The West Antarctic Ice Sheet (WAIS) is thinning at an accelerating rate, driven by melting at its margins by warm Circumpolar Deep Water (CDW). However, this understanding is largely based on observations from recent decades, leaving the long-term influence of ocean temperature on WAIS stability uncertain. Here we reconstruct bottom water temperatures and water mass properties over the past 18 kyr using benthic foraminiferal Mg/Ca and δ¹³C records from sediment cores in the Amundsen Sea. Our data indicate that warm CDW occupied the continental shelf between ~ 18.0 and 10.1 kyr BP, coincident with major WAIS retreat from the shelf break to near its present-day grounding-line position along the Marie Byrd Land coast. Bottom waters cooled after ~ 10.1 kyr BP and remained relatively stable thereafter, with no evidence for substantial grounding-line migration. Continued atmospheric warming across West Antarctica until a mid-Holocene thermal maximum (~6-3 kyr BP) without further retreat indicates that ocean heat was the primary driver of WAIS variability since the Last Glacial Maximum.

The study evaluates radar-based quantitative precipitation estimations (QPEs) for 10 extreme rain events that occurred between 2013 and 2019 in the Kansas City metropolitan area, United States. These precipitation estimates were derived at hourly and approximately 0.5-km scales using two polarimetric QPE algorithms one based on specific attenuation (A) and the other on specific differential phase (KDP) for the study area covered by two overlapping radars in Topeka, Kansas, and Kansas City, Missouri. The polarimetric QPE assessment for extreme rain events was motivated by improved flood forecasting and precipitation frequency analysis. The analysis utilizes ground reference observations from a dense network of about 170 rain gauges over the study area to quantitatively assess the accuracy of these polarimetric rainfall (R) estimates. The comparison of R(A) and R(KDP) with the conventional algorithm based on radar reflectivity observations reveals that the two polarimetric algorithms outperform the reflectivity-based approach. While R(KDP) shows a systematic conditional feature (i.e., underestimation at high rain rates) with reduced scatter, R(A) appears to be less biased but with relatively large scatter. The significanct overestimation of R(A) for one of the extreme events was attributed to the misestimation of its key parameter (a), which resulted from hail contaminated data samples. To examine the observed underestimation tendency of R(KDP), we characterized the magnitude of underestimation (bias) with rainfall spatial variability as this variability may account for different rainfall regimes or the smoothing effect of KDP to reduce its inherent noisiness. Our result demonstrates that the underestimation tendency of R(KDP) becomes more pronounced as rainfall spatial variability increases.

Abstract The stability of the West Antarctic Ice Sheet (WAIS) remains a major uncertainty in sea‐level projections, and geologic records provide important constraints on its past behavior. We present 40Ar/39Ar ages of biotite and hornblende grains from iceberg‐rafted debris (IRD) in two Amundsen Sea sediment cores (PC493 and PS58/254), located south and north of the southern boundary of the Antarctic Circumpolar Current (sbACC), respectively. Over the past 850,000 years, PC493 records a stable IRD provenance dominated by eastern Amundsen Sea sources, consistent with transport by the westward‐flowing Antarctic Coastal Current. In contrast, PS58/254 shows temporally variable sources, with southeastern Amundsen Sea inputs during glacials and increased Marie Byrd Land contributions during interglacials, indicating latitudinal sbACC shifts. The absence of East Antarctic IRD is consistent with no open‐marine connection between the Weddell and Amundsen Seas, while abundant <10 Ma grains during Marine Isotope Stages 5, 11, and 15 imply reduced WAIS elevation.

Reconstructing environmental changes near ice margins that have deglaciated since the Last Glacial Maximum (LGM) is essential for understanding future changes of the Antarctic Ice Sheet. Here, we conducted a multiproxy reconstruction of the Holocene environmental history of Cranton Bay, a small, bathymetrically enclosed, biologically productive embayment north of Pine Island Bay in the Amundsen Sea Embayment (ASE), West Antarctica. We present a detailed analysis of sediment core NBP20-02 KC72, which provides a record of environmental changes in the bay. We analyzed sediment grain size, magnetic susceptibility, computed tomography scans, stable carbon isotopes on bulk sediments, total diatom abundance and assemblages, and radiocarbon-dated calcareous benthic foraminifera. Our findings suggest that an ice canopy covered Cranton Bay early in the Holocene, evidenced by low primary productivity. During the mid-Holocene, the bay was seasonally sea-ice covered, as documented by the increase in total diatom abundance and the presence of diatom taxa with sea-ice affinity. The appearance of the offshore diatom Fragilariopsis kerguelensis during the mid-Holocene may suggest the advection of modified Circumpolar Deep Water (mCDW) into Cranton Bay. This implies that mCDW delivery across the ASE during the Holocene was spatially and/or temporally variable, possibly due to boundary conditions (e.g., bathymetry). Primary productivity increased during the latest Holocene, consistent with longer seasonally open-marine conditions. Absolute diatom abundances in Cranton Bay are among the highest within the ASE. Understanding past environments and drivers of glacial retreat since the LGM will help contextualize recent West Antarctic Ice Sheet changes.

