Atmospheric and oceanic warming over the past century have driven rapid glacier thinning and retreat, destabilizing hillslopes and increasing the frequency of landslides. The impact of these landslides on glacier dynamics and resultant secondary landslide hazards are not fully understood. We investigated how a 262 ± 77 × 106 m3 landslide affected the flow of Amalia Glacier, Chilean Patagonia. Despite being one of the largest recorded landslides in a glaciated region, it emplaced little debris onto the glacier surface. Instead, it left a series of landslide-perpendicular ridges, landslide-parallel fractures, and an apron of ice debris—with blocks as much as 25 m across. Our observations suggest that a deep-seated failure of the mountainside impacted the glacier flank, propagating brittle deformation through the ice and emplacing the bulk of the rock mass below the glacier. The landslide triggered a brief downglacier acceleration of Amalia Glacier followed by a slowdown of as much as 60% of the pre-landslide speed and increased suspended-sediment concentrations in the fjord. These results highlight that landslides may induce widespread and long-lasting disruptions to glacier dynamics.Glaciers produce landslide-prone conditions (Záruba and Mencl, 1982) by eroding and oversteepening slopes, depositing unconsolidated moraines (Shulmeister et al., 2009; Shugar and Clague, 2011), and propagating bedrock fractures (Sanders et al., 2012; Grämiger et al., 2017). Ongoing global glacier retreat and thinning (Radić and Hock, 2011; Leclercq et al., 2014; Shannon et al., 2019) exposes and debuttresses these ice-marginal hillslopes (Holm et al., 2004; Fischer et al., 2006; Huggel et al., 2012; Deline et al., 2015), further increasing landslide potential.These factors increase the likelihood of landslides onto glaciers, which may then also feed back into change in glacier dynamics and hazards. Observational (Hewitt, 1988; Gardner and Hewitt, 1990; Shugar et al., 2012; Higman et al., 2018) and geological (Santamaria Tovar et al., 2008; Vacco et al., 2010) data record or support glacier advance in response to landsliding and mine-tailings loading (Jamieson et al., 2015). A causal link between a supraglacial landslide and a glacier surge was also proposed at Bualtar Glacier, Pakistan, although it could not be confirmed through direct observations (Hewitt, 1988; Gardner and Hewitt, 1990). In an extreme case, a 2002 CE supraglacial landslide at Kolka Glacier, Russia, triggered a full glacier detachment, resulting in 125 fatalities (Haeberli et al., 2004). Landslides in supraglacial and paraglacial environments may also generate tsunamis (Blikra et al., 2006; Higman et al., 2018). We provide a new example of the effect that landslides may have on glacier dynamics through the study of a large landslide at the fast-flowing tidewater Amalia Glacier (Chilean Patagonia; 50°55′S, 73°37′W).Amalia Glacier is a rapidly thinning, 160 km2 tidewater glacier draining a portion of the Southern Patagonian Icefield toward the Pacific Ocean. Historical photography from 1908 CE to preset demonstrates >8 km of monotonic frontal retreat over the past century (Fig. 1). The >300 m of ice thinning associated with this retreat has exposed the unconsolidated flank of the active volcano (Harambourg, 1988) Reclus along the southern margin of Amalia Glacier, which yields a quasi-annual flux of small landslides, with larger events in 1979, in 2017, and on 26 April 2019 (Fig. 1).We investigated the 2019 landslide, originating from the northeastern flank of Reclus volcano. We note a temporal correlation between rapid ice thinning and landslide emplacement but did not investigate causal links. We instead applied repeat satellite imagery to resolve unusual characteristics of the 2019 landslide and its impact on Amalia Glacier's dynamics.We use remotely sensed data to observe changes in both Amalia Glacier and the adjacent flank of Reclus volcano from 2015 to 2021. We calculated the 2019 landslide volume by subtracting a pre-event (May 2017) digital elevation model (DEM) from the earliest post-event (August 2019) DEM (see the Supplemental Material1). We derived a glacier-front thickness anomaly using the same DEM pair, subtracting the long-term glacier-elevation