Earth geologist, is still largely impossible on planetary bodies, at least nowadays, or limited to small regions with the help of rovers. Likewise, microstructural analysis – an important branch in structural geology - is not possible, or is limited to meteorites and the few mission return samples. Those deficits are compensated by remote sensing data. Their quality, spatial resolution and coverage varies greatly, but is steadily improving, and sometimes reaches decimeter resolution (Mars). Most data are sufficient for tectonic work, and sometimes allow the measurement of strike and dip of layers and faults and even enable the construction of cross-sections. The outcrop conditions are usually better on planetary surfaces and the context between geomorphology and tectonics is apparent and similar to neotectonics on Earth due to lower resurfacing rates. Determination of surface ages using crater size-frequency-distributions also allows dating of tectonic processes, although this approach is much less sensitive than Earth-based methods. The exploration of the subsurface by drilling and geophysical surveying is strongly limited in planetary tectonics (e.g., GPR). Detailed seismic surveys cannot be performed yet. However, geophysical measurements (gravity and magnetic field) are often available, which at least allow to decipher crustal-scale processes.

(ii) Rock-mechanical experiments are key for determining the rheology of crustal rocks in planetary and terrestrial tectonics. However, some of the physical boundary conditions to be considered in planetary tectonics are less well constrained and cover a larger range of temperatures. In planetary tectonics, basalts and various types of ices play a central role, which receive little attention in terrestrial structural geology. In tectonic analogue modeling, the parameter gravity poses a challenge. Gravity affects the scaling relationships of faults (displacement–length–width) but gravity can only be modified in centrifuges, space, or parabola flights.

(iii) The mathematical simulation of deformation processes on planetary bodies works in the same way as for terrestrial processes by discretization of the continuum. It is easily adaptable but the systems to be modeled are sometimes underdetermined with regard to the parameter space.

To conclude the methodological tools in planetary tectonics are somewhat limited compared to those applied in terrestrial structural geology. Analogue field studies in specific terrestrial environments (e.g., Svalbard, Iceland) are aimed to compensate the missing field acquisition in planetary tectonics. Despite these limitations, planetary tectonics is a fascinating endeavor that allows us to better understand the dynamic geological processes and narrow down the physical boundary conditions of planetary bodies. With the ever improving remote sensing data by recent and upcoming missions (e.g., BepiColombo, EnVision, Veritas, Juice) the field of planetary tectonics will continue to gain importance.

How to cite: Kenkmann, T.: Planetary tectonics versus Earth tectonics: a comparative approach of working principles, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11631, https://doi.org/10.5194/egusphere-egu23-11631, 2023.

08:45–08:55
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EGU23-7383
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On-site presentation
Simon C. Stähler, Savas Ceylan, Domenico Giardini, John Clinton, Doyeon Kim, Amir Khan, Géraldine Zenhäusern, Nikolaj Dahmen, Cecilia Duran, Anna Horleston, Taichi Kawamura, Constantinos Charalambous, Martin Knapmeyer, Raphaël Garcia, Philippe Lognonné, Mark Panning, W. Thomas Pike, and W. Bruce Banerdt

The InSight mission collected an astounding seismic dataset from Mars during more than four years (1450 sols) of operation until it was retired on 21 December 2022.

The Marsquake Service MQS detected more than 1300 events of seismic origins. Two of these events (S1000a and S1094b) were later confirmed as distant impacts (Figure 1), with magnitudes of MWMa=4.0 and 4.2 and crater diameters of 130 and 150 m, respectively. Finally, the largest marsquake (S1222a, MWMa=4.6) that occurred during InSight's lifetime was recorded on May 4, 2022.

Here, we present the current understanding of the Martian seismicity and the different types of events we observed on Mars, based on the data collected over the whole mission.

Low-frequency (LF) and broadband (BB)
The LF family of events include energy predominantly below 1 Hz. They are similar to teleseismic events observed on Earth, and clear P and S waves are often identified. The hypocenter is known for about half of the recorded LF-BB events, owing to the difficulty of determining back-azimuth and in some cases also distance for the smaller events. The following elements are now understood:

  • Seismicity appears to be located only in few spots around Mars (Figure 2) and no tectonic events were located within 25° from the InSight station.
  • A large number of LF-BB events are located 26–30° from the station, interpreted to be associated with the active dynamics of the volcanic Cerberus Fossae area.
  • A group of events show only a weak S-wave energy and are aligned using the P-wave and length of its coda to around 46°. Their tectonic origin is yet unknown.
  • A few events are located around 60° with relatively emergent P- and S-wave energy.
  • Two large events (S0976a and S1000a) lie beyond the core shadow and have PP and SS phases; S0976a in the Valles Marineris region 146° away from InSight, and S1000a as the result of a meteoritic impact.
  • A number of events of uncertain location are clustered in the same distance, around 100-120° distance.
  • LF events have the largest magnitudes with S1222a reaching MWMa=4.6 and a few others at or above MWMa=3.5.

High-frequency (HF)
The HF family of events are predominantly at and above the 2.4 Hz, local subsurface resonance. The HF events have magnitudes below MWMa 2.5 and originate from a distance range of 25–30°, likely a single area in the central Cerberus Fossae region, as very shallow events associated to active volcanic dykes. 

Very high frequency (VF):
A small number of HF events are characterized by higher frequency content, up to 20–30 Hz with a notable amplification on the horizontal components at very high frequency, and are termed VF events. The amplification is plausibly explained by the local subsurface structure. These events are observed only close to the lander. Remote imaging of recent craters and the presence of a distinctive acoustic signal confirmed that the closest events were produced by meteoric impacts. Investigations are being conducted to understand if other VF events can be confirmed as impacts, too.