Green infrastructure (GI) is increasingly used for managing developed watershed stormwater and GI designs are quickly developing. Performance monitoring data to guide GI design are challenging to collect and sparse, especially for multiple design types within the same study area. Evaluating GI performance with monitoring data can be done in multiple ways, with different managers using different metrics for evaluation. In this study, the year-round field performance of four roadside GI practices (bioretention, grass channel [GC], compost-amended grass channel [CAGC], and bioswale) in Northern Virginia were monitored to investigate the effectiveness of different designs in managing stormwater. Stormwater runoff volumes and 12 water quality parameters (including nutrients, carbon, sediment, and metals) were measured year-round during 27 storm events. Multiple metrics were used to assess GI performance, including effluent concentration, concentration reduction, load reduction, effluent load/contributing drainage area, and load reduced/footprint. The four GI designs displayed widely ranging performance, with three out of four primarily acting as pollutant sinks but one (CAGC) primarily as a pollutant source. Results indicate that GI design differences (e.g., compost amendment) can alter GI performance and evaluation varies based on water quality parameter and evaluation metric used. While regionally relevant individual pollutants of concern and regulations typically incentivize managers to design GI based on a single parameter or metric, the use of multiple parameters and metrics may better optimize overall water quality benefits. GI design guidelines based on multiple performance metrics and robust performance databases will improve stormwater management and help avoid unintended performance.

The Hudson Mountains are situated in the eastern Amundsen Sea sector of the West Antarctic Ice Sheet, adjacent to Pine Island Glacier. They form a volcanic field of 17 stratovolcanoes and parasitic vents, preserved as nunataks. Two former tributaries of Pine Island Glacier (Larter and Lucchitta glaciers) flow through the mountains. Here we present a detailed study of the glacial geology of the area. We describe field observations and measurements of geomorphological features from 15 of the nunataks, meltwater ponds found on the surface of three nunataks and supraglacial features (ice dolines) from two sites near the present grounding line. Together these provide constraints on the past ice sheet extent, flow pathways and thermal regime, and enhance our understanding of the present hydrological regime - all of which are important as context for the observed modern ice sheet behaviour. We find evidence suggesting that all nunataks in the Hudson Mountains were covered by ice during the Last Glacial Maximum (defined here as 26.5-19 ka; Clark et al., 2009) and have since deglaciated. Faceted and polished erratic cobbles and boulders of exotic lithologies (syenites, alkali granites, granites, granodiorites, tonalites and gabbros) are numerous and perched on nunatak surfaces. A marked difference between the dominant erratic lithologies on nunataks adjacent to Pine Island Glacier (granite) and Lucchitta Glacier (granodiorite-tonalite) indicates that the ice sheet was transporting clasts from at least two distinct upstream source regions. The similarity in degree of weathering suggests, however, that all the erratics were transported by one phase of (warm-based) glaciation; their presence on or close to the summits of all except one nunatak indicates that the ice sheet during that time was at least 700 m thicker than present. These results are consistent with ice sheet model simulations which suggest that all nunataks in the Hudson Mountains were completely submerged by the Last Glacial Maximum ice sheet.

