Articles | Volume 18, issue 4
https://doi.org/10.5194/tc-18-2081-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/tc-18-2081-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
30 Apr 2024
Research article |
| 30 Apr 2024
| 30 Apr 2024
Towards the systematic reconnaissance of seismic signals from glaciers and ice sheets – Part 2: Unsupervised learning for source process characterization
Rebecca B. Latto
CORRESPONDING AUTHOR
School of Natural Sciences (Physics), University of Tasmania, Private Bag 37, Hobart, TAS 7001, Australia
Ross J. Turner
School of Natural Sciences (Physics), University of Tasmania, Private Bag 37, Hobart, TAS 7001, Australia
Anya M. Reading
School of Natural Sciences (Physics), University of Tasmania, Private Bag 37, Hobart, TAS 7001, Australia
Australian Antarctic Program Partnership, Institute for Marine and Antarctic Studies, 20 Castray Esplanade, Battery Point, TAS 7004, Australia
Bernd Kulessa
Glaciology Group, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
J. Paul Winberry
Department of Geological Sciences, Central Washington University, Ellensburg, WA, USA
Related authors
Rebecca B. Latto, Ross J. Turner, Anya M. Reading, and J. Paul Winberry
The Cryosphere, 18, 2061–2079, https://doi.org/10.5194/tc-18-2061-2024, https://doi.org/10.5194/tc-18-2061-2024, 2024
Short summary
Short summary
The study of icequakes allows for investigation of many glacier processes that are unseen by typical reconnaissance methods. However, detection of such seismic signals is challenging due to low signal-to-noise levels and diverse source mechanisms. Here we present a novel algorithm that is optimized to detect signals from a glacier environment. We apply the algorithm to seismic data recorded in the 2010–2011 austral summer from the Whillans Ice Stream and evaluate the resulting event catalogue.
Robert G. Bingham, Julien A. Bodart, Marie G. P. Cavitte, Ailsa Chung, Rebecca J. Sanderson, Johannes C. R. Sutter, Olaf Eisen, Nanna B. Karlsson, Joseph A. MacGregor, Neil Ross, Duncan A. Young, David W. Ashmore, Andreas Born, Winnie Chu, Xiangbin Cui, Reinhard Drews, Steven Franke, Vikram Goel, John W. Goodge, A. Clara J. Henry, Antoine Hermant, Benjamin H. Hills, Nicholas Holschuh, Michelle R. Koutnik, Gwendolyn J.-M. C. Leysinger Vieli, Emma J. Mackie, Elisa Mantelli, Carlos Martín, Felix S. L. Ng, Falk M. Oraschewski, Felipe Napoleoni, Frédéric Parrenin, Sergey V. Popov, Therese Rieckh, Rebecca Schlegel, Dustin M. Schroeder, Martin J. Siegert, Xueyuan Tang, Thomas O. Teisberg, Kate Winter, Shuai Yan, Harry Davis, Christine F. Dow, Tyler J. Fudge, Tom A. Jordan, Bernd Kulessa, Kenichi Matsuoka, Clara J. Nyqvist, Maryam Rahnemoonfar, Matthew R. Siegfried, Shivangini Singh, Verjan Višnjević, Rodrigo Zamora, and Alexandra Zuhr
EGUsphere, https://doi.org/10.5194/egusphere-2024-2593, https://doi.org/10.5194/egusphere-2024-2593, 2024
Short summary
Short summary
The ice sheets covering Antarctica have built up over millenia through successive snowfall events which become buried and preserved as internal surfaces of equal age detectable with ice-penetrating radar. This paper describes an international initiative to work together on this archival data to build a comprehensive 3-D picture of how old the ice is everywhere across Antarctica, and how this will be used to reconstruct past and predict future ice and climate behaviour.
Rebecca B. Latto, Ross J. Turner, Anya M. Reading, and J. Paul Winberry
The Cryosphere, 18, 2061–2079, https://doi.org/10.5194/tc-18-2061-2024, https://doi.org/10.5194/tc-18-2061-2024, 2024
Short summary
Short summary
The study of icequakes allows for investigation of many glacier processes that are unseen by typical reconnaissance methods. However, detection of such seismic signals is challenging due to low signal-to-noise levels and diverse source mechanisms. Here we present a novel algorithm that is optimized to detect signals from a glacier environment. We apply the algorithm to seismic data recorded in the 2010–2011 austral summer from the Whillans Ice Stream and evaluate the resulting event catalogue.
Felicity S. McCormack, Jason L. Roberts, Bernd Kulessa, Alan Aitken, Christine F. Dow, Lawrence Bird, Benjamin K. Galton-Fenzi, Katharina Hochmuth, Richard S. Jones, Andrew N. Mackintosh, and Koi McArthur
The Cryosphere, 17, 4549–4569, https://doi.org/10.5194/tc-17-4549-2023, https://doi.org/10.5194/tc-17-4549-2023, 2023
Short summary
Short summary
Changes in Antarctic surface elevation can cause changes in ice and basal water flow, impacting how much ice enters the ocean. We find that ice and basal water flow could divert from the Totten to the Vanderford Glacier, East Antarctica, under only small changes in the surface elevation, with implications for estimates of ice loss from this region. Further studies are needed to determine when this could occur and if similar diversions could occur elsewhere in Antarctica due to climate change.
Sarah S. Thompson, Bernd Kulessa, Adrian Luckman, Jacqueline A. Halpin, Jamin S. Greenbaum, Tyler Pelle, Feras Habbal, Jingxue Guo, Lenneke M. Jong, Jason L. Roberts, Bo Sun, and Donald D. Blankenship
The Cryosphere, 17, 157–174, https://doi.org/10.5194/tc-17-157-2023, https://doi.org/10.5194/tc-17-157-2023, 2023
Short summary
Short summary
We use satellite imagery and ice penetrating radar to investigate the stability of the Shackleton system in East Antarctica. We find significant changes in surface structures across the system and observe a significant increase in ice flow speed (up to 50 %) on the floating part of Scott Glacier. We conclude that knowledge remains woefully insufficient to explain recent observed changes in the grounded and floating regions of the system.
Molly O. Patterson, Richard H. Levy, Denise K. Kulhanek, Tina van de Flierdt, Huw Horgan, Gavin B. Dunbar, Timothy R. Naish, Jeanine Ash, Alex Pyne, Darcy Mandeno, Paul Winberry, David M. Harwood, Fabio Florindo, Francisco J. Jimenez-Espejo, Andreas Läufer, Kyu-Cheul Yoo, Osamu Seki, Paolo Stocchi, Johann P. Klages, Jae Il Lee, Florence Colleoni, Yusuke Suganuma, Edward Gasson, Christian Ohneiser, José-Abel Flores, David Try, Rachel Kirkman, Daleen Koch, and the SWAIS 2C Science Team
Sci. Dril., 30, 101–112, https://doi.org/10.5194/sd-30-101-2022, https://doi.org/10.5194/sd-30-101-2022, 2022
Short summary
Short summary
How much of the West Antarctic Ice Sheet will melt and how quickly it will happen when average global temperatures exceed 2 °C is currently unknown. Given the far-reaching and international consequences of Antarctica’s future contribution to global sea level rise, the SWAIS 2C Project was developed in order to better forecast the size and timing of future changes.
Lisa Craw, Adam Treverrow, Sheng Fan, Mark Peternell, Sue Cook, Felicity McCormack, and Jason Roberts
The Cryosphere, 15, 2235–2250, https://doi.org/10.5194/tc-15-2235-2021, https://doi.org/10.5194/tc-15-2235-2021, 2021
Short summary
Short summary
Ice sheet and ice shelf models rely on data from experiments to accurately represent the way ice moves. Performing experiments at the temperatures and stresses that are generally present in nature takes a long time, and so there are few of these datasets. Here, we test the method of speeding up an experiment by running it initially at a higher temperature, before dropping to a lower target temperature to generate the relevant data. We show that this method can reduce experiment time by 55 %.
Mohammed Bello, David G. Cornwell, Nicholas Rawlinson, Anya M. Reading, and Othaniel K. Likkason
Solid Earth, 12, 463–481, https://doi.org/10.5194/se-12-463-2021, https://doi.org/10.5194/se-12-463-2021, 2021
Short summary
Short summary
In this study, ground motion caused by distant earthquakes recorded in southeast Australia is used to image the structure of the crust and underlying mantle. This part of the Australian continent was assembled over the last 500 million years, but it remains poorly understood. By studying variations in crustal properties and thickness, we find evidence for the presence of an old microcontinent that is embedded in the younger terrane and forms a connection between Victoria and Tasmania.
Alex Brisbourne, Bernd Kulessa, Thomas Hudson, Lianne Harrison, Paul Holland, Adrian Luckman, Suzanne Bevan, David Ashmore, Bryn Hubbard, Emma Pearce, James White, Adam Booth, Keith Nicholls, and Andrew Smith
Earth Syst. Sci. Data, 12, 887–896, https://doi.org/10.5194/essd-12-887-2020, https://doi.org/10.5194/essd-12-887-2020, 2020
Short summary
Short summary
Melting of the Larsen C Ice Shelf in Antarctica may lead to its collapse. To help estimate its lifespan we need to understand how the ocean can circulate beneath. This requires knowledge of the geometry of the sub-shelf cavity. New and existing measurements of seabed depth are integrated to produce a map of the ocean cavity beneath the ice shelf. The observed deep seabed may provide a pathway for circulation of warm ocean water but at the same time reduce rapid tidal melt at a critical location.
Sue Cook, Benjamin K. Galton-Fenzi, Stefan R. M. Ligtenberg, and Richard Coleman
The Cryosphere, 12, 3853–3859, https://doi.org/10.5194/tc-12-3853-2018, https://doi.org/10.5194/tc-12-3853-2018, 2018
Short summary
Short summary
When the porous compacted snow layers on an ice shelf extend below sea level, seawater is able to infiltrate onto the shelf. Here it can affect measurements of ice shelf thickness by changing the average density and affect iceberg calving if the seawater enters fractures. Seawater infiltration has only been directly observed in a few locations around Antarctica. Using continent-wide geometry and snow density data we show that it may be more widespread than previously realised.