How to cite: Stähler, S. C., Ceylan, S., Giardini, D., Clinton, J., Kim, D., Khan, A., Zenhäusern, G., Dahmen, N., Duran, C., Horleston, A., Kawamura, T., Charalambous, C., Knapmeyer, M., Garcia, R., Lognonné, P., Panning, M., Pike, W. T., and Banerdt, W. B.: Review of the seismicity on Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7383, https://doi.org/10.5194/egusphere-egu23-7383, 2023.

08:55–09:05
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EGU23-12524
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ECS
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On-site presentation
Doyeon Kim, Simon Stähler, Christian Boehm, Ved Lekic, Domenico Giardini, Savas Ceylan, John Clinton, Paul Davis, Cecilia Duran, Amir Khan, Brigitte Knapmeyer-Endrun, Ross Maguire, Mark Panning, Ana-Catalina Plesa, Nicholas Schmerr, Mark Wieczorek, Géraldine Zenhäusern, Philippe Lognonné, and William Banerdt

After more than 4 Earth years of operation on the martian surface monitoring the planet’s ground vibrations, the InSight’s seismometer is now retired. Throughout the mission, analyses of body waves from marsquakes and impacts have led to important discoveries about the martian interior structure of the crust, mantle, and core. Recent detection of surface waves, together with gravimetric modeling enabled the characterization of crustal structure variations away from the InSight landing site and showed that average crustal velocity and density structure is similar between the northern lowlands and the southern highlands. Especially for the observed overtones and multi-orbiting surface waves in S1222a, we find the depth sensitivity expands down to the uppermost mantle close to 90 km. Furthermore, our 3D wavefield simulations show significantly broadened volumetric sensitivity of the higher-orbit surface waves. These new constraints obtained by our surface wave analyses provide an important opportunity not only to refine and verify our previous radially symmetric models of the planet’s interior structure but also to improve understanding of seismo-tectonic environments on Mars. Here, we summarize our recent effort in the analyses of surface waves on Mars and discuss the inferred crustal property and its global implications.

How to cite: Kim, D., Stähler, S., Boehm, C., Lekic, V., Giardini, D., Ceylan, S., Clinton, J., Davis, P., Duran, C., Khan, A., Knapmeyer-Endrun, B., Maguire, R., Panning, M., Plesa, A.-C., Schmerr, N., Wieczorek, M., Zenhäusern, G., Lognonné, P., and Banerdt, W.: Crustal structure observed by the InSight mission to Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12524, https://doi.org/10.5194/egusphere-egu23-12524, 2023.

09:05–09:15
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EGU23-15069
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On-site presentation
Brigitte Knapmeyer-Endrun, Jiaqi Li, Doyeon Kim, Ana-Catalina Plesa, Scott McLennan, Ernst Hauber, Rakshit Joshi, Jing Shi, Caroline Beghein, Mark Wieczorek, Mark P. Panning, Philippe Lognonne, and W. Bruce Banerdt

Analysis of data from the seismometer SEIS on NASA’s InSight mission has by now provided a wealth of information on the crustal structure of Mars, both beneath the lander and at other locations on the planet. Here, we collect the P- and S-wave velocity information for kilometer-scale crustal layers available up to now and compare it to predictions by rock physics models to guide the interpretation in terms of crustal lithology.

Modeling is performed based on the Hertz-Mindlin model for un- or poorly consolidated sediments, Dvorkin and Nur’s cemented-sand model for consolidated sediments and Berryman’s self-consistent approximation to simulate cracked rocks. Considered lithologies include basalt, andesite, dacite, kaolinite, and plagioclase, and cementation due to calcite, gypsum, halite and ice. We use Gassmann fluid substitution to study the effect of liquid water instead of atmosphere filling the pores or cracks.

Below the lander, available constraints are based on Ps-receiver functions and vertical component autocorrelations for SV- and P-wave velocities, whereas SH-reflections and SsPp phases provide additional information on SH- and P-wave velocities in the uppermost 8-10 km, respectively. SS and PP precursors at the bouncing point of the most distant marsquake contain information on crustal velocities at a near-equatorial location far from InSight. Surface wave observations from two large impacts as well as the largest marsquake recorded by InSight provide average crustal velocities along their raypaths, which are distinct from the body wave results.

The subsurface structure beneath the lander can be explained by 2 km of either unconsolidated basaltic sands, clay with a low amount (2%) of cementation, or cracked rocks (e.g. basalts with at least 12% porosity). Within the range of lithologies considered, the seismic velocities can neither be explained by intact rocks, nor rocks with completely filled pores, e.g. by ice, nor by fluid-saturated rocks. Below, down to a depth of about 10 km beneath InSight, both P- and SV-wave velocities are consistent with fractured basaltic rocks or plagioclase of at least 5% porosity, depending on crack aspect ratios. About 10% of that porosity needs to have a preferred orientation to explain the observed anisotropy. For porosities exceeding 12%, the measured velocities would also be consistent with water-saturated rocks. The transition to higher velocities at about 10 km depth beneath InSight can be modeled by more intact material, i.e. a porosity reduction by 50% compared to the layer above, which can be achieved by either cementation or a lower initial porosity.

The SV-velocities derived by surface waves down to 25-30 km depth, averaging over a large part of Mars, are consistent with basalts of a porosity of less than 5% or nearly intact plagioclase. They could also be explained by rocks with a higher porosity if pores are filled by ice, but that is unlikely for the whole depth range considered. The velocities at larger depth, i.e. below about 20 km beneath InSight and 25-30 km along the surface wave paths, are consistent with intact basalt.

How to cite: Knapmeyer-Endrun, B., Li, J., Kim, D., Plesa, A.-C., McLennan, S., Hauber, E., Joshi, R., Shi, J., Beghein, C., Wieczorek, M., Panning, M. P., Lognonne, P., and Banerdt, W. B.: Constraints on Martian Crustal Lithology from Seismic Velocities by InSight, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15069, https://doi.org/10.5194/egusphere-egu23-15069, 2023.