A number of studies have defined a boundary in the Amundsen Sea embayment between an inner continental shelf, which contains areas where crystalline bedrock is at or near the seabed, and the shelf further offshore, which is underlain by sedimentary strata that increase in overall thickness oceanward. Other studies have shown that much of the inner shelf in Pine Island Bay is covered by a drape of sandy mud averaging about 1 m in thickness, interpreted as having been deposited from meltwater plumes during the mid-late Holocene. Much thicker sediments have been shown to be present in isolated deep basins based on acoustic sub-bottom profiles and sparse seismic reflection profiles, including an estimated maximum thickness of >400 m in one basin close to the front of Pine Island Glacier. Thus, the widespread impression exists that, apart from the thin Holocene drape, sedimentary cover in Pine Island Bay is restricted to isolated basins.Here we examine the distribution and thickness of sediments in Pine Island Bay using a network of high-resolution seismic reflection profiles collected in 2020 on RV Nathaniel B Palmer cruise NBP20-02. We show that more extensive thick sediments are present near the front of Pine Island Glacier than have been reported previously. In some places sediment units exhibit characteristics that suggest their deposition was influenced by bottom currents. We also show that sedimentary deposits are present over the tops and on the flanks of some bathymetric highs that must have been former ice shelf pinning points. Finally, we consider what the extent, thickness and character of the sedimentary units identified tell us about glacial/glacimarine processes and ice sheet history in the area, and what could be learned by further study and sampling.

For communities without access to uninterrupted, piped water, household water storage (HWS) practices can lead to adverse public health outcomes caused by water degradation and mosquito proliferation. With over 700,000 deaths caused by vector-borne diseases annually, the objective of this study was to determine whether water disinfectants, at concentrations deemed safe for human consumption and beneficial for water treatment, are effective in reducing the emergence of adult mosquitoes that transmit disease. Laboratory bioassays, designed to resemble the context of treating HWS containers, were conducted to assess the larvicidal effects of chemicals at concentrations below regulatory limits for drinking water: silver (20, 40, 80 μg/L Ag), copper (300, 600, 1200 μg/L Cu), and chlorine (500, 1000, 2000 ug/L free chlorine). The water disinfectants demonstrated the ability to significantly reduce the population of juvenile Ae. aegypti. Sodium hypochlorite was found to be the most effective in decreasing the survival rate of late first instar larvae, while silver nitrate exhibited the highest effectiveness in inhibiting the emergence of late third instar larvae. Ultimately, this study highlights the potential of an integrated approach to Water, Sanitation, and Health (WASH) solutions with vector control management.

Abstract Thwaites Glacier is one of the fastest‐changing ice‐ocean systems in Antarctica. Basal melting beneath Thwaites' floating ice shelf, especially around pinning points and at the grounding line, sets the rate of ice loss and Thwaites' contribution to global sea‐level rise. The rate of basal melting is controlled by the transport of heat into and through the ice–ocean boundary layer toward the ice base. Here we present the first turbulence observations from the grounding line of Thwaites Eastern Ice Shelf. We demonstrate that contrary to expectations, the turbulence‐driven vertical flux of heat into the ice–ocean boundary layer is insufficient to sustain the basal melt rate. Instead, most of the heat required must be delivered by lateral fluxes driven by the large‐scale advective circulation. Lateral processes likely dominate beneath the most unstable warm‐cavity ice shelves, and thus must be fully incorporated into parameterizations of ice shelf basal melting.

This paper presents new marine geophysical data and radiocarbon dated sediment cores to reconstruct the maximum extent of the Northeast Greenland Ice Stream (NEGIS) during the last glaciation and the timing of its initial retreat from the continental shelf. The NEGIS is the largest ice stream to drain the Greenland Ice Sheet (GrIS) today, and holds a sea-level equivalent of 1.1-1.4 m. It has undergone recent retreat but the longer-term history of NEGIS on the adjoining continental shelf is still relatively poorly constrained. Two cross-shelf bathymetric troughs, Westwind and Norske troughs, acted as pathways for offshore-flowing ice during the last glaciation but little is known about the acoustic stratigraphy, sedimentology and chronology of ice sheet retreat in the outer shelf sections of both troughs. Multibeam swath bathymetry and acoustic data from both troughs show flow parallel and flow transverse glacial landforms in the outer shelf sections of both troughs. Mega-scale glacial lineations in Westwind Trough record former streaming flow towards the shelf-edge. Grounding-zone wedges record episodic stabilisation during retreat from the shelf-edge. Sediment cores recovered subglacial tills and grounding-zone proximal sediments overlain by glacimarine sediments. The slope beyond Norske Trough is characterised by glacigenic debris flows typical of submarine slopes offshore of shelf-edge terminating palaeo-ice streams. Radiocarbon dates indicate that initial retreat of the ancestral NEGIS from the northeast Greenland shelf-edge was underway by 21.5-21.6 cal ka BP in Norske Trough and c. >= 19.0 cal ka BP in Westwind Trough. Retreat rates across the outer shelf were slow at 19-23 m a-1 but increased across the inner shelf. Our data provides the first direct chronological support for a shelf-edge terminating GrIS offshore of northeast Greenland during the last glacial maximum and demonstrates this sector of the GrIS underwent relatively early retreat from the shelf-edge.