Sue Cook, Jan Åström, Thomas Zwinger, Benjamin Keith Galton-Fenzi, Jamin Stevens Greenbaum, and Richard Coleman
The Cryosphere, 12, 2401–2411, https://doi.org/10.5194/tc-12-2401-2018, https://doi.org/10.5194/tc-12-2401-2018, 2018
Short summary
Short summary
The growth of fractures on Antarctic ice shelves is important because it controls the amount of ice lost as icebergs. We use a model constructed of multiple interconnected blocks to predict the locations where fractures will form on the Totten Ice Shelf in East Antarctica. The results show that iceberg calving is controlled not only by fractures forming near the front of the ice shelf but also by fractures which formed many kilometres upstream.
Suzanne L. Bevan, Adrian Luckman, Bryn Hubbard, Bernd Kulessa, David Ashmore, Peter Kuipers Munneke, Martin O'Leary, Adam Booth, Heidi Sevestre, and Daniel McGrath
The Cryosphere, 11, 2743–2753, https://doi.org/10.5194/tc-11-2743-2017, https://doi.org/10.5194/tc-11-2743-2017, 2017
Short summary
Short summary
Five 90 m boreholes drilled into an Antarctic Peninsula ice shelf show units of ice that are denser than expected and must have formed from refrozen surface melt which has been buried and transported downstream. We used surface flow speeds and snow accumulation rates to work out where and when these units formed. Results show that, as well as recent surface melt, a period of strong melt occurred during the 18th century. Surface melt is thought to be a factor in causing recent ice-shelf break-up.
Peter Kuipers Munneke, Daniel McGrath, Brooke Medley, Adrian Luckman, Suzanne Bevan, Bernd Kulessa, Daniela Jansen, Adam Booth, Paul Smeets, Bryn Hubbard, David Ashmore, Michiel Van den Broeke, Heidi Sevestre, Konrad Steffen, Andrew Shepherd, and Noel Gourmelen
The Cryosphere, 11, 2411–2426, https://doi.org/10.5194/tc-11-2411-2017, https://doi.org/10.5194/tc-11-2411-2017, 2017
Short summary
Short summary
How much snow falls on the Larsen C ice shelf? This is a relevant question, because this ice shelf might collapse sometime this century. To know if and when this could happen, we found out how much snow falls on its surface. This was difficult, because there are only very few measurements. Here, we used data from automatic weather stations, sled-pulled radars, and a climate model to find that melting the annual snowfall produces about 20 cm of water in the NE and over 70 cm in the SW.
Sarah S. Thompson, Bernd Kulessa, Richard L. H. Essery, and Martin P. Lüthi
The Cryosphere, 10, 433–444, https://doi.org/10.5194/tc-10-433-2016, https://doi.org/10.5194/tc-10-433-2016, 2016
Short summary
Short summary
We show that strong electrical self-potential fields are generated in melting in in situ snowpacks at Rhone Glacier and Jungfraujoch Glacier, Switzerland. We conclude that the electrical self-potential method is a promising snow and firn hydrology sensor, owing to its suitability for sensing lateral and vertical liquid water flows directly and minimally invasively, complementing established observational programs and monitoring autonomously at a low cost.
D. Jansen, A. J. Luckman, A. Cook, S. Bevan, B. Kulessa, B. Hubbard, and P. R. Holland
The Cryosphere, 9, 1223–1227, https://doi.org/10.5194/tc-9-1223-2015, https://doi.org/10.5194/tc-9-1223-2015, 2015
Short summary
Short summary
Within the last year, a large rift in the southern part of the Larsen C Ice Shelf, Antarctic Peninsula, propagated towards the inner part of the ice shelf. In this study we present the development of the rift as derived from remote sensing data and assess the impact of possible calving scenarios on the future stability of the Larsen C Ice Shelf, using a numerical model. We find that the calving front is likely to become unstable after the anticipated calving events.
S. H. Doyle, A. L. Hubbard, C. F. Dow, G. A. Jones, A. Fitzpatrick, A. Gusmeroli, B. Kulessa, K. Lindback, R. Pettersson, and J. E. Box
The Cryosphere, 7, 129–140, https://doi.org/10.5194/tc-7-129-2013, https://doi.org/10.5194/tc-7-129-2013, 2013
Related subject area
Discipline: Ice sheets | Subject: Antarctic
Thwaites Glacier thins and retreats fastest where ice-shelf channels intersect its grounding zone
Melt sensitivity of irreversible retreat of Pine Island Glacier
A model framework for atmosphere–snow water vapor exchange and the associated isotope effects at Dome Argus, Antarctica – Part 1: The diurnal changes
The long-term sea-level commitment from Antarctica
The influence of present-day regional surface mass balance uncertainties on the future evolution of the Antarctic Ice Sheet
How well can satellite altimetry and firn models resolve Antarctic firn thickness variations?
Feedback mechanisms controlling Antarctic glacial-cycle dynamics simulated with a coupled ice sheet–solid Earth model
The effect of ice shelf rheology on shelf edge bending
Hysteresis of idealized, instability-prone outlet glaciers in response to pinning-point buttressing variation
A physics-based Antarctic melt detection technique: combining Advanced Microwave Scanning Radiometer 2, radiative-transfer modeling, and firn modeling
Brief communication: Precision measurement of the index of refraction of deep glacial ice at radio frequencies at Summit Station, Greenland
Widespread increase in discharge from west Antarctic Peninsula glaciers since 2018
Surface dynamics and history of the calving cycle of Astrolabe Glacier (Adélie Coast, Antarctica) derived from satellite imagery
Detecting Holocene retreat and readvance in the Amundsen Sea sector of Antarctica: assessing the suitability of sites near Pine Island Glacier for subglacial bedrock drilling
Weak relationship between remotely detected crevasses and inferred ice rheological parameters on Antarctic ice shelves
Extensive palaeo-surfaces beneath the Evans–Rutford region of the West Antarctic Ice Sheet control modern and past ice flow
Towards the systematic reconnaissance of seismic signals from glaciers and ice sheets – Part 1: Event detection for cryoseismology
Geometric amplification and suppression of ice-shelf basal melt in West Antarctica
Alpine topography of the Gamburtsev Subglacial Mountains, Antarctica, mapped from ice sheet surface morphology
A fast and unified subglacial hydrological model applied to Thwaites Glacier, Antarctica
Impact of boundary conditions on the modeled thermal regime of the Antarctic ice sheet
The staggered retreat of grounded ice in the Ross Sea, Antarctica, since the Last Glacial Maximum (LGM)
The effect of landfast sea ice buttressing on ice dynamic speedup in the Larsen B embayment, Antarctica
ISMIP6-based Antarctic Projections to 2100: simulations with the BISICLES ice sheet model
Meteoric water and glacial melt in the southeastern Amundsen Sea: a time series from 1994 to 2020
Evaporative controls on Antarctic precipitation: an ECHAM6 model study using innovative water tracer diagnostics
Disentangling the drivers of future Antarctic ice loss with a historically calibrated ice-sheet model
Modelling GNSS-observed seasonal velocity changes of the Ross Ice Shelf, Antarctica, using the Ice-sheet and Sea-level System Model (ISSM)
Insights into the vulnerability of Antarctic glaciers from the ISMIP6 ice sheet model ensemble and associated uncertainty
Evaluation of four calving laws for Antarctic ice shelves
Oceanic gateways in Antarctica – Impact of relative sea-level change on sub-shelf melt
Englacial architecture of Lambert Glacier, East Antarctica
Mass changes of the northern Antarctic Peninsula Ice Sheet derived from repeat bi-static synthetic aperture radar acquisitions for the period 2013–2017
The evolution of future Antarctic surface melt using PISM-dEBM-simple
Characteristics and rarity of the strong 1940s westerly wind event over the Amundsen Sea, West Antarctica
Sensitivity of the MAR regional climate model snowpack to the parameterization of the assimilation of satellite-derived wet-snow masks on the Antarctic Peninsula
Stratigraphic noise and its potential drivers across the plateau of Dronning Maud Land, East Antarctica
Modes of Antarctic tidal grounding line migration revealed by Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) laser altimetry
Evaluating the impact of enhanced horizontal resolution over the Antarctic domain using a variable-resolution Earth system model
Statistically parameterizing and evaluating a positive degree-day model to estimate surface melt in Antarctica from 1979 to 2022
Widespread slowdown in thinning rates of West Antarctic ice shelves
Seasonal variability in Antarctic ice shelf velocities forced by sea surface height variations
Revisiting temperature sensitivity: how does Antarctic precipitation change with temperature?
Cosmogenic-nuclide data from Antarctic nunataks can constrain past ice sheet instabilities
Exploring ice sheet model sensitivity to ocean thermal forcing and basal sliding using the Community Ice Sheet Model (CISM)
High mid-Holocene accumulation rates over West Antarctica inferred from a pervasive ice-penetrating radar reflector
Seasonal and interannual variability of the landfast ice mass balance between 2009 and 2018 in Prydz Bay, East Antarctica
Megadunes in Antarctica: migration and characterization from remote and in situ observations
Slowdown of Shirase Glacier, East Antarctica, caused by strengthening alongshore winds
Timescales of outlet-glacier flow with negligible basal friction: theory, observations and modeling
Allison M. Chartrand, Ian M. Howat, Ian R. Joughin, and Benjamin E. Smith
The Cryosphere, 18, 4971–4992, https://doi.org/10.5194/tc-18-4971-2024, https://doi.org/10.5194/tc-18-4971-2024, 2024
Short summary
Short summary
This study uses high-resolution remote-sensing data to show that shrinking of the West Antarctic Thwaites Glacier’s ice shelf (floating extension) is exacerbated by several sub-ice-shelf meltwater channels that form as the glacier transitions from full contact with the seafloor to fully floating. In mapping these channels, the position of the transition zone, and thinning rates of the Thwaites Glacier, this work elucidates important processes driving its rapid contribution to sea level rise.