09:15–09:25
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EGU23-5378
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ECS
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On-site presentation
Salvatore Buoninfante, Valentina Galluzzi, Luigi Ferranti, Maurizio Milano, and Pasquale Palumbo

Geological cartography and structural analysis are essential for understanding Mercury’s geological history and tectonic processes. This work focuses on the Michelangelo quadrangle (H-12), located at latitudes 22.5°S-65°S and longitudes 180°E-270°E. We present the preliminary results derived from the photointerpretation of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) Mercury Dual Imaging System (MDIS) imagery. The first geological map of this quadrangle was produced by [1] at 1:5M scale using Mariner 10 data. The Authors identified and mapped five classes of craters and four main plain units. The present study is a contribution to the 1:3M geological map series, planned to identify targets to be observed at high resolution during the ESA-JAXA BepiColombo mission [2]. Geologic contacts and linear features were drawn at a mapping scale between 1:300,000 and 1:600,000.

We mapped tectonic structures and geological contacts using the MDIS derived basemaps, with an average resolution of 166 m/pixel. Linear features are subdivided into large craters (crater rim diameter > 20 km), small craters (5 km < crater rim diameter < 20 km), subdued or buried craters, certain or uncertain thrusts, certain or uncertain faults, wrinkle ridges and irregular pits. Geological contacts, mapped as certain or approximate, delimit the geological units grouped into three classes of crater materials (c1-c3) based on degradation degree, and plains (smooth, intermediate and intercrater plains).

We identified two main regional thrust systems with a NW-SE strike. The presence of old impact basins influenced the arrangement of faults because of the frequent reactivation of crater rims. Beethoven basin (20.8°S–236.1°E) and Vincente-Yakovlev basin (52.6°S–197.9°E) represent clear examples of tectonic inversion. The reactivation structures [3] are the result of previous impact-related normal faults that were reactivated due to the compressive tectonic regime deriving from the global contraction. Similarly to the Victoria quadrangle (H-02) [4], in the Michelangelo quadrangle the NW-SE system borders the southwestern edge of the high-Mg region, although the accuracy of XRS data at these latitudes is much lower than the accuracy of data acquired in the Northern hemisphere. We noted the frequent interaction between volcanic vents and thrusts, as already suggested by [5]. These vents are often located along lobate scarps or in soft-linkage zones between thrust segments. Indeed, as also observed on Earth, curved thrust surfaces or linkage areas between fault segments represent weakness zones acting as preferential pathways for magma uprising.

 

Acknowledgements: We gratefully acknowledge funding from the Italian Space Agency (ASI) under ASI-INAF agreement 2017-47-H.0.

 

References:

[1] Spudis P. D. and Prosser J. G., (1984). U.S. Geological Survey, IMAP 1659.

[2] Galluzzi et al. (2021). LPI Contrib., 2610.

[3] Fegan E. R. et al., (2017). Icarus, 288, 226-234.

[4] Galluzzi et al. (2019). Journal of Geophysical Research Planets, 124, 2543-2562.

[5] Thomas R. J. et al., (2014). Journal of Geophysical Research Planets, 119, 2239-2254.

How to cite: Buoninfante, S., Galluzzi, V., Ferranti, L., Milano, M., and Palumbo, P.: Geological mapping and structural analysis of the Michelangelo (H-12) quadrangle of Mercury, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5378, https://doi.org/10.5194/egusphere-egu23-5378, 2023.

09:25–09:35
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EGU23-1295
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ECS
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solicited
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On-site presentation
Jan Oliver Eisermann and Ulrich Riller

Meteorite impact is recognized as a fundamental geological process of the solar system. Although mechanisms of large impact cratering have been studied intensely, mostly by numerical modelling, an outstanding problem concerns long-term crater modification, which operates on time scales of tens of thousands of years after impact. Localized deformation in the form of radial and concentric floor fractures (FFCs) are known from large craters on all terrestrial planets. On Earth, we can observe the occurrence of radial and concentric impact melt rock dikes in the eroded basement of large impact structures, such as Sudbury (Canada) and Vredefort (South Africa). Two mechanisms were proposed in the past to explain the formation of FFCs: the intrusion and inflation of igneous bodies below the crater floor and long-term isostatic re-equilibration of impacted target rocks. Using two-layer analogue experiments scaled to physical conditions on Earth, we explore to what extent isostatic re-equilibration of crust may account for the observed dike and fracture patterns of FFCs.

The structural evolution of model upper crust was examined for a variety of initial depths and diameters of crater floors. The crater diameter-to-depth ratio was scaled according to numerical models for average continental crust. Specifically, a tank, 80cm by 80cm in size, was filled with PDMS, representing the viscous middle and lower crust and granular material, simulating the brittle upper crust. Moreover, we introduce a method, which allowed us to generate any shapes of model impact crater floors.

The experiment surfaces were monitored with a 3D digital image correlation system allowing us to quantify key parameters, such as surface motion as well as the distribution and evolution of surface strain. The results of our scale models enabled us to quantify the duration, geometry and distribution of brittle deformation of upper crust. Most importantly, the analogue experiments provided, for the first time, a quantitative relationship between diameter, depth and fracture geometry of crater floors.

Our results indicate that FFCs are caused by long-term uplift of the crater floor, compensated by crustal flow toward the crater center. Such radial convergent flow generated radial and concentric dilation fractures. Crater floor uplift is accompanied by long-wavelength subsidence of the crater periphery on the order of 50 minutes, amounting to some 3000 years in nature. The formation of radial versus concentric fractures depends on the ratio between crater diameter and crater depth and, hence, is controlled by isostacy and crustal strength. The geometry and distribution of fractures in analogue experiments are strikingly similar to the geometry of impact melt rock dikes at Sudbury and Vredefort.

