Journal of Glaciology最新文献

Rift propagation signals the last act of the Thwaites Eastern Ice Shelf despite low basal melt rates 尽管基底融化率较低，但裂谷扩展预示着斯怀兹东部冰架的最后一幕

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2024-09-19 DOI: 10.1017/jog.2024.64

Christian T. Wild, Samuel B. Kachuck, Adrian Luckman, Karen E. Alley, Meghan A. Sharp, Haylee Smith, Scott W. Tyler, Christopher Kratt, Tiago S. Dotto, Daniel Price, Keith W. Nicholls, Suzanne L. Bevan, Gabriela Collao-Barrios, Atsuhiro Muto, Martin Truffer, Ted A. Scambos, Karen J. Heywood, Erin C. Pettit, the TARSAN team

{"title":"Rift propagation signals the last act of the Thwaites Eastern Ice Shelf despite low basal melt rates","authors":"Christian T. Wild, Samuel B. Kachuck, Adrian Luckman, Karen E. Alley, Meghan A. Sharp, Haylee Smith, Scott W. Tyler, Christopher Kratt, Tiago S. Dotto, Daniel Price, Keith W. Nicholls, Suzanne L. Bevan, Gabriela Collao-Barrios, Atsuhiro Muto, Martin Truffer, Ted A. Scambos, Karen J. Heywood, Erin C. Pettit, the TARSAN team","doi":"10.1017/jog.2024.64","DOIUrl":"https://doi.org/10.1017/jog.2024.64","url":null,"abstract":"Rift propagation, rather than basal melt, drives the destabilization and disintegration of the Thwaites Eastern Ice Shelf. Since 2016, rifts have episodically advanced throughout the central ice-shelf area, with rapid propagation events occurring during austral spring. The ice shelf's speed has increased by ~70% during this period, transitioning from a rate of 1.65 m d−1 in 2019 to 2.85 m d−1 by early 2023 in the central area. The increase in longitudinal strain rates near the grounding zone has led to full-thickness rifts and melange-filled gaps since 2020. A recent sea-ice break out has accelerated retreat at the western calving front, effectively separating the ice shelf from what remained of its northwestern pinning point. Meanwhile, a distributed set of phase-sensitive radar measurements indicates that the basal melting rate is generally small, likely due to a widespread robust ocean stratification beneath the ice–ocean interface that suppresses basal melt despite the presence of substantial oceanic heat at depth. These observations in combination with damage modeling show that, while ocean forcing is responsible for triggering the current West Antarctic ice retreat, the Thwaites Eastern Ice Shelf is experiencing dynamic feedbacks over decadal timescales that are driving ice-shelf disintegration, now independent of basal melt.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"43 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Retreat of the Greenland Ice Sheet leads to divergent patterns of reconfiguration at its freshwater and tidewater margins 格陵兰冰盖的退缩导致其淡水和潮水边缘出现不同的重组模式

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2024-09-16 DOI: 10.1017/jog.2024.61

Jonathan Ryan, Theo Ross, Sarah Cooley, Dominik Fahrner, Nicole Abib, Victoria Benson, David Sutherland

{"title":"Retreat of the Greenland Ice Sheet leads to divergent patterns of reconfiguration at its freshwater and tidewater margins","authors":"Jonathan Ryan, Theo Ross, Sarah Cooley, Dominik Fahrner, Nicole Abib, Victoria Benson, David Sutherland","doi":"10.1017/jog.2024.61","DOIUrl":"https://doi.org/10.1017/jog.2024.61","url":null,"abstract":"Greenland's marine- and land-terminating glaciers are retreating inland due to climate warming, reconfiguring the way the ice sheet interacts with its proglacial environment. Here we use three decades of satellite imagery to determine whether the ice-sheet margin is becoming more or less exposed to marine and lacustrine processes. During our 1990–2019 study period, we find that the length of ice-sheet perimeter in contact with the ocean shrank by 12.3 ± 3.8% (196.2 ± 10.4 km), due to the retreat of marine-terminating glaciers into narrower fjords. On the other hand, we find that the length of the ice-sheet perimeter in contact with freshwater lakes exhibited more divergent trends that is better explored at regional scales. The length of ice–lake boundaries increased in southwest, north and northwest Greenland but declined in southeast and central east Greenland. The magnitude of change we document during our study period leads us to conclude that the ice sheet is poised for further, substantial reconfiguration in the coming decades with consequences for the flux of fresh water, nutrients and primary productivity in Greenland's terrestrial and oceanic environment.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"46 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Implications of high-resolution velocity and strain rate observations for modelling of Greenlandic tidewater glaciers 高分辨率速度和应变率观测对格陵兰潮水冰川建模的影响