Brad Reed, J. A. Mattias Green, Adrian Jenkins, and G. Hilmar Gudmundsson
The Cryosphere, 18, 4567–4587, https://doi.org/10.5194/tc-18-4567-2024, https://doi.org/10.5194/tc-18-4567-2024, 2024
Short summary
Short summary
We use a numerical ice-flow model to simulate the response of a 1940s Pine Island Glacier to changes in melting beneath its ice shelf. A decadal period of warm forcing is sufficient to push the glacier into an unstable, irreversible retreat from its long-term position on a subglacial ridge to an upstream ice plain. This retreat can only be stopped when unrealistic cold forcing is applied. These results show that short warm anomalies can lead to quick and substantial increases in ice flux.
Tianming Ma, Zhuang Jiang, Minghu Ding, Pengzhen He, Yuansheng Li, Wenqian Zhang, and Lei Geng
The Cryosphere, 18, 4547–4565, https://doi.org/10.5194/tc-18-4547-2024, https://doi.org/10.5194/tc-18-4547-2024, 2024
Short summary
Short summary
We constructed a box model to evaluate the isotope effects of atmosphere–snow water vapor exchange at Dome A, Antarctica. The results show clear and invisible diurnal changes in surface snow isotopes under summer and winter conditions, respectively. The model also predicts that the annual net effects of atmosphere–snow water vapor exchange would be overall enrichments in snow isotopes since the effects in summer appear to be greater than those in winter at the study site.
Ann Kristin Klose, Violaine Coulon, Frank Pattyn, and Ricarda Winkelmann
The Cryosphere, 18, 4463–4492, https://doi.org/10.5194/tc-18-4463-2024, https://doi.org/10.5194/tc-18-4463-2024, 2024
Short summary
Short summary
We systematically assess the long-term sea-level response from Antarctica to warming projected over the next centuries, using two ice-sheet models. We show that this committed Antarctic sea-level contribution is substantially higher than the transient sea-level change projected for the coming decades. A low-emission scenario already poses considerable risk of multi-meter sea-level increase over the next millennia, while additional East Antarctic ice loss unfolds under the high-emission pathway.
Christian Wirths, Thomas F. Stocker, and Johannes C. R. Sutter
The Cryosphere, 18, 4435–4462, https://doi.org/10.5194/tc-18-4435-2024, https://doi.org/10.5194/tc-18-4435-2024, 2024
Short summary
Short summary
We investigated the influence of several regional climate models on the Antarctic Ice Sheet when applied as forcing for the Parallel Ice Sheet Model (PISM). Our study shows that the choice of regional climate model forcing results in uncertainties of around a tenth of those in future sea level rise projections and also affects the extent of grounding line retreat in West Antarctica.
Maria T. Kappelsberger, Martin Horwath, Eric Buchta, Matthias O. Willen, Ludwig Schröder, Sanne B. M. Veldhuijsen, Peter Kuipers Munneke, and Michiel R. van den Broeke
The Cryosphere, 18, 4355–4378, https://doi.org/10.5194/tc-18-4355-2024, https://doi.org/10.5194/tc-18-4355-2024, 2024
Short summary
Short summary
The interannual variations in the height of the Antarctic Ice Sheet (AIS) are mainly due to natural variations in snowfall. Precise knowledge of these variations is important for the detection of any long-term climatic trends in AIS surface elevation. We present a new product that spatially resolves these height variations over the period 1992–2017. The product combines the strengths of atmospheric modeling results and satellite altimetry measurements.
Torsten Albrecht, Meike Bagge, and Volker Klemann
The Cryosphere, 18, 4233–4255, https://doi.org/10.5194/tc-18-4233-2024, https://doi.org/10.5194/tc-18-4233-2024, 2024
Short summary
Short summary
We performed coupled ice sheet–solid Earth simulations and discovered a positive (forebulge) feedback mechanism for advancing grounding lines, supporting a larger West Antarctic Ice Sheet during the Last Glacial Maximum. During deglaciation we found that the stabilizing glacial isostatic adjustment feedback dominates grounding-line retreat in the Ross Sea, with a weak Earth structure. This may have consequences for present and future ice sheet stability and potential rates of sea-level rise.
W. Roger Buck
The Cryosphere, 18, 4165–4176, https://doi.org/10.5194/tc-18-4165-2024, https://doi.org/10.5194/tc-18-4165-2024, 2024
Short summary
Short summary
Standard theory predicts that the edge of an ice shelf should bend downward. Satellite observations show that the edges of many ice shelves bend upward. A new theory for ice shelf bending is developed that, for the first time, includes the kind of vertical variations in ice flow properties expected for ice shelves. Upward bending of shelf edges is predicted as long as the ice surface is very cold and the ice flow properties depend strongly on temperature.
Johannes Feldmann, Anders Levermann, and Ricarda Winkelmann
The Cryosphere, 18, 4011–4028, https://doi.org/10.5194/tc-18-4011-2024, https://doi.org/10.5194/tc-18-4011-2024, 2024
Short summary
Short summary
Here we show in simplified simulations that the (ir)reversibility of the retreat of instability-prone, Antarctica-type glaciers can strongly depend on the depth of the bed depression they rest on. If it is sufficiently deep, then the destabilized glacier does not recover from its collapsed state. Our results suggest that glaciers resting on a wide and deep bed depression, such as Antarctica's Thwaites Glacier, are particularly susceptible to irreversible retreat.
Marissa E. Dattler, Brooke Medley, and C. Max Stevens
The Cryosphere, 18, 3613–3631, https://doi.org/10.5194/tc-18-3613-2024, https://doi.org/10.5194/tc-18-3613-2024, 2024
Short summary
Short summary
We developed an algorithm based on combining models and satellite observations to identify the presence of surface melt on the Antarctic Ice Sheet. We find that this method works similarly to previous methods by assessing 13 sites and the Larsen C ice shelf. Unlike previous methods, this algorithm is based on physical parameters, and updates to this method could allow the meltwater present on the Antarctic Ice Sheet to be quantified instead of simply detected.
Christoph Welling and The RNO-G Collaboration
The Cryosphere, 18, 3433–3437, https://doi.org/10.5194/tc-18-3433-2024, https://doi.org/10.5194/tc-18-3433-2024, 2024
Short summary
Short summary
We report on the measurement of the index of refraction in glacial ice at radio frequencies. We show that radio echoes from within the ice can be associated with specific features of the ice conductivity and use this to determine the wave velocity. This measurement is especially relevant for the Radio Neutrino Observatory Greenland (RNO-G), a neutrino detection experiment currently under construction at Summit Station, Greenland.
Benjamin J. Davison, Anna E. Hogg, Carlos Moffat, Michael P. Meredith, and Benjamin J. Wallis
The Cryosphere, 18, 3237–3251, https://doi.org/10.5194/tc-18-3237-2024, https://doi.org/10.5194/tc-18-3237-2024, 2024
Short summary
Short summary
Using a new dataset of ice motion, we observed glacier acceleration on the west coast of the Antarctic Peninsula. The speed-up began around January 2021, but some glaciers sped up earlier or later. Using a combination of ship-based ocean temperature observations and climate models, we show that the speed-up coincided with a period of unusually warm air and ocean temperatures in the region.
Floriane Provost, Dimitri Zigone, Emmanuel Le Meur, Jean-Philippe Malet, and Clément Hibert
The Cryosphere, 18, 3067–3079, https://doi.org/10.5194/tc-18-3067-2024, https://doi.org/10.5194/tc-18-3067-2024, 2024
Short summary
Short summary
The recent calving of Astrolabe Glacier in November 2021 presents an opportunity to better understand the processes leading to ice fracturing. Optical-satellite imagery is used to retrieve the calving cycle of the glacier ice tongue and to measure the ice velocity and strain rates in order to document fracture evolution. We observed that the presence of sea ice for consecutive years has favoured the glacier extension but failed to inhibit the growth of fractures that accelerated in June 2021.
Joanne S. Johnson, John Woodward, Ian Nesbitt, Kate Winter, Seth Campbell, Keir A. Nichols, Ryan A. Venturelli, Scott Braddock, Brent M. Goehring, Brenda Hall, Dylan H. Rood, and Greg Balco
EGUsphere, https://doi.org/10.5194/egusphere-2024-1452, https://doi.org/10.5194/egusphere-2024-1452, 2024
Short summary
Short summary
Determining where and when the Antarctic ice sheet was smaller than present requires recovery and exposure dating of subglacial bedrock. Here we use ice sheet model outputs and field data (geological and glaciological observations, bedrock samples and ground-penetrating radar from subglacial ridges) to assess the suitability for drilling of sites in the Hudson Mountains, West Antarctica. We find that no sites are perfect, but two are feasible, with the most suitable being Winkie Nunatak.
Cristina Gerli, Sebastian Rosier, G. Hilmar Gudmundsson, and Sainan Sun
The Cryosphere, 18, 2677–2689, https://doi.org/10.5194/tc-18-2677-2024, https://doi.org/10.5194/tc-18-2677-2024, 2024
Short summary
Short summary
Recent efforts have focused on using AI and satellite imagery to track crevasses for assessing ice shelf damage and informing ice flow models. Our study reveals a weak connection between these observed products and damage maps inferred from ice flow models. While there is some improvement in crevasse-dense regions, this association remains limited. Directly mapping ice damage from satellite observations may not significantly improve the representation of these processes within ice flow models.
Charlotte M. Carter, Michael J. Bentley, Stewart S. R. Jamieson, Guy J. G. Paxman, Tom A. Jordan, Julien A. Bodart, Neil Ross, and Felipe Napoleoni
The Cryosphere, 18, 2277–2296, https://doi.org/10.5194/tc-18-2277-2024, https://doi.org/10.5194/tc-18-2277-2024, 2024
Short summary
Short summary
We use radio-echo sounding data to investigate the presence of flat surfaces beneath the Evans–Rutford region in West Antarctica. These surfaces may be what remains of laterally continuous surfaces, formed before the inception of the West Antarctic Ice Sheet, and we assess two hypotheses for their formation. Tectonic structures in the region may have also had a control on the growth of the ice sheet by focusing ice flow into troughs adjoining these surfaces.