trend (calculated from the 2014 DEM to the 2017 DEM).We used optical satellite imagery from the European Space Agency Sentinel-2 mission and the feature-tracking toolbox Glacier Image Velocimetry (GIV, https://www.maxgeohub.com/giv/; Van Wyk de Vries and Wickert, 2021) to calculate Amalia Glacier's surface velocity. Starting with 160 cloud-free Sentinel-2 images, we generated a set of all possible image pairs with temporal separations of between 1 week and 9 months (n = 3459). We then filtered and resampled the results into monthly velocity maps using a weighted averaging scheme (Van Wyk de Vries and Wickert, 2021) and difference pre- and post-landslide velocities to generate monthly speed-anomaly maps.We calculated changes in glacier frontal position and relative suspended-sediment concentrations (rSSCs) in the fjord using all cloud-free Sentinel 2 images from October 2015 to June 2021 (71 images). We calculated maximum frontal change as the maximum change in frontal position relative to October 2015; mean frontal change by dividing the frontal area change relative to October 2015 by the fjord width; and frontal ablation rate by differencing mean frontal speed and mean frontal position change (Dryak and Enderlin., 2020). We used the radiance of Sentinel-2 band 5 (705 nm) as a proxy for rSSC through a modified version of the Ulyssys Water Quality Viewer (Zlinszky and Padányi-Gulyás, 2020).To investigate the effect of subglacial landslide emplacement on ice velocities in a more general case, we applied the Ice-Sheet and Sea-Level System Model (ISSM, https://issm.jpl.nasa.gov/; Larour et al., 2012) to a synthetic approximation of Amalia Glacier, with a length of 10 km, width of 3 km, maximum thickness of 400 m (Carrivick et al., 2016; Millan et al., 2019), and surface slope of 3.5°. We ran a transient-stress-balance glacier model with higher-order field equations. We executed an initial 10 yr “spin up” phase (time step = 0.1 yr) to achieve steady state, followed by six scenarios (see the Supplemental Material) for another 5 yr (time step = 0.01 yr) with and without the occurrence of an ~250 × 106 m3 landslide.We calculated a landslide volume of 262 ± 77 × 106 m3. The scar area was not glaciated at the time of collapse, so the landslide must have been predominantly composed of rock. The landslide disrupted 3.5 km2 of Amalia Glacier's surface, although detailed inspection of high-resolution satellite imagery reveals that the ice surface is free of rock debris (see the Supplemental Material).The landslide-disrupted region consists of a proximal zone of mixed rock and ice debris, an intermediate zone dominated by transverse ridges and radial fractures, and a distal ice-debris apron (Fig. 1). In the proximal zone, the pre-landslide glacier margin has been locally displaced >100 m, replaced by a mix of rock and ice debris. In the debris-free intermediate zone, 10–30-m-high ice ridges oriented transverse to the landslide-emplacement direction overprint the preexisting crevasse fabric (Fig. 1). Amalia Glacier's surface-fracture pattern and surface-elevation change suggest an upward and lateral displacement of the glacier ice, with the bulk of the debris emplaced at the glacier bed and margin. The distal ice-debris apron contains ice fragments as much as 25 m in size and is free of rock debris. January 2021 Sentinel-2 imagery shows that the anomalous fracture fabric remains present 1.5 yr post-landslide, although the southern margin of Amalia Glacier has re-advanced 300 m into the landslide scar.Amalia Glacier's surface speed shows rapid changes following the landslide emplacement. Downglacier from the landslide, Amalia Glacier accelerated by as much as 400 m yr−1 in May 2019 (a 40% increase relative to May 2018), while the portion of Amalia Glacier upglacier of the landslide slowed by a similar magnitude (Figs. 2 and 3). In the 4 months following the landslide, the zone of increased ice-surface speed migrated downglacier and decayed. This was associated with between 15 and 90 m of ice thickening totaling 209 × 106 m3—comparable to the landslide volume—and concentrated at the calving front (Fig. 3). In addition, Amalia Glacier reversed a centennial retreat trend (Fig. 1) and advanced one kilometer to