How to cite: Eisermann, J. O. and Riller, U.: Long-term crustal modification of large terrestrial meteorite impact structures: insights from scaled analogue experiments, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1295, https://doi.org/10.5194/egusphere-egu23-1295, 2023.

09:35–09:45
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EGU23-3108
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ECS
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Highlight
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On-site presentation
Alexandra Le Contellec, Chloé Michaut, Francesco Maccaferri, and Virginie Pinel

On terrestrial bodies other than Earth, volcanism and magmatism are often related to impact craters. On Venus, RADAR observations of the surface have revealed two categories of craters: bright-floored and dark-floored craters, the latter being interpreted as partial filling of the crater by lava. On the Moon, volcanic deposits and evidence of pyroclastic activities are also frequently located within impact craters, especially within floor-fractured craters. These craters are characterized by uplifted, fractured floors resulting from underlying shallow magmatic intrusions. 

The elastic stress induced within the crust by a crater excavation indeed has two competitive effects. It induces a depressurization of the encasing elastic medium, which provides a driving pressure to the magma. This allows its ascent through the crust despite the magma’s negative buoyancy and explains why the magma tends to erupt preferentially within impact craters (Michaut and Pinel, 2018). However, the state of stress below the unloading is such that the minimum compressive stress is vertical at the unloading axis, which tends to horizontalize the dyke intrusion, therefore favoring magma storage below a crater at the expense of eruption.

We calculated the stress fields generated by surface unloadings of different radius on top of a semi-infinite half-space and use them in numerical mechanical models of magma ascent (Maccaferri et al, 2011) to evaluate the path followed by a dyke below a crater. We identify several types of behavior (ascent to the crater floor, horizontalization of the intrusion, storage at depth, ascent to the planet surface) depending on the physical properties of the magma and crust, as well as on the dyke and crater unloading characteristics. We draw a regime diagram for magma ascent below craters as a function of two characteristic dimensionless numbers depending on these different physical parameters.

Our results show that magma ascent to the crater interior requires relatively small density contrasts between the crust and magma and rather small crustal thicknesses as opposed to dyke horizontalization that results from larger crust-magma density contrasts and crustal thicknesses. Furthermore, on the Moon, craters are considerably deeper than on Venus, leading to a larger dimensionless deviatoric stress below a crater of a given radius, favoring dyke horizontalization and storage. This well explains why the magma tends to store as horizontal intrusions below floor-fractured craters on the Moon while it tends to erupt on the floor of dark-floored craters on Venus.

ACKNOWLEDGMENT: This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 101001689).

How to cite: Le Contellec, A., Michaut, C., Maccaferri, F., and Pinel, V.: A comparative study of magma ascent and storage below impact craters on terrestrial planets, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3108, https://doi.org/10.5194/egusphere-egu23-3108, 2023.

09:45–09:55
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EGU23-16365
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ECS
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solicited
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On-site presentation
Sam Poppe, Alexandra Morand, Anne Cornillon, and Claire Harnett

Floors of impact craters on rocky planetary bodies in our Solar System are often fractured and bulged. Such deformation features are thought to form by the ascent of impact-generated magma and the inflation of laccolith-shaped magma bodies at a shallow depth below the crater floor. Only the final surface deformation features can be observed from space, and so modeling is the only manner to understand controls on magma emplacement depth and volume, and deformation of the overlying rock. The existing models of crater floor fracturing mostly assume linearly elastic deformation of the shallow planetary crust and are not capable of simulating dynamic opening and propagation of fractures. In contrast, magma-induced deformation on Earth often displays non-elastic deformation features. This mismatch between the realistic mechanical response of planetary crust to magma intrusion and the one assumed by numerical models leads to significant inaccuracies in the modeled magma intrusion characteristics. This has important consequences for volcanic unrest monitoring on Earth and our understanding of structural deformation generated by volcanism throughout the Solar System.

We propose a new two-dimensional (2D) Discrete Element Method (DEM) approach to model dynamic fracturing and displacement in a particle-based host medium during the simulated inflation of a laccolith intrusion. The model indicates highly discontinuous deformation and dynamic fracturing and visualizes the localization of subsurface strain. We explored the effect of different gravitational conditions on the Moon, Mars and Earth on the spatial distribution of strain, stress, and fracturing above an inflating laccolith. Moreover, by systematically exploring a range of numerical parameters that govern host rock strength (bond cohesion, bond tensile strength, bond elastic modulus), and intrusion depth, we find complex controls of mechanical properties of planetary crust on the magma intrusion characteristics. Our models help understand fracture distribution patterns above laccolith intrusions in the shallow crust of rocky planetary bodies. We demonstrate that considering dynamic deformation and fracturing mechanisms in numerical models of magma-induced deformation is essential to better understand the formation of floor-fractured craters and the magmatic intrusions that lie beneath.

How to cite: Poppe, S., Morand, A., Cornillon, A., and Harnett, C.: Modeling of surface displacement and dynamic fracturing during magma emplacement at floor-fractured craters on the Moon and Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16365, https://doi.org/10.5194/egusphere-egu23-16365, 2023.

09:55–10:05
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EGU23-6827
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Highlight
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On-site presentation
Petr Brož, Vojtěch Patočka, Marie Běhounková, Matthew Sylvest, and Manish Patel

Exploration of the Solar System has revealed that the surfaces of many icy bodies have been resurfaced by cryovolcanism: a process during which liquid and vapour are released from the surface into extremely cold and low pressure conditions. Water is one of the most commonly released liquids, and its stability and behavior under such conditions are thus of special interest. When exposed to low pressure, water boils, but it may also start freezing at the phase boundary due to evaporative cooling, as indicated by previous studies. There is only limited insight into how exactly the multiple phase transitions interact and what parameters control the dynamics of the system. To overcome this knowledge gap, we performed experiments in which we simulated the release of water at low pressure and low temperatures, such as could be encountered at local conditions at the  surface of an icy moon.