Rebecca B. Latto, Ross J. Turner, Anya M. Reading, and J. Paul Winberry
The Cryosphere, 18, 2061–2079, https://doi.org/10.5194/tc-18-2061-2024, https://doi.org/10.5194/tc-18-2061-2024, 2024
Short summary
Short summary
The study of icequakes allows for investigation of many glacier processes that are unseen by typical reconnaissance methods. However, detection of such seismic signals is challenging due to low signal-to-noise levels and diverse source mechanisms. Here we present a novel algorithm that is optimized to detect signals from a glacier environment. We apply the algorithm to seismic data recorded in the 2010–2011 austral summer from the Whillans Ice Stream and evaluate the resulting event catalogue.
Jan De Rydt and Kaitlin Naughten
The Cryosphere, 18, 1863–1888, https://doi.org/10.5194/tc-18-1863-2024, https://doi.org/10.5194/tc-18-1863-2024, 2024
Short summary
Short summary
The West Antarctic Ice Sheet is losing ice at an accelerating pace. This is largely due to the presence of warm ocean water around the periphery of the Antarctic continent, which melts the ice. It is generally assumed that the strength of this process is controlled by the temperature of the ocean. However, in this study we show that an equally important role is played by the changing geometry of the ice sheet, which affects the strength of the ocean currents and thereby the melt rates.
Edmund J. Lea, Stewart S. R. Jamieson, and Michael J. Bentley
The Cryosphere, 18, 1733–1751, https://doi.org/10.5194/tc-18-1733-2024, https://doi.org/10.5194/tc-18-1733-2024, 2024
Short summary
Short summary
We use the ice surface expression of the Gamburtsev Subglacial Mountains in East Antarctica to map the horizontal pattern of valleys and ridges in finer detail than possible from previous methods. In upland areas, valleys are spaced much less than 5 km apart, with consequences for the distribution of melting at the bed and hence the likelihood of ancient ice being preserved. Automated mapping techniques were tested alongside manual approaches, with a hybrid approach recommended for future work.
Elise Kazmierczak, Thomas Gregov, Violaine Coulon, and Frank Pattyn
EGUsphere, https://doi.org/10.5194/egusphere-2024-466, https://doi.org/10.5194/egusphere-2024-466, 2024
Short summary
Short summary
We introduce a new fast model for the water flow beneath the ice sheet capable of handling in a unified way various hydrological and bed conditions. Applying this model to Thwaites Glacier, we show that accounting for this water flow in ice-sheet model projections has the potential to greatly increase the contribution to future sea-level rise. We also demonstrate that the sensitivity of the ice sheet in response to external changes depends on both the efficiency of the drainage and the bed type.
In-Woo Park, Emilia Kyung Jin, Mathieu Morlighem, and Kang-Kun Lee
The Cryosphere, 18, 1139–1155, https://doi.org/10.5194/tc-18-1139-2024, https://doi.org/10.5194/tc-18-1139-2024, 2024
Short summary
Short summary
This study conducted 3D thermodynamic ice sheet model experiments, and modeled temperatures were compared with 15 observed borehole temperature profiles. We found that using incompressibility of ice without sliding agrees well with observed temperature profiles in slow-flow regions, while incorporating sliding in fast-flow regions captures observed temperature profiles. Also, the choice of vertical velocity scheme has a greater impact on the shape of the modeled temperature profile.
Matthew A. Danielson and Philip J. Bart
The Cryosphere, 18, 1125–1138, https://doi.org/10.5194/tc-18-1125-2024, https://doi.org/10.5194/tc-18-1125-2024, 2024
Short summary
Short summary
The post-Last Glacial Maximum (LGM) retreat of the West Antarctic Ice Sheet in the Ross Sea was more significant than for any other Antarctic sector. Here we combined the available dates of retreat with new mapping of sediment deposited by the ice sheet during overall retreat. Our work shows that the post-LGM retreat through the Ross Sea was not uniform. This uneven retreat can cause instability in the present-day Antarctic ice sheet configuration and lead to future runaway retreat.
Trystan Surawy-Stepney, Anna E. Hogg, Stephen L. Cornford, Benjamin J. Wallis, Benjamin J. Davison, Heather L. Selley, Ross A. W. Slater, Elise K. Lie, Livia Jakob, Andrew Ridout, Noel Gourmelen, Bryony I. D. Freer, Sally F. Wilson, and Andrew Shepherd
The Cryosphere, 18, 977–993, https://doi.org/10.5194/tc-18-977-2024, https://doi.org/10.5194/tc-18-977-2024, 2024
Short summary
Short summary
Here, we use satellite observations and an ice flow model to quantify the impact of sea ice buttressing on ice streams on the Antarctic Peninsula. The evacuation of 11-year-old landfast sea ice in the Larsen B embayment on the East Antarctic Peninsula in January 2022 was closely followed by major changes in the calving behaviour and acceleration (30 %) of the ocean-terminating glaciers. Our results show that sea ice buttressing had a negligible direct role in the observed dynamic changes.
James F. O'Neill, Tamsin L. Edwards, Daniel F. Martin, Courtney Shafer, Stephen L. Cornford, Helene L. Seroussi, Sophie Nowicki, and Mira Adhikari
EGUsphere, https://doi.org/10.5194/egusphere-2024-441, https://doi.org/10.5194/egusphere-2024-441, 2024
Short summary
Short summary
We use an ice sheet model to simulate the Antarctic contribution to sea level over the 21st century, under a range of future climates, varying how sensitive the ice sheet is to different processes. We find that, under stronger warming scenarios, ocean temperatures increases and more snow falls on the ice sheet. When the ice sheet is sensitive to ocean warming, ocean melting driven loss exceeds snowfall driven gains, so that the sea level contribution is greater with more climate warming.
Andrew N. Hennig, David A. Mucciarone, Stanley S. Jacobs, Richard A. Mortlock, and Robert B. Dunbar
The Cryosphere, 18, 791–818, https://doi.org/10.5194/tc-18-791-2024, https://doi.org/10.5194/tc-18-791-2024, 2024
Short summary
Short summary
A total of 937 seawater paired oxygen isotope (δ18O)–salinity samples collected during seven cruises on the SE Amundsen Sea between 1994 and 2020 reveal a deep freshwater source with δ18O − 29.4±1.0‰, consistent with the signature of local ice shelf melt. Local mean meteoric water content – comprised primarily of glacial meltwater – increased between 1994 and 2020 but exhibited greater interannual variability than increasing trend.
Qinggang Gao, Louise C. Sime, Alison J. McLaren, Thomas J. Bracegirdle, Emilie Capron, Rachael H. Rhodes, Hans Christian Steen-Larsen, Xiaoxu Shi, and Martin Werner
The Cryosphere, 18, 683–703, https://doi.org/10.5194/tc-18-683-2024, https://doi.org/10.5194/tc-18-683-2024, 2024
Short summary
Short summary
Antarctic precipitation is a crucial component of the climate system. Its spatio-temporal variability impacts sea level changes and the interpretation of water isotope measurements in ice cores. To better understand its climatic drivers, we developed water tracers in an atmospheric model to identify moisture source conditions from which precipitation originates. We find that mid-latitude surface winds exert an important control on moisture availability for Antarctic precipitation.
Violaine Coulon, Ann Kristin Klose, Christoph Kittel, Tamsin Edwards, Fiona Turner, Ricarda Winkelmann, and Frank Pattyn
The Cryosphere, 18, 653–681, https://doi.org/10.5194/tc-18-653-2024, https://doi.org/10.5194/tc-18-653-2024, 2024
Short summary
Short summary
We present new projections of the evolution of the Antarctic ice sheet until the end of the millennium, calibrated with observations. We show that the ocean will be the main trigger of future ice loss. As temperatures continue to rise, the atmosphere's role may shift from mitigating to amplifying Antarctic mass loss already by the end of the century. For high-emission scenarios, this may lead to substantial sea-level rise. Adopting sustainable practices would however reduce the rate of ice loss.
Francesca Baldacchino, Nicholas R. Golledge, Huw Horgan, Mathieu Morlighem, Alanna V. Alevropoulos-Borrill, Alena Malyarenko, Alexandra Gossart, Daniel P. Lowry, and Laurine van Haastrecht
EGUsphere, https://doi.org/10.5194/egusphere-2023-2793, https://doi.org/10.5194/egusphere-2023-2793, 2023
Short summary
Short summary
Understanding how the Ross Ice Shelf flow is changing in a warming world is important for monitoring mass changes. The flow displays an intra-annual variation; however, it is unclear what mechanisms drive this variability. Sensitivity maps are modelled showing areas of the ice shelf where changes in basal melt most influence the ice flow. We suggest that basal melting partly drives the flow variability along the calving front of the ice shelf and will continue to do so in a warming world.
Hélène Seroussi, Vincent Verjans, Sophie Nowicki, Antony J. Payne, Heiko Goelzer, William H. Lipscomb, Ayako Abe-Ouchi, Cécile Agosta, Torsten Albrecht, Xylar Asay-Davis, Alice Barthel, Reinhard Calov, Richard Cullather, Christophe Dumas, Benjamin K. Galton-Fenzi, Rupert Gladstone, Nicholas R. Golledge, Jonathan M. Gregory, Ralf Greve, Tore Hattermann, Matthew J. Hoffman, Angelika Humbert, Philippe Huybrechts, Nicolas C. Jourdain, Thomas Kleiner, Eric Larour, Gunter R. Leguy, Daniel P. Lowry, Chistopher M. Little, Mathieu Morlighem, Frank Pattyn, Tyler Pelle, Stephen F. Price, Aurélien Quiquet, Ronja Reese, Nicole-Jeanne Schlegel, Andrew Shepherd, Erika Simon, Robin S. Smith, Fiammetta Straneo, Sainan Sun, Luke D. Trusel, Jonas Van Breedam, Peter Van Katwyk, Roderik S. W. van de Wal, Ricarda Winkelmann, Chen Zhao, Tong Zhang, and Thomas Zwinger
The Cryosphere, 17, 5197–5217, https://doi.org/10.5194/tc-17-5197-2023, https://doi.org/10.5194/tc-17-5197-2023, 2023
Short summary
Short summary
Mass loss from Antarctica is a key contributor to sea level rise over the 21st century, and the associated uncertainty dominates sea level projections. We highlight here the Antarctic glaciers showing the largest changes and quantify the main sources of uncertainty in their future evolution using an ensemble of ice flow models. We show that on top of Pine Island and Thwaites glaciers, Totten and Moscow University glaciers show rapid changes and a strong sensitivity to warmer ocean conditions.
