Seismological methods have become increasingly important in glaciology, particularly for studying icequakes associated with glacier dynamics. In this study, we analyze more than 14,000 icequakes recorded over 35 days by a dense seismic network of 98 3-component sensors deployed on the Argentière Glacier(French Alps). Using the Matched Field Processing (MFP)technique, we detect and localize icequakes primarily near surface crevasses, highlighting their connection to crevasse activity. To investigate their source mechanisms, we perform a joint elastic full waveform inversion for moment tensor and source wavelet assuming homogeneous mechanical properties, taking into account the topography of the glacier using a spectralelement waveform modeling tool. The synthetic data computed with the reconstructed source wavelet and moment tensors accurately fit the observed data, validating our approach. Our results reveal that most icequakes exhibit an opening-type mechanism, with the principal stress direction (resp. minor stress direction) oriented along the normal to crevasse (resp. oriented along the crevasse). These findings provide new insights into the stress distribution within a moving glacier and the mechanical processes governing icequake generation.

As part of the SEIS-ADELICE project (2020–2025), hundreds of seismological instruments were deployed on and around the Astrolabe Glacier in Terre Adélie, East Antarctica. The aim was to monitor the cryoseismic activity of an Antarctic outlet glacier as it reaches the ocean, image its internal structure and thickness, and investigate its interactions with the underlying ocean and local bedrock. This paper describes the sequential deployment of broadband, mid-band, and short-period instruments on land and at sea, the noise levels obtained in various environments and the quality of the seismological data in different frequency bands. It also presents a few non-exhaustive examples of data to demonstrate their quality and potential for analysing various cryoseismic sources at different times, frequencies, and geographic scales.

The seasonal evolution of subglacial hydrology exerts a primary control on ice sheet flow, yet the spatial structure and temporal evolution of subglacial drainage systems remains incompletely characterized. Here, we apply Sentinel-1 double-difference SAR interferometry across a land-terminating sector of the western Greenland Ice Sheet to resolve two distinct surface motion signals: (1) widespread late-summer flow deceleration followed by gradual recovery across an area extending ~110 km inland, and; (2) localized ice-surface subsidence, primarily aligned with bed troughs, persisting for several weeks after surface melt cessation. We interpret these signals as the dynamic response to coexisting subglacial drainage system components. The broad-scale flow speed recovery reflects progressive repressurization of the widespread weakly connected cavity system, driven by basal meltwater recharge. The trough-localized subsidence reflects a multi-week buffered release of stored water through well-connected corridors. Together, these signals provide a spatially-continuous view of the geometry and spatial extent of both the well- and weakly connected components of the late-season drainage system. Our findings highlight the disproportionate role of bed trough environments in late-season meltwater storage and drainage, demonstrate that the well-connected drainage system remains hydraulically active well beyond surface melt cessation, and emphasize the weakly connected system as the driver of large-scale seasonal ice flow changes.

Ice-marginal lakes are increasingly common around Greenland and are important for modulating glacier runoff and dynamics. This study investigates the evolution of a ~3 km2 and up to ~100 m deep ice-dammed lake at Isunnguata Sermia, West Greenland. Satellite observations between 1987 and 2024, and field observations of a 2023 drainage using passive seismics, GNSS and time-lapse imagery reveal that the lake drains subglacially and has undergone 12 fill-drain cycles since 1987, a drainage periodicity of 1-3 years. Peak lake volume has decreased since 2010, associated with glacier thinning. Lake drainage can perturb the wider subglacial hydrology system, including triggering the release of stored subglacial water along the flood path in 2019. During the extreme melt year of 2012, the lake drained but did not refill, suggesting that subglacial leakage under the ice dam was sustained by record runoff. Transient ice flow acceleration was observed during the late season drainage in 2023 when the subglacial hydrological system was less efficient and therefore more easily overwhelmed. Our results indicate that ice-dammed lake fill-drain cycles, and the downstream impact on subglacial hydrology and ice dynamics, are modulated by ice dam thickness, melt supply and the antecedent subglacial hydraulic capacity.

