Figure 10 . Stress-flow angles for non-rift scenario
(a ), rift-scenario 1 (b ), and rift-scenario 2
(c , enhanced weakening). First principal stress field for
non-rift scenario (d ), and differences between rift-scenario 1
and non-rift scenario (e ), and between rift-scenario 2 and
rift-scenario 1 (f ). The extent of R1 is shown (dashed line)
with the rift tip locations between 2006 and 2017.
6 Discussion
The multidecadal satellite data and modeling experiments indicate the
primary role of rifting processes in controlling the retreat of Larsen C
over the past six decades. The two retreat cycles were characterized by
tabular iceberg calving due to rift propagation. The rifts leading to
calving developed near the Bawden Ice Rise in the north and the Gipps
Ice Rise in the south. The time series of satellite data allowed us to
analyze the rifting processes causing the 2017 calving event in a high
level of detail. The 2017 calving event resulted from the propagation of
two rifts, including a transverse rift (R1) formed downstream of Kenyon
Peninsula and an oblique rift (R2) formed near Gipps Ice Rise. The
observed flow accelerations were mainly related to the propagation of
these two rifts. Enhanced weakening due to R2 near Gipps Ice Rise
increased both longitudinal and first principal stresses around R1, and
modified the stress-flow angles, creating favorable conditions for the
northward propagation of R1. This indicates the importance of
considering feedbacks between different rifts. Several studies (e.g.,
Borstad et al., 2017; Jansen et al., 2015) discussed the rift
development causing the 2017 calving event, but treated R1 and R2 as one
single rift and mainly focused on the northward propagation. Our results
suggest that the southward propagation of both R1 and R2 preconditioned
the northward propagation.
According to linear elastic fracture mechanics (LEFM), a fracture
propagates when the stress intensity factor at a crack tip exceeds the
material fracture toughness (Hulbe et al., 2010; Lipovsky, 2020). At the
fracture tip, the stress intensity factor is determined by fracture
geometry, fracture length, and stress field. The stress intensity factor
has three modes: Mode I–opening (tensile), Mode II–sliding (in-plane
shear), and Mode III–tearing (antiplane shear). The propagation of R1
was dominated by Mode I. Fracture propagation continues until the stress
intensity factor is less than the fracture toughness. Suture zones are
suggested to have resistive effect on rift propagation because of the
high fracture toughness of marine ice underneath (Borstad et al., 2017;
Kulessa et al., 2019; McGrath et al., 2014). Marine ice has different
material properties from meteoric ice originating from glacial ice, and
was detected underneath the Larsen C suture zones (Holland et al., 2009;
Jansen et al., 2013). Assuming that the spatial distribution of fracture
toughness is fixed, the increased tensile stresses at the crack tips of
R1 are necessary conditions to activate the propagation of R1. The
modeling results indicate the R2-induced weakening near Gipps Ice Rise
caused the enhanced tensile stresses around R1, highlighting the
importance of rift features around ice rises. Meanwhile, reduced
fracture toughness of suture zones due to ice shelf thinning should also
be considered. Widespread thinning has been observed over Antarctic ice
shelves from satellite altimetry data (Adusumilli et al., 2020),
including Larsen C (Adusumilli et al., 2018; Shepherd et al., 2003). The
surface lowering of Larsen C has been attributed to multiple factors,
including firn compaction, ice divergence due to flow acceleration, and
basal melt (Holland et al., 2015; Shepherd et al., 2003). A high basal
melt rate was observed near Bawden Ice Rise (Adusumilli et al., 2018).
Ocean-driven melting underneath Larsen C can enhance the rifting
processes by 1) reducing marine ice underneath the suture zones,
decreasing the fracture toughness of suture zones; 2) destabilizing the
ice rises and reducing the buttressing force from ice rises (Borstad et
al., 2013); and 3) thinning and weakening shear margins (Alley et al.,
2019; Dow et al., 2018; Lhermitte et al., 2020).
To better predict ice shelf retreat due to rifts, we not only need to
know whether a rift would propagate until calving occurs, but also where
rifts tend to initiate. Rifts initiate at preexisting cracks or flaws
(Hulbe et al., 2010). A recent study based on ICESat-2 data (Wang et
al., 2021) found that the vertical depth of preexisting fracture
features is critical for predicting rift locations. Theoretical modeling
studies (e.g., Lipovsky 2020) suggest that the loss of marginal
strength, when ice flows out of an embayment, can trigger rift growth.
