Abstract It is commonly asserted that there are two distinct classes of glacier surges: slow, long-duration ‘Svalbard-type’ surges, triggered by a transition from cold- to warm-based conditions (thermal switching), and fast, shorter-duration ‘Alaska-type’ surges triggered by a reorganisation of the basal drainage system (hydraulic switching). This classification, however, reflects neither the diversity of surges in Svalbard and Alaska (and other regions), nor the fundamental dynamic processes underlying all surges. We argue that enthalpy balance theory offers a framework for understanding the spectrum of glacier surging behaviours while emphasising their essential dynamic unity. In this paper, we summarise enthalpy balance theory, illustrate its potential to explain so-called ‘Svalbard-type’ and ‘Alaska-type’ surges using a single set of principles, and show examples of a much wider range of glacier surge behaviour than previously observed. We then identify some future directions for research, including strategies for testing predictions of the theory against field and remote sensing data, and priorities for numerical model development.
{"title":"Enthalpy balance theory unifies diverse glacier surge behaviour","authors":"D. Benn, I. Hewitt, A. Luckman","doi":"10.1017/aog.2023.23","DOIUrl":"https://doi.org/10.1017/aog.2023.23","url":null,"abstract":"Abstract It is commonly asserted that there are two distinct classes of glacier surges: slow, long-duration ‘Svalbard-type’ surges, triggered by a transition from cold- to warm-based conditions (thermal switching), and fast, shorter-duration ‘Alaska-type’ surges triggered by a reorganisation of the basal drainage system (hydraulic switching). This classification, however, reflects neither the diversity of surges in Svalbard and Alaska (and other regions), nor the fundamental dynamic processes underlying all surges. We argue that enthalpy balance theory offers a framework for understanding the spectrum of glacier surging behaviours while emphasising their essential dynamic unity. In this paper, we summarise enthalpy balance theory, illustrate its potential to explain so-called ‘Svalbard-type’ and ‘Alaska-type’ surges using a single set of principles, and show examples of a much wider range of glacier surge behaviour than previously observed. We then identify some future directions for research, including strategies for testing predictions of the theory against field and remote sensing data, and priorities for numerical model development.","PeriodicalId":8211,"journal":{"name":"Annals of Glaciology","volume":"63 1","pages":"88 - 94"},"PeriodicalIF":2.9,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43203621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Markov, P. Talalay, M. Sysoev, Andrey Miller, A. Cherepakhin
Abstract This article presents the main aspects of the design solutions (based on the application of sensors MEMS and cantilevers), testing and applying of the multi-functional borehole logger ANTTIC (Antarctic Thermo-barometer, Inclinometer, Caliper) for geophysical high-precision monitoring (when simultaneous registering of temperature, pressure, axis inclination angle and radii of borehole cross-sections at 12 points), which is designed specifically for ultra-low temperatures and ultra-high pressures, and to determine an elliptical borehole shape and registration anisotropy factor in deep ice boreholes in the central region of Eastern Antarctica, in the areas of dome A at the Kunlun station (China) and/or of lake Vostok at the Vostok station (Russia).
{"title":"Borehole multi-functional logger for geophysical high-precision monitoring in Antarctic and Greenland ice sheets and glaciers","authors":"A. Markov, P. Talalay, M. Sysoev, Andrey Miller, A. Cherepakhin","doi":"10.1017/aog.2021.17","DOIUrl":"https://doi.org/10.1017/aog.2021.17","url":null,"abstract":"Abstract This article presents the main aspects of the design solutions (based on the application of sensors MEMS and cantilevers), testing and applying of the multi-functional borehole logger ANTTIC (Antarctic Thermo-barometer, Inclinometer, Caliper) for geophysical high-precision monitoring (when simultaneous registering of temperature, pressure, axis inclination angle and radii of borehole cross-sections at 12 points), which is designed specifically for ultra-low temperatures and ultra-high pressures, and to determine an elliptical borehole shape and registration anisotropy factor in deep ice boreholes in the central region of Eastern Antarctica, in the areas of dome A at the Kunlun station (China) and/or of lake Vostok at the Vostok station (Russia).","PeriodicalId":8211,"journal":{"name":"Annals of Glaciology","volume":"62 1","pages":"374 - 384"},"PeriodicalIF":2.9,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44533795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Akane Tsushima, Morihiro Miyahara, Tetsuhide Yamasaki, Nao Esashi, Yota Sato, R. Kayastha, A. Sherpa, M. Sano, K. Fujita
Abstract We drilled an 81.2-m-long ice core in the accumulation area (5860 m a.s.l.) of Trambau Glacier in the Rolwaling region during October–November 2019. The drilling operation was conducted with a lightweight electro-mechanical drill system after two reconnaissance fieldworks in 2017 and 2018, during which two shallow firn cores were drilled with a hand auger. The drill system and ice core samples were transported by helicopters at a high elevation of 6000 m a.s.l. A further challenging issue was the ice core transportation between Nepal and Japan, as no regular commercial flight was available for the frozen samples. The addition of dry ice imported from India immediately prior to leaving Nepal allowed the ice core samples to be successfully transported to a cold room in Japan, and remain in a frozen state. Stratigraphic observations during the drilling operation suggest the drill site has been affected by melting and refreezing.
