For the first time, from early 2019 to the end of 2022, Mars’ shallow and deep interiors have been explored by seismology with the InSight mission. Thanks to the performances of its seismometers and the quality of their robotic installation on the ground, 1,319 seismic events have been detected, including about 90 marsquakes at teleseismic distances, with Mw from 2.5 to 4.7 and at least 6 impacts, the largest ones with craters larger than 130 m. A large fraction of these marsquakes occur in Cerberus Fossae, demonstrating active regional tectonics. Records of pressure-induced seismic noise and signals from the penetration of a heat flow probe have provided subsurface models below the lander. Deeper direct and secondary body wave phase travel time, receiver function, and surface wave analysis have provided the first interior models of Mars, including crustal thickness and crustal layering, mantle structure, thermal lithospheric thickness, and core radius and state. ▪ With InSight's SEIS (Seismic Experiment for Interior Structure of Mars) experiment and for the first time in planetary exploration, Mars’ internal structure and seismicity are constrained. ▪ More than 1,300 seismic events and seismic noise records enable the first comparative seismology studies together with Earth and lunar seismic data. ▪ Inversion of seismic travel times and waveforms provided the first interior model of another terrestrial planet, down to the core. ▪ Several impacts were also seismically recorded with their craters imaged from orbit, providing the first data on impact dynamic on Mars. Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 51 is May 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

https://www.annualreviews.org/doi/pdf/10.1146/annurev-earth-031621-073318

Mars Seismology

Large wood drives both the form and function of gravel‐bed rivers draining forested basins. Previously overlooked benefits of wood in rivers are now widely recognized. Together with flow and sediment regimes, the wood regime controls rivers' physical and ecological integrity. Yet large quantities of wood transported during floods can pose additional hazards, potentially damaging infrastructures like bridges or dams and exacerbating flooding. However, unlike the water and sediment regimes intensively studied over the past decades, the instream wood regime or budgeting has been only recently defined and thus is still rarely quantified. The instream wood budget describes the cascading processes from supply or recruitment, entrainment, and transport to deposition, storage and decay (i.e., fragmentation or decomposition). These processes show high spatial and temporal variability but can be characterized by magnitude, frequency, timing, duration and mode. Instream wood budgeting is challenging, primarily because of the lack of observations, monitoring stations, and standardized protocols to acquire data. This contribution reviews the most recent advances to quantify the different instream wood budget components, notably the wood supply, and transfer. Case studies showing applications of biogeochemistry, videography, artificial intelligence, numerical modelling or tracking illustrate the current progress. Because critical challenges remain, we identify and describe some of them and discuss how the wood in riverine sciences may develop in the future.

Current progress in quantifying and monitoring instream large wood supply and transfer in rivers

&amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Motivation&amp;lt;/strong&amp;gt;&amp;amp;#160;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Granular avalanches such as slope streaks, have been observed on Mars since the beginning of the high resolution era with MOC on MGS. Such mass wasting processes are active and their dynamics has a few implications in terms of climatic conditions. However, understanding the slope streaks dynamics is still undergoing. Many authors have proposed dry spreading of fine dust or wet processes (e.g., Schorghofer et al., 2002; 2007). For instance, Head et al., (2007) have proposed spring discharge involving salty ground-water. Many of those studies have been performed from interpretations of geomorphic features by comparing knowing processes occurring on Earth and/or a few comparisons with experimental works. Consequently, a key parameter is the triggering conditions, along with the dynamical behavior of these avalanches. We hence propose a combined approach involving numerical simulations, seismology and orbital imagery in order to provide new insights.&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Orbital image constraints&amp;lt;/strong&amp;gt;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;We investigate the orbital images from CTX and HiRISE cameras, both onboard MRO spacecraft. They provide a complete coverage of the two regions of interest being the InSight landing site (135.61&amp;amp;#186;E 4.49&amp;amp;#186;N) and the vicinity of the large quake (170.85&amp;amp;#186;E, 7.05&amp;amp;#186;S, being at 37&amp;amp;#186; from the SEIS instrument) named 1222 which occurred on 5 May 2020. In both areas, we identified many past avalanche events (Figure 1-A). More specifically, we investigate the complete set of orbital data (imagery, topography, and thermo-physical properties) to estimate in particular the rate of formation of these avalanches in the vicinity of the 1222 event location (Fig. 1-B,C). This has led to request new orbital observations targeted to the most favorable areas for avalanches and hence try to link the ground acceleration resulting from the 1222 event with the triggering of new avalanches by using detection techniques (Fig. 1-D). This work, essentially observational, is combined with the following part on the detectability of this type of source by the SEIS sensor.&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;img src=&amp;quot;&amp;quot; alt=&amp;quot;&amp;quot; /&amp;gt;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Figure 1 -&amp;lt;/strong&amp;gt; (A) Location of identifiable landslides and avalanches (rockfall sign) around the InSight landing site (symbolized with the SEIS/WTS sign). The circles show epicentral distance from the receiver at 5&amp;amp;#186; (red), 10&amp;amp;#186; (orange), 15&amp;amp;#186; (yellow) and 20&amp;amp;#186; (light gray), which correspond to &amp;amp;#8764;300, &amp;amp;#8764;600, &amp;amp;#8764;900 and &amp;amp;#8764;1200 km respectively. Active avalanches (slope streaks) are detected at 150&amp;amp;#176;E. (B) Location of active avalanches (rockfall sign) around the 1222 event location (green flag). (C) Examples of avalanches in the vicinity of the 1222 event location as seen by the CTX camera. This image was taken in May 2011 and reflects the high occurrence of such processes in the area. (D) Detection of slope streaks (and old craters) from neural networks (i.e., using darknet algorithm).&amp;amp;#160;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;amp;#160;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;amp;#160;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Dynamics and source function of avalanches from numerical simulations&amp;lt;/strong&amp;gt;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;In order to generate synthetic seismic sources due to gravity-driven sediment transport we based our simulations on a depth-averaged Saint-Venant equations model, named SHATLOP, which accounts for the curvature of the topography and on various frictional behavior for the source term following (Lucas &amp;amp; Mangeney, 2007; Lucas et al., 2011;2014). Volumes involved are around 8,000-40,000 m3 with a total drop height up to 1 km.&amp;amp;#160; The typical duration of the event is of a few minutes up to 20 minutes for a +2 km runout slope streaks, depending on the frictional law considered and small fluctuation on the bottom topography, which&amp;amp;#160; generates surges as shown on Fig. 2-A. &amp;amp;#8203;&amp;amp;#8203;The source is considered as a point force applied at the surface from the spatial integration of the avalanche resultant force, where the velocity, the resistance force, the density of the flow and the acceleration due to gravity accounting for the bottom topography curvature are all taken into account (Fig. 2-B). The velocity models are obtained after geological considerations after Pan et al., (2019), where active mass wasting processes have been identified (Fig. 2-C). Examples of resulting seismograms are shown in Fig. 2-D.&amp;amp;#160; The velocity model, still under investigation for Mars, is also an important open issue that has a strong impact on the resulting seismic signal. Finally, depending on source functions, velocity models, such an event may be detectable, in particular when occurring during the night at local time of the sensors, when the noise level is low and when spectral content is above SEIS sensitivity (Fig. 2-E).&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;amp;#160;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;img src=&amp;quot;&amp;quot; alt=&amp;quot;&amp;quot; width=&amp;quot;503&amp;quot; height=&amp;quot;741&amp;quot; /&amp;gt;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;Figure 2 -&amp;lt;/strong&amp;gt; (A) Example numerical simulation of a martian dust avalanche over a DTM generated from HiRISE stereo pair (Color scales with the velocity). (B) Resulting source force history. (C) Example of a velocity and attenuation model for Mars. (D) Synthetic seismograms accounting source distance for various velocity models and epicentral distances. (E) ADS example for a small event at 140 km.&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;amp;#160;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;strong&amp;gt;References&amp;lt;/strong&amp;gt;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Head, J., Marchant, D., Dickson, J.,Levy, J., Morgan, G. Slope streaks in the Antarctic Dry Valleys: Characteristics, candidate formation mechanisms, and implications for slope streak formation in the Martian environment. 7 th International Conf. (2007)&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Lucas A., and A. Mangeney. &amp;amp;#8220;Mobility and topographic effects for large Valles Marineris landslides on Mars&amp;amp;#8221;. In: &amp;lt;em&amp;gt;Geophys. Res. Lett., 34, L10201 &amp;lt;/em&amp;gt;(2007)&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Lucas A., et al. &amp;amp;#8220;Influence of the scar geometry on landslide dy-namics and deposits: Application to Martian landslides&amp;amp;#8221;. In: &amp;lt;em&amp;gt;J. Geophys. Res. - Planets, 116, E10001 &amp;lt;/em&amp;gt;(2011)&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Lucas, A., A. Mangeney, and J-P. Ampuero. &amp;amp;#8220;Frictional velocity-weakening in landslides on Earth and on other planetary bodies&amp;amp;#8221;. In: &amp;lt;em&amp;gt;Nature Comm.,5:3417 &amp;lt;/em&amp;gt;(2014)&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Pan L.,&amp;amp;#160; et al. &amp;amp;#8220;Crust stratigraphy and heterogeneities of the first kilometers at the dichotomy boundary in western Elysium Planitia and implications for InSight lander&amp;amp;#8221;. In: Icarus (2019)&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Schorghofer N., Aharonson O., and Khatiwala S. &amp;amp;#8220;Slope streaks on Mars: Correlations with surface properties and the potential role of water&amp;amp;#8221;. In: &amp;lt;em&amp;gt;Geophys. Res. Lett.,29(23) &amp;lt;/em&amp;gt;(2002)&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Schorghofer, N., Aharonson, O.,&amp;amp;#160; Gerstell, M. &amp;amp; Tatsumi, L. Three decades of slope streak activity on Mars. Icarus. 191. 132-140 (2007)&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;br /&amp;gt;&amp;lt;br /&amp;gt;&amp;lt;br /&amp;gt;&amp;lt;/p&amp;gt; 