We used the Mars Simulation Chamber at The Open University (UK), in which a 60 x 40 cm container containing 5 and 17 litres of water was exposed to a reduced atmospheric pressure of ~4.5 mbar. Deionised water was mixed with a small amount of NaCl to achieve a salinity of 0.5% and was precooled to ~3.8°C to be close to the freezing point. Experiments were documented by video cameras situated around the container and the temperature inside the chamber and of the water was recorded by thermocouples.

At the beginning of each experiment, the atmospheric pressure was gradually reduced from ambient, which triggered boiling within the entire volume of water and evaporative cooling in its uppermost layer. This caused a gradual drop in the water temperature down to the freezing point, forming pieces of floating ice. The area where ice was present slowly grew and within timescales of a few minutes the entire surface of the container was covered with ice. However, the ice layer was broken into blocks with uneven surfaces. This was due to active boiling below the freezing layer of the water, with the intense formation of vapour bubbles which were capable of breaking and/or uplifting the ice. Once the fracture(s) developed, trapped vapour was released and deflation followed. Experimental results show that the process was more intense when larger amounts of water were used within the container, which significantly disrupted the freezing of water in those experiments and affected the final topography of the ice layer.

Our experiments show that water phase transition during effusive cryovolcanic eruptions are likely to be a highly complex process due to boiling causing major ice fracturing and the formation of topographical anomalies on the frozen surface.

How to cite: Brož, P., Patočka, V., Běhounková, M., Sylvest, M., and Patel, M.: The complexity of water freezing under reduced atmospheric pressure – insights on effusive cryovolcanism from laboratory experiments, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6827, https://doi.org/10.5194/egusphere-egu23-6827, 2023.

10:05–10:15
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EGU23-3625
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Virtual presentation
Albert Conrad, Steve Ertel, Imke de Pater, Ned Molter, Deepashri Thatte, Joel Sanchez-Bermudez, Anand Sivaramakrishnan, Joseph Shields, Katherine de Kleer, Rachel Cooper, and Jarron Leisenring

During late spring 2022, using JWST aperture masking interferometry (ERS program #1373) and ground-based adaptive optics at the Keck telescope, we detected a new emission feature in Io’s Bosphorus Regio.  To pinpoint the location more accurately we followed up with the Large Binocular Telescope (LBT).  An accurate location will help determine if this feature is part of the Emakong Patera, is part of the Seth Patera, or is an independent volcano emitting lava from its own magma source.  Here we report on the LBT observation and data analysis.

On UT November 8th, 2022, we observed Io with the Large Binocular Telescope Interferometer (LBTI).  We acquired over 30,000 14ms frames over a period of 4 hours and parallactic angle coverage of approximately 70 degrees.  Data were acquired at both M-band (4.8 microns) and a wide band-pass spanning 2.2 to 5.0 microns.  As in past LBTI observations of Io (Conrad et al., 2015), we employed lucky fringing and frame selection to assemble a data set in which all frames are co-phased.  From these data (taken with a 23-meter baseline), we expect to determine the location of the feature to a degree of accuracy approximately three times greater than is possible with adaptive optics on 8-10 meter ground-based telescopes.

Image reconstruction is the preferred method for combining interferometer data for most science programs.  However, for science programs that a) require only accurate astrometry of point sources (all volcanoes in our data are unresolved at the observed wavelengths) and b) utilize data taken with a Fizeau interferometer like LBTI, we have developed a simpler method.  This method has two advantages.  First, the method preserves the spatial information available in the raw data.  Image reconstruction can sometimes shift the location of a measured source.  Second, with our method data taken at different wavelengths can still be combined to yield a single measurement.  Image reconstruction methods can only combine images which were all taken with the same filter.

The method is quite simple.  Because a Fizeau interferometer like LBTI provides complete images (i.e., the image is not reconstructed from visibilities and closure phases), we can take a one-dimensional cut through each fringe pattern as it appears in the raw data.  From each cut we compute a one-dimensional centroid to get a sub-pixel location along that baseline.  These results, taken at different baseline angles (the LBTI baseline rotates with parallactic angle) are statistically combined to produce a single location measurement.  This location is then mapped from detector space to a latitude and longitude on the sphere of Io.  The uncertainty in the measurement is reflected as two orthogonal error bars, one for latitude and one for longitude, computed by statistically combining the individual uncertainties of each cut.

This same method can be used to locate other volcanoes visible in our data set, which will be the subject of a future work.

How to cite: Conrad, A., Ertel, S., de Pater, I., Molter, N., Thatte, D., Sanchez-Bermudez, J., Sivaramakrishnan, A., Shields, J., de Kleer, K., Cooper, R., and Leisenring, J.: Locating a new emission source in Io’s Bosphorus Regio, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3625, https://doi.org/10.5194/egusphere-egu23-3625, 2023.

Posters on site: Tue, 25 Apr, 16:15–18:00 | Hall X2

Chairpersons: Matteo Massironi, Iris van Zelst
X2.294
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EGU23-14918
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ECS
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Highlight
Doyeon Kim, John Clinton, Savas Ceylan, Anna Horleston, Simon Stähler, Taichi Kawamura, Constantinos Charalambous, Nikolaj Dahmen, Cecilia Duran, Matthieu Plasman, Géraldine Zenhäusern, Fabian Euchner, Martin Knapmeyer, Domenico Giardini, Philippe Lognonné, Tom Pike, Mark Panning, and William Banerdt