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2024-09-16 DOI: 10.1017/jog.2024.63

Dominik Fahrner, Pablo J. González, Douglas W. F. Mair, James M. Lea

{"title":"Implications of high-resolution velocity and strain rate observations for modelling of Greenlandic tidewater glaciers","authors":"Dominik Fahrner, Pablo J. González, Douglas W. F. Mair, James M. Lea","doi":"10.1017/jog.2024.63","DOIUrl":"https://doi.org/10.1017/jog.2024.63","url":null,"abstract":"Synthetic Aperture Radar (SAR) has been used extensively to determine the surface ice flow velocity of tidewater glaciers and investigate changes in seasonal or annual ice dynamics at medium spatial resolution (⩾100 m). However, assessing tidewater glacier behaviour at these resolutions risks missing key details of glacier dynamics, which is particularly important for determination of strain rates that relate to crevasse formation, depth, and ice damage. Here we present surface ice velocity and strain maps with a 16 m posting derived from high-resolution (1 m) PAZ Ciencia spotlight mode SAR imagery for Narsap Sermia, SW Greenland, for October 2019 to February 2021. Results reveal fine details in strain rate, including an area of compression proximal to the terminus, with an upstream shift of strains through time. The velocity evolution of Narsap Sermia shows distinct seasonal changes starting in summer 2020, which are largely modulated by the subglacial drainage system. Comparison of our results with medium-resolution velocity products shows that while these can capture general strain and velocity patterns, our high-resolution data reveals considerably larger ranges of strain values. This is likely to have implications for tuning strain rate dependent calving and ice damage parameterisations within numerical models.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"8 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanical properties of pressure-frozen ice under triaxial compressive stress 压力冻结冰在三轴压应力作用下的机械特性

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2024-09-16 DOI: 10.1017/jog.2024.59

Peixin Sun, Weihao Yang, Jukka Tuhkuri

{"title":"Mechanical properties of pressure-frozen ice under triaxial compressive stress","authors":"Peixin Sun, Weihao Yang, Jukka Tuhkuri","doi":"10.1017/jog.2024.59","DOIUrl":"https://doi.org/10.1017/jog.2024.59","url":null,"abstract":"Artificial ground freezing is an effective method for underground constructions in deep alluvium. To study the compressive strength of frozen soil under high ground pressure and high hydraulic pressure, it is necessary to understand the mechanical behaviour of ice that is formed under triaxial compressive stress. A low-temperature triaxial test system was developed and used to study both formation and deformation of columnar ice under hydrostatic pressure. Cylindrical ice specimens 125 mm in height and 61.8 mm in diameter were prepared and tested under constant strain rates. At a strain rate of 5 × 10−5 s−1, the peak axial stress showed a linear increase as the confining pressure increased from 2 to 30 MPa, while the peak deviatoric stress exhibited a slight decrease. At a confining pressure of 30 MPa, the peak deviatoric stress showed a logarithmic increase with the strain rate increasing from 5 × 10−6 to 5 × 10−4 s−1, and the failure strain nearly doubled. A power law relationship between the time to failure and the strain rate was also observed. In this study, each test consistently demonstrated a ductile failure mode, with a noticeable reduction in cracking as the confining pressure increased. Due to the effect of the high confining pressure, crack propagation was suppressed, and an apparent recrystallization after peak stress was observed.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"1 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exploring canyons beneath Devon Ice Cap for sub-glacial drainage using radar and thermodynamic modeling 利用雷达和热力学建模探索德文冰帽下的峡谷冰川下排水系统