In mountainous regions, risk mitigation requires an understanding of sediment-transport processes. We present new experiments conducted on a steep slope (33%) to study the transition from bedload to debris flow. The flume design was adapted to mimic alpine streams: instead of studying the mobility of a channel bed composed of uniform-sediments, we generate pulses of sediment by injecting water over a self-formed deposit of poorly sorted mixtures located at the flume entrance. The setup comprises ultrasonic sensors measuring the height of the water-sediment mixture and a force sensor measuring normal and tangential forces exerted on the bed. The experiments show that the highest discharges generate bedload. At lower discharges, mass failure of the deposit generates two regimes: a "static-dynamic" regime, where a granular pulse propagates without a clear water phase, and a "full-dynamic" regime, where concentrated pulses are driven by water flows. In both regimes, pulses are vertically and longitudinally sorted: the front contains coarse particles, the tail contains finer particles, and the body a mix, with coarser particles concentrated near the surface. Force analysis shows that, in the static-dynamic regime, mobility is governed by resistance at the front and thrust from body weight. In the full-dynamic regime, weight alone cannot explain the observed stresses, suggesting roles for additional factors, such as non-hydrostatic water pressure, acceleration, and vertical transfers. In both regimes, front resistance controls pulse mobility. Basal friction coefficient () analysis further shows that the transition to bedload occurs at the threshold discharge required to mobilize coarse particles alone in the channel.

Accelerating mass loss from the Greenland Ice Sheet is affected by meltwater-driven changes in ice dynamics, which remain poorly understood due to limited observations. Here, we present a 2.5 km2 wide dense passive seismic array experiment conducted in the ablation zone of Isunnguata Sermia, West Greenland. We target varying surface melt conditions through one-month long monitoring periods in spring, summer, and fall using 82-117 nodes deployed in 2023 and 2024 complemented by multi-week surface Distributed Acoustic Sensing acquisitions in 2024. We assess data quality using power spectral densities and noise correlation functions. We find that low-frequency seismic power is highly correlated to ice surface velocity, suggesting a strong control of subglacial hydrology on ice dynamics. We retrieve stable and high signal-to-noise ratio noise correlations containing Rayleigh, Love, and P wave arrivals, suggesting these may successfully be used for glacier structure imaging and monitoring. We finally demonstrate we can locate numerous seismic events with resolution down to a few meters using Matched Field Processing and which exhibit characteristic spatial patterns evolving across seasons. These findings establish the potential of such experiment to infer glacier hydrology, dynamics, and structure at high spatial and temporal resolution.

Ice is a polycrystalline material whose microstructure can induce strong viscoplastic anisotropy. Ice fabric (i.e preferred crystal orientations) and ice flow are closely linked: strong anisotropy of a polycristal develops as a result of its deformation history. Strong fabrics have indeed been observed both in nature and in laboratory experiments. In a glacier flow, such anisotropy can modify the directional viscosity of ice, making it locally harder or softer. Preferred crystal orientations may therefore influence glacier flow at large scale.To better characterize this influence, several models have been developed to predict fabric evolution coupled with glacier flow. However, the impact of fabric under near-melting temperature remains poorly quantified. In such conditions, dynamic recrystallization (DRX) is expected to strongly affect fabric evolution. Moreover, field observations that could constrain and validate fabric-evolution models in warm and highly dynamic flow are still scarce, leaving the role of ice textures in glacier dynamics unconstrained. As a result most large-scale glacier simulations still rely on isotropic rheologies combined with enhancement factors, which cannot adequately represent local anisotropy induced by evolving fabrics.R3iCe [1] is a full-field model using a finite element method that couples both the mechanical behavior and the texture evolution of polycrystalline ice. It was recently developed to predict the evolution of crystal orientations under constant strain rate or deviatoric stress, driven by viscoplastic deformation and dynamic recrystallization. R3iCe has been validated against different laboratory creep experiments, where it successfully reproduces both texture evolution and the associated mechanical softening during tertiary creep. However, the model remains untested under more complex deformation cases, such as those experienced by ice particles within real glacier flows.In this contribution, we extend the validated R3iCe model toward glacier-scale applications by constructing a R3iCe Flow Line (RFL) approach. It extracts the deformation history of Lagrangian ice parcels from large-scale glacier flow simulations, such as Elmer/ice, and provides the kinematic inputs required to drive R3iCe along glacier flow lines. The scheme is first validated using torsion experiments, which allow us to quantify the errors involved in predicting fabric evolution along a flow line in this controlled setting.R3iCe Flow Line is then applied to Argentière Glacier (French Alps), which is a temperate glacier. Near-surface samples collected in the ablation area are assumed to represent end-of-flow line fabrics, and are compared with RFL predictions driven by a transient Elmer/Ice flow simulation.By combining R3iCe Flow Line, a state-of-the-art Elmer/Ice simulation of Argentière Glacier flow, and field observations, this work aims to demonstrate the importance of accounting for fabric and its evolution under temperate, highly deforming conditions, where DRX is at play.[1] T.Chauve; M. Montagnat; V. Dansereau; P. Saramito; K. Fourteau; A. Tommasi. Comptes Rendus. Mécanique, Volume 352 (2024), pp. 99-134. doi: 10.5802/crmeca.243

