Preprints
Filtering by Subject: Geomorphology
Topology-Aware Quality Control of Triangulated Terrain Models Using Local Euler Curvature and Elevation-Filtration Curves
Published: 2026-09-19
Subjects: Earth Sciences, Environmental Sciences, Geomorphology, Mathematics, Physical Sciences and Mathematics
Triangulated irregular networks (TINs) are widely used to represent topography and bathymetry, but their quali-ty control is usually dominated by geometric criteria such as minimum angle and aspect ratio, which do not test whether connectivity errors have changed the topology of the mesh. We present a topology-aware quali-ty-control framework based on a local Euler-curvature identity and on [...]
Was the Pre-Event SWIR Anomaly at Tsangbu Ri a Genuine Glacier-Collapse Precursor? A Calibrated Multi-Glacier Test of the 2026 Case
Published: 2026-09-19
Subjects: Applied Statistics, Geographic Information Sciences, Geology, Geomorphology, Glaciology, Hydrology, Planetary Geology, Planetary Glaciology, Remote Sensing, Spatial Science, Tectonics and Structure
On 26 August 2026 a compound bedrock-and-glacier failure on the northern flank of the Langtang Lirung–Tsangbu Ri (Kimshung) massif, Nepal–China border, generated a rock–ice avalanche and a catastrophic downstream flood along the Bhotekoshi–Trishuli river system. A pre-event Sentinel-2 shortwave-infrared (SWIR2–NIR–Red) composite (12 August 2026) shows a sharply bounded, strongly saturated [...]
The single-pair unwrapping ceiling is a property of the track, not of the radar: Sentinel-1 evidence from rock–ice avalanches at Langtang Lirung and Ronti Peak
Published: 2026-09-18
Subjects: Earth Sciences, Geomorphology
This study asks what single-pair satellite data can detect before rock–ice avalanches, such as the Langtang Lirung (Nepal) and Ronti Peak (Chamoli, India) failures. The single-pair line-of-sight limit of 0.42 m yr⁻¹ for 12-day Sentinel-1 pairs is treated as a property of the radar, but the downslope ceiling depends on the track. I measure sensitivity to downslope motion f across Copernicus GLO-30 [...]
Very-high-resolution optical imagery reveals key clues to the Langtang Lirung ice–rock avalanche
Published: 2026-09-14
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Ice–rock avalanches and resulting cascading processes are increasingly recognized to pose an exceptional risk to high-mountain systems. Once initiated, they often transition from dense multiphase mixtures to water-saturated debris flows and even hyper-concentrated floods, thus attaining sufficient runout potential to move from highly remote to populated regions. The event that originated from the [...]
Bounded at both ends: the detection window of routine 12-day C-band InSAR at rock–ice avalanche sources
Published: 2026-09-14
Subjects: Earth Sciences, Geomorphology
A negative result from satellite radar — "no precursory deformation was detected" — carries no information unless the range of signals the measurement could have detected is reported alongside it. We measure that range at two rock–ice avalanche sources, Langtang Lirung, Nepal (2026) and Ronti Peak, India (2021), using a single procedure, and identify four determinants of it that are site-specific [...]
Calibrated detection limits in routine Sentinel-1 products 50.6 hours before the Langtang Lirung rock–ice avalanche, Nepal
Published: 2026-09-09
Subjects: Earth Sciences, Geomorphology
On 26 August 2026 a rock–ice avalanche detached from Langtang Lirung, Nepal, and released a debris flood that crossed the Nepal–China border. Deformation preceding the failure has since been reported from a multi-month Sentinel-1 stack, and pre-event indications have been identified in commercial optical imagery. Both analyses began from a known failure location. This paper asks a different [...]
No detectable precursor in Sentinel-1 backscatter before the 26 August 2026 Langtang Lirung rock–ice avalanche, Nepal
Published: 2026-09-06
Subjects: Earth Sciences, Geomorphology
On 26 August 2026 a rock–ice avalanche on the west flank of Langtang Lirung, Nepal, initiated a debris flow and flood that ran roughly 100 km down the Lhende Khola, Bhote Koshi and Trishuli. Several contemporaneous reports asserted that satellite radar had tracked a month of accelerating slope movement before failure. This note tests that claim in the amplitude record. Using Copernicus Sentinel-1 [...]
Deglacial Mass-Movement Floods as a Potential Source of Catastrophic Flood Traditions: A Testable Geomythological Hypothesis
Published: 2026-09-05
Subjects: Earth Sciences, Geology, Geomorphology, Glaciology, Hydrology
Catastrophic flood traditions occur in many geographically separated cultures, but their possible geological substrates need not be uniform. Existing explanations include river floods, earthquake and volcanic tsunamis, glacial-lake outburst floods, postglacial sea-level rise, and cultural transmission. This paper proposes a complementary, explicitly testable hypothesis: during the terminal [...]