After ~4 years of deployment on the martian surface monitoring the planet’s ground motion, the InSight seismometer is now retired. Here, we review the procedures and methods the Marsquake Service (MQS) used to curate the seismic event catalog and describe the content of the catalog. The marsquake catalogue is different from normal catalogues on Earth as it aims to provide the authoritative catalog for the mission, covering the entire planet, using only a single station. As of January 1st, 2023, the MQS catalog contains 1319 seismic events of which 6 are known meteorite impacts. We have also identified 1383 superhigh frequency events that are interpreted as thermal cracking nearby the InSight lander. Late in the project large distant events occurred that allowed MQS to detect surface waves. Multiple events have been associated as impacts using orbital imaging, confirming the MQS single station location procedures. All of these new seismic phases have contributed to advance our understanding of the internal structure of Mars. The marsquake S1222a, the largest event recorded during the mission (MW 4.7) occurred in March 2022 and is also documented in our latest MQS catalog, V13, with many associated seismic phases including both Rayleigh and Love waves, their first-order overtones, and multi-orbiting surface waves that have not been identified in other marsquake records from our previous catalogues. The InSight mission is now closed but the MQS operation continues to analyze the ~4 years of seismic recordings on Mars and a final catalog, including event-specific products such as filter banks, and spectra, is in preparation. This final catalog will inform capabilities and field strategies in geophysical explorations for future martian science missions.

How to cite: Kim, D., Clinton, J., Ceylan, S., Horleston, A., Stähler, S., Kawamura, T., Charalambous, C., Dahmen, N., Duran, C., Plasman, M., Zenhäusern, G., Euchner, F., Knapmeyer, M., Giardini, D., Lognonné, P., Pike, T., Panning, M., and Banerdt, W.: The Marsquake Service since the InSight mission to Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14918, https://doi.org/10.5194/egusphere-egu23-14918, 2023.

X2.295
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EGU23-3719
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ECS
Keisuke Onodera, Yuki Imagawa, and Satoshi Tanaka

The beginning of planetary seismology dates back to the Apollo lunar seismic observations (1969 – 1977), where two types of seismometers were deployed at four places on the nearside of the Moon. The seismic observation package consisted of (i) two horizontal and one vertical long-period (LP) sensors and (ii) one vertical short-period (SP) sensor. About 8 years of observation brought us 13000 seismic events and contributed to the understanding of the internal structure and the seismicity of the Moon (see Nunn et al., 2020 and Garcia et al., 2019 for the recent review).

On the other hand, because the existing moonquake catalog by Nakamura et al. (1981) builds on the LP data, it has been expected that there are potential events only observable in the SP data (Nakamura, 2021, pers. comm.). Referring to the already cataloged events, shallow moonquakes and thermal moonquakes excite the energy at a high-frequency range more sensible with the SP sensor (> 1-2 Hz). Especially, shallow moonquakes being used to define the lunar seismicity (Banerdt et al., 2020), it is of great importance to investigate the SP data for re-evaluating the current seismic activities on the Moon.

In this study, utilizing the re-archived Apollo lunar seismic data by Nunn et al. (2022), we searched for undetected moonquakes by looking into the coherence between the reference moonquakes and the SP time series. As a result, we succeeded in discovering seismic events that were not cataloged before. A new SP event catalog will be released with our future publication. 

In the presentation, we will show the newly detected moonquakes and describe their characteristics.

 

References

  • Banerdt et al. (2020), Nat. Geosci.,13, 183–189.
  • Garcia et al. (2019), Space Sci. Rev., 215, 50.
  • Nakamura et al. (1981), UTIG Technical Report, 18.
  • Nunn et al. (2020), Space Sci. Rev., 216, 89.
  • Nunn et al. (2022), Planet. Sci. J., 3 219.

 

How to cite: Onodera, K., Imagawa, Y., and Tanaka, S.: Newly discovered moonquakes from Apollo short-period seismometer data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3719, https://doi.org/10.5194/egusphere-egu23-3719, 2023.

X2.296
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EGU23-10833
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ECS
Meenakshi Yellapragada and Raghukanth stg

In recent years, estimating the possible ground motion on the Moon became quite essential as various researchers are exploring safe extra-terrestrial habitats close to the Earth. From the high-resolution imageries, it is observed that seismic sources like lobate scarps and wrinkle ridges are identified representing that there is seismic activity on the Moon which is considered a hazard to the lunar base. Therefore, it is essential to include topographic amplification factors in the ground motion predictions on the Moon which are in turn used in the seismic hazard analysis. It is well known that there is a wide variation of topographical features in the lunar south pole region (LSPR). Hence in this study, the spectral element method is preferred to model the seismic wave propagation in such complex topographic regions. The main objective of this study is to estimate the ground motion amplification on the Artemis landing sites that are present in the LSPR region. The topography for the study region is extracted from the entire South-pole topographic map which is obtained from the LRO-LOLA. A grid elevation data is incorporated with a resolution of 30m. The shallow moonquake event that occurred on March 13, 1973, is considered a seismic source, located at [84⁰ S, 134⁰ W] and has a focal depth of 5 km. The seismic wave simulations can generate up to a frequency of up to 2Hz from the developed model. The simulations have been performed with and without topography. The amplification ratio i.e., Peak ground displacement with topography/ Peak ground displacement without topography is calculated for the considered landing sites. In addition, an amplification map of the shake intensity maps is also generated for the considered study region. Results show that there is amplification on ridges and de-amplification in the valleys.

How to cite: Yellapragada, M. and stg, R.: Ground motion amplification due to lunar topography, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10833, https://doi.org/10.5194/egusphere-egu23-10833, 2023.

X2.297
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EGU23-708
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ECS
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Caroline Haslebacher and Nicolas Thomas

The surface of Jupiter's icy moon Europa shows curvilinear geological features, so called lineaments. Some of them span over a hemisphere, while others appear only on a regional scale. These curvilinear surface features that potentially stem from cracks in the ice shell are of keen interest because they might provide a direct or indirect connection to Europa's subsurface ocean, allowing a remote sensing study of the subsurface ocean.
The solid-state imager onboard the Galileo mission observed Europa between 1996 and 2002 during 11 flybys and sent back data of almost 2 gigabyte. Based on a global map mosaicked from Galileo and Voyager images at a scale of 1:15M, Leonard et al. (2019) created a global map of the surface of Europa. Their mapping shows that ridged plains make up a major part of the surface area. Ridged plains are seemingly smooth but contain a high amount of undifferentiated lineae visible at higher resolution. 