Subglacial hydrology controls basal sliding of hard-bedded glaciers by modulating basal drag through changes in ice-bed separation. Yet, the underlying mechanisms that control ice-bed separation and its links with basal friction remain poorly understood. In this study, we contribute to a better understanding of this problem by evaluating spatial and temporal changes in bed separation in relation to changes in glacier horizontal velocity using three years of continuous and dense GPS records from Glacier d'Argenti & egrave;re (French Alps). We confirm a previous study showing that spatial and temporal variations in glacier vertical motion mainly reflect changes in ice-bed separation, as they cannot be explained by variations in internal strain rates. We find that the rate of uplift is in anti-phase with subglacial water discharge, being positive in winter in the absence of surface melt and negative during summer melt. We suggest that this behavior results from basal cavities being weakly connected in winter, allowing them to fill slowly under low water input from englacial storage release or basal melt, and then rapidly transitioning to a connected state in summer, enabling efficient drainage of surface meltwater and reduced cavity sizes. A key finding is that changes in horizontal velocity are well correlated, both in time and space, with changes in ice-bed separation. This results in an increase in horizontal velocity in winter that can be quantitatively compared with modeled values related to subsequent variations in basal cavity size. This contrasts strongly with previous observations in steeper parts of Glacier d'Argenti & egrave;re, where velocities were found to decrease consistently in winter and where it was argued that seasonal motion was primarily controlled by cavities being connected year-round. We discuss the potential mechanisms underlying these discrepancies and how they may also explain observations of seasonal glacier dynamics in Greenland.

Abstract. As they reach the ocean, Antarctic outlet glaciers transition from grounded to floating at their so-called grounding lines (GL). This transition is known to be mechanically controlled by tides, which induce ice flexure visible at the surface from satellite and ground geodesy and often used as a proxy for grounding line position. Here, we use a dense seismic node array to study the spatial and temporal dynamics of surface, crevasse-induced icequake activity and basal, sliding-induced seismicity at the grounding zone of the Astrolabe Glacier, a fast-moving outlet glacier in East Antarctica. We observe that surface icequakes mimic the expected, tide-induced, ice flexure pattern, as they delineate the grounding line position inferred from previous geodetic studies, and migrate landward as tides rise. We show, however, that the mechanical grounded to floating transition is better evidenced by the spatial distribution of basal sliding-induced stick-slip events, occurring on a limited number of clusters and which depict a grounding line position that is offset inland compared to that identified from the surface. These basal events undergo tidally-driven cycles of activation and de-activation, consistent with sea water intrusion inland over at least 3 kilometers at high tides. Following these results, we propose that the monitoring of stick-slip events could be used as the most accurate means of tracking grounding line retreat over long timescales.

The subglacial hydraulic system strongly modulates glacier motion, yet the links between subglacial water flow, basal pressure, and short-lived drainage reorganization remain difficult to observe directly. Seismology can track seismic power generated by turbulent subglacial water flow, known as glaciohydraulic tremor (GHT). At Rhône Glacier, Switzerland, previous observations documented periods of GHT quieting around stick-slip tremor during elevated basal water pressure, but the physical origin of this quieting remained incompletely understood. Here, we combine seismic power analysis, matched-field processing, borehole water pressure measurements, surface velocity, runoff, and hydraulic-potential routing to investigate the origin of GHT quieting. The quieting is strongest in the 10–20 Hz band and recurs across stick-slip episodes, whereas the 6–8 Hz band shows a weaker response. Matched-field processing shows that coherent GHT sources persist during quieting near an inferred subglacial drainage pathway, suggesting reduced hydraulic–seismic coupling rather than disappearance of the hydraulic source. Physics-based hydraulic calculations show that near-complete filling of broad, low-aspect-ratio conduits can increase wetted perimeter and frictional resistance, producing modeled local discharge reductions of ∼20–28% and seismic-power decreases of ∼1.2–1.8 dB. We interpret GHT quieting as a seismic signature of transient drainage reorganization during rising basal water pressure. Our results suggest that localized, transiently flow-limiting drainage elements can redistribute water across the wider subglacial drainage system, modulating basal water pressure and glacier motion well beyond the element itself. More broadly, cryoseismic observations can help identify shortlived changes in drainage-system state, hydraulic resistance, and ice–water coupling beneath glaciers.