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2024-09-16 DOI: 10.1017/jog.2024.49

Chris Pierce, Mark Skidmore, Lucas Beem, Don Blankenship, Ed Adams, Christopher Gerekos

{"title":"Exploring canyons beneath Devon Ice Cap for sub-glacial drainage using radar and thermodynamic modeling","authors":"Chris Pierce, Mark Skidmore, Lucas Beem, Don Blankenship, Ed Adams, Christopher Gerekos","doi":"10.1017/jog.2024.49","DOIUrl":"https://doi.org/10.1017/jog.2024.49","url":null,"abstract":"Sub-glacial canyon features up to 580 m deep between flat terraces were identified beneath Devon Ice Cap during a 2023 radar echo sounding (RES) survey. The largest canyon connects a hypothesized brine network near the Devon Ice Cap summit with the marine-terminating Sverdrup outlet glacier. This canyon represents a probable drainage route for the hypothesized water system. Radar bed reflectivity is consistently 30 dB lower along the canyon floor than on the terraces, contradicting the signature expected for sub-glacial water. We compare these data with backscattering simulations to demonstrate that the reflectivity pattern may be topographically induced. Our simulated results indicated a 10 m wide canal-like water feature is unlikely along the canyon floor, but smaller features may be difficult to detect via RES. We calculated basal temperature profiles using a 2D finite difference method and found the floor may be up to 18°C warmer than the terraces. However, temperatures remain below the pressure melting point, and there is limited evidence that the canyon floor supports a connected drainage system between the DIC summit and Sverdrup Glacier. The terrain beneath Devon Ice Cap demonstrates limitations for RES. Future studies should evaluate additional correction methods near complex terrain, such as RES simulation as we demonstrate here.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"31 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142262629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

DAS to discharge: using distributed acoustic sensing (DAS) to infer glacier runoff 利用分布式声学传感（DAS）推断冰川径流

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2024-08-27 DOI: 10.1017/jog.2024.46

John-Morgan Manos, Dominik Gräff, Eileen Rose Martin, Patrick Paitz, Fabian Walter, Andreas Fichtner, Bradley Paul Lipovsky

{"title":"DAS to discharge: using distributed acoustic sensing (DAS) to infer glacier runoff","authors":"John-Morgan Manos, Dominik Gräff, Eileen Rose Martin, Patrick Paitz, Fabian Walter, Andreas Fichtner, Bradley Paul Lipovsky","doi":"10.1017/jog.2024.46","DOIUrl":"https://doi.org/10.1017/jog.2024.46","url":null,"abstract":"Observations of glacier melt and runoff are of fundamental interest in the study of glaciers and their interactions with their environment. Considerable recent interest has developed around distributed acoustic sensing (DAS), a sensing technique which utilizes Rayleigh backscatter in fiber optic cables to measure the seismo-acoustic wavefield in high spatial and temporal resolution. Here, we present data from a month-long, 9 km DAS deployment extending through the ablation and accumulation zones on Rhonegletscher, Switzerland, during the 2020 melt season. While testing several types of machine learning (ML) models, we establish a regression problem, using the DAS data as the dependent variable, to infer the glacier discharge observed at a proglacial stream gauge. We also compare two predictive models that only depend on meteorological station data. We find that the seismo-acoustic wavefield recorded by DAS can be utilized to infer proglacial discharge. Models using DAS data outperform the two models trained on meteorological data with mean absolute errors of 0.64, 2.25 and 2.72 m3 s−1, respectively. This study demonstrates the ability of in situ glacier DAS to be used for quantifying proglacial discharge and points the way to a new approach to measuring glacier runoff.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"53 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142216894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Observed meltwater-induced flexure and fracture at a doline on George VI Ice Shelf, Antarctica 在南极洲乔治六世冰架上观察到的融水引起的挠曲和断裂