/pdf/insight-for-seismically-detectability-and-seismically-fajm8pjp.pdf

InSight for seismically detectability and seismically triggered avalanches on Mars

Abstract. We develop a phenomenological model of suspended-sediment transport on the basis of data acquired in the Capesterre river, which drains a small tropical catchment in Guadeloupe. The model correctly represents the transport of suspended sediment during floods, provided that the relation between concentration and water-level forms a counterclockwise loop. In the model, the properties of the sediment and of the river are all lumped into four parameters: a settling velocity related to the size of the suspended sediment, a threshold water-level which acts as a proxy for the threshold shear stress, a characteristic erosion rate and a dimensionless exponent, both of which are related to the availability of fine sediment. The assimilation of field data to our model shows that the value of the parameters change from one flood to the next, probably reflecting changes in the characteristics of the river and the sediment. Finally, a test of the model against data acquired in a small catchment in the french Alps, suggests that the model is versatile enough to be used in diverse hydrological settings. 

/pdf/phenomenological-model-of-suspended-sediment-transport-in-a-2tjedh1u.pdf

Phenomenological model of suspended sediment transport in a small tropical catchment

&amp;lt;p&amp;gt;The icy surfaces of Saturn's synchronous satellites exhibit variations in thermal properties across their leading and trailing hemispheres. They are qualitatively attributed to changes in grain size properties and/or chemical composition which may originate from exogenous pollution, alteration by solar UV rays, or plasma and energetic charged particles trapped in Saturn magnetosphere, or from the coating or sandblasting by the particle of the E ring (Howett et al. 2018). It is difficult to understand which of these weathering processes dominates and what are the effects actually induced on the regolith.&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;On the surface of Mimas, the famous so-called &amp;amp;#8220;Pacman&amp;amp;#8221; asymmetry is very contrasted, with an asymmetry in thermal inertia of &amp;amp;#915;&amp;lt;sub&amp;gt;in&amp;lt;/sub&amp;gt;= 66 &amp;amp;#177; 23 SI within a lens-shaped oval centered on the leading hemisphere, against &amp;amp;#915;&amp;lt;sub&amp;gt;out&amp;lt;/sub&amp;gt; &amp;lt; 16 SI outside of it, for Bond albedos A&amp;lt;sub&amp;gt;in&amp;lt;/sub&amp;gt; &amp;amp;#8764; A&amp;lt;sub&amp;gt;out&amp;lt;/sub&amp;gt; &amp;amp;#8764; 0.6 (Howett et al. 2010, 2011). These estimates were obtained thanks to the high spatial resolution offered by the FP3 plane of the CIRS spectrometer which operates at wavelengths between 9 and 17 &amp;amp;#956;m. They were recently revised to &amp;amp;#915;&amp;lt;sub&amp;gt;in&amp;lt;/sub&amp;gt; = 98 &amp;amp;#177; 42 SI and &amp;amp;#915;&amp;lt;sub&amp;gt;out&amp;lt;/sub&amp;gt; = 34 &amp;amp;#177; 32 SI for albedos A&amp;lt;sub&amp;gt;in&amp;lt;/sub&amp;gt; = 0.45 &amp;amp;#177; 0.08 and A&amp;lt;sub&amp;gt;out&amp;lt;/sub&amp;gt; = 0.41 &amp;amp;#177;0.07 after analysis of the whole set of FP3 observations acquired during the Cassini mission (Howett et al 2020). FP3 data did not cover the trailing hemisphere of Mimas. The thermal anomaly discovered on the leading hemisphere correlates well with the region where the energy accumulation due to high energy electrons bombardment occurs the fastest (Howett et al. 2020). The Bond albedo are systematically lower than those derived from near-infrared observations (Pitman et al. 2010).