Joel A. Wilner, Mathieu Morlighem, and Gong Cheng
The Cryosphere, 17, 4889–4901, https://doi.org/10.5194/tc-17-4889-2023, https://doi.org/10.5194/tc-17-4889-2023, 2023
Short summary
Short summary
We use numerical modeling to study iceberg calving off of ice shelves in Antarctica. We examine four widely used mathematical descriptions of calving (
calving laws), under the assumption that Antarctic ice shelf front positions should be in steady state under the current climate forcing. We quantify how well each of these calving laws replicates the observed front positions. Our results suggest that the eigencalving and von Mises laws are most suitable for Antarctic ice shelves.
Moritz Kreuzer, Torsten Albrecht, Lena Nicola, Ronja Reese, and Ricarda Winkelmann
EGUsphere, https://doi.org/10.5194/egusphere-2023-2737, https://doi.org/10.5194/egusphere-2023-2737, 2023
Short summary
Short summary
The study investigates how changing sea levels around Antarctica can potentially affect the floating ice shelves. It utilizes numerical models for both the Antarctic Ice Sheet and the solid Earth, investigating features like troughs and sills that control the flow of ocean water onto the continental shelf. The research finds that variations in sea level alone can significantly impact the melting rates of ice shelves.
Rebecca J. Sanderson, Kate Winter, S. Louise Callard, Felipe Napoleoni, Neil Ross, Tom A. Jordan, and Robert G. Bingham
The Cryosphere, 17, 4853–4871, https://doi.org/10.5194/tc-17-4853-2023, https://doi.org/10.5194/tc-17-4853-2023, 2023
Short summary
Short summary
Ice-penetrating radar allows us to explore the internal structure of glaciers and ice sheets to constrain past and present ice-flow conditions. In this paper, we examine englacial layers within the Lambert Glacier in East Antarctica using a quantitative layer tracing tool. Analysis reveals that the ice flow here has been relatively stable, but evidence for former fast flow along a tributary suggests that changes have occurred in the past and could change again in the future.
Thorsten Seehaus, Christian Sommer, Thomas Dethinne, and Philipp Malz
The Cryosphere, 17, 4629–4644, https://doi.org/10.5194/tc-17-4629-2023, https://doi.org/10.5194/tc-17-4629-2023, 2023
Short summary
Short summary
Existing mass budget estimates for the northern Antarctic Peninsula (>70° S) are affected by considerable limitations. We carried out the first region-wide analysis of geodetic mass balances throughout this region (coverage of 96.4 %) for the period 2013–2017 based on repeat pass bi-static TanDEM-X acquisitions. A total mass budget of −24.1±2.8 Gt/a is revealed. Imbalanced high ice discharge, particularly at former ice shelf tributaries, is the main driver of overall ice loss.
Julius Garbe, Maria Zeitz, Uta Krebs-Kanzow, and Ricarda Winkelmann
The Cryosphere, 17, 4571–4599, https://doi.org/10.5194/tc-17-4571-2023, https://doi.org/10.5194/tc-17-4571-2023, 2023
Short summary
Short summary
We adopt the novel surface module dEBM-simple in the Parallel Ice Sheet Model (PISM) to investigate the impact of atmospheric warming on Antarctic surface melt and long-term ice sheet dynamics. As an enhancement compared to traditional temperature-based melt schemes, the module accounts for changes in ice surface albedo and thus the melt–albedo feedback. Our results underscore the critical role of ice–atmosphere feedbacks in the future sea-level contribution of Antarctica on long timescales.
Gemma K. O'Connor, Paul R. Holland, Eric J. Steig, Pierre Dutrieux, and Gregory J. Hakim
The Cryosphere, 17, 4399–4420, https://doi.org/10.5194/tc-17-4399-2023, https://doi.org/10.5194/tc-17-4399-2023, 2023
Short summary
Short summary
Glaciers in West Antarctica are rapidly melting, but the causes are unknown due to limited observations. A leading hypothesis is that an unusually large wind event in the 1940s initiated the ocean-driven melting. Using proxy reconstructions (e.g., using ice cores) and climate model simulations, we find that wind events similar to the 1940s event are relatively common on millennial timescales, implying that ocean variability or climate trends are also necessary to explain the start of ice loss.
Thomas Dethinne, Quentin Glaude, Ghislain Picard, Christoph Kittel, Patrick Alexander, Anne Orban, and Xavier Fettweis
The Cryosphere, 17, 4267–4288, https://doi.org/10.5194/tc-17-4267-2023, https://doi.org/10.5194/tc-17-4267-2023, 2023
Short summary
Short summary
We investigate the sensitivity of the regional climate model
Modèle Atmosphérique Régional(MAR) to the assimilation of wet-snow occurrence estimated by remote sensing datasets. The assimilation is performed by nudging the MAR snowpack temperature. The data assimilation is performed over the Antarctic Peninsula for the 2019–2021 period. The results show an increase in the melt production (+66.7 %) and a decrease in surface mass balance (−4.5 %) of the model for the 2019–2020 melt season.
Nora Hirsch, Alexandra Zuhr, Thomas Münch, Maria Hörhold, Johannes Freitag, Remi Dallmayr, and Thomas Laepple
The Cryosphere, 17, 4207–4221, https://doi.org/10.5194/tc-17-4207-2023, https://doi.org/10.5194/tc-17-4207-2023, 2023
Short summary
Short summary
Stable water isotopes from firn cores provide valuable information on past climates, yet their utility is hampered by stratigraphic noise, i.e. the irregular deposition and wind-driven redistribution of snow. We found stratigraphic noise on the Antarctic Plateau to be related to the local accumulation rate, snow surface roughness and slope inclination, which can guide future decisions on sampling locations and thus increase the resolution of climate reconstructions from low-accumulation areas.
Bryony I. D. Freer, Oliver J. Marsh, Anna E. Hogg, Helen Amanda Fricker, and Laurie Padman
The Cryosphere, 17, 4079–4101, https://doi.org/10.5194/tc-17-4079-2023, https://doi.org/10.5194/tc-17-4079-2023, 2023
Short summary
Short summary
We develop a method using ICESat-2 data to measure how Antarctic grounding lines (GLs) migrate across the tide cycle. At an ice plain on the Ronne Ice Shelf we observe 15 km of tidal GL migration, the largest reported distance in Antarctica, dominating any signal of long-term migration. We identify four distinct migration modes, which provide both observational support for models of tidal ice flexure and GL migration and insights into ice shelf–ocean–subglacial interactions in grounding zones.
Rajashree Tri Datta, Adam Herrington, Jan T. M. Lenaerts, David P. Schneider, Luke Trusel, Ziqi Yin, and Devon Dunmire
The Cryosphere, 17, 3847–3866, https://doi.org/10.5194/tc-17-3847-2023, https://doi.org/10.5194/tc-17-3847-2023, 2023
Short summary
Short summary
Precipitation over Antarctica is one of the greatest sources of uncertainty in sea level rise estimates. Earth system models (ESMs) are a valuable tool for these estimates but typically run at coarse spatial resolutions. Here, we present an evaluation of the variable-resolution CESM2 (VR-CESM2) for the first time with a grid designed for enhanced spatial resolution over Antarctica to achieve the high resolution of regional climate models while preserving the two-way interactions of ESMs.
Yaowen Zheng, Nicholas R. Golledge, Alexandra Gossart, Ghislain Picard, and Marion Leduc-Leballeur
The Cryosphere, 17, 3667–3694, https://doi.org/10.5194/tc-17-3667-2023, https://doi.org/10.5194/tc-17-3667-2023, 2023
Short summary
Short summary
Positive degree-day (PDD) schemes are widely used in many Antarctic numerical ice sheet models. However, the PDD approach has not been systematically explored for its application in Antarctica. We have constructed a novel grid-cell-level spatially distributed PDD (dist-PDD) model and assessed its accuracy. We suggest that an appropriately parameterized dist-PDD model can be a valuable tool for exploring Antarctic surface melt beyond the satellite era.
Fernando S. Paolo, Alex S. Gardner, Chad A. Greene, Johan Nilsson, Michael P. Schodlok, Nicole-Jeanne Schlegel, and Helen A. Fricker
The Cryosphere, 17, 3409–3433, https://doi.org/10.5194/tc-17-3409-2023, https://doi.org/10.5194/tc-17-3409-2023, 2023
Short summary
Short summary
We report on a slowdown in the rate of thinning and melting of West Antarctic ice shelves. We present a comprehensive assessment of the Antarctic ice shelves, where we analyze at a continental scale the changes in thickness, flow, and basal melt over the past 26 years. We also present a novel method to estimate ice shelf change from satellite altimetry and a time-dependent data set of ice shelf thickness and basal melt rates at an unprecedented resolution.
Cyrille Mosbeux, Laurie Padman, Emilie Klein, Peter D. Bromirski, and Helen A. Fricker
The Cryosphere, 17, 2585–2606, https://doi.org/10.5194/tc-17-2585-2023, https://doi.org/10.5194/tc-17-2585-2023, 2023
Short summary
Short summary
Antarctica's ice shelves (the floating extension of the ice sheet) help regulate ice flow. As ice shelves thin or lose contact with the bedrock, the upstream ice tends to accelerate, resulting in increased mass loss. Here, we use an ice sheet model to simulate the effect of seasonal sea surface height variations and see if we can reproduce observed seasonal variability of ice velocity on the ice shelf. When correctly parameterised, the model fits the observations well.