Our modeling results (Figure 8) suggest that the transitional area from
a compressive (longitudinal) condition to a tensile (longitudinal)
condition resulting from ice shelf geometry conditions is also a
potential location for rift initiation and opening. There were three
such transitional areas at the downstream portion of Larsen C, including
the area near Bawden Ice Rise, the area near Gipps Ice Rise, and the
area downstream of Kenyon Peninsula. Satellite images showed that the
rifts causing the northern and southern calving events were initiated in
these areas. The area downstream of Kenyon Peninsula is a typical
transitional area from strong to weak shear margins, consistent with the
modeling study of Lipovsky (2020). The transitional areas can be
identified through diagnostic modeling given a front geometry condition
without considering ice shelf damage. Once a rift is initiated, the
rift-induced weakening must be incorporated to examine whether the rift
will propagate in response to the modification of stress field. The
weakening is enhanced when the rift growth continues, further altering
the stress field. Therefore, it is important to capture the time-varying
effect of rifts on ice rigidity in ice flow models. Capturing such
feedbacks appears to be essential for modeling flow velocity fields and
subsequent rift propagation. Continuum damage mechanics (Borstad et al.,
2012, 2013; Krug et al., 2014) have been recently utilized to
incorporate fracture-induced weakening into a viscous continuum damage
model. The damage factor is a scalar variable that is quantified by an
inversion (ice rigidity) approach. In this case, damage-related flow
velocities are required to invert for the damage factor. Further
investigation into the temporal evolution of rift length and associated
damage is needed to enable parameterization of these processes within a
modeling framework.
The velocity data indicate that the impact of the 2017 calving event is
limited on the ice shelf flow dynamics. The calved portion was located
in the “passive ice” zone (Fürst et al., 2016; Reese et al., 2017),
where the front retreat has little effect on ice shelf buttressing. We
observed flow accelerations in the central ice shelf after 2000, which
might be a velocity adjustment to the front geometry change resulting
from the calving events before 1990. The modeling experiments (Figures
7c, 7k) show the front geometry change due to the 2017 calving would
increase the velocity (although at a low magnitude) and decrease the
backstress in the central ice shelf, suggesting a potential time-lag
between front retreat and ice shelf flow acceleration. If the retreat
continues and the ice front reaches the compressive arch, widespread
flow accelerations will be triggered due to front retreat. The observed
flow accelerations were mainly caused by the rift development in the
south. To predict future ice shelf flow dynamics due to front retreat,
rift initiation and propagation and associated weakening effect on ice
rigidity should be considered for modeling flow velocity fields.
Following the disintegration of Larsen A and Larsen B, one pressing
question is whether Larsen C will disintegrate in the same manner. The
collapses of Larsen A and Larsen B were preceded by extensive surface
melt, and hydrofracturing has been the prevailing hypothesis for
explaining the ice shelf collapse (e.g., van den Broeke, 2005; MacAyeal
et al., 2003). Abundant meltwater, surface fractures, and favorable
stress conditions are the necessary elements of hydrofracturing. Lai et
al. (2020) applied LEFM and assessed the vulnerability to
hydrofracturing across all Antarctic ice shelves, in which Larsen C was
classified as vulnerable to hydrofracturing. However, it is still
questionable whether there will be sufficient meltwater to fill the
crevasses on Larsen C. Although several studies indicated that foehn
wind enhances the surface melt rate over Larsen C (Datta et al., 2019;
Elvidge et al., 2020; King et al., 2017), the extent of ponded water is
limited in space, mostly occurring at the northern upstream portion at
the Cabinet Inlet (C3 unit). Besides excessive melt occurred on Larsen A
and Larsen B, their pre-collapse front geometries were already in
unstable conditions after the compressive arch was reached (Doake et
al., 1998). Larsen C will resemble the pre-collapse Larsen B if the
front geometry reaches the position of H3 and the compressive arch is
absent (Figure 6). The disintegration of Larsen C is less likely to
occur in the current condition. However, given the importance of rifting
processes to the stability of Larsen C, it is critical to monitor how
atmospheric warming and oceanic forcing will affect rifting processes in
the future.
7 Conclusions
We combined multi-source satellite data over the past six decades to
investigate changes occuring over the Larsen C ice shelf. The total ice
shelf area was reduced by more than 20% from 1963 to 2020, as a result
of two large retreat cycles. Each cycle was characterized by a northern
retreat near Bawden Ice Rise followed by a southern retreat near Gipps
Ice Rise, in which rifting-induced tabular iceberg calving was the
dominant mechanism. We analyzed the temporal evolutions of two rifts
that caused the 2017 calving event in the south, and found their close
interactions in weakening the ice shelf. In particular, the weakening
due to R2 near Gipps Ice Rise preconditioned the rapid propagation of
the major rift R1. We observed a lagged response of flow acceleration to
front retreat, which leads to our conjecture that there will be a
gradual velocity increase in response to the 2017 calving event, despite
relatively small recent changes. The ice shelf retreat away from pinning
points (ice rises) to the location of compressive arch will reduce the
ice shelf backstress and lead to widespread flow accelerations. When the
compressive arch ceases to exist, small retreat events can trigger
large-scale backstress loss and flow accelerations extending to the
upstream glaciers.