{"title":"Ice core drilling on a high-elevation accumulation zone of Trambau Glacier in the Nepal Himalaya","authors":"Akane Tsushima, Morihiro Miyahara, Tetsuhide Yamasaki, Nao Esashi, Yota Sato, R. Kayastha, A. Sherpa, M. Sano, K. Fujita","doi":"10.1017/aog.2021.15","DOIUrl":"https://doi.org/10.1017/aog.2021.15","url":null,"abstract":"Abstract We drilled an 81.2-m-long ice core in the accumulation area (5860 m a.s.l.) of Trambau Glacier in the Rolwaling region during October–November 2019. The drilling operation was conducted with a lightweight electro-mechanical drill system after two reconnaissance fieldworks in 2017 and 2018, during which two shallow firn cores were drilled with a hand auger. The drill system and ice core samples were transported by helicopters at a high elevation of 6000 m a.s.l. A further challenging issue was the ice core transportation between Nepal and Japan, as no regular commercial flight was available for the frozen samples. The addition of dry ice imported from India immediately prior to leaving Nepal allowed the ice core samples to be successfully transported to a cold room in Japan, and remain in a frozen state. Stratigraphic observations during the drilling operation suggest the drill site has been affected by melting and refreezing.","PeriodicalId":8211,"journal":{"name":"Annals of Glaciology","volume":"62 1","pages":"353 - 359"},"PeriodicalIF":2.9,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41867227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Jiskoot, D. Dahl-Jensen, Nicolas Eckert, F. Pattyn, R. Greve, T. Popp, S. B. Hansen, P. Talalay, O. Alemany, K. Kawamura, Keith Makinson, H. Motoyama, K. Nielsen, J. Schwander, Kristina R. Slawny, F. Wilhelms, G. Flowers, C. Hulbe, J. Stroeve, A. Leeson
{"title":"AOG volume 62 issue 85-86 Cover and Front matter","authors":"H. Jiskoot, D. Dahl-Jensen, Nicolas Eckert, F. Pattyn, R. Greve, T. Popp, S. B. Hansen, P. Talalay, O. Alemany, K. Kawamura, Keith Makinson, H. Motoyama, K. Nielsen, J. Schwander, Kristina R. Slawny, F. Wilhelms, G. Flowers, C. Hulbe, J. Stroeve, A. Leeson","doi":"10.1017/aog.2021.19","DOIUrl":"https://doi.org/10.1017/aog.2021.19","url":null,"abstract":"","PeriodicalId":8211,"journal":{"name":"Annals of Glaciology","volume":" ","pages":"f1 - f3"},"PeriodicalIF":2.9,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45890769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Joseph M. Souney, M. Twickler, M. Aydin, E. Steig, T. J. Fudge, L. V. Street, M. R. Nicewonger, Emma C. Kahle, Jay A. Johnson, Tanner W. Kuhl, K. Casey, J. Fegyveresi, R. M. Nunn, Geoffrey M. Hargreaves
An intermediate-depth (1751 m) ice core was drilled at the South Pole between 2014 and 2016 using the newly designed US Intermediate Depth Drill. The South Pole ice core is the highestresolution interior East Antarctic ice core record that extends into the glacial period. The methods used at the South Pole to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the National Science Foundation Ice Core Facility (NSF-ICF), and the methods used to process and sample the ice at the NSF-ICF are described. The South Pole ice core exhibited minimal brittle ice, which was likely due to site characteristics and, to a lesser extent, to drill technology and core handling procedures.