We attempt to create a global map of lineaments at a higher resolution than the global geologic map. Although for the Galileo dataset, this mapping could be done manually, we need to prepare for a bigger data return by NASA's Europa Clipper mission. For this purpose, we introduce a deep learning framework that can map linear surface features in Galileo images on Europa autonomously and apply it on a global scale. More specifically, we train a Mask R-CNN that can detect, classify and segment lineaments. The current status of the work is presented.

References:
[1] Leonard, E. J., Senske, D. A., Patthoff, D. A., Global and Regional scale Geologic Mapping of Europa, EPSC-DPS2019-57-1, Vol. 13, 2019

How to cite: Haslebacher, C. and Thomas, N.: Mapping linear surface features on Europa using a deep learning framework, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-708, https://doi.org/10.5194/egusphere-egu23-708, 2023.

X2.298
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EGU23-12423
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ECS
Costanza Rossi, Paola Cianfarra, Alice Lucchetti, Riccardo Pozzobon, Luca Penasa, Giovanni Munaretto, and Maurizio Pajola

The icy satellites of the Solar System, such as Europa and Ganymede, show widespread evidence for tectonic structures that provide insights to infer the kinematics and the mechanical properties of their crusts. Their investigation is pivotal for the understanding of the regimes responsible for their formation and the connection with subsurface layers. Icy satellite tectonics is dominated by extension and shear regimes, while paucity evidence for compression represents an open issue. Structural investigation is constrained at regional-scale coverage of the remote sensing imagery. The research of analogues on Earth represents a strong support for the geologic analysis of the icy satellites. Glaciers represent optimal terrestrial analogues, showing deformation styles similar to those in the icy satellites, and being the excellent sites to further explore, verify and confirm what observed through remote sensing on the icy satellite geology. Although the formation processes differ, the similarity of their structures at surface allows quantifying and predicting the state of deformation in the icy satellites at different scales of investigation. Moreover, glacier deformation shows corridor-like pattern, analogous to the main tectonic setting recognized in the icy satellites. The UPSIDES project aims to investigate and compare the tectonic structures of the glaciers with those on the icy satellites, by means of multi-scale approach of both remote-sensing and field survey. We propose a structural investigation in the Russell and Isunguata Sermia glaciers, located at the western margin of the Greenland Ice Sheet, where field campaign has been conducted under the Europlanet 2024 RI's Transnational Access field analogue in Kangerlussuaq. This project aims i) to achieve knowledge of the tectonic setting at local-scale, ii) to compare with that at regional-scale, and in turn iii) to better understand the tectonic process and to characterize structures that are exclusively identified at regional-scale (such as in the icy satellites). Field measurements of brittle structures (fractures/faults), concerning the quantification of their azimuth, dip, length, width, throw and spacing, have been performed. In parallel, remote sensing analysis, concerning structural mapping on areas covering the locations of the investigated outcrops, allowed to derive the same quantities at regional-scale. In this way, both local- and regional-scale tectonic setting has been investigated, and the stress analysis has been performed. Obtained results have been compared and in turn related with areas that show similar tectonic setting on Ganymede. In particular, the lack of detection of the regional-scale counterpart of the compressional structures that have been recognized at local-scale in the investigated glaciers, has been related to the lack of evidence of such structures in the icy satellite’s surfaces. Such comparison allows us to prepare a tectonic model that suggests deep zones of existence of compressional structures and explains their limited detection at surface and regional-scale investigations.

Acknowledgments: This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 871149. The activity has been realized under the ASI-INAF contract 2018-25-HH.0.

How to cite: Rossi, C., Cianfarra, P., Lucchetti, A., Pozzobon, R., Penasa, L., Munaretto, G., and Pajola, M.: UPSIDES - Unravelling icy Planetary Surfaces: Insights on their tectonic DEformation from field Survey, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12423, https://doi.org/10.5194/egusphere-egu23-12423, 2023.

X2.299
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EGU23-14136
Hanjin Choe, Daniel Mege, and Jerome Dyment

The Danakil Depression is an active divergent boundary opening between the southern Red Sea rift and the Afar triple junction at a rate of ~1 cm/yr. Despite its geological interest, it is becoming increasingly difficult to study due to regional political instability and extreme environment. Our study area, located between the Erta ‘Ale volcano and Dallol, exhibits thick salt layers and iron-rich clay intercalations locally covered by mud volcanism deposits. The heat from the volcanic rift segment and the occasional influx of saltwater from Lake Karum create a unique hydrothermal system on land. In 2019 we collected ground magnetic field data around the main active hydrothermal fissure to investigate the magnetic signature of this hydrothermal system.  Our data show a clear linear magnetic anomaly low associated with the fissure, indicating a loss of magnetization due to the active hydrothermal activity. Local anomaly lows are observed at hydrothermal pools and in areas of subsurface bubbling. Apart from the hydrothermal areas, a relatively uniform magnetic anomaly is observed above the resurfaced reddish mud. Its slow decay away from the fissure may correspond to the progressive attenuation of the superficial iron-rich mud layer considered the most likely coherent magnetized source in the area. Our inference of the iron-rich mud layer as the bearer of a coherent magnetization that is altered by the hydrothermal activity needs however to be confirmed by sample analyses.

How to cite: Choe, H., Mege, D., and Dyment, J.: High-resolution magnetic investigation of hydrothermal circulation in the Danakil Depression, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14136, https://doi.org/10.5194/egusphere-egu23-14136, 2023.