The results of this study in combination with observations of the
pre-collapsed Larsen B suggest a chronology of ice shelf destabilization
processes for embayment-confined ice shelves. Rifts initiate at
preexisting cracks and/or areas with favorable stress conditions, such
as the transitional area from compressive to tensile longitudinal
conditions. Ice rises and locations with a transition from strong
lateral shear margins to weak margins (e.g., occurring near an island or
peninsula) generally have such characteristic stress patterns. Rifts
would propagate at these transition areas, if the stress intensity at
the crack tips exceeds the fracture toughness. Rift growth leads to
mechanical weakening of ice and a change in ice rigidity property. The
weakening, particularly near ice rises and/or shear margins, results in
flow accelerations, further modifies the stress field by increasing
longitudinal stretching and decreasing stress-flow angles, hence creates
more favorable conditions for rift propagation, and eventually causes
ice front retreat. If the front retreat occurs within the “passive
ice” area and does not extend to the compressive arch, a limited or
lagged response in flow velocity and stress field would be triggered. If
the front retreats behind the compressive arch, widespread flow
accelerations and backstress loss would be triggered, causing dynamic
thinning and stress field change across the ice shelf. The compressive
arch location may move further upstream or become fully absent. The
absence of a compressive arch would create an unstable front condition,
followed by persistent front retreat. If surface melting and ponding are
prevalent due to atmospheric warming, hydrofracturing can destabilize
the ice shelf rapidly. Oceanic forcing can affect this process by
thinning shear margins and reducing marine ice underneath suture zones,
both of which lower the fracture toughness and therefore enhance
weakening and fracturing. Our results emphasize the need for capturing
key processes in ice shelf evolution models. In particular, the response
of the ice shelf mechanical strength to the presence of rifts and the
feedbacks that can accelerate ice shelf retreat need to be incorporated
in the models.
Acknowledgments
This research was supported in part by a Seed Grant award from the
Institute for Computational and Data Sciences at the Pennsylvania State
University. Part of the work was supported by the University of
Cincinnati Graduate School Dean’s Fellowship When S. Wang was a graduate
student. The authors acknowledge the United States Geological Survey
(USGS) for the Declassified Intelligence Satellite Photography and
Landsat images, the Alaska Satellite Facility for the ALOS PALSAR
images, the European Space Agency for the ERS-1/2 and Envisat SAR
images, the Byrd Polar and Climate Research Center at Ohio State
University for the orthorectified Radarsat-1 SAR images and other RAMP
data products, the National Snow and Ice Data Center for the Antarctic
DEM data and the MEaSUREs phase-based Antarctica ice velocity data, and
the Jet Propulsion Laboratory and University of California at Irvine for
the Ice-sheet and Sea-level System Model (ISSM).
There are no restrictions to access the data used for this study. The
DISP imagery (https://doi.org/10.5066/F78P5XZM), Landsat-4/5 TM
(https://doi.org/10.5066/F7N015TQ), Landsat-7 ETM+
(https://doi.org/10.5066/F7WH2P8G), and Landsat-8 OLI
(https://doi.org/10.5066/F71835S6) images were downloaded from the
USGS EarthExplorer data portal (https://earthexplorer.usgs.gov/),
courtesy of the U.S. Geological Survey. The ALOS PALSAR images
(© JAXA/METI ALOS
PALSAR L1.5 2006-2010. Accessed
through ASF DAAC 1 February 2014) were
downloaded from the Alaska Satellite Facility data portal
(https://asf.alaska.edu/). The Radarsat Antarctic Mapping Project
(RAMP) data (https://doi.org/10.5067/HHK2QT3LQMEL) are availabe at
https://asf.alaska.edu/data-sets/derived-data-sets/ramp/ramp-get-ramp-data/.
ERS-1/2 SAR images were assessed from
https://earth.esa.int/eogateway/catalog/ers-1-2-sar-im-l0-sar_im__0p-
, and Envisat ASAR images were accessed from
https://earth.esa.int/eogateway/catalog/envisat-asar-im-precision-l1-asa_imp_1p-,
courtesy of European Space Agency. The DEM data were accessed from the
National Snow and Ice Data Center
(https://nsidc.org/data/nsidc-0082 and
https://nsidc.org/data/NSIDC-0422/versions/1) (Liu et al., 2001;
Bamber et al., 2009). The MEaSUREs phase-based Antarctica ice velocity
data are availabe at https://nsidc.org/data/NSIDC-0754/versions/1
(Mouginot et al., 2019b). The Ice-sheet and Sea-level System Model
(ISSM) is open source and publicly available at
https://issm.jpl.nasa.gov/ (Larour et al., 2012).