its farthest extent within the past five years. Both the thickening and frontal advance continue as of June 2021, more than two years post-landside.For the 4 months immediately following landslide emplacement, slowdown occurred upglacier of the landslide. Between August and November 2019, the slowdown propagated through the entire glacier (Figs. 2 and 3). After November 2019, the slowdown became greatest at the glacier front, where glacier speed dropped from >1000 m yr−1 in June 2019 to 600–700 m yr−1 in November 2019 (Fig. 4). As of June 2021, ice speed in the vicinity of the landslide has recovered to within 10% of pre-collapse levels, whereas ice speed near Amalia Glacier's calving front remained slow (700 m yr−1 in June 2021 compared to 1175 m yr−1 in June 2018). Amalia Glacier's frontal ablation rate dropped by 35% in 2020 relative to pre-landslide values and remains at that level as of June 2021. The rSSC at the front of Amalia Glacier peaked at more than five times the pre-landslide maximum in austral summer 2020 and 2021 (Fig. 2C).In the simulated glacier model, landslide emplacement increases ice-surface speed downglacier of the landslide center by ~600 m yr−1 and reduces it by ~250 m yr−1 upglacier (Fig. 4). Two years after the landslide, the modeled glacier remains ~100 m yr−1 slower near the zone of landslide emplacement. A model run with a 20% increase in basal friction shows a similar overall trend, with a further ~200 m yr−1 glacier-wide slowdown.The landslide-induced dynamic glacier changes may relate to changes in the stress field, frontal conditions, or basal hydrology, or some combination of these factors. Immediately following the landslide event, the glacier decelerated upglacier and accelerated downglacier of the landslide center. The synthetic glacier model, which does not account for any change in basal friction, basal hydrology, or calving-front conditions (Figs. 4E–4H), exhibits a similar speed-anomaly pattern for the first 3 months following landslide emplacement. Disruptions to the ice-surface and basal topography alone provide a viable mechanism for the short-term post-landslide downglacier acceleration at Amalia Glacier.Starting at ~3 months following the landslide, slowdown of ice surface speed increased in magnitude and propagated downglacier. The focus of the slowdown was first located at the zone of landslide emplacement, followed by a switch to the glacier calving front after 9 months. Changes in driving stresses alone, as represented by our model outputs, cannot explain this longer-term slowdown and its pattern.One explanation for the slowdown could be a change in basal hydrology. An increase in the efficiency of subglacial drainage reduces subglacial water pressure, increases basal friction, and lowers ice speed (Iken and Truffer, 1997; Cuffey and Paterson, 2010). Without direct measurements of Amalia Glacier's subglacial conditions, we examine fjord rSSC as a proxy. Glacier sediment export is controlled by the availability of subglacial sediment and the subglacial drainage system's sediment-transport capacity, with the latter being higher in efficient (i.e., internally connected) drainage systems.We observed high rSSC in the Amalia Fjord during austral summer 2020 and summer 2021 (Fig. 2) when compared to prior summers, including the period following the 2017 supraglacial landslide. Times of highest rSSC coincide with the melt season. The 2019 landslide injected large quantities of loose sediment at the base of Amalia Glacier while also locally disrupting englacial and supraglacial fracture networks. This latter effect may have changed subglacial flow paths, allowing sediment to be sourced from new areas of the glacier bed (e.g., Anderson et al., 1999). In addition, any increase in the efficiency of Amalia Glacier's subglacial drainage system could explain the initial 9 month slowdown centered on the zone of landslide emplacement. We cannot, however, distinguish the relative contributions of increased drainage efficiency and greater sediment availability to the observed increase in rSSC.Conversion of a formerly marine-terminating glacier to a land-terminating glacier increases its basal friction, thereby reducing its speed at the ice front. This buttressing at