Abstract The evolution and connectivity of subglacial drainage systems control basal sliding and therefore modulate ice motion, yet direct observations of these systems remain limited. Here, we investigate hydraulic connectivity and its influence on ice motion at Isunnguata Sermia, a large land‐terminating outlet glacier of the Greenland Ice Sheet. We use “Cryoegg” wireless sensors to obtain moulin water pressure and electrical conductivity, in conjunction with passive seismics to measure glacio‐hydraulic tremor and GNSS‐derived measurements of ice motion. We identify rapid switching (<24 hr) of subglacial hydraulic connectivity between distinct subsystems: a large, primary drainage axis located in a deep trough, and secondary subglacial channels. When surface melt inputs are high, the secondary subsystem fed by the instrumented moulins connects with the efficient primary drainage axis and exhibits smoothed diurnal variability and synchronization with regional ice motion and seismic tremor. When surface melt decreases, hydraulic connectivity is reduced, and the secondary subsystem becomes disconnected and responds sensitively to variations in local melt inputs, increasing local meltwater residence time. Regional ice motion is controlled by the characteristics of the primary drainage axis and is insensitive to local inputs into the secondary subsystem.

Slip at the ice-bed interface (basal motion) dominates the flow of many glaciers, and it is uncertain whether this velocity component will increase or slow in a warmer world. Past results from an idealized flowline glacier model show that declining basal motion induces a two-phase response that initially accelerates glacier retreat in a warming climate on a multidecadal timescale but lessens centennial-scale retreat and mass loss. In the present work, we utilize existing field-collected and remotely-sensed constraints on ice thickness, ice surface velocity, and the change in each of these terms to constrain the current rate of basal motion and its change over the past ~40 years. We focus on the ~1500 global glaciers with higher density of field-based ice thickness measurements in the GlaThiDa dataset (>18 measurements points per glacier). Utilizing these ice thickness and surface velocity constraints, we employ a flow model to estimate the rate of basal motion as the residual between observed surface velocity and modeled ice deformation. We first estimate the contribution of varying basal motion to observed changes in surface velocity across the study glaciers. We then estimate these glaciers’ retreat and thinning responses to changing velocity and compare these with the magnitudes expected from atmospheric warming, constrained by published point measurements, mass balance models, and snowline observations. These results will constrain the extent to which evolving ice dynamics have amplified or mitigated the response of global glaciers to climate change over past decades. Further, this knowledge will provide insight into the potential importance of varying basal motion on projections of future glacier change, with implications for global sea level rise as well as local water resource and ecosystem management.

Abstract. Natural glacier ice is not a monophasic, isotropic material as commonly assumed in models based on Glen-Nye's flow law. It can contain crevasses, develop crystallographic preferred orientations, and include mixtures of debris and interstitial water in temperate glaciers. Understanding the influence of such structural heterogeneities on deformation is therefore essential for accurately modeling glacier dynamics. In this study, we investigate the multi-scale evolution of structural heterogeneities with depth in the Planpincieux Glacier (Italian Mont Blanc massif) and evaluate their respective influence on ice deformation using a borehole instrumented with an optical televiewer, a full-waveform sonic logger, a piezometer, and an inclinometer chain. Complementary GNSS and seismic data provide additional constraints on hydrological activity and surface motion. Optical and sonic logging reveal two main families of heterogeneities: open and closed crevasses in the upper 60 m, and debris-rich layers near the bedrock interface. Acoustic data show continuous but opposite trends in both P- and Stoneley-wave velocities with depth, interpreted as reflecting an increase in water content but a decrease in permeability. Tiltmeter measurements indicate that roughly one-third of the surface velocity is accommodated by internal deformation, with pronounced strain localization near the bedrock, particularly within debris-rich layers. These layers exhibit enhanced strain following hydrological drainage events, suggesting a coupling between mechanical heterogeneity, basal hydrology, and strain localization. The results highlight that glacier friction laws may be significantly influenced by such heterogeneities, including the effects of interstitial water and debris on local mechanical behavior.