X2.300
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EGU23-11093
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ECS
Bartosz Pieterek, Petr Brož, and Ernst Hauber

The majority of Tharsis is covered by relatively young and low-viscous widespread lava plains, being of basaltic composition. They likely buried older volcanic landforms which could have provided important data about ancient eruptive style and magma composition. However, several fractured regions forming topographic raises survived regional resurfacing, and they are providing an insight into the volcanic history of the planet. To date, these Noachian/Hesperian-aged fractured terrains revealed the presence of putative scoria cones in Ulysses (Brož and Hauber, 2012) and Noctis Fossaes (Pieterek et al., 2022) supporting a hypothesis that the volcanic activity differed in the past from waste eruptions of young low-viscous lavas. Here, we present results of mapping that focused on the edifices superimposed on the Noachian-age fractured crust within the Claritas Fossae region. The aim was to decipher their origin and provide additional constraints on the volcanism emplaced on the ancient terrains.

In the studied region, we mapped 39 topographically positive edifices of constructional character. They are spread on the ancient crust showing NW-SE trending alignment over an area of 170 x 500 km. Based on the CTX observations, we noted that their majority is characterized by elongated (WNW-trending) to irregular or circular outlines and relatively steep-appearing flanks without associated flow-like units. Among these edifices, one circular-shaped edifice located in the easternmost part of the studied area is associated with short-distance flow-like units and rimmed by a caldera-like structure. We also determined the mineralogical composition for several edifices with available CRISM spectral data. This showed that edifices are spatially associated with high concentrations of igneous-origin low-calcium pyroxenes (LCP). Based on the relative stratigraphy, we showed that volcanic activity postdates the fracturing, the age of which has been estimated to space between ~3.4 to ~2.6 Ga and likely predates the formation of Thaumasia graben (Late Hesperian/Early Amazonian).

The shapes, sizes, distribution pattern, and mineralogical composition of the mapped edifices are consistent with putative volcanic origin. Therefore, we argue that Claritas Fossae’s field mainly experienced effusive eruptions characterized by highly viscous, volatile-poor magma(s). Such composition limited the ability of the effused lavas to spread from the site into the surroundings. The elongation and spatial distribution of the edifices together with their LCP-rich composition indicate volcanic eruptions might be controlled by the migration of subsurface dike(s) from the shallow magma chamber(s). Altogether the comprehensive study of the volcanic evolution of the Thaumasia region showed that the studied edifices might express the late-stage dike migration of LCP-rich magmas that used the reactivated WNW-ESE tectonic pathways.

Besides the effusive-origin edifices, the area might contain one of the best-preserved kilometer-sized, explosive-type volcanic edifice emplaced within the putative caldera-like rim known from Mars.

This research was funded by the “GEO-INTER-APLIKACJE” project no. POWR.03.02.00-00-I027/17.

References

Brož, P., Hauber, E., 2012. A unique volcanic field in Tharsis, Mars: Pyroclastic cones as evidence for explosive eruptions. Icarus 218, 88–99. https://doi.org/10.1016/j.icarus.2011.11.030

Pieterek, B., Laban, M., Ciążela, J., Muszyński, A., 2022. Explosive volcanism in Noctis Fossae on Mars. Icarus 375, 114851. https://doi.org/doi.org/10.1016/j.icarus.2021.114851

How to cite: Pieterek, B., Brož, P., and Hauber, E.: Low-voluminous, mafic-dominated volcanism in Claritas Fossae, Thaumasia region on Mars, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11093, https://doi.org/10.5194/egusphere-egu23-11093, 2023.

Posters virtual: Tue, 25 Apr, 16:15–18:00 | vHall TS/EMRP

vTE.6
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EGU23-15312
Riccardo Pozzobon, Francesco Mazzarini, and Ilaria Isola

Long-lasting widespread volcanism contributed to heavily shaping the surface of Mars. In fact, the Tharsis volcanic province is one of the largest volcanic provinces with the largest shield volcanoes of the Solar System, Mount Olympus and the NE-SE trending Tharsis Montes, namely Ascareaus, Pavonis and Arsia Mons.

However, volcanism on Mars is characterized also by the presence of wide volcanic fields, either in form of small shields or monogenic cones. The region of Syria Planum (SP), located eastern to the Tharsis province and encompassed between Noctis Labyrinthus on the North and Claritas Fossae on the southwest, is an example of diffuse volcanism. SP presents hundreds of small edifices which insist on top of a large bulge roughly 300x200 km in size.

New chronological results pointed out a complex magmatic history and volcano-tectonic evolution of the whole Tharsis and SP area spanning from the early-Noachian to the more recent times such as the 130 Ma of the Arsia Mons’ single caldera and the 140 Ma for the Pavonis Mons’ composite calderas. Although through the years SP has been considered the by-product of the enormous volcano-tectonic activity forming the Tharsis, it has been shown that this magmatic complex could be related to large multiple episodes of mantle upwelling forming minor edifices that do not necessarily overlap with the major volcanic centres. Moreover, the NW-SE elongated SP volcanic field grew just south of the Noctis Labyrinthus canyon systems that form a dissected highland and is located at the western tip of the Valles Marineris.

In this work, we investigate the geometry of the plumbing system of the SP volcanic field as well as the structures (vent elongation and vent alignment) that fed the magma to forward a possible tectonic and volcanic evolution of the area. The spatial distribution of vents and the overall shape of the volcanic field have been studied in terms of vent clustering and spatial distribution. Moreover, analyzing the lineament pattern on SP and surrounding areas possible links with the formation and evolution of the Noctis Labyrinthus graben, the Valles Marineris and the Tharsis province are forwarded.

How to cite: Pozzobon, R., Mazzarini, F., and Isola, I.: Syria Planum volcanic province, an example of diffuse volcanism on Mars: insights from vents distribution analysis and spatial clustering, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15312, https://doi.org/10.5194/egusphere-egu23-15312, 2023.