the terminus may consequently reduce ice speeds upglacier. Amalia Glacier's southern ice front slowed 40% when a delta formed ~9 months post-landslide, and portions of its terminus became land-terminating. Amalia Glacier continues to advance as of November 2021, and its calving flux has remained at approximately two-thirds of its pre-landslide value since early 2020.In summary, we ascribe Amalia Glacier's speed changes to three sources: (1) topographically induced changes in the glacier's stress field, related to subglacial landslide emplacement and uplift of the ice surface; (2) a reduction in basal slip related to more efficient meltwater evacuation and consequent depressurization of the subglacial hydrological system; and (3) proglacial delta formation and partial grounding of Amalia Glacier's ice front. Our results highlight the potential of remote sensing for understanding glacier dynamic changes in remote areas, although field data would be valuable for better assessing glacier basal processes and stress changes.Certain characteristics of Amalia Glacier's response to the emplacement of a large landslide are reminiscent of glacier surges. In a typical surge-type glacier, ice gradually accumulates in a reservoir zone until it reaches a critical level, before destabilizing and rapidly draining downglacier during the surge (Eisen et al., 2001, 2005). At Amalia Glacier, landslide emplacement instantaneously formed a “reservoir zone” by uplifting the ice surface and drove rapid downglacier thickening and acceleration (Figs. 2 and 3). The long-term (2 + yr) frontal slowdown and proglacial delta formation are more reminiscent of the advance phase of a tidewater glacier, where a shallow proglacial shoal reduces frontal ablation and enables glacier advance (Post et al., 2011). Future studies of Amalia Glacier are needed to evaluate whether the disruption is temporary or the glacier has shifted into a new steady state.The hazard related to this glacier response at Amalia Glacier is minor due to its remoteness. However, large-magnitude, rapid, and long-term changes in glacier dynamics may be of concern in more populated regions (e.g., Gardner and Hewitt, 1990; Deline et al., 2015). Our results underscore the importance of glacier-related landslide monitoring, including how interactions between landslides and glacier dynamics may extend the effects of a landslide many kilometers beyond its runout zone.A 262 ± 77 × 106 m3 landslide impacted Amalia Glacier on 26 April 2019. Unusually, this landslide deposited little to no debris on the glacier surface but instead displaced the glacier margin, thickened the glacier through brittle faulting and accretion of eroded ice debris, and imprinted a strong brittle-contractional fracture pattern. Remotely sensed glacier-surface speed and DEMs show that Amalia Glacier accelerated by 100–400 m yr−1, thickened by 10–50 m, and advanced more than 1 km following the landslide. This acceleration was succeeded by glacier-wide slowdown, centered first on the landslide runout zone and then on Amalia Glacier's calving front. We ascribe this complex spatiotemporal change in glacier speed to three factors: (1) a change in driving stresses, related to the altered ice-surface and basal topography; (2) a shift in glacier basal hydrology, with the landslide increasing basal drainage-network efficiency; and (3) increased glacier-front stability due to proglacial delta formation and grounding of the ice front. Two years after the landslide, frontal speed and calving flux remain suppressed. These results highlight that landslides, forecast to increase in frequency with climatic warming, can alter the dynamics of even very large glaciers.Van Wyk de Vries has been supported by the University of Minnesota College of Science and Engineering and a Doctoral Dissertation Fellowship. This work is supported by U.S. National Science Foundation grant EAR-1714614 to Wickert, E. Ito, and A. Noren, and lead Principal Investigator M.B. Magnani. Imagery was provided by the European Space Agency (proposal N57129). Reviews by K. Cuffey, F. Beaud, and M. Truffer guided revisions that improved the quality of the manuscript, the focus of our modeling, and our placement of this event in its scientific context.