References
Adusumilli, S., Fricker, H. A., Siegfried, M. R., Padman, L., Paolo, F.
S., & Ligtenberg, S. R. M. (2018). Variable Basal Melt Rates of
Antarctic Peninsula Ice Shelves, 1994-2016. Geophysical Research
Letters, 45 (9), 4086–4095. https://doi.org/10.1002/2017gl076652
Adusumilli, S., Fricker, H. A., Medley, B., Padman, L., & Siegfried, M.
R. (2020). Interannual variations in meltwater input to the Southern
Ocean from Antarctic ice shelves. Nature Geoscience, 13 (9),
616–620. https://doi.org/10.1038/s41561-020-0616-z
Alley, K. E., Scambos, T. A., Anderson, R. S., Rajaram, H., Pope, A., &
Haran, T. M. (2018). Continent-wide estimates of Antarctic strain rates
from Landsat 8-derived velocity grids. Journal of Glaciology,
64 (244), 321–332. https://doi.org/10.1017/jog.2018.23
Alley, K. E., Scambos, T. A., Alley, R. B., & Holschuh, N. (2019).
Troughs developed in ice-stream shear margins precondition ice shelves
for ocean-driven breakup. Science Advances , 5 (10),
eaax2215.
Bamber, J. L., Gomez-Dans, J. L., & Griggs, J. A. (2009). Antarctic 1
km Digital Elevation Model (DEM) from Combined ERS-1 Radar and ICESat
Laser Satellite Altimetry, Version 1. [Antarctic Peninsula].
Boulder, Colorado USA. NASA National Snow and Ice Data Center
Distributed Active Archive Center.
doi: https://doi.org/10.5067/H0FQ1KL9NEKM. [Date Accessed:
2019-01-01].
Banwell, A. F., MacAyeal, D. R., & Sergienko, O. V. (2013). Breakup of
the Larsen B Ice Shelf triggered by chain reaction drainage of
supraglacial lakes. Geophysical Research Letters , 40 (22),
2013GL057694.
Bell, R. E., Chu, W., Kingslake, J., Das, I., Tedesco, M., Tinto, K. J.,
et al. (2017). Antarctic ice shelf potentially stabilized by export of
meltwater in surface river. Nature , 544 (7650), 344–348.
Benn, D. I., Warren, C. R., & Mottram, R. H. (2007). Calving processes
and the dynamics of calving glaciers. Earth-Science Reviews ,82 (3), 143–179.
Bevan, S., Luckman, A., Hendon, H., & Wang, G. (2020). The 2020 Larsen
C Ice Shelf surface melt is a 40-year record high. The
Cryosphere , 14 (10), 3551–3564.
Borstad, C., McGrath, D., & Pope, A. (2017). Fracture propagation and
stability of ice shelves governed by ice shelf heterogeneity.Geophysical Research Letters , 44 (9), 4186–4194.
Borstad, C. P., Khazendar, A., Larour, E., Morlighem, M., Rignot, E.,
Schodlok, M. P., & Seroussi, H. (2012). A damage mechanics assessment
of the Larsen B ice shelf prior to collapse: Toward a physically-based
calving law. Geophysical Research Letters , 39 (18), L18502.
Borstad, C. P., Rignot, E., Mouginot, J., & Schodlok, M. P. (2013).
Creep deformation and buttressing capacity of damaged ice shelves:
theory and application to Larsen C ice shelf. The Cryosphere ,7 (6), 1931–1947.
van den Broeke, M. (2005). Strong surface melting preceded collapse of
Antarctic Peninsula ice shelf. Geophysical Research Letters ,32 (12), L12815.
Colgan, W., Rajaram, H., Abdalati, W., McCutchan, C., Mottram, R.,
Moussavi, M. S., & Grigsby, S. (2016). Glacier crevasses: Observations,
models, and mass balance implications. Reviews of Geophysics ,54 (1), 119–161.
Cook, A. J., Fox, A. J., Vaughan, D. G., & Ferrigno, J. G. (2005).
Retreating glacier fronts on the Antarctic Peninsula over the past
half-century. Science , 308 (5721), 541–544.
Cuffey, K. M., & Paterson, W. S. B. (2010). The Physics of
Glaciers . Academic Press.
