Daniel Melnick

The M9.5 1960 Chile earthquake, the largest instrumentally recorded, caused over 2 m of coseismic subsidence in the Valdivia estuary, converting fluvial terraces into open water and, later, tidal marshes. We quantify the decadal‐scale post‐seismic recovery of these estuarine wetlands using historical aerial photography, Landsat/Sentinel imagery, GNSS‐derived vertical land motion, tide‐gauge and satellite altimetry sea‐level records, and dated sediment cores. Open water area expanded ∼8.8‐fold after the earthquake and has since contracted from ∼94 km ² in 1985 to 61 km ² in 2024, following a strongly linear trend ( r = −0.97) implying recovery to the pre‐earthquake fluvial extent by ∼2056. Interseismic uplift across the estuary (6.2–9.5 mm/yr) currently exceeds regional absolute sea‐level rise (∼2.3 mm/yr), producing a falling relative sea level that correlates strongly with vegetation expansion across tributary basins, indicating tectonic vertical land motion, rather than climate forcing, dominates wetland recovery at this timescale. Sediment accretion rates increase after subsidence and then decrease from subtidal to intertidal facies, reflecting the open water‐to‐marsh transition during interseismic emergence. A Monte Carlo projection combining vertical land motion, accretion, and IPCC sea‐level scenarios estimates the estuary will return to supratidal elevations by a median year of 2063 (5%–95% range 2047–2099), with coseismic subsidence magnitude and sea‐level rise dominating the uncertainty. These findings underscore the need to account for seismic‐cycle vertical land motion alongside climate‐driven sea‐level rise when assessing the long‐term resilience and carbon‐storage capacity of coastal wetlands in tectonically active subduction zones.

Uplifted Pleistocene marine terraces in the Illapel area along the forearc of central Chile record spatially and temporally variable uplift rates on glacial‐cycle timescales. However, the underlying mechanisms for this uplift variability and its potential relationship with the megathrust‐earthquake cycle remain poorly understood. The Illapel region was affected by the 2015 M _W 8.3 Illapel earthquake and provides an opportunity to assess the relationship between the megathrust seismic cycle and permanent coastal uplift. We combined mapping of late Pleistocene marine terraces along 300 km of coast with stratigraphic and sedimentological analyses, luminescence dating, morphometry, and numerical modeling to constrain the timing and rates of deformation. Our results reveal modest uplift rates of 0.1–0.2 m/ka during Marine Isotope stages (MIS) 9 and 5e that were superseded by rates between 0.5 and 0.9 m/ka during MIS 7, lasting for about 200 ka. The lack of a correlation between terrace‐uplift rates and GPS velocities at the decadal scale suggests that permanent forearc deformation is unrelated to the coseismic and interseismic phases of the Illapel earthquake cycle. We also discard the influence of upper‐plate normal faulting on patterns of surface deformation, as our dislocation modes suggest that it plays a secondary role. Instead, we propose that the short period of uplift acceleration was linked with changes in the margin boundary conditions caused by subduction of bathymetric anomalies from adjacent sea‐mount chains. These results highlight the complexity of mechanisms controlling forearc deformation and the hidden dynamics of deep processes in subduction systems.

Coseismic uplift along convergent margins drives rapid coastal progradation, yet its short-term morpho-stratigraphic response remains poorly documented at human timescales. Here we integrate four complementary high-resolution proxies: satellite-derived shorelines, multi-temporal mapping of the seaward dune vegetation line (SVDL), ground-penetrating radar stratigraphy, and UAV–LiDAR topographic surveys to reconstruct 15 years of post-seismic coastal evolution at Laraquete–Horcones Beach following the 2010 Mw 8.8 Maule earthquake. Pre-seismic records confirm a sediment-starved coast lacking long-term progradation. The earthquake produced an instantaneous shoreline advance of 25 ± 4.9 m, followed by sustained post-seismic SVDL progradation of 45–48 m. This distance closely matches the mean inter-ridge spacing of the adjacent Holocene Laraquete–Carampangue strandplain (48.9 m). GPR data reveal a replicable prograding beach–berm stratigraphic succession (PBF→BBF), locally capped by an aeolian drape, with abrupt landward signal attenuation indicating rapid coastal abandonment and subaerial stabilization. By integrating short-term morphodynamics with subsurface stratigraphy, these results provide the first multi-proxy observational evidence consistent with repeated coseismic uplift driving Holocene strandplain construction along sediment-limited convergent margins, supporting this mechanism as a first-order control in sediment-starved convergent settings. Coseismic uplift thus functions as a recurring tectonic buffer, temporarily offsetting sediment deficits and interseismic subsidence, with implications for coastal resilience under sea-level rise.