For children in low-resource settings, repeated exposure to enteric pathogens, including through unsafe water, can have long-term effects and is potentially associated with impaired cognitive development. Access to effective, low-cost point-of-use (POU) water treatment technologies may therefore improve cognitive function. A community-based randomized controlled trial of two POU water treatment technologies was conducted in rural Limpopo, South Africa. In total, 404 households with a primary study child younger than 3 years were randomly assigned to one of four groups: 1) a silver-impregnated ceramic filter and a silver-impregnated ceramic tablet group, 2) a silver-impregnated ceramic tablet only group, 3) a safe-storage water container group, or 4) a no-intervention group. Follow-up surveys were conducted every quarter for the following 2 years. Approximately 2 years after the baseline assessment, 236 of the primary study children were evaluated using the Wechsler Preschool and Primary Scale of Intelligence, Third Edition (WPPSI-III) examination to estimate the effects of the water treatment technologies on cognitive function. There was no significant difference found in WPPSI-III composite scores between intervention groups, and the individual presence of enteric pathogens at enrollment, reported diarrhea, and water service level exhibited no associations with WPPSI-III scores after controlling for covariates. However, several sociodemographic variables were significant predictors of cognitive function within the study population. These results are consistent with the lack of significant effects of the interventions on more proximal outcomes, such as enteric infections, diarrhea, and growth stunting, for the same study population, despite significant improvements in microbial water quality.

Campylobacter and Shigella are leading causes of enteric infections, especially in low-resource settings, and are transmitted through contaminated food, milk, and water. Detecting these pathogens in environmental samples and differentiating between viable and nonviable bacteria is critical for understanding their transmission and for risk assessment. This study optimized and evaluated laboratory methods for detecting viable Campylobacter and Shigella in water and raw cow milk using viability polymerase chain reaction (PCR). To optimize sample processing and extraction, seven water concentration methods, two water DNA extraction protocols, eight milk concentration methods, and nine milk DNA extraction protocols were compared. Water and milk were spiked with known amounts of bacteria, concentrated, and then subjected to DNA extraction and quantitative polymerase chain reaction (qPCR). For concentrating milk, centrifugation at 16,000xg for 20 min at room temperature using 1.5-mL samples yielded optimal results, while for water, the concentrating pipette approach was selected. For viability PCR, concentrated samples were treated with propidium monoazide (PMAxx) prior to DNA extraction. The results demonstrated exceptional linearity (0.992 to 0.999) and precision across various concentrations, with detection limits ranging from 3.75x102 to 4.54 CFU/mL for Shigella and 4.67x103 to 9.84x101 CFU/mL for Campylobacter. The assays had a within-run variance from 1.9% to 2.7% (repeatability) and between-run variance from 1.6% to 5.2% (reproducibility). The PMAxx-treated dead bacteria showed delayed cycle threshold (Ct) values compared to the viable bacteria, representing an inhibition of the detection of dead bacterial DNA by approximately 94% in milk and 99.6% in water. Viability PCR was successful in differentiating live from dead bacteria, offering a robust method for tracking the transmission of these pathogens in water and milk. These results support the application of viability PCR for more precise public health interventions.

The Northeast Greenland Ice Stream (NEGIS), the largest ice stream draining the Greenland Ice Sheet (GrIS), is losing mass at an accelerating rate due to atmospheric and ocean-driven melting. Holding the equivalent of 1.1–1.4 metres of sea-level rise, its collapse will have a significant impact on global sea levels making it crucial to understand the controls on its dynamic behaviour. The NEGIS retreated from the continental shelf edge by 21.6 ka BP, with this study confirming continued grounding line retreat to ~100 km from the shelf edge by 20.3 ka BP, earlier than previously reported. This early retreat was driven by warm Return Atlantic Water (RAW) and amplified by a retrograde seabed, which together drove initial grounding line retreat. The presence of a series of grounding zone wedges indicates a quasi-stable grounding line, which was fronted by an ice shelf. Grounding-line retreat took place between 20.3 and 15.2 ka BP. However, ice-shelf break up caused by enhanced sub-ice shelf melt rates driven by RAW ingression, coupled with surface thinning instigated by atmospheric warming during Greenland Interstadial I, triggered rapid retreat of the ice stream after 15.2 ka BP. Our findings confirm the dominant role of oceanic forcing in grounding line stability and ice-shelf break up.