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2024-05-03 DOI: 10.1017/jog.2024.31

Alison F. Banwell, Ian C. Willis, Laura A. Stevens, Rebecca L. Dell, Douglas R. MacAyeal

{"title":"Observed meltwater-induced flexure and fracture at a doline on George VI Ice Shelf, Antarctica","authors":"Alison F. Banwell, Ian C. Willis, Laura A. Stevens, Rebecca L. Dell, Douglas R. MacAyeal","doi":"10.1017/jog.2024.31","DOIUrl":"https://doi.org/10.1017/jog.2024.31","url":null,"abstract":"Global Navigation Satellite System (GNSS) observations and ground-based timelapse photography obtained over the record-high 2019/2020 melt season are combined to characterise the flexure and fracture behaviour of a previously formed doline on George VI Ice Shelf, Antarctica. The GNSS timeseries shows a downward vertical displacement of the doline centre with respect to the doline rim of ~60 cm in response to loading from a central meltwater lake. The GNSS data also show a tens-of-days episode of rapid-onset, exponentially decaying horizontal displacement, where the horizontal distance between the doline rim and its centre increases by ~70 cm. We interpret this event as the initiation and/or widening of a fracture, aided by stress perturbations associated with meltwater loading in the doline basin. Viscous flexure modelling indicates that the meltwater loading generates tensile surface stresses exceeding 75 kPa. This, together with our timelapse photos of circular fractures around the doline, suggests the first such documentation of meltwater-loading-induced ‘ring fracture’ formation on an ice shelf, equivalent to the fracture type proposed as part of the chain-reaction lake drainage process involved in the 2002 breakup of the Larsen B Ice Shelf.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"42 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140835293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Elevation bias due to penetration of spaceborne radar signal on Grosser Aletschgletscher, Switzerland 瑞士 Grosser Aletschgletscher 航天雷达信号穿透造成的高程偏差

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2024-04-30 DOI: 10.1017/jog.2024.37

Jacqueline Bannwart, Livia Piermattei, Inés Dussaillant, Lukas Krieger, Dana Floricioiu, Etienne Berthier, Claudia Roeoesli, Horst Machguth, Michael Zemp

{"title":"Elevation bias due to penetration of spaceborne radar signal on Grosser Aletschgletscher, Switzerland","authors":"Jacqueline Bannwart, Livia Piermattei, Inés Dussaillant, Lukas Krieger, Dana Floricioiu, Etienne Berthier, Claudia Roeoesli, Horst Machguth, Michael Zemp","doi":"10.1017/jog.2024.37","DOIUrl":"https://doi.org/10.1017/jog.2024.37","url":null,"abstract":"Digital elevation models (DEMs) from the spaceborne interferometric radar mission TanDEM-X hold a large potential for glacier change assessments. However, a bias is potentially introduced through the penetration of the X-band signal into snow and firn. To improve our understanding of radar penetration on glaciers, we compare DEMs derived from the almost synchronous acquisition of TanDEM-X and Pléiades optical stereo-images of Grosser Aletschgletscher in March 2021. We found that the elevation bias – averaged per elevation bin – can reach up to 4–8 m in the accumulation area, depending on post co-registration corrections. Concurrent in situ measurements (ground-penetrating radar, snow cores, snow pits) reveal that the signal is not obstructed by the last summer horizon but reaches into perennial firn. Because of volume scattering, the TanDEM-X surface is determined by the scattering phase centre and does not coincide with a specific firn layer. We show that the bias corresponds to more than half of the decadal ice loss rate. To minimize the radar penetration bias, we recommend to select DEMs from the same time of the year and over long observation periods. A correction of the radar penetration bias is recommended, especially when combining optical and TanDEM-X DEMs.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"2012 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141196967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improved processing methods for eddy covariance measurements in calculating sensible heat fluxes at glacier surfaces 在计算冰川表面显热通量时改进涡度协方差测量的处理方法