Jara‐Muñoz et al. (2024), https://doi.org/10.1029/2024gc011541 , presented a new reconstruction of the lake level for the transition between paleolake Lisan and the Dead Sea, which prompted further discussion by Torfstein et al. (2025), https://doi.org/10.1029/2024gc011972 . We appreciate their interest in our work, although their critique partly relies on inaccurate statements and methodological misconceptions regarding our approach. Our study reconstructs past lake levels using lake‐level index points derived from dated stromatolites and surveyed paleoshorelines corrected for ground deformation. It thus appears that these methodological details may not have been fully considered in their evaluation. Contrary to their claim, earlier data sets were not ignored by us but compared based on a critical assessment. Our systematic approach requires index points with well‐constrained vertical and temporal uncertainties, a condition often not achieved in earlier data sets of lake level histories. While facies data remain important for interpreting lake dynamics, these cannot serve as index points in our reconstruction framework. Based on 89 radiocarbon and U‐series ages, our reconstruction constrains the Lisan highstand to 30–28.5 ka, approximately 5 ka earlier than previously estimated. This discrepancy does not arise from omission but from improved handling of uncertainties and tectonic corrections. The U‐Th dating bias alleged by Torfstein et al. (2025), https://doi.org/10.1029/2024gc011972 , to be caused by acid leaching seems to stem from a misunderstanding of our methods. In light of the careful data collection and analysis, our reconstruction remains internally consistent, statistically robust, and fully reproducible, qualities we hope will guide future discussions toward data‐based observations.

Wave-abrasion terraces are geomorphic marker horizons that provide information of past water levels, in marine and lacustrine environments. By integrating elevation measurements and age constraints, they serve as strain markers to assess vertical deformation rates associated with tectonic and/or climatic processes. As most geomorphic markers, wave-abrasion terraces are ephemeral features, and their topographic signature has variable levels of noise. Therefore, accurate and precise estimates of marine terrace morphology are essential to obtain significant uplift/subsidence rates. The open source TerraceM-3 enables operators to reduce non-systematic and systematic errors in terrace mapping by integrating machine learning techniques to replicate human mapping criteria, and standardized and reproducible workflows to handle systematic errors. In many regions, the availability of high-resolution topographic data remains relatively scarce limiting precision in geomorphic marker mapping. TerraceM-3 introduces a new module for downloading, filtering, and processing centimeter-resolution topographic data from the ICESat-2 satellite at global scale. The TerraceM-ICESat module produces vegetation-free profiles ready for assisted machine-learning mapping into a graphical user interface. Shallow bathymetry may be also extracted to extend the mapping of drowned terraces offshore. The new functionalities of TerraceM-3 were tested along tectonically active coasts in Peru and Algeria, revealing detailed deformation histories controlled by subducted seamounts and crustal faults. TerraceM-3 is designed to support research in tectonic geomorphology and paleoclimate studies by enhancing the precision and accuracy of wave-abrasion terrace mapping with applications in the assessment of coastal hazards.