DeConto, R. M., Pollard, D., Alley, R. B., Velicogna, I., Gasson, E.,
Gomez, N., et al. (2021). The Paris Climate Agreement and future
sea-level rise from Antarctica. Nature , 593 (7857), 83–89.
Depoorter, M. A., Bamber, J. L., Griggs, J. A., Lenaerts, J. T. M.,
Ligtenberg, S. R. M., van den Broeke, M. R., & Moholdt, G. (2013).
Calving fluxes and basal melt rates of Antarctic ice shelves.Nature , 502 (7469), 89–92.
Doake, C. S. M., & Vaughan, D. G. (1991). Rapid disintegration of the
Wordie Ice Shelf in response to atmospheric warming. Nature ,350 (6316), 328–330.
Doake, C. S. M., Corr, H. F. J., Rott, H., Skvarca, P., & Young, N. W.
(1998). Breakup and conditions for stability of the northern Larsen Ice
Shelf, Antarctica. Nature , 391 (6669), 778–780.
Dow, C. F., Lee, W. S., Greenbaum, J. S., Greene, C. A., Blankenship, D.
D., Poinar, K., et al. (2018). Basal channels drive active surface
hydrology and transverse ice shelf fracture. Science Advances ,4 (6), eaao7212.
Dupont, T. K., & Alley, R. B. (2005). Assessment of the importance of
ice-shelf buttressing to ice-sheet flow. Geophysical Research
Letters , 32 (4). https://doi.org/10.1029/2004GL022024
Elvidge, A. D., Renfrew, I. A., King, J. C., Orr, A., Lachlan-Cope, T.
A., Weeks, M., & Gray, S. L. (2015). Foehn jets over the Larsen C Ice
Shelf, Antarctica. Quarterly Journal of the Royal Meteorological
Society , 141 (688), 698–713.
Elvidge, A. D., Kuipers Munneke, P., King, J. C., Renfrew, I. A., &
Gilbert, E. (2020). Atmospheric drivers of melt on Larsen C ice shelf:
Surface energy budget regimes and the impact of foehn. Journal of
Geophysical Research , 125 (17).
https://doi.org/10.1029/2020jd032463
Favier, L., & Pattyn, F. (2015). Antarctic ice rise formation,
evolution, and stability. Geophysical Research Letters ,42 (11), 2015GL064195.
Ferrigno, J. G., & Gould, W. G. (1987). Substantial changes in the
coastline of Antarctica revealed by satellite imagery. Polar
Record , 23 (146), 577–583.
https://doi.org/10.1017/s003224740000807x
Fürst, J. J., Durand, G., Gillet-Chaulet, F., Tavard, L., Rankl, M.,
Braun, M., & Gagliardini, O. (2016). The safety band of Antarctic ice
shelves. Nature Climate Change , 6 (5), 479–482.
Gagliardini, O., Durand, G., Zwinger, T., Hindmarsh, R. C. A., & Le
Meur, E. (2010). Coupling of ice-shelf melting and buttressing is a key
process in ice-sheets dynamics. Geophysical Research Letters ,37 (14). https://doi.org/10.1029/2010GL043334
Glasser, N. F., Kulessa, B., Luckman, A., Jansen, D., King, E. C.,
Sammonds, P. R., et al. (2009). Surface structure and stability of the
Larsen C ice shelf, Antarctic Peninsula. Journal of Glaciology ,55 (191), 400–410.
Gudmundsson, G. H. (2013). Ice-shelf buttressing and the stability of
marine ice sheets. The Cryosphere , 7 (2), 647–655.
Heid, T., & Kääb, A. (2012). Evaluation of existing image matching
methods for deriving glacier surface displacements globally from optical
satellite imagery. Remote Sensing of Environment , 118 ,
339–355. https://doi.org/10.1016/j.rse.2011.11.024
Hogg, A. E., & Hilmar Gudmundsson, G. (2017). Impacts of the Larsen-C
Ice Shelf calving event. Nature Climate Change , 7 (8),
540–542. https://doi.org/10.1038/nclimate3359
Holland, P. R., Corr, H. F. J., Vaughan, D. G., Jenkins, A., & Skvarca,
P. (2009). Marine ice in Larsen Ice Shelf. Geophysical Research
Letters , 36 (11), L11604.
Holland, P. R., Brisbourne, A., Corr, H. F. J., McGrath, D., Purdon, K.,
Paden, J., et al. (2015). Oceanic and atmospheric forcing of Larsen C
Ice-Shelf thinning. The Cryosphere , 9 (3), 1005–1024.
Howat, I. M., Porter, C., Smith, B. E., Noh, M.-J., & Morin, P. (2019).