中文翻译：

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非典型滑坡导致潮水冰川加速、推进和长期减速

过去一个世纪的大气和海洋变暖导致冰川迅速变薄和退缩，破坏了山坡的稳定并增加了山体滑坡的频率。这些滑坡对冰川动力学和由此产生的次生滑坡灾害的影响尚不完全清楚。我们调查了 262 ± 77 × 106 m3 的滑坡如何影响智利巴塔哥尼亚阿马利亚冰川的流动。尽管它是冰川地区记录到的最大的山体滑坡之一，但它在冰川表面上留下的碎片很少。相反，它留下了一系列滑坡垂直山脊、滑坡平行裂缝和冰碎片围裙 - 块宽达 25 m。我们的观察表明，山腰的深层故障影响了冰川的侧面，通过冰传播脆性变形并将大部分岩体置于冰川下方。滑坡引发了阿玛利亚冰川的冰川下移短暂加速，随后减缓了高达滑坡前速度的 60%，并增加了峡湾的悬浮沉积物浓度。这些结果表明，滑坡可能会对冰川动力学造成广泛而持久的破坏。冰川通过侵蚀和过度陡峭的斜坡，沉积松散的冰碛（Shulmeister 等，2009；Shugar 和 Clague , 2011) 和扩展的基岩裂缝 (Sanders et al., 2012; Grämiger et al., 2017)。正在进行的全球冰川退缩和变薄（Radić 和 Hock，2011；Leclercq 等，2014；Shannon 等，2019）暴露并修复这些冰缘山坡（Holm et al., 2004; Fischer et al., 2006; Huggel et al., 2012; Deline et al., 2015），进一步增加了滑坡的可能性。这些因素增加了可能性山体滑坡到冰川上，这也可能反馈给冰川动态和危害的变化。观测（Hewitt，1988；Gardner 和 Hewitt，1990；Shugar 等，2012；Higman 等，2018）和地质（Santamaria Tovar 等，2008；Vacco 等，2010）数据记录或支持冰川推进以应对滑坡和尾矿装载（Jamieson 等人，2015 年）。巴基斯坦 Bualtar 冰川也提出了冰上滑坡和冰川涌动之间的因果关系，尽管无法通过直接观察来证实（Hewitt，1988；Gardner 和 Hewitt，1990）。在极端情况下，2002 年在俄罗斯科尔卡冰川发生的一次冰上滑坡引发了冰川完全脱离，导致 125 人死亡（Haeberli 等，2004）。冰上和冰旁环境中的滑坡也可能引发海啸（Blikra 等，2006；Higman 等，2018）。我们通过研究快速流动的潮水阿马利亚冰川（智利巴塔哥尼亚；50°55′S，73°37′W）的大型滑坡，提供了一个滑坡可能对冰川动力学产生影响的新例子。阿马利亚冰川是一个迅速变薄的 160 平方公里的潮水冰川，将巴塔哥尼亚南部冰原的一部分引向太平洋。从公元 1908 年到预设的历史照片展示了过去一个世纪 > 8 公里的单调锋面后退（图 1）。> 与这次撤退相关的 300 m 冰变薄暴露了沿阿马利亚冰川南缘的活火山松散的侧面（Harambourg，1988），这产生了小滑坡的准年通量，1979 年发生了更大的事件，在2017 年和 2019 年 4 月 26 日（图 1）。我们调查了 2019 年的滑坡，起源于 Reclus 火山的东北侧。我们注意到快速冰变薄和滑坡就位之间的时间相关性，但没有调查因果关系。相反，我们应用重复的卫星图像来解决 2019 年滑坡的不寻常特征及其对阿马利亚冰川动力学的影响。我们使用遥感数据来观察阿马利亚冰川和雷克勒斯火山相邻侧翼从 2015 年到 2021 年的变化。