The southern Central Andes forearc preserves extensive low-relief wave-cut platforms and fluvial terraces that record long-term margin uplift, yet the timing and driving mechanisms are still debated. Here we present eleven new in situ ¹⁰Be exposure ages from high fluvial terraces and four ages from a lower terrace, combined with geomorphic analyses across eight adjacent catchments, to reassess the age and tectonic significance of the degradational surfaces (pediplain) present between 29.5 and 32.5°S. Erosion-corrected exposure ages indicate that the high terrace formed during the Early Pleistocene, while a lower terrace records incision at Middle Pleistocene. Longitudinal terrace–channel profiles reveal systematically increasing relief toward the coast that terminates near the surface projection of the 50–60 km slab-depth contour, coincident with the downdip limit of megathrust domain-C earthquakes. This spatial relationship supports a regionally coherent uplift signal produced by the cumulative effect of deep coseismic deformation. In peninsular settings, notably the Altos de Talinay, this long-wavelength signal is overprinted by short-wavelength uplift consistent with localized underplating. Our results demonstrate that the high fluvial terraces and the shore wave-cut platform constitute a single, regionally continuous geomorphic marker recording an Early Pleistocene forearc uplift phase extending from ~16° to 42°S. This orogen-scale emergence implies a subtle but widespread change in subduction dynamics during the last Early Pleistocene, the causes of which are not clearly understood.

The landscape evolution of forearc ranges along accretionary convergent margins, such as the southern Chilean Coastal Cordillera, is strongly influenced by deep-seated accretion dynamics, enhancing reactivation of inherited upper-plate structures. The Nahuelbuta Range is the fastest uplifting and exhuming sector of the southern Chilean subduction margin. Stratigraphic markers and uplifted marine terraces indicate dome-shaped uplift across a ~100-km-wide zone since ~2 Ma. However, uplift mechanisms remain debated, and rates are resolved only for the last ~0.3 Myr. Furthermore, dense vegetation and weathering have hindered fault mapping, limiting the understanding of the Nahuelbuta Range deformational history.We combined new surface geomorphic mapping, morphometric drainage analysis, and river inversion modeling to explore the tectonic and climatic influences on the Nahuelbuta Range landscape evolution. We identify a regional low-relief relic surface atop the Nahuelbuta Range, now warped and dissected by fluvial incision and faults. Drainage morphometric anomalies and microseismicity align with WSW- and ENE-trending faults, indicating ongoing trench-parallel shortening. River inversion analysis shows uplift and topographic rejuvenation between 3 and 2.5 Ma approximately, followed by two later discrete uplift episodes. Uplift transients correlate with Late Pliocene to Pleistocene Patagonian glacial expansion periods, suggesting that glacially intensified sediment flux to the trench enhanced basal accretion of sedimentary material. The location and wavelength of surface uplift events match depth and scale expected for slices of basal acreeted material. Seismic imaging of the sediment-rich subduction channel and microseismicity patterns supports this interpretation. We propose glacially driven tectonic underplating drives the oscillatory uplift history of the Nahuelbuta Range, while ongoing trench-parallel shortening enhance trench-parallel shortening and fault reactivation.

Wave-abrasion terraces are geomorphic marker horizons that provide information of past water levels, in marine and lacustrine environments. By integrating elevation measurements and age knowledge they serve as strain markers to assess vertical deformation rates associated with tectonic and/or climatic processes. As most geomorphic markers, wave-abrasion terraces are ephemeral features, and their topographic signature has variable levels of noise. Therefore, accurate and precise estimates of marine terrace morphology are essential to obtain significant uplift/subsidence rates. TerraceM-3 enables users to reduce non-systematic and systematic errors in terrace mapping by integrating machine learning techniques to replicate human mapping criteria, and standardized and reproducible workflows to handle systematic errors. In many regions, the availability of high-resolution topographic data remains relatively scarce limiting precision in geomorphic marker mapping. TerraceM-3 introduces a new module for downloading, filtering, and processing centimeter-resolution topographic data from the ICESat-2 satellite at global scale. The TerraceM-ICESat module produces vegetation-free profiles ready for assisted machine-learning mapping into a graphical user interface. Shallow bathymetry may be also extracted to extend the mapping of drowned terraces offshore. The new functionalities of TerraceM-3 were tested along tectonically active coasts in Peru and Algeria, revealing detailed deformation histories controlled by subducted seamounts and crustal faults. TerraceM-3 is designed to support research in tectonic geomorphology and paleoclimate studies by enhancing the precision and accuracy of wave-abrasion terrace mapping with applications in the assessment of coastal hazards.