{"title":"Core handling, transportation and processing for the South Pole ice core (SPICEcore) project — ERRATUM","authors":"Joseph M. Souney, M. Twickler, M. Aydin, E. Steig, T. J. Fudge, L. V. Street, M. R. Nicewonger, Emma C. Kahle, Jay A. Johnson, Tanner W. Kuhl, K. Casey, J. Fegyveresi, R. M. Nunn, Geoffrey M. Hargreaves","doi":"10.1017/aog.2021.18","DOIUrl":"https://doi.org/10.1017/aog.2021.18","url":null,"abstract":"An intermediate-depth (1751 m) ice core was drilled at the South Pole between 2014 and 2016 using the newly designed US Intermediate Depth Drill. The South Pole ice core is the highestresolution interior East Antarctic ice core record that extends into the glacial period. The methods used at the South Pole to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the National Science Foundation Ice Core Facility (NSF-ICF), and the methods used to process and sample the ice at the NSF-ICF are described. The South Pole ice core exhibited minimal brittle ice, which was likely due to site characteristics and, to a lesser extent, to drill technology and core handling procedures.","PeriodicalId":8211,"journal":{"name":"Annals of Glaciology","volume":"62 1","pages":"391 - 391"},"PeriodicalIF":2.9,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44906364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yazhou Li, P. Talalay, Xiaopeng Fan, Bing Li, Jialin Hong
Abstract Hot-point drills have been widely used for drilling boreholes in glaciers, ice caps and ice sheets. A hot-point drill melts ice through the thermal head at its bottom end. Penetration occurs through a close-contact melting (CCM) process, in which the ice is melted, and the meltwater is squeezed out by the exerted force applied on the thermal head. During the drilling, a thin water film is formed to separate the thermal head from the surrounding ice. For the hot-point drill, the rate of penetration (ROP) is influenced by several variables, such as thermal head shape, buoyancy corrected force (BCF), thermal head power (or temperature) and ice temperature. In this study, we developed a model to describe the CCM process, where a constant power or temperature on the working surface of a thermal head is assumed. The model was developed using COMSOL Multiphysics 5.3a software to evaluate the effects of different variables on the CCM process. It was discovered that the effect of thermal head shape and the cone angle of conical thermal head on ROP is less significant, whereas the increase in the BCF and the power (or temperature) of the thermal head can continuously enhance the ROP.
{"title":"Modeling of hot-point drilling in ice","authors":"Yazhou Li, P. Talalay, Xiaopeng Fan, Bing Li, Jialin Hong","doi":"10.1017/aog.2021.16","DOIUrl":"https://doi.org/10.1017/aog.2021.16","url":null,"abstract":"Abstract Hot-point drills have been widely used for drilling boreholes in glaciers, ice caps and ice sheets. A hot-point drill melts ice through the thermal head at its bottom end. Penetration occurs through a close-contact melting (CCM) process, in which the ice is melted, and the meltwater is squeezed out by the exerted force applied on the thermal head. During the drilling, a thin water film is formed to separate the thermal head from the surrounding ice. For the hot-point drill, the rate of penetration (ROP) is influenced by several variables, such as thermal head shape, buoyancy corrected force (BCF), thermal head power (or temperature) and ice temperature. In this study, we developed a model to describe the CCM process, where a constant power or temperature on the working surface of a thermal head is assumed. The model was developed using COMSOL Multiphysics 5.3a software to evaluate the effects of different variables on the CCM process. It was discovered that the effect of thermal head shape and the cone angle of conical thermal head on ROP is less significant, whereas the increase in the BCF and the power (or temperature) of the thermal head can continuously enhance the ROP.","PeriodicalId":8211,"journal":{"name":"Annals of Glaciology","volume":"62 1","pages":"360 - 373"},"PeriodicalIF":2.9,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45980936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"AOG volume 62 issue 85-86 Cover and Back matter","authors":"","doi":"10.1017/aog.2021.20","DOIUrl":"https://doi.org/10.1017/aog.2021.20","url":null,"abstract":"","PeriodicalId":8211,"journal":{"name":"Annals of Glaciology","volume":"357 1","pages":"b1 - b1"},"PeriodicalIF":2.9,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41274418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Schroeder, R. Bingham, D. Blankenship, K. Christianson, O. Eisen, G. Flowers, N. Karlsson, M. Koutnik, J. Paden, M. Siegert