Morphological changes in alluvial rivers are very active and remain very complex to predict because of the high spatio-temporal variability of bedload. This strongly limits the ability of river managers to assess risk or conduct ecological restoration. With the recent development of non-intrusive methods to monitor bedload, such as seismic or acoustic tools, acquisition of data has been highly facilitated compared to direct measurement methods involving in-situ sampling. The challenging task remains in the interpretation of the signals during phases of intense bedload transport which are responsible for major morphological changes. The analysis of such signals requires a good understanding of the underlying physics as well as in-situ field observations to confort interpretation. In this work, we combine seismic with timelapse camera observations with the objective to have a better understanding of bedload behavior and its consequences on the morphology during floods on an alluvial reach of the Severaisse river in the French Alps. Data consists in 3 seismic sensors continuously recording at 200Hz from upstream to downstream along the reach, as well as data from 2 cameras taking timelapse photos of the reach at a 10 min interval during flood. We We find that high frequency seismic power, attributed to bedload, exhibits a characteristic scaling relationship against discharge, materialized by two different phases: a scaling of about 5 from above the threshold of motion (around 12m3/s water discharge) up to a critical discharge of 25 m3/s, and a scaling of about 1.4 above 25 m3/s. We interpret the first scaling to be due to bedload occurring in a diluted regime as described in previous models, and the second scaling to be due to bedload in an intense transport phase. This shift only occur during floods where we observe channel shifting or important re-working of the bed and we suppose that it represents a phase of intense transport responsible for morphological changes. Interestingly, for the most extreme flood with a return period of 50-years, the seismic power versus discharge relationship shows a distinct behavior form the other floods, materialized by a particularly larger and singular hysteresis. Next steps include understanding why this distinct signature occurs, quantify the morphological changes by calculating indexes from image analysis and investigate how bedload and hence the morphological changes depends on the season, characterized by a snow-melting spring and summer and rainy autumn and winter through a multi-year scale.

The state and evolution of subglacial channels strongly impact glacier motion and as a result the mass balance of flowing ice bodies. Yet, the subglacial environment is difficult to access and thus often poorly constrained over significant temporal and spatial scales. This limits our understanding of complex subglacial hydraulic processes and consequently ice dynamics. Seismology can help overcome these observational constraints, providing new insights into fundamental processes in the cryosphere, such as frictional sliding and subglacial water flow. However, different seismogenic processes of the cryosphere often overlap in both time and space. Differentiating between them and interpreting associated seismic signals require appropriate methodological and instrumental approaches. Here, we investigate subglacial channel dynamics at the Rhone glacier (Switzerland) over one month in the summer of 2020, focusing on periods coinciding with glacier sliding episodes. To this end, we leverage the sensitivity of near-bed borehole geophones combined with seismic interferometry and beamforming techniques. We show that the hydraulic tremor, generated by turbulent water flow and resulting pressure variations acting against the subglacial channel bed and walls, acts as a dominant, stable, and coherent noise source. Beamforming analysis reveals the directional stability of the hydraulic tremor and points toward the junction of two subglacial hydraulic channels from which stick-slip asperities originate. The analysis also reveals instances of sudden hydraulic tremor quieting, in agreement with previous observations before and after seismogenic sliding episodes. We explain this quieting as sudden changes in frictional conditions within the subglacial channel corresponding to a rapid transition between a fully and partially filled channel. We discuss channel properties (geometry and bed conditions) that are needed to satisfy the physical conditions for the frictional quieting mechanism. Our analysis offers new insights into the complex mechanical interactions between ice, water, and bed properties and the hydraulic control of glacier sliding.