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2024-04-30 DOI: 10.1017/jog.2024.39

Cole Lord-May, Valentina Radić

{"title":"Improved processing methods for eddy covariance measurements in calculating sensible heat fluxes at glacier surfaces","authors":"Cole Lord-May, Valentina Radić","doi":"10.1017/jog.2024.39","DOIUrl":"https://doi.org/10.1017/jog.2024.39","url":null,"abstract":"Bulk aerodynamic methods have been shown to perform poorly in computing turbulent heat fluxes at glacier surfaces during shallow katabatic winds. Katabatic surface layers have different wind shear and flux profiles to the surface layers for which the bulk methods were developed, potentially invalidating their use in these conditions. In addition, eddy covariance-derived turbulent heat fluxes are unlikely to be representative of surface conditions when eddy covariance data are collected close to the wind speed maximum (WSM). Here we utilize two months of eddy covariance and meteorological data measured at three different heights (1 m, 2 m, and 3 m) at Kaskawulsh Glacier in the Yukon, Canada, to re-examine the performance of bulk methods relative to eddy covariance-derived fluxes under different near-surface flow regimes. We propose a new set of processing methods for one-level eddy covariance data to ensure the validity of calculated fluxes during highly variable flows and low-level wind speed maxima, which leads to improved agreement between eddy covariance-derived and modelled fluxes across all flow regimes, with the best agreement (correlation >0.9) 1 m above the surface. Contrary to previous studies, these results show that adequately processed eddy covariance data collected at or above the WSM can provide valid estimates of surface heat fluxes.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"13 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141197160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Topographic and hydrological controls on partial and full surges of Little Kluane Glacier, Yukon 育空地区小克卢恩冰川部分和全部涌浪的地形和水文控制因素

IF 3.4 3区地球科学

Journal of Glaciology Pub Date : 2024-04-15 DOI: 10.1017/jog.2024.35

Brittany Main, Luke Copland, Gwenn Elizabeth Flowers, Christine Fiona Dow, Wesley Van Wychen, Sergey Samsonov, William Kochtitzky

{"title":"Topographic and hydrological controls on partial and full surges of Little Kluane Glacier, Yukon","authors":"Brittany Main, Luke Copland, Gwenn Elizabeth Flowers, Christine Fiona Dow, Wesley Van Wychen, Sergey Samsonov, William Kochtitzky","doi":"10.1017/jog.2024.35","DOIUrl":"https://doi.org/10.1017/jog.2024.35","url":null,"abstract":"We demonstrate that a ~20 km long valley glacier in the St. Elias Mountains, Yukon, can experience both partial and full surges, likely controlled by the presence of a topographic constriction and the formation and drainage of supraglacial lakes. Based on analysis of air photos, satellite images and field observations since the 1940s, we identify a full surge of ‘Little Kluane Glacier’ from 2013 to 2018, and a partial surge of just the upper north arm between 1963 and 1972. Repeat digital elevation models and velocity profiles indicate that the recent surge initiated from the upper north arm in 2013, which developed into a full surge of the main trunk from 2017 to 2018 with peak velocities of ~3600 m a−1 and frontal advance of ~1.7 km from May to September 2018. In 2016, a mass movement from the north arm to the main trunk generated a surface depression in a region immediately downstream of a topographic constriction, which promoted the formation and rapid drainage of supraglacial lakes to the glacier bed, and likely established the conditions to propel the initial partial surge into a full surge. Our results underscore the complex interplay between glacier geometry, surface hydrology and topography required to drive full surges of this glacier.","PeriodicalId":15981,"journal":{"name":"Journal of Glaciology","volume":"22 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141149028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0