Lena Nicola, Dirk Notz, and Ricarda Winkelmann
The Cryosphere, 17, 2563–2583, https://doi.org/10.5194/tc-17-2563-2023, https://doi.org/10.5194/tc-17-2563-2023, 2023
Short summary
Short summary
For future sea-level projections, approximating Antarctic precipitation increases through temperature-scaling approaches will remain important, as coupled ice-sheet simulations with regional climate models remain computationally expensive, especially on multi-centennial timescales. We here revisit the relationship between Antarctic temperature and precipitation using different scaling approaches, identifying and explaining regional differences.
Anna Ruth W. Halberstadt, Greg Balco, Hannah Buchband, and Perry Spector
The Cryosphere, 17, 1623–1643, https://doi.org/10.5194/tc-17-1623-2023, https://doi.org/10.5194/tc-17-1623-2023, 2023
Short summary
Short summary
This paper explores the use of multimillion-year exposure ages from Antarctic bedrock outcrops to benchmark ice sheet model predictions and thereby infer ice sheet sensitivity to warm climates. We describe a new approach for model–data comparison, highlight an example where observational data are used to distinguish end-member models, and provide guidance for targeted sampling around Antarctica that can improve understanding of ice sheet response to climate warming in the past and future.
Mira Berdahl, Gunter Leguy, William H. Lipscomb, Nathan M. Urban, and Matthew J. Hoffman
The Cryosphere, 17, 1513–1543, https://doi.org/10.5194/tc-17-1513-2023, https://doi.org/10.5194/tc-17-1513-2023, 2023
Short summary
Short summary
Contributions to future sea level from the Antarctic Ice Sheet remain poorly constrained. One reason is that ice sheet model initialization methods can have significant impacts on how the ice sheet responds to future forcings. We investigate the impacts of two key parameters used during model initialization. We find that these parameter choices alone can impact multi-century sea level rise by up to 2 m, emphasizing the need to carefully consider these choices for sea level rise predictions.
Julien A. Bodart, Robert G. Bingham, Duncan A. Young, Joseph A. MacGregor, David W. Ashmore, Enrica Quartini, Andrew S. Hein, David G. Vaughan, and Donald D. Blankenship
The Cryosphere, 17, 1497–1512, https://doi.org/10.5194/tc-17-1497-2023, https://doi.org/10.5194/tc-17-1497-2023, 2023
Short summary
Short summary
Estimating how West Antarctica will change in response to future climatic change depends on our understanding of past ice processes. Here, we use a reflector widely visible on airborne radar data across West Antarctica to estimate accumulation rates over the past 4700 years. By comparing our estimates with current atmospheric data, we find that accumulation rates were 18 % greater than modern rates. This has implications for our understanding of past ice processes in the region.
Na Li, Ruibo Lei, Petra Heil, Bin Cheng, Minghu Ding, Zhongxiang Tian, and Bingrui Li
The Cryosphere, 17, 917–937, https://doi.org/10.5194/tc-17-917-2023, https://doi.org/10.5194/tc-17-917-2023, 2023
Short summary
Short summary
The observed annual maximum landfast ice (LFI) thickness off Zhongshan (Davis) was 1.59±0.17 m (1.64±0.08 m). Larger interannual and local spatial variabilities for the seasonality of LFI were identified at Zhongshan, with the dominant influencing factors of air temperature anomaly, snow atop, local topography and wind regime, and oceanic heat flux. The variability of LFI properties across the study domain prevailed at interannual timescales, over any trend during the recent decades.
Giacomo Traversa, Davide Fugazza, and Massimo Frezzotti
The Cryosphere, 17, 427–444, https://doi.org/10.5194/tc-17-427-2023, https://doi.org/10.5194/tc-17-427-2023, 2023
Short summary
Short summary
Megadunes are fields of huge snow dunes present in Antarctica and on other planets, important as they present mass loss on the leeward side (glazed snow), on a continent characterized by mass gain. Here, we studied megadunes using remote data and measurements acquired during past field expeditions. We quantified their physical properties and migration and demonstrated that they migrate against slope and wind. We further proposed automatic detections of the glazed snow on their leeward side.
Bertie W. J. Miles, Chris R. Stokes, Adrian Jenkins, Jim R. Jordan, Stewart S. R. Jamieson, and G. Hilmar Gudmundsson
The Cryosphere, 17, 445–456, https://doi.org/10.5194/tc-17-445-2023, https://doi.org/10.5194/tc-17-445-2023, 2023
Short summary
Short summary
Satellite observations have shown that the Shirase Glacier catchment in East Antarctica has been gaining mass over the past 2 decades, a trend largely attributed to increased snowfall. Our multi-decadal observations of Shirase Glacier show that ocean forcing has also contributed to some of this recent mass gain. This has been caused by strengthening easterly winds reducing the inflow of warm water underneath the Shirase ice tongue, causing the glacier to slow down and thicken.
Johannes Feldmann and Anders Levermann
The Cryosphere, 17, 327–348, https://doi.org/10.5194/tc-17-327-2023, https://doi.org/10.5194/tc-17-327-2023, 2023
Short summary
Short summary
Here we present a scaling relation that allows the comparison of the timescales of glaciers with geometric similarity. According to the relation, thicker and wider glaciers on a steeper bed slope have a much faster timescale than shallower, narrower glaciers on a flatter bed slope. The relation is supported by observations and simplified numerical simulations. We combine the scaling relation with a statistical analysis of the topography of 13 instability-prone Antarctic outlet glaciers.
Cited articles
Aggarwal, C. C., Hinneburg, A., and Keim, D. A.: On the surprising behavior of distance metrics in high dimensional space, in: Database Theory – ICDT 2001: 8th International Conference London, UK, 4–6 January 2001, Proceedings 8, 420–434, Springer, 2001. a
Aksoy, S. and Haralick, R. M.: Feature normalization and likelihood-based similarity measures for image retrieval, Pattern Recogn. Lett., 22, 563–582, 2001. a
Anderberg, M. R.: Cluster analysis for applications: probability and mathematical statistics: a series of monographs and textbooks, vol. 19, Academic press, 2014. a
Arthur, D. and Vassilvitskii, S.: k-means++: The advantages of careful seeding, Tech. rep., Stanford, 2006. a
Aster, R. and Winberry, J.: Glacial seismology, Reports on Progress in Physics, 80, 126801, https://doi.org/10.1088/1361-6633/aa8473, 2017. a
Beem, L., Tulaczyk, S., King, M., Bougamont, M., Fricker, H., and Christoffersen, P.: Variable deceleration of Whillans Ice Stream, West Antarctica, J. Geophys. Res.-Earth Surf., 119, 212–224, 2014. a
Benn, D., Gulley, J., Luckman, A., Adamek, A., and Glowacki, P. S.: Englacial drainage systems formed by hydrologically driven crevasse propagation, J. Glaciol., 55, 513–523, 2009. a
Bergen, K. J. and Beroza, G. C.: Earthquake fingerprints: Extracting waveform features for similarity-based earthquake detection, Pure Appl. Geophys., 176, 1037–1059, 2019. a
Bergen, K. J., Chen, T., and Li, Z.: Preface to the focus section on machine learning in seismology, Seismol. Res. Lett., 90, 477–480, 2019. a
Beyer, K., Goldstein, J., Ramakrishnan, R., and Shaft, U.: When is “nearest neighbor” meaningful?, in: Database Theory – ICDT'99: 7th International Conference Jerusalem, Israel, 10–12 January 1999, Proceedings 7, 217–235, Springer, 1999. a
Beyreuther, M., Barsch, R., Krischer, L., Megies, T., Behr, Y., and Wassermann, J.: ObsPy: A Python toolbox for seismology, Seismol. Res. Lett., 81, 530–533, 2010. a
Bhargavi, M. and Gowda, S. D.: A novel validity index with dynamic cut-off for determining true clusters, Pattern Recogn., 48, 3673–3687, 2015. a
Bindschadler, R., Vornberger, P. L., and Shabtaie, S.: The detailed net mass balance of the ice plain on Ice Stream B, Antarctica: a geographic information system approach, J. Glaciol., 39, 471–482, 1993. a
Bindschadler, R., Vornberger, P., and Gray, L.: Changes in the ice plain of Whillans Ice Stream, West Antarctica, J. Glaciol., 51, 620–636, 2005. a
Bougamont, M., Tulaczyk, S., and Joughin, I.: Numerical investigations of the slow-down of Whillans Ice Stream, West Antarctica: is it shutting down like Ice Stream C?, Ann. Glaciol., 37, 239–246, 2003. a
Bouveyron, C., Girard, S., and Schmid, C.: High-dimensional data clustering, Comput. Stat. Data An., 52, 502–519, 2007. a
Breiman, L.: Random forests, Mach. Learn., 45, 5–32, 2001. a
Burton-Johnson, A., Black, M., Fretwell, P. T., and Kaluza-Gilbert, J.: An automated methodology for differentiating rock from snow, clouds and sea in Antarctica from Landsat 8 imagery: a new rock outcrop map and area estimation for the entire Antarctic continent, The Cryosphere, 10, 1665–1677, https://doi.org/10.5194/tc-10-1665-2016, 2016. a