This study evaluates the larvicidal effects of three common water disinfectants, silver (AgNO3), copper (CuSO4·5H2O), and hypochlorite (NaOCl) ions. The treatments were combined at 40–50% of their recommended drinking water guidelines and tested against late first instar and third instar Ae. aegypti larvae. The findings demonstrate that the combined application of water disinfectants yields greater efficacy in suppressing the emergence of Aedes aegypti compared to the use of the individual disinfectants alone. The silver (Ag) and copper (Cu) combination treatment (40 ppb Ag + 600 ppb Cu) showed the greatest efficacy, achieving nearly complete inhibition of emergence of the older instar larvae (98.52% [96.50, 99.47]). All treatments demonstrated high efficacy against late 1st instar Ae. aegypti larvae, with the combined copper and chlorine (Cl) treatment yielding the lowest survival rates, though individual disinfectants also produced substantial mortality. The results of this study provide critical insights to inform the design and implementation of point-of-use water treatment technologies for household water storage containers that both ensure safe drinking water and also strategically target mosquito breeding within household storage containers, thus supporting integrated vector management approaches essential for controlling neglected tropical diseases.

Sedimentary records can illuminate relationships between the climate, topography, and glaciation of West Antarctica by revealing its Cenozoic topographic and paleoenvironmental history. Eocene fluvial drainage patterns have previously been inferred using geochemical provenance data from an ~44– to 34–million year deltaic sandstone recovered from the Amundsen Sea Embayment. One interpretation holds that a low-relief, low-lying West Antarctic landscape supported a >1500-kilometer transcontinental river system. Alternatively, higher-relief topography in central West Antarctica formed a drainage divide between the Ross and Amundsen seas. Here, zircon U-Pb data from Amundsen Sea Embayment sediments are examined alongside known regional bedrock provenance signatures. These analyses suggest that all observed provenance indicators in the Eocene sandstone derive from West Antarctic rocks. This implies that a local river system flowed off a West Antarctic drainage divide, helping constrain the mid-Late Eocene evolution of West Antarctic topography with implications for the history of rifting and the characteristics of sediments infilling interior basins.

Silt-rich meltwater plume deposits (MPDs) analyzed from marine sediment cores have elucidated relationships that are clearly connected, yet difficult to constrain, between subglacial hydrology, ice-marginal landforms, and grounding-zone retreat patterns for several glacial catchments. Few attempts have been made to infer details of subglacial hydrology, such as flow regime, geometry of drainage pathways, and mode(s) of sediment transport through time, from grain-scale characteristics of MPDs. Using sediment samples from MPD, till, and grounding-zone proximal diamicton collected offshore of six modern and relict glacial catchments in both hemispheres, we examine grain shape distributions and microtextures (collectively, grain micromorphology) of the silt fraction to explore whether grains are measurably altered from their subglacial sources via meltwater action. We find that 75 % of all imaged grains (n = 9400) can be described by 25 % of the full range of measured shape morphometrics, indicating grain shape homogenization through widespread and efficient abrasive processes in subglacial environments. Although silt grains from MPDs exhibit edge rounding more often than silt grains from tills, grain surface textures indicative of fluvial transport (e.g., v-shaped percussions) occur in only a modest number of grains. Furthermore, MPD grain surfaces retain several textures consistent with transport beneath glacial ice (e.g., straight or arcuate steps, (sub)linear fractures) in comparable abundances to till grains. Significant grain shape alteration in MPDs compared to their till sources is observed in sediments from glacial regions where (1) high-magnitude, potentially catastrophic meltwater drainage events are inferred from marine sediment records and (2) submarine landforms suggest supraglacial melt contributed to the subglacial hydrological budget. This implies that quantifiable grain shape alteration in MPDs could reflect a combination of high-energy flow of subglacial meltwater, persistent sediment entrainment, and/or long sediment transport distances through subglacial drainage pathways. Integrating grain micromorphology into analysis of MPDs in site-specific studies could therefore aid in distinguishing periods of persistent, well-connected subglacial discharge from periods of sluggish or disorganized drainage. In the wider context of deglacial marine sedimentary and bathymetric records, a grain micromorphological approach may bolster our ability to characterize ice response to subglacial meltwater transmission through time. This work additionally demonstrates that glacial and fluvial surface textures are retained on silt-sized quartz grains in adequate amounts for microtexture analysis, which has heretofore been conducted exclusively on the sand fraction. Therefore, grain microtextures can be examined on silt-rich glaciogenic deposits that contain little to no sand as a means to evaluate sediment transport processes.