DOUBLE JEOPARDY: Do Coastal Rules Reach the People at Risk? Comparing Five Island Jurisdictions
Published: 2026-09-05
Subjects: Biodiversity, Earth Sciences, Environmental Monitoring, Environmental Sciences, Environmental Studies, Geographic Information Sciences, Geography, Geomorphology, Hydrology, International and Area Studies, Marine Biology, Natural Resource Economics, Nature and Society Relations, Oceanography and Atmospheric Sciences and Meteorology, Other Environmental Sciences, Other Geography, Remote Sensing, Spatial Science, Statistical Methodology, Statistical Models, Sustainability
Low islands face a rising sea at the same time as the reefs and mangroves that shelter them are under stress. I measured both across 5 island groups in 3 ocean basins (Maldives, Lakshadweep, Seychelles, Fiji and the Canary Islands), testing mangroves and coral reefs as separate pathways. Exposure is the share of people (WorldPop 2020) living on land at or below 1 m, on a bare earth elevation [...]
Stolen Strata: Brick Kilns and the Loss of Karewa Tableland in Budgam, Kashmir,1993–2025, with a Correction to an Earlier Estimate
Published: 2026-09-04
Subjects: Agriculture, Biodiversity, Earth Sciences, Environmental Sciences, Environmental Studies, Geographic Information Sciences, Geography, Geomorphology, Nature and Society Relations, Other Geography, Remote Sensing, Spatial Science
Karewa tablelands are the flat-topped, scarp-bounded remnants of the old lake and river deposits of the Kashmir Valley. Reporting from Kashmir has said for years that they are being dug away for brick clay and fill, but I did not find a satellite measurement of how much, where and when. This study asks three questions: how much karewa tableland that was vegetated in 2013–2015 is no longer [...]
A cascade, not a flood: testing the competing accounts of the 26 August 2026 Lhende Khola–Bhote Koshi disaster
Published: 2026-09-02
Subjects: Earth Sciences, Geomorphology, Glaciology, Hydrology, Physical Sciences and Mathematics
On 26 August 2026 a rock–ice mass detached above the Lhende Khola on the China–Nepal border, blocked the channel, and released a flow that travelled about 100 km down the Bhote Koshi and Trishuli, killing hundreds of people and removing about a tenth of Nepal's generating capacity in a single morning. Reporting produced mutually incompatible accounts of the cause, while the agency best placed to [...]
The 26 August 2026 Langtang Lirung ice–rock avalanche and its transboundary cascade: a multi-source observational reconstruction in the Bhote Koshi basin
Published: 2026-08-31
Subjects: Geomorphology, Glaciology, Hydrology
On 26 August 2026, an ice–rock avalanche detached from the northern flank of Langtang Lirung (7,227 m) at about 5,200 m a.s.l., transformed into a debris flow that travelled roughly 22 km in 6–7 minutes, destroyed the Gyirong border port (China) and dammed the river; a flood then propagated a reported ~170 km down the Bhote Koshi–Trishuli–Narayani system into Nepal and India. At least 16 people [...]
Landslide Susceptibility Modelling and Infrastructure Exposure in the Zillertal, Austrian Alps
Published: 2026-08-31
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Physical and Environmental Geography, Spatial Science
Landslides are a major threat in alpine regions, as steep terrain, complex geology and locally concentrated infrastructure increase societal exposure to landslide hazards. This study develops a landslide susceptibility model for the Zillertal (Tyrol, Austria), utilizing a Random Forest modelling approach. A high-resolution landslide susceptibility map was created using seven geomorphometric, [...]
An Open-Source, Data-Driven Interactive Web Framework for 3D Visualization of Geoheritage Sites: A Case Study of the Grand Canyon Arizona, United States
Published: 2026-08-28
Subjects: Computer and Systems Architecture, Geology, Geomorphology
Effective dissemination, public engagement, and educational utilization of prominent geoheritage sites are often hindered by the steep learning curves, high computational requirements, and licensing costs inherent to professional Geographic Information Systems (GIS) and 3D geological modeling software. To bridge this accessibility gap and democratize spatial data, we present a universal, [...]
Desert pavements stabilise arid vegetation patterns
Published: 2026-08-26
Subjects: Desert Ecology, Earth Sciences, Geomorphology
Some vegetation patterns have aridity-dependent morphology. On low-angle arid hillslopes, vegetation organises into bands which follow topographic contours. Terraces emerge with these bands due to vegetation’s drag on sediment-laden runoff, creating a topographic signature of life diagnostic of precipitation rate. Another widespread feature of arid environments is desert pavement, surficial [...]