Campbell, A. J., Hulbe, C. L., and Lee, C.-K.: Ice stream slowdown will drive long-term thinning of the Ross ice shelf, with or without ocean warming, Geophys. Res. Lett., 45, 201–206, 2018. a
Carmichael, J. D., Pettit, E. C., Hoffman, M., Fountain, A., and Hallet, B.: Seismic multiplet response triggered by melt at Blood Falls, Taylor Glacier, Antarctica, J. Geophys. Res.-Earth Surf., 117, F03004, https://doi.org/10.1029/2011JF002221, 2012. a
Caruana, R. and Niculescu-Mizil, A.: An empirical comparison of supervised learning algorithms, in: Proceedings of the 23rd international conference on Machine learning, 25–29 June 2006, Pittsburgh Pennsylvania USA, 161–168, 2006. a
Chamarczuk, M., Nishitsuji, Y., Malinowski, M., and Draganov, D.: Unsupervised learning used in automatic detection and classification of ambient-noise recordings from a large-N array, Seismol. Res. Lett., 91, 370–389, 2020. a
Chen, Z., Bromirski, P., Gerstoft, P., Stephen, R., Lee, W. S., Yun, S., Olinger, S., Aster, R., Wiens, D., and Nyblade, A.: Ross Ice Shelf icequakes associated with ocean gravity wave activity, Geophys. Res. Lett., 46, 8893–8902, 2019. a
Colgan, W., Rajaram, H., Abdalati, W., McCutchan, C., Mottram, R., Moussavi, M. S., and Grigsby, S.: Glacier crevasses: Observations, models, and mass balance implications, Rev. Geophys., 54, 119–161, 2016. a
Cracknell, M. J. and Reading, A. M.: The upside of uncertainty: Identification of lithology contact zones from airborne geophysics and satellite data using random forests and support vector machines, Geophysics, 78, WB113–WB126, 2013. a
Demartines, P. and Hérault, J.: Curvilinear component analysis: A self-organizing neural network for nonlinear mapping of data sets, IEEE T. Neural Networ., 8, 148–154, 1997. a
Ekström, G., Nettles, M., and Abers, G. A.: Glacial earthquakes, Science, 302, 622–624, 2003. a
Erofeeva, L., Padman, L., and Howard, S. L.: Tide Model Driver (TMD) version 2.5, Toolbox for Matlab 2020, GitHub [code], https://www.github.com/EarthAndSpaceResearch/TMD_Matlab_Toolbox_v2.5 (last access: 18 March 2024), 2020. a
Famili, A. F., Liu, G., and Liu, Z.: Evaluation and optimization of clustering in gene expression data analysis, Bioinformatics, 20, 1535–1545, 2004. a
Fountain, A. G. and Walder, J. S.: Water flow through temperate glaciers, Rev. Geophys., 36, 299–328, 1998. a
Galvis, I. S., Villa, Y., Duarte, C., Sierra, D., and Agudelo, W.: Seismic attribute selection and clustering to detect and classify surface waves in multicomponent seismic data by using k-means algorithm, The Leading Edge, 36, 239–248, 2017. a
George, A.: Efficient high dimension data clustering using constraint-partitioning k-means algorithm., Int. Arab J. Inf. Technol., 10, 467–476, 2013. a
Glynn, C. and Naylor, P.: GeoDataViz-Toolkit, GitHub [code], https://github.com/OrdnanceSurvey/GeoDataViz-Toolkit (last access: 18 March 2024), 2021. a
Hardy, A.: On the number of clusters, Comput. Stat. Data An., 23, 83–96, 1996. a
He, Z. and Yu, C.: Clustering stability-based evolutionary k-means, Soft Comput., 23, 305–321, 2019. a
Heck, M., Hammer, C., van Herwijnen, A., Schweizer, J., and Fäh, D.: Automatic detection of snow avalanches in continuous seismic data using hidden Markov models, Nat. Hazards Earth Syst. Sci., 18, 383–396, https://doi.org/10.5194/nhess-18-383-2018, 2018. a
Helmstetter, A., Moreau, L., Nicolas, B., Comon, P., and Gay, M.: Intermediate-depth icequakes and harmonic tremor in an Alpine glacier (Glacier d'Argentière, France): Evidence for hydraulic fracturing?, J. Geophys. Res.-Earth Surf., 120, 402–416, 2015. a
Hibert, C., Michéa, D., Provost, F., Malet, J., and Geertsema, M.: Exploration of continuous seismic recordings with a machine learning approach to document 20 yr of landslide activity in Alaska, Geophys. J. Int., 219, 1138–1147, 2019. a
Hotelling, H.: Analysis of a complex of statistical variables into principal components, J. Educ. Psychol., 24, 417, https://doi.org/10.1037/h0071325, 1933. a
Howard, S. L., Erofeeva, S., and Padman, L.: CATS2008: Circum-Antarctic Tidal Simulation version 2008, U.S. Antarctic Program (USAP) Data Center [data set], https://doi.org/10.15784/601235, 2019. a, b
Hudson, T. S., Brisbourne, A. M., White, R. S., Kendall, J.-M., Arthern, R., and Smith, A. M.: Breaking the ice: Identifying hydraulically forced crevassing, Geophys. Res. Lett., 47, e2020GL090597, https://doi.org/10.1029/2020GL090597, 2020. a
Jain, A. K. and Dubes, R. C.: Algorithms for clustering data, Prentice-Hall, Inc., 1988. a
Jenkins, W. F., Gerstoft, P., Bianco, M. J., and Bromirski, P. D.: Unsupervised deep clustering of seismic data: Monitoring the Ross Ice Shelf, Antarctica, J. Geophys. Res.-Sol. Ea., 126, e2021JB021716, https://doi.org/10.1029/2021JB021716, 2021. a, b
Johnson, C. W., Ben-Zion, Y., Meng, H., and Vernon, F.: Identifying different classes of seismic noise signals using unsupervised learning, Geophys. Res. Lett., 47, e2020GL088353, https://doi.org/10.1029/2020GL088353, 2020. a
Joughin, I., Tulaczyk, S., Bindschadler, R., and Price, S. F.: Changes in West Antarctic ice stream velocities: observation and analysis, J. Geophys. Res.-Sol. Ea., 107, EPM–3, https://doi.org/10.1029/2001JB001029, 2002. a
Kanao, M.: A New Trend in Cryoseismology: A Proxy for Detecting the Polar Surface Environment, Polar Seismology: Advances and Impact, p. 75, 2018. a
Köhler, A., Ohrnberger, M., and Scherbaum, F.: Unsupervised pattern recognition in continuous seismic wavefield records using self-organizing maps, Geophys. J. Int., 182, 1619–1630, 2010. a
Köhler, A., Chapuis, A., Nuth, C., Kohler, J., and Weidle, C.: Autonomous detection of calving-related seismicity at Kronebreen, Svalbard, The Cryosphere, 6, 393–406, https://doi.org/10.5194/tc-6-393-2012, 2012. a
Krischer, L., Megies, T., Barsch, R., Beyreuther, M., Lecocq, T., Caudron, C., and Wassermann, J.: ObsPy: A bridge for seismology into the scientific Python ecosystem, Comput. Sci. Discov., 8, 014003, https://doi.org/10.1088/1749-4699/8/1/014003, 2015. a
Latto, B.: beccalatto/multi_sta_lta: Towards the systematic reconnaissance of seismic signals from glaciers and ice sheets – Part 1: Event detection for cryoseismology (v1.0.0), Zenodo [code], https://doi.org/10.5281/zenodo.11062070, 2024. a
Latto, R. B., Turner, R. J., Reading, A. M., and Winberry, J. P.: Towards the systematic reconnaissance of seismic signals from glaciers and ice sheets – Part 1: Event detection for cryoseismology, The Cryosphere, 18, 2061–2079, https://doi.org/10.5194/tc-18-2061-2024, 2024. a, b, c, d, e, f, g, h, i, j, k
Legany, C., Juhasz, S., and Babos, A.: Cluster validity measurement techniques, in: Proceedings of the 5th WSEAS international conference on artificial intelligence, knowledge engineering and data bases, 388–393, World Scientific and Engineering Academy and Society (WSEAS) Stevens Point, 15–17 February 2006, Madrid Spain, edited by: Lopez Espi, P. L., Giron-Sierra, J. M., Drigas, A. S., World Scientific and Engineering Academy and Society (WSEAS) Stevens Point, Wisconsin, United States, ISBN 1112222339, 2006. a
Lombardi, D., Gorodetskaya, I., Barruol, G., and Camelbeeck, T.: Thermally induced icequakes detected on blue ice areas of the East Antarctic ice sheet, Ann. Glaciol., 60, 45–56, 2019. a
MacAyeal, D. R., Banwell, A. F., Okal, E. A., Lin, J., Willis, I. C., Goodsell, B., and MacDonald, G. J.: Diurnal seismicity cycle linked to subsurface melting on an ice shelf, Ann. Glaciol., 60, 137–157, 2019. a
Marsland, S.: Machine learning: an algorithmic perspective, CRC press, Chapman and Hall/CRC, https://doi.org/10.1201/9781420067194, 2015. a
McInnes, L., Healy, J., and Melville, J.: Umap: Uniform manifold approximation and projection for dimension reduction, arXiv [preprint], arXiv:1802.03426, 2018. a
Megies, T., Beyreuther, M., Barsch, R., Krischer, L., and Wassermann, J.: ObsPy – What can it do for data centers and observatories?, Ann. Geophys., 54, 47–58, 2011. a
Meilă, M.: The uniqueness of a good optimum for k-means, in: Proceedings of the 23rd international conference on Machine learning, 25–29 June 2006, Pittsburgh, Pennsylvania, USA, ISBN 978-1-59593-383-6, 625–632, 2006. a
Minowa, M., Podolskiy, E. A., and Sugiyama, S.: Tide-modulated ice motion and seismicity of a floating glacier tongue in East Antarctica, Ann. Glaciol., 60, 57–67, https://doi.org/10.1017/aog.2019.25, 2019. a
Mouginot, J., Rignot, E., , and Scheuchl, B.: MEaSUREs Antarctic Boundaries for IPY 2007-2009 from Satellite Radar, Version 2, Boulder, Colorado, USA, https://doi.org/10.5067/AXE4121732AD, 2017. a