我们通过从最早的事件后（2019 年 8 月）DEM（见补充材料 1）中减去事件前（2017 年 5 月）数字高程模型（DEM）来计算 2019 年的滑坡体积。我们使用相同的 DEM 对得出冰川前缘厚度异常，减去长期冰川海拔趋势（从 2014 年 DEM 到 2017 年 DEM 计算）。我们使用来自欧洲航天局 Sentinel-2 任务的光学卫星图像和特征跟踪工具箱 Glacier Image Velocimetry (GIV, https://www.maxgeohub.com/giv/; Van Wyk de Vries and Wickert, 2021) 来计算 Amalia Glacier 的表面速度。从 160 个无云 Sentinel-2 图像开始，我们生成了一组所有可能的图像对，时间间隔在 1 周到 9 个月之间（n = 3459）。然后，我们使用加权平均方案（Van Wyk de Vries 和 Wickert，2021 年）对结果进行过滤并重新采样到月度速度图中，并使用滑坡前后速度差异来生成月度速度异常图。我们计算了冰川正面位置的变化使用 2015 年 10 月至 2021 年 6 月的所有无云 Sentinel 2 图像（71 幅图像）得出峡湾中的相对悬浮沉积物浓度 (rSSCs)。我们将最大正面变化计算为相对于 2015 年 10 月的正面位置的最大变化；通过将相对于 2015 年 10 月的锋面面积变化除以峡湾宽度来平均锋面变化；和通过区分平均额叶速度和平均额叶位置变化的额叶消融率（Dryak 和 Enderlin.，2020）。我们通过修改版的 Ulyssys 水质查看器（Zlinszky 和 ​​Padányi-Gulyás，2020 年）使用 Sentinel-2 波段 5（705 nm）的辐射作为 rSSC 的代理。研究冰下滑坡侵位对冰速的影响在更一般的情况下，我们将冰盖和海平面系统模型 (ISSM, https://issm.jpl.nasa.gov/; Larour et al., 2012) 应用于阿玛利亚冰川的合成近似值，其中长10 km，宽3 km，最大厚度400 m（Carrivick et al., 2016; Millan et al., 2019），地表坡度3.5°。我们使用高阶场方程运行了瞬态应力平衡冰川模型。我们执行了最初的 10 年“加速”阶段（时间步长 = 0.1 年）以达到稳定状态，然后是另外 5 年（时间步长 = 0.0）的六个场景（参见补充材料）。01 年）有和没有发生~250 × 106 m3 的滑坡。我们计算的滑坡体积为 262 ± 77 × 106 m3。崩塌时疤痕区域没有冰川作用，因此滑坡一定主要由岩石组成。滑坡破坏了阿玛利亚冰川 3.5 平方公里的表面，尽管对高分辨率卫星图像的详细检查表明冰面没有岩石碎片（见补充材料）。滑坡破坏区域由混合岩石和冰屑，以横脊和径向裂缝为主的中间带，以及远端冰屑围裙（图1）。在近端区域，滑坡前的冰川边缘已局部位移 > 100 m，取而代之的是岩石和冰屑的混合物。在无碎片中间地带，10-30 米高的冰脊垂直于滑坡就位方向，覆盖了先前存在的裂缝织物（图 1）。Amalia Glacier 的地表裂缝模式和地表海拔变化表明冰川冰向上和横向移动，大部分碎片位于冰川床和边缘。远端冰屑围裙包含大小高达 25 m 的冰碎片，并且没有岩石碎片。2021 年 1 月的 Sentinel-2 图像显示，异常断裂结构在滑坡后 1.5 年仍然存在，尽管阿马利亚冰川的南缘重新推进了 300 m 进入滑坡疤痕。阿马利亚冰川的表面速度在滑坡就位后显示出快速变化。从山体滑坡下来的冰川，2019 年 5 月，Amalia Glacier 加速了 400 m yr-1（相对于 2018 年 5 月增加了 40%），而滑坡的 Amalia Glacier 上冰川部分减速了类似的幅度（图 2 和图 3）。