Department of Geophysics, Stanford University, Stanford, USA; Department of Electrical Engineering, Stanford University, Stanford, USA; School of GeoSciences, University of Edinburgh, Edinburgh, UK; Institute for Geophysics, University of Texas, Austin, USA; Department of Earth and Space Sciences, University of Washington, Seattle, USA; Alfred-Wegener-Institut, Helmholtz-Zentrum für Polarund Meeresforschung, Bremerhaven, Germany; University of Bremen, Bremen, Germany; Department of Earth Sciences, Simon Fraser University, Vancouver, Canada; Geological Survey of Denmark and Greenland, Copenhagen, Denmark; Center for the Remote Sensing of Ice Sheets, University of Kansas, Lawrence, USA and Grantham Institute, and Department of Earth Science and Engineering, Imperial College London, London, UK
{"title":"Five decades of radioglaciology — CORRIGENDUM","authors":"D. Schroeder, R. Bingham, D. Blankenship, K. Christianson, O. Eisen, G. Flowers, N. Karlsson, M. Koutnik, J. Paden, M. Siegert","doi":"10.1017/aog.2021.14","DOIUrl":"https://doi.org/10.1017/aog.2021.14","url":null,"abstract":"Department of Geophysics, Stanford University, Stanford, USA; Department of Electrical Engineering, Stanford University, Stanford, USA; School of GeoSciences, University of Edinburgh, Edinburgh, UK; Institute for Geophysics, University of Texas, Austin, USA; Department of Earth and Space Sciences, University of Washington, Seattle, USA; Alfred-Wegener-Institut, Helmholtz-Zentrum für Polarund Meeresforschung, Bremerhaven, Germany; University of Bremen, Bremen, Germany; Department of Earth Sciences, Simon Fraser University, Vancouver, Canada; Geological Survey of Denmark and Greenland, Copenhagen, Denmark; Center for the Remote Sensing of Ice Sheets, University of Kansas, Lawrence, USA and Grantham Institute, and Department of Earth Science and Engineering, Imperial College London, London, UK","PeriodicalId":8211,"journal":{"name":"Annals of Glaciology","volume":"62 1","pages":"390 - 390"},"PeriodicalIF":2.9,"publicationDate":"2021-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43420179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Goodge, J. Severinghaus, Jay A. Johnson, D. Tosi, R. Bay
Abstract Rapid Access Ice Drill is a new drilling technology capable of quickly accessing the glacial bed of Antarctic ice sheets, retrieving ice core and rock core samples, and providing boreholes for downhole logging of physical properties. Scientific goals include searching for old ice near the glacial bed and sampling subglacial bedrock. During field trials near McMurdo Station on a piedmont glacier at Minna Bluff in the 2019–20 austral summer, we successfully completed a ‘top-to-bottom’ operational sequence in three boreholes by (1) augering through firn, (2) creating a borehole packer seal in non-porous ice, (3) establishing fluid circulation, (4) quickly drilling a borehole in ice at penetration rates up to 1.2 m min−1, (5) acquiring a short ice core at depth, (6) penetrating the glacial bed at a depth of ~677 m, (7) recovering a 3.2 m core of ice, basal till and subglacial bedrock, (8) optically logging the borehole on wireline, (9) testing hydrofracture potential by overpressuring the borehole fluid and (10) operating in an environmentally benign yet rapid field mode. Minna Bluff testing, therefore, demonstrates the effectiveness of this integrated system to drill rapidly through thick ice and penetrate across the glacial bed to take cores of bedrock.
{"title":"Deep ice drilling, bedrock coring and dust logging with the Rapid Access Ice Drill (RAID) at Minna Bluff, Antarctica","authors":"J. Goodge, J. Severinghaus, Jay A. Johnson, D. Tosi, R. Bay","doi":"10.1017/aog.2021.13","DOIUrl":"https://doi.org/10.1017/aog.2021.13","url":null,"abstract":"Abstract Rapid Access Ice Drill is a new drilling technology capable of quickly accessing the glacial bed of Antarctic ice sheets, retrieving ice core and rock core samples, and providing boreholes for downhole logging of physical properties. Scientific goals include searching for old ice near the glacial bed and sampling subglacial bedrock. During field trials near McMurdo Station on a piedmont glacier at Minna Bluff in the 2019–20 austral summer, we successfully completed a ‘top-to-bottom’ operational sequence in three boreholes by (1) augering through firn, (2) creating a borehole packer seal in non-porous ice, (3) establishing fluid circulation, (4) quickly drilling a borehole in ice at penetration rates up to 1.2 m min−1, (5) acquiring a short ice core at depth, (6) penetrating the glacial bed at a depth of ~677 m, (7) recovering a 3.2 m core of ice, basal till and subglacial bedrock, (8) optically