&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;This gain in high spatial resolution was achieved at the cost of the assumption of an emissivity equal to one. The emissivity of an icy regolith is expected to vary with the size of grains, the topography and the mixing of temperatures within the footprint of the observing instrument. The heat transfer within the regolith also depends on composition and size of grains, and on its porosity (Ferrari and Lucas 2016). On the other hand, CIRS focal plane FP1 plane (17-1000 &amp;amp;#956;m) can be used to derive both the temperature and the emissivity at the cost of spatial resolution. We have therefore developed a thermal model that takes into account the size, composition of grains and the porosity of the regolith (Ferrari et al. 2021). It also includes the effect of topography and temperature mixing within the footprints of FP1 focal plane along an observation. Confronted with FP1 data, the model therefore makes it possible to interpret the regional variations in thermal emission with the variations in physical properties of the regolith.&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Two FP1 observations of Mimas in which significant regional variations of emissivity e&amp;lt;sub&amp;gt;F&amp;lt;/sub&amp;gt; can be observed (figure 1), have been analyzed with this model. We have tested whether these regional variations observed on both the leading and trailing hemispheres around the predicted oval patterns of electrons energy deposition (Nordheim et al 2017) could be explained by variations in grain or regolith properties. Results obtained for both hemispheres will be presented and compared with constraints obtained thanks to near-infrared spectroscopy, in particular the variations in grain sizes and Bond albedo. The eventual sintering or amorphization of grains under MeV electrons bombardment on the leading side (Schaible et al 2016) or the competing processes of E ring deposition or sandblasting competing with eventual darkening by cold plasma on the trailing hemisphere will be discussed (Howett et al 2018).&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;lt;img src=&amp;quot;&amp;quot; alt=&amp;quot;&amp;quot; /&amp;gt;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Figure 1- Apparent Temperature T&amp;lt;sub&amp;gt;F&amp;lt;/sub&amp;gt; versus emissivity e&amp;lt;sub&amp;gt;F&amp;lt;/sub&amp;gt; within the footprints of one FP1 observation led in February 2005 on the trailing hemisphere of Mimas (Black full line). The red (dashed-dot) curve is the model best fit assuming uniform properties of the regolith. The green (dashed) curve yields a better fit assuming a lens-shaped pattern with maximum latitudinal extension of +/- 20 &amp;amp;#176; at the center of the hemisphere. Crystalline water ice and loose contacts between grains are considered here (Ferrari et al. 2021). Within the oval pattern, grains size may be R&amp;lt;sub&amp;gt;in&amp;lt;/sub&amp;gt; &amp;amp;#8764; 100 &amp;amp;#956;m with Bond albedo A&amp;lt;sub&amp;gt;in&amp;lt;/sub&amp;gt; &amp;amp;#8764; 0.45, whereas grains outside of it, they may be much smaller, &amp;amp;#8764; 15 &amp;amp;#956;m with a brighter albedo A&amp;lt;sub&amp;gt;out&amp;lt;/sub&amp;gt;&amp;amp;#8764; &amp;amp;#160;0.61. In the uniform case, grains size may be &amp;amp;#8764; &amp;amp;#160;20 &amp;amp;#956;m in size with a Bond albedo A&amp;amp;#8764; 0.43.&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;&amp;amp;#160;&amp;lt;/p&amp;gt; &amp;lt;p&amp;gt;Ferrari, C. and A. Lucas 2016, A&amp;amp;A 588, A133&amp;lt;br /&amp;gt;Ferrari, C., Lucas, A., Jacquemoud, S., A&amp;amp;A, EDP Sciences, 2021, 655, pp. A&amp;lt;br /&amp;gt;Pitman, K.M., B.J. Buratti and J.A. Mosher, 2010, Icarus, 206, 537&amp;lt;br /&amp;gt;Schaible, M.J., R.E. Johnson, L.V. Zhigile and S. Piqueux, 2016, Icarus 0,1&amp;lt;br /&amp;gt;Nordheim, T.A., Hand, K.P., Paranicas, C., Howett, C.J.A. et al., 2017, Icarus 286, 56&amp;lt;br /&amp;gt;Howett, C.J.A., Spencer, J.R., Pearl, J. and M. Segura, 2010, Icarus 206, 573&amp;lt;br /&amp;gt;Howett, C.J.A, Spencer, J.R., Schenk, P., Johnson, R.E.et al., 2011, Icarus 216, 221&amp;lt;br /&amp;gt;Howett, C.J.A, Spencer, J.R., Nordheim, T., 2020, Icarus 348, 113745&amp;lt;br /&amp;gt;Howett, C.J.A, et al. 2018, in: Schenk, P.M., Clark, R.N., Howett, C.J.A., Verbiscer, A.J., Waite, J.H (Eds.), Enceladus and the Icy Moons of Saturn. U. Arizona Press.&amp;lt;/p&amp;gt; 