Mousavi, S. M., Horton, S. P., Langston, C. A., and Samei, B.: Seismic features and automatic discrimination of deep and shallow induced-microearthquakes using neural network and logistic regression, Geophys. J. Int., 207, 29–46, 2016. a
Mousavi, S. M., Sheng, Y., Zhu, W., and Beroza, G. C.: STanford EArthquake Dataset (STEAD): A global data set of seismic signals for AI, IEEE Access, 7, 179464–179476, 2019. a
Nath, P. and Vaughan, D.: Subsurface crevasse formation in glaciers and ice sheets, J. Geophys. Res.-Sol. Ea., 108, ECV–7, https://doi.org/10.1029/2001JB000453, 2003. a, b
Pedregosa, F., Varoquaux, G., Gramfort, A., Michel, V., Thirion, B., Grisel, O., Blondel, M., Prettenhofer, P., Weiss, R., Dubourg, V., Vanderplas, J., Passos, A., Cournapeau, D., Brucher, M., Perrot, M., and Duchesnay, E.: Scikit-learn: Machine Learning in Python, J. Mach. Learn. Res., 12, 2825–2830, 2011. a
Pérez-Campos, X., Singh, S. K., and Beroza, G. C.: Reconciling teleseismic and regional estimates of seismic energy, B. Seismol. Soc. Am., 93, 2123–2130, 2003. a
Podolskiy, E. A., Sugiyama, S., Funk, M., Walter, F., Genco, R., Tsutaki, S., Minowa, M., and Ripepe, M.: Tide-modulated ice flow variations drive seismicity near the calving front of Bowdoin Glacier, Greenland, Geophys. Res. Lett., 43, 2036–2044, https://doi.org/10.1002/2016GL067743, 2016. a
Podolskiy, E. A., Fujita, K., Sunako, S., Tsushima, A., and Kayastha, R. B.: Nocturnal thermal fracturing of a Himalayan debris-covered glacier revealed by ambient seismic noise, Geophys. Res. Lett., 45, 9699–9709, 2018. a
Podolskiy, E. A., Fujita, K., Sunako, S., and Sato, Y.: Viscoelastic Modeling of Nocturnal Thermal Fracturing in a Himalayan Debris-Covered Glacier, J. Geophys. Res.-Earth Surf., 124, 1485–1515, https://doi.org/10.1029/2018JF004848, 2019. a
Pomeroy, J., Brisbourne, A., Evans, J., and Graham, D.: The search for seismic signatures of movement at the glacier bed in a polythermal valley glacier, Ann. Glaciol., 54, 149–156, 2013. a
Pratt, M. J., Winberry, J. P., Wiens, D. A., Anandakrishnan, S., and Alley, R. B.: Seismic and geodetic evidence for grounding-line control of Whillans Ice Stream stick-slip events, J. Geophys. Res.-Earth Surf., 119, 333–348, https://doi.org/10.1002/2013JF002842, 2014. a, b, c, d, e, f, g, h, i, j, k, l
Retzlaff, R. and Bentley, C. R.: Timing of stagnation of Ice Stream C, West Antarctica, from short-pulse radar studies of buried surface crevasses, J. Glaciol., 39, 553–561, 1993. a
Reynen, A. and Audet, P.: Supervised machine learning on a network scale: Application to seismic event classification and detection, Geophys. J. Int., 210, 1394–1409, 2017. a
Riggelsen, C. and Ohrnberger, M.: A machine learning approach for improving the detection capabilities at 3C seismic stations, Pure Appl. Geophys., 171, 395–411, 2014. a
Rignot, E., Mouginot, J., and Scheuchl, B.: Ice Flow of the Antarctic Ice Sheet, Science, 333, 1427–1430, https://doi.org/10.1126/science.1208336, 2011. a
Rignot, E., Jacobs, S., Mouginot, J., and Scheuchl, B.: Ice-shelf melting around Antarctica, Science, 341, 266–270, 2013. a
Röösli, C., Walter, F., Husen, S., Andrews, L. C., Lüthi, M. P., Catania, G. A., and Kissling, E.: Sustained seismic tremors and icequakes detected in the ablation zone of the Greenland ice sheet, J. Glaciol., 60, 563–575, 2014. a
Rousseeuw, P. J.: Silhouettes: a graphical aid to the interpretation and validation of cluster analysis, J. Comput. Appl. Math., 20, 53–65, 1987. a
Sawi, T., Holtzman, B., Walter, F., and Paisley, J.: An Unsupervised Machine-Learning Approach to Understanding Seismicity at an Alpine Glacier, J. Geophys. Res.-Earth Surf., 127, e2022JF006909, https://doi.org/10.1029/2022JF006909, 2022. a
Seydoux, L., Balestriero, R., Poli, P., De Hoop, M., Campillo, M., and Baraniuk, R.: Clustering earthquake signals and background noises in continuous seismic data with unsupervised deep learning, Nat. Commun., 11, 1–12, 2020. a
Sibi, P., Jones, S. A., and Siddarth, P.: Analysis of different activation functions using back propagation neural networks, J. Theor. Appl. Inf. Technol., 47, 1264–1268, 2013. a
Stål, T. and Reading, A. M.: A grid for multidimensional and multivariate spatial representation and data processing, J. Open Res. Softw., 8, 1–10, https://doi.org/10.5334/JORS.287, 2020. a, b
Trebuňa, P., Halčinová, J., Fil'o, M., and Markovič, J.: The importance of normalization and standardization in the process of clustering, in: 2014 IEEE 12th International Symposium on Applied Machine Intelligence and Informatics (SAMI), 381–385, IEEE, 2014. a
Tulaczyk, S., Kamb, W. B., and Engelhardt, H. F.: Basal mechanics of ice stream B, West Antarctica: 1. Till mechanics, J. Geophys. Res.-Sol. Ea., 105, 463–481, 2000. a
Turner, R. J., Latto, R. B., and Reading, A. M.: An ObsPy library for event detection and seismic attribute calculation: preparing waveforms for automated analysis, J. Open Res. Softw., 9, 29, https://doi.org/10.5334/jors.365, 2021 (code available at: https://github.com/rossjturner/seismic_attributes, last access: 18 March 2024). a, b
Turner, R. J., Latto, R. B., and Reading, A. M.: An ObsPy library for event detection and seismic attribute calculation: preparing waveforms for automated analysis (v1.0.3.post1), Zenodo [code], https://doi.org/10.5281/zenodo.5499909, 2021. a
U.S. Geological Survey, E. H. P.: Advanced National Seismic System (ANSS) Comprehensive Catalog of Earthquake Events and Products, https://doi.org/10.5066/F7MS3QZH, 2022. a
Van der Maaten, L. and Hinton, G.: Visualizing data using t-SNE, J. Mach. Learn. Res., 9, 2579–2605, 2008. a
VanWormer, D. and Berg, E.: Seismic Evidence for Glacier Motion, J. Glaciol., 12, 259–265, https://doi.org/10.3189/S002214300003207X, 1973. a
Wiens, D., Pratt, M., Aster, R., Nyblade, A., Bromirski, P., Stephen, R., and Gerstoft, P.: Longitudinal seismic waves in the Ross Ice Shelf excited by Whillans Ice Stream stick-slip events, Geoscience, 7, 677–681, 2016. a
Wiens, D. A., Anandakrishnan, S., Winberry, J. P., and King, M. A.: Simultaneous teleseismic and geodetic observations of the stick–slip motion of an Antarctic ice stream, Nature, 453, 770–774, https://doi.org/10.1038/nature06990, 2008. a
Winberry, J. P., Anandakrishnan, S., and Alley, R. B.: Seismic observations of transient subglacial water-flow beneath MacAyeal Ice Stream, West Antarctica, Geophys. Res. Lett., 36, L11502, https://doi.org/10.1029/2009GL037730, 2009a. a
Winberry, J. P., Anandakrishnan, S., Alley, R. B., Bindschadler, R. A., and King, M. A.: Basal mechanics of ice streams: Insights from the stick-slip motion of Whillans Ice Stream, West Antarctica, J. Geophys. Res.-Earth Surf., 114, F01016, https://doi.org/10.1029/2008JF001035, 2009b. a
Winberry, J. P., Anandakrishnan, S., and Wiens, D.: Geophysical Study of Ice Stream Stick-slip dynamics, International Federation of Digital Seismograph Networks [data set], https://doi.org/10.7914/SN/2C_2010, 2010. a, b
Winberry, J. P., Anandakrishnan, S., Wiens, D. A., Alley, R. B., and Christianson, K.: Dynamics of stick–slip motion, Whillans Ice Stream, Antarctica, Earth Planet. Sc. Lett., 305, 283–289, 2011. a
Winberry, J. P., Anandakrishnan, S., Wiens, D. A., and Alley, R. B.: Nucleation and seismic tremor associated with the glacial earthquakes of Whillans Ice Stream, Antarctica, Geophys. Res. Lett., 40, 312–315, https://doi.org/10.1002/grl.50130, 2013. a
Wright, A. and Siegert, M.: A fourth inventory of Antarctic subglacial lakes, Antarct. Sci., 24, 659–664, 2012. a
Yoon, C. E., O'Reilly, O., Bergen, K. J., and Beroza, G. C.: Earthquake detection through computationally efficient similarity search, Sci. Adv., 1, e1501057, https://doi.org/10.1126/sciadv.1501057, 2015. a
Zadeh, R. B. and Ben-David, S.: A Uniqueness Theorem for Clustering, in: Proceedings of the Twenty-Fifth Conference on Uncertainty in Artificial Intelligence, UAI '09, 639–646, AUAI Press, Arlington, Virginia, USA, ISBN 9780974903958, 2009. a
Zu Eissen, B. and Wißbrock, F.: On cluster validity and the information need of users, ACTA Press, 216–221, 2003. a
Short summary
Seismic catalogues are potentially rich sources of information on glacier processes. In a companion study, we constructed an event catalogue for seismic data from the Whillans Ice Stream. Here, we provide a semi-automated workflow for consistent catalogue analysis using an unsupervised cluster analysis. We discuss the defining characteristics of identified signal types found in this catalogue and possible mechanisms for the underlying glacier processes and noise sources.
Seismic catalogues are potentially rich sources of information on glacier processes. In a...