logging the borehole on wireline, (9) testing hydrofracture potential by overpressuring the borehole fluid and (10) operating in an environmentally benign yet rapid field mode. Minna Bluff testing, therefore, demonstrates the effectiveness of this integrated system to drill rapidly through thick ice and penetrate across the glacial bed to take cores of bedrock.","PeriodicalId":8211,"journal":{"name":"Annals of Glaciology","volume":"62 1","pages":"324 - 339"},"PeriodicalIF":2.9,"publicationDate":"2021-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/aog.2021.13","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56969050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Priscu, Jonas Kalin, J. Winans, T. Campbell, M. Siegfried, M. Skidmore, J. Dore, A. Leventer, D. Harwood, Dennis Duling, R. Zook, J. Burnett, D. Gibson, E. Krula, Anatoly Mironov, J. mcmanis, G. Roberts, B. Rosenheim, B. Christner, Kathy Kasic, H. Fricker, W. Lyons, Joel Barker, M. Bowling, B. Collins, C. Davis, A. Gagnon, C. Gardner, C. Gustafson, O. Kim, Wei Li, A. Michaud, M. Patterson, M. Tranter, R. Venturelli, T. Vick‐Majors, Cooper W. Elsworth
Abstract The Subglacial Antarctic Lakes Scientific Access (SALSA) Project accessed Mercer Subglacial Lake using environmentally clean hot-water drilling to examine interactions among ice, water, sediment, rock, microbes and carbon reservoirs within the lake water column and underlying sediments. A ~0.4 m diameter borehole was melted through 1087 m of ice and maintained over ~10 days, allowing observation of ice properties and collection of water and sediment with various tools. Over this period, SALSA collected: 60 L of lake water and 10 L of deep borehole water; microbes >0.2 μm in diameter from in situ filtration of ~100 L of lake water; 10 multicores 0.32–0.49 m long; 1.0 and 1.76 m long gravity cores; three conductivity–temperature–depth profiles of borehole and lake water; five discrete depth current meter measurements in the lake and images of ice, the lake water–ice interface and lake sediments. Temperature and conductivity data showed the hydrodynamic character of water mixing between the borehole and lake after entry. Models simulating melting of the ~6 m thick basal accreted ice layer imply that debris fall-out through the ~15 m water column to the lake sediments from borehole melting had little effect on the stratigraphy of surficial sediment cores.
{"title":"Scientific access into Mercer Subglacial Lake: scientific objectives, drilling operations and initial observations","authors":"J. Priscu, Jonas Kalin, J. Winans, T. Campbell, M. Siegfried, M. Skidmore, J. Dore, A. Leventer, D. Harwood, Dennis Duling, R. Zook, J. Burnett, D. Gibson, E. Krula, Anatoly Mironov, J. mcmanis, G. Roberts, B. Rosenheim, B. Christner, Kathy Kasic, H. Fricker, W. Lyons, Joel Barker, M. Bowling, B. Collins, C. Davis, A. Gagnon, C. Gardner, C. Gustafson, O. Kim, Wei Li, A. Michaud, M. Patterson, M. Tranter, R. Venturelli, T. Vick‐Majors, Cooper W. Elsworth","doi":"10.1017/aog.2021.10","DOIUrl":"https://doi.org/10.1017/aog.2021.10","url":null,"abstract":"Abstract The Subglacial Antarctic Lakes Scientific Access (SALSA) Project accessed Mercer Subglacial Lake using environmentally clean hot-water drilling to examine interactions among ice, water, sediment, rock, microbes and carbon reservoirs within the lake water column and underlying sediments. A ~0.4 m diameter borehole was melted through 1087 m of ice and maintained over ~10 days, allowing observation of ice properties and collection of water and sediment with various tools. Over this period, SALSA collected: 60 L of lake water and 10 L of deep borehole water; microbes >0.2 μm in diameter from in situ filtration of ~100 L of lake water; 10 multicores 0.32–0.49 m long; 1.0 and 1.76 m long gravity cores; three conductivity–temperature–depth profiles of borehole and lake water; five discrete depth current meter measurements in the lake and images of ice, the lake water–ice interface and lake sediments. Temperature and conductivity data showed the hydrodynamic character of water mixing between the borehole and lake after entry. Models simulating melting of the ~6 m thick basal accreted ice layer imply that debris fall-out through the ~15 m water column to the lake sediments from borehole melting had little effect on the stratigraphy of surficial sediment cores.","PeriodicalId":8211,"journal":{"name":"Annals of Glaciology","volume":"62 1","pages":"340 - 352"},"PeriodicalIF":2.9,"publicationDate":"2021-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/aog.2021.10","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42511936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：