Beryllium-10 (10Be) is proposed to be a potential proxy for investigating ice shelf presence and absence, or meltwater discharge in coastal polar environments. However, the sources and distribution of atmospherically produced meteoric-10Be in the Antarctic marine realm are yet to be fully characterized. We present a dataset of 9Be and 10Be concentrations, and 10Be/9Be ratios in seafloor surface sediments from the Antarctic continental shelf to assess the sources and processes contributing Be-isotopes to ice-sheet proximal marine settings. We show that upwelling waters (e.g. Circumpolar Deep Water) are a significant source of 10Be to continental shelf sediments. This limits the use of 10Be/9Be as a proxy for ice shelf environment or meltwater discharge, but instead provides a potential proxy for reconstructing Circumpolar Deep Water incursions onto Antarctic continental shelves.

In many low- and middle-income countries, school children consume untreated water that has been pumped into storage tanks. The water is often of poor quality and consumption can cause gastrointestinal illnesses resulting in missed school days, growth stunting, and cognitive impairment. This study deployed a silver-ceramic technology (MadiDrop) to disinfect drinking water in school storage tanks. While silver ionization is effective at the household scale, relatively little research has been conducted on its effectiveness at the community scale. To address this gap, we assessed disinfection via MadiDrop at three schools that serve vulnerable populations in rural India. Tank inflow and treated outflow samples were tested for total coliforms (TCs) and Escherichia coli (EC). TC was significantly reduced overall and in two of three intervention tanks. Compared to the baseline, reductions in TC were significant in all three tanks and overall, while EC reductions were significant overall and in two of three tanks. TC reduction was negatively correlated with silver concentration and tank residence time, and silver concentrations were maintained below the drinking water quality guideline. While the intervention could be considered successful, several barriers and caveats are provided as are study limitations and areas for future research.

The Northeast Greenland Ice Stream (NEGIS) is the main artery for ice discharge from the northeast sector of the Greenland Ice Sheet (GrIS) to the North Atlantic. Understanding the past, present and future stability of the NEGIS with respect to atmospheric and oceanic forcing is of global importance as it drains around 17% of the GrIS and has a sea-level equivalent of 1.6 m. This paper reconstructs the deglacial and Holocene history of Nioghalvfjerdsbr ae (or 79N Glacier); a major outlet of the NEGIS. At high elevation (>900 m asl) autochthonous blockfield, a lack of glacially moulded bedrock and pre LGM exposure ages point to a complex exposure/burial history extending back over half a million years. However, post Marine Isotope Stage 12, enhanced glacial erosion led to fjord incision and plateaux abandonment. Between 900 and 600 m asl the terrain is largely unmodified by glacial scour but post LGM erratics indicate the advection of cold-based ice through the fjord. In contrast, below similar to 600 m asl Nioghalvfjerdsfjorden exhibits a geomorphological signal indicative of a warm-based ice stream operating during the last glacial cycle. Dated ice marginal landforms and terrain along the fjord walls show initial thinning rates were slow between similar to 23 and 10 ka, but post -10 ka it is evident that Nioghalvfjerdsfjorden deglaciated extremely quickly with complete fjord deglaciation below similar to 500 m asl between 10.0 and 8.5 ka. Both increasing air and ocean temperatures were pivotal in driving surface lowering and submarine melt during deglaciation, but the final withdrawal of ice through Nioghalvfjerdsfjorden was facilitated by the action of marine ice sheet instability. Our estimates show that thinning and retreat rates reached a maximum of 5.29 ma(-1) and 613 ma(-1), respectively, as the ice margin withdrew westwards. This would place the Early Holocene disintegration of this outlet of the NEGIS at the upper bounds of contemporary thinning and retreat rates seen both in Greenland and Antarctica. Combined with recent evidence of ice stream shutdown during the Holocene, as well as predictions of changing ice flow dynamics within downstream sections of the NEGIS catchment, this suggests that significant re-organisation of the terminal zone of the ice stream is imminent over the next century.