The Reference Elevation Model of Antarctica. The
Cryosphere , 13 (2), 665–674.
https://doi.org/10.5194/tc-13-665-2019
Hulbe, C. L., LeDoux, C., & Cruikshank, K. (2010). Propagation of long
fractures in the Ronne Ice Shelf, Antarctica, investigated using a
numerical model of fracture propagation. Journal of Glaciology ,56 (197), 459–472.
Jansen, D., Kulessa, B., Sammonds, P. R., Luckman, A., King, E. C., &
Glasser, N. F. (2010). Present stability of the Larsen C ice shelf,
Antarctic Peninsula. Journal of Glaciology , 56 (198),
593–600.
Jansen, D., Luckman, A., Kulessa, B., Holland, P. R., & King, E. C.
(2013). Marine ice formation in a suture zone on the Larsen C Ice Shelf
and its influence on ice shelf dynamics. Journal of Geophysical
Research: Earth Surface , 118 (3), 1628–1640.
Jansen, D., Luckman, A. J., Cook, A., Bevan, S., Kulessa, B., Hubbard,
B., & Holland, P. R. (2015). Brief Communication: Newly developing rift
in Larsen C Ice Shelf presents significant risk to stability. The
Cryosphere , 9 (3), 1223–1227.
Jezek, K. C. (2003). Observing the Antarctic Ice Sheet Using the
RADARSAT-1 Synthetic Aperture Radar. Polar Geography ,27 (3), 197–209.
Jezek, K. C., Sohn, H. G., & Noltimier, K. F. (1998). The RADARSAT
Antarctic Mapping Project. IGARSS ’98. Sensing and Managing the
Environment. 1998 IEEE International Geoscience and Remote Sensing.
Symposium Proceedings. (Cat. No.98CH36174) .
https://doi.org/10.1109/igarss.1998.702246
Joughin, I., Howat, I. M., Fahnestock, M., Smith, B., Krabill, W.,
Alley, R. B., et al. (2008). Continued evolution of Jakobshavn Isbrae
following its rapid speedup. Journal of Geophysical Research ,113 (F4). https://doi.org/10.1029/2008jf001023
King, J. C., Kirchgaessner, A., Bevan, S., Elvidge, A. D., Kuipers
Munneke, P., Luckman, A., et al. (2017). The Impact of Föhn Winds on
Surface Energy Balance During the 2010–2011 Melt Season Over Larsen C
Ice Shelf, Antarctica. Journal of Geophysical Research, D:
Atmospheres , 122 (22), 2017JD026809.
Krug, J., Weiss, J., Gagliardini, O., & Durand, G. (2014). Combining
damage and fracture mechanics to model calving. The
Cryosphere , 8 (6), 2101–2117.
https://doi.org/10.5194/tcd-8-1111-2014
Kulessa, B., Jansen, D., Luckman, A. J., King, E. C., & Sammonds, P. R.
(2014). Marine ice regulates the future stability of a large Antarctic
ice shelf. Nature Communications , 5 , 3707.
Kulessa, B., Booth, A. D., O’Leary, M., McGrath, D., King, E. C.,
Luckman, A. J., et al. (2019). Seawater softening of suture zones
inhibits fracture propagation in Antarctic ice shelves. Nature
Communications , 10 (1), 5491.
Lai, C.-Y., Kingslake, J., Wearing, M. G., Chen, P.-H. C., Gentine, P.,
Li, H., et al. (2020). Vulnerability of Antarctica’s ice shelves to
meltwater-driven fracture. Nature , 584 (7822), 574–578.
https://doi.org/10.1038/s41586-020-2627-8
Larour, E., Seroussi, H., Morlighem, M., & Rignot, E. (2012).
Continental scale, high order, high spatial resolution, ice sheet
modeling using the Ice Sheet System Model (ISSM). Journal of
Geophysical Research: Earth Surface , 117 (F1).
https://doi.org/10.1029/2011jf002140
Lhermitte, S., Sun, S., Shuman, C., Wouters, B., Pattyn, F., Wuite, J.,
et al. (2020). Damage accelerates ice shelf instability and mass loss in
Amundsen Sea Embayment. Proceedings of the National Academy of
Sciences of the United States of America , 117 (40), 24735–24741.
Lipovsky, B. P. (2020). Ice shelf rift propagation: stability,
three-dimensional effects, and the role of marginal weakening. The
Cryosphere, 14 (5), 1673–1683.
https://doi.org/10.5194/tc-14-1673-2020
Liu, H., Jezek, K., Li, B., & Zhao, Z. (2001). Radarsat Antarctic
Mapping Project digital elevation model version 2. Radarsat
Antarctic Mapping Project Digital Elevation Model Version 2, Boulder,
Colorado USA: National Snow and Ice Data Center. Digital Media.