Accurate knowledge of glacier bed topography is critical for quantifying ice volumes and modelling ice and subglacial hydrology dynamics. Bed topography observations are traditionally obtained from airborne and ice penetrating radar, which offers the crucial advantage of recovering the detailed glacier structure over a range of scales. A main difficulty with radar, however, is that waves can be strongly scattered and attenuated by englacial heterogeneities, in particular by water inclusions, which can potentially limit the applicability of the technique under certain conditions. Here we present a case study on Isunguata Sermia, West Greenland, where we conducted an ice penetrating radar survey together with dense seismic array acquisitions from 87 nodes spread over a 1 km2 area. We show that, in the area of investigation, radar observations were only partially successful in identifying the ice-bed interface, likely due to the thick warm ice, presence of some surface water and near-surfacing crevassing and other englacial structures. The H/V analysis performed over the seismic array yielded surprisingly coherent estimates of ice thickness, along with its spatial variation along and across the glacier. These findings raise questions about the interpretation of traditional radar measurements under certain glacier conditions, and how dense seismic arrays could retrieve bed topography more systematically.

The field of fluvial seismology has undergone significant advances over the past decade. The development of dedicated physical theories and their applications in various contexts have allowed separating the respective contributions of turbulent flow and bedload transport, such that physical parameters like flow depth and sediment flux may be inferred from seismic observations. However, the quantitative link between signal characteristics (amplitude, frequency) and the underlying physics yet involves simplified considerations that do not necessarily apply to more complex situations, such as for example under rough flow conditions or during extreme floods. In this talk I will present results from laboratory experiments that we designed specifically in order to quantify the seismic signature of flow turbulence and intense bedload transport under a range of conditions using force sensors coupled to the river bed. On one hand, I will show that existing theory regarding turbulent flow properly captures the main characteristics of the seismic source, but that additional dependencies on flow conditions and particle-wake development need to be included for more accurate predictions. On the other hand, I will show that existing theory regarding bedload transport fails at capturing the main characteristics of the seismic source under intense bedload transport conditions associated with complex changes in internal flow dynamics. In this case the seismic source appears to be a decreased function of solid concentration, as opposed to an increased function such as considered in current theories, which we suggest is due to grain impacts being agitation-controlled rather than bed-roughness controlled. Finally, I will discuss possible ways towards building more generic theories of ground motion induced by sediment transport.

Glacier internal deformation is usually described by Glen's flow law using two material parameters: the creep factor (A) and the flow law exponent (n). However, the values of these parameters and their spatial and temporal variability are rather uncertain due to the difficulty in quantifying internal strain and stress fields at natural scales. In this study, we combine 1-year-long continuous measurements of borehole inclinometry and surface velocity with three-dimensional full-Stokes ice flow modeling to infer ice rheologies and sliding velocities for the ablation zone of the Argentière Glacier, a temperate glacier in the French Alps. We demonstrate that the observed deformation rate profile has limited sensitivity to the flow law exponent (n) and instead mainly reflects an increase in the creep factor (A) with depth, with A departing from its surface value by up to a factor of 2.5 below 160 m depth. We interpret this creep factor enhancement as an effect of increasing interstitial water content with depth (from 0 % to 1.3 %), which results in an average value of A=148 MPa−3 a−1. We further observe that internal ice deformation exhibits seasonal variability similar to that concerning surface velocity, indicating that the local basal sliding velocity exhibits no significant seasonal variation. We suggest that these changes in deformation rate are due to variations in the stress field, driven by contrasting changes in subglacial hydrology conditions between the sides and center of the glacier. Our study provides further evidence that borehole inclinometry, combined with full-Stokes flow modeling, allows for the constraining of both ice rheology and basal friction at scales that cannot be inferred from surface velocity measurements alone.

Sediment transport is a key process that strongly influences river morphology but remains difficult to measure and understand, especially during floods in mountainous regions. The paper aims to detect and interpret changes in bedload transport regimes during high‐magnitude flood events in an Alpine braided reach (La Séveraisse, French Alps) using continuous seismic monitoring. For the seven investigated floods identified over the 5 years of record, we observe a consistent break in the scaling relationship between the low‐frequency seismic power and the high‐frequency seismic power, suggesting a change in bedload transport regime linked to sediment mobility. Using time‐lapse cameras and hydrological conditions, we find this breakpoint is associated with significant morphological changes occurring at Shields stress ratios approaching a critical value of 2. Based on these results and existing literature, we suggest the break in seismic power corresponds to a transition in bedload regime associated with the disruption of the bed armour layer and particle dynamics being highly influenced by grain–grain interactions. This study demonstrates that changes in sediment transport regime can be accurately identified from seismic observations near rivers, furthering our understanding of the links between sediment transport and channel morphology dynamics.