Properties of Icy Surfaces from their Thermal Emission: the Mimas case.

&amp;lt;p&amp;gt;Our study looks at how to use the landform called &amp;amp;#8220;molard&amp;amp;#8221; as a marker of permafrost degradation in arctic, sub-arctic and mountain environments. Molards in permafrost terrains are mound of loose debris that derive from the degradation of blocks of ice-rich sediments mobilised by a landslide. Such molards cannot form without ground ice, which cements the source material, allowing it to behave like solid during transport. Once the ground ice has thawed, its cementing action is lost, inducing collapse of the material into molards. We reconstruct the permafrost, geological, geographical settings of more than 50 landslides characterised by molards, compiling data available in the literature. We apply quantitative terrain analysis using high-resolution DEMs to describe, quantify and compare their topographic characteristics, morphometry, dynamics, and molards distribution and density. Our results show that landslides with molards can occur in terrains characterised by various permafrost distribution, from continuous to isolated. These landslides show a variety of morphological and morphometric characteristics, source materials often composed of loose debris or rheologically weak bedrock, and their molard distribution reflects the dynamics of the landslide. In this study, we show that molards are an indicator landform of permafrost degradation under different permafrost, geomorphological and geological conditions, and that they can be used to decipher landslide dynamics in cold environments.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Acknowledgements: This study is funded by the Agence Nationale de la Recherche in the framework of the project ANR-19-CE01-0010 PERMOLARDS&amp;lt;br&amp;gt;&amp;lt;br&amp;gt;&amp;lt;/p&amp;gt; 

Molards, a new geomorphological tool for the identification of permafrost degradation in periglacial terrains around the globe

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InSight for seismically detectability and seismically triggered avalanches on Mars

Phenomenological model of suspended sediment transport in a small tropical catchment

Properties of Icy Surfaces from their Thermal Emission: the Mimas case.

Molards, a new geomorphological tool for the identification of permafrost degradation in periglacial terrains around the globe