Liu, H., Wang, L., Tang, S.-J., & Jezek, K. C. (2012). Robust
multi-scale image matching for deriving ice surface velocity field from
sequential satellite images. International Journal of Remote
Sensing , 33 (6), 1799–1822.
Liu, Y., Moore, J. C., Cheng, X., Gladstone, R. M., Bassis, J. N., Liu,
H., et al. (2015). Ocean-driven thinning enhances iceberg calving and
retreat of Antarctic ice shelves. Proceedings of the National
Academy of Sciences of the United States of America , 112 (11),
3263–3268.
Luckman, A., Elvidge, A., Jansen, D., Kulessa, B., Munneke, P. K., King,
J., & Barrand, N. E. (2014). Surface melt and ponding on Larsen C Ice
Shelf and the impact of föhn winds. Antarctic Science / Blackwell
Scientific Publications , 26 (6), 625–635.
MacAyeal, D. R. (1989). Large-scale ice flow over a viscous basal
sediment: Theory and application to ice stream B, Antarctica.Journal of Geophysical Research , 94 (B4), 4071–4087.
MacAyeal, D. R., Scambos, T. A., Hulbe, C. L., & Fahnestock, M. A.
(2003). Catastrophic ice-shelf break-up by an ice-shelf-fragment-capsize
mechanism. Journal of Glaciology , 49 (164), 22–36.
Matsuoka, K., Hindmarsh, R. C. A., Moholdt, G., Bentley, M. J.,
Pritchard, H. D., Brown, J., et al. (2015). Antarctic ice rises and
rumples: Their properties and significance for ice-sheet dynamics and
evolution. Earth-Science Reviews , 150 , 724–745.
McGrath, D., Steffen, K., Holland, P. R., Scambos, T., Rajaram, H.,
Abdalati, W., & Rignot, E. (2014). The structure and effect of suture
zones in the Larsen C Ice Shelf, Antarctica. Journal of
Geophysical Research: Earth Surface , 119 (3), 588–602.
Morland, L. W. (1987). Unconfined Ice-Shelf Flow. In Dynamics of
the West Antarctic Ice Sheet (pp. 99–116). Springer Netherlands.
Morlighem, M., Seroussi, H., Larour, É., Schlegel, N., Borstad, C., de
Fleurian, B., et al. (2015). Ice sheet system model 2015 (4.9) user
guide. Retrieved June 30, 2021, from
http://www.ccpo.odu.edu/~klinck/Reprints/PDF/ISSMguide2015.pdf
Morris, E. M., & Vaughan, D. G. (2003). Spatial and Temporal Variation
of Surface Temperature on the Antarctic Peninsula And The Limit of
Viability of Ice Shelves. In Antarctic Peninsula Climate
Variability: Historical and Paleoenvironmental Perspectives (pp.
61–68). American Geophysical Union.
Mouginot, J., Rignot, E., & Scheuchl, B. (2019a). Continent‐wide,
interferometric SAR phase, mapping of antarctic ice velocity.Geophysical Research Letters , 46 (16), 9710–9718.
Mouginot, J., Rignot, E., & Scheuchl, B. (2019b). MEaSUREs
Phase-Based Antarctica Ice Velocity Map, Version 1 . [Antarctic
Peninsula]. Boulder, Colorado USA. NASA National Snow and Ice Data
Center Distributed Active Archive Center.
doi: https://doi.org/10.5067/PZ3NJ5RXRH10. [Access date:
2020-10-01].
Noble, T. L., Rohling, E. J., Aitken, A. R. A., Bostock, H. C., Chase,
Z., Gomez, N., et al. (2020). The sensitivity of the antarctic ice sheet
to a changing climate: Past, present, and future. Reviews of
Geophysics, 58 (4). https://doi.org/10.1029/2019rg000663
Paolo, F. S., Fricker, H. A., & Padman, L. (2015). Ice sheets. Volume
loss from Antarctic ice shelves is accelerating. Science ,348 (6232), 327–331.
Pattyn, F., & Morlighem, M. (2020). The uncertain future of the
Antarctic Ice Sheet. Science , 367 (6484), 1331–1335.
Pritchard, H. D., Ligtenberg, S. R. M., Fricker, H. A., Vaughan, D. G.,
van den Broeke, M. R., & Padman, L. (2012). Antarctic ice-sheet loss
driven by basal melting of ice shelves. Nature , 484 (7395),
502–505.
Reese, R., Gudmundsson, G. H., Levermann, A., & Winkelmann, R. (2017).
The far reach of ice-shelf thinning in Antarctica. Nature Climate
Change , 8 (1), 53–57.
Rignot, E., Casassa, G., Gogineni, P., Krabill, W., Rivera, A., &
Thomas, R. (2004). Accelerated ice discharge from the Antarctic
Peninsula following the collapse of Larsen B ice shelf.Geophysical Research Letters , 31 (18), L18401.
Rignot, E., Jacobs, S., Mouginot, J., & Scheuchl, B. (2013). Ice-shelf
melting around Antarctica. Science , 341 (6143), 266–270.
Robel, A. A., & Banwell, A. F. (2019). A speed limit on ice shelf
collapse through hydrofracture. Geophysical Research Letters ,46 (21), 12092–12100.
Rott, H., Skvarca, P., & Nagler, T. (1996). Rapid collapse of northern
Larsen ice shelf, Antarctica. Science , 271 (5250), 788.
Scambos, T., Hulbe, C., & Fahnestock, M. (2003). Climate-induced ice
shelf disintegration in the Antarctic peninsula. Antarctic
Peninsula Climate Variability: Historical and Paleoenvironmental
Perspectives , 79–92.
Scambos, T., Fricker, H. A., Liu, C.-C., Bohlander, J., Fastook, J.,
Sargent, A., et al. (2009). Ice shelf disintegration by plate bending
and hydro-fracture: Satellite observations and model results of the 2008
Wilkins ice shelf break-ups. Earth and Planetary Science Letters ,280 (1), 51–60.
Scambos, T. A., Dutkiewicz, M. J., Wilson, J. C., & Bindschadler, R. A.
(1992). Application of image cross-correlation to the measurement of
glacier velocity using satellite image data. Remote Sensing of
Environment , 42 (3), 177–186.
Scambos, T. A., Hulbe, C., Fahnestock, M., & Bohlander, J. (2000). The
link between climate warming and break-up of ice shelves in the
Antarctic Peninsula. Journal of Glaciology , 46 (154),
516–530.
Scambos, T. A., Bohlander, J. A., Shuman, C. A., & Skvarca, P. (2004).
Glacier acceleration and thinning after ice shelf collapse in the Larsen
B embayment, Antarctica. Geophysical Research Letters ,31 (18), L18402.
Shepherd, A., Wingham, D., Payne, T., & Skvarca, P. (2003). Larsen ice
shelf has progressively thinned. Science , 302 (5646),
856–859.
Skvarca, P. (1994). Changes and surface features of the Larsen Ice
Shelf, Antarctica, derived from Landsat and Kosmos mosaics. Annals
of Glaciology , 20 , 6-12.
https://doi.org/10.3189/1994aog20-1-6-12
Small, D., Schubert, A., Rosich, B., Meier, E., Lacoste, H., &
Ouwehand, L. (2007). Geometric and radiometric correction of ESA SAR
products. In H. Lacoste & L. Ouwehand (Eds.) (p. online). Presented at
the Envisat Symposium 2007, Montreux (CH): European Space Agency *
Communication Production Office.
Thomas, R. H. (1979). Ice Shelves: A Review. Journal of
Glaciology , 24 (90), 273–286.
Vaughan, D. G., & Doake, C. S. M. (1996). Recent atmospheric warming
and retreat of ice shelves on the Antarctic Peninsula. Nature ,379 (6563), 328–331.
Vaughan, D. G., Marshall, G. J., Connolley, W. M., Parkinson, C.,
Mulvaney, R., Hodgson, D. A., et al. (2003). Recent Rapid Regional
Climate Warming on the Antarctic Peninsula. Climatic Change ,60 (3), 243–274.
Vieli, A., Payne, A. J., Shepherd, A., & Du, Z. (2007). Causes of
pre-collapse changes of the Larsen B ice shelf: Numerical modelling and
assimilation of satellite observations. Earth and Planetary
Science Letters , 259 (3), 297–306.
Wang, S., Liu, H., Yu, B., Zhou, G., & Cheng, X. (2016). Revealing the
early ice flow patterns with historical Declassified Intelligence
Satellite Photographs back to 1960s. Geophysical Research
Letters , 43 (11), 2016GL068990.
Wang, S., Alexander, P., Wu, Q., Tedesco, M., & Shu, S. (2021).
Characterization of ice shelf fracture features using ICESat-2 – A case
study over the Amery Ice Shelf. Remote Sensing of the
Environment , 255 , 112266.
Weis, M., Greve, R., & Hutter, K. (1999). Theory of shallow ice
shelves. Continuum Mechanics and Thermodynamics , 11 (1),
15–50.