在滑坡后的4个月内，冰面速度增加的区域向冰川下迁移并腐烂。这与 15 至 90 m 之间的冰增厚有关，总计 209 × 106 m3（与滑坡体积相当）并集中在产犊前缘（图 3）。此外，阿玛利亚冰川逆转了百年后退的趋势（图1），前进了1公里，达到了过去五年来的最远距离。到 2021 年 6 月，加厚和正面推进都在继续，在滑坡后两年多。在滑坡就位后的 4 个月里，滑坡上冰川出现减速。在 2019 年 8 月至 11 月期间，放缓蔓延到整个冰川（图 2 和图 3）。2019 年 11 月之后，冰川前缘的减速幅度最大，冰川速度从 2019 年 6 月的 >1000 m yr-1 下降到 2019 年 11 月的 600-700 m yr-1（图 4）。截至 2021 年 6 月，滑坡附近的冰速已恢复到崩塌前水平的 10% 以内，而阿马利亚冰川崩塌前缘附近的冰速仍然缓慢（2021 年 6 月为 700 m-1，而 1175 m-yr- 1 于 2018 年 6 月）。相对于滑坡前的值，2020 年阿马利亚冰川的正面消融率下降了 35%，并且截至 2021 年 6 月仍保持在该水平。阿马利亚冰川前部的 rSSC 在 2020 年南方夏季达到了滑坡前最大值的五倍以上和2021（图2C）。在模拟冰川模型中，滑坡侵位使滑坡中心的冰川下冰面速度增加了约 600 m yr-1 并减少了约 250 m yr-1 上冰川（图 4）。滑坡两年后，模拟的冰川在滑坡就位区附近仍然慢了约 100 m yr-1。基础摩擦力增加 20% 的模型显示出类似的总体趋势，冰川范围进一步减速约 200 m yr−1。滑坡引起的动态冰川变化可能与应力场、锋面条件、或基础水文学，或这些因素的某种组合。滑坡事件发生后，冰川立即加速滑坡中心的冰川上移和冰川下移。合成冰川模型，不考虑基础摩擦、基础水文或崩解前沿条件的任何变化（图 4E-4H），在滑坡就位后的前 3 个月表现出类似的速度异常模式。仅对冰面和基底地形的破坏就为阿马利亚冰川的短期滑坡后冰川下加速提供了可行的机制。从滑坡后约 3 个月开始，冰面速度减慢的幅度增加并传播到冰川下。减速的焦点首先位于滑坡就位区，随后在 9 个月后转向冰川崩解前沿。正如我们的模型输出所代表的，仅驱动应力的变化无法解释这种长期放缓及其模式。对这种放缓的一种解释可能是基础水文的变化。冰下排水效率的提高会降低冰下水压，增加基础摩擦力，并降低冰速（Iken 和 Truffer，1997；Cuffey 和 Paterson，2010）。在没有直接测量 Amalia Glacier 的冰下条件的情况下，我们将峡湾 rSSC 作为代理进行检查。冰川沉积物的输出受冰下沉积物的可用性和冰下排水系统的沉积物运输能力控制，后者在高效（即内部连接）排水系统中更高。我们在 2020 年夏季的夏季观察到阿马利亚峡湾的高 rSSC 和2021 年夏季（图 2）与之前的夏季相比，包括 2017 年冰上滑坡之后的时期。最高 rSSC 的时间与融化季节一致。2019 年的滑坡在阿马利亚冰川底部注入了大量松散沉积物，同时也局部破坏了冰河和冰上断裂网络。后一种效应可能改变了冰下流动路径，允许沉积物来自冰川床的新区域（例如，Anderson 等，1999）。此外，阿玛利亚冰川冰下排水系统效率的任何提高都可以解释最初 9 个月以滑坡侵位区为中心的减速。然而，我们无法区分增加的排水效率和更大的沉积物可用性对观察到的 rSSC 增加的相对贡献。从以前的海洋终止冰川转变为陆地终止冰川增加了它的基础摩擦，从而降低了它在冰上的速度正面。因此，终点处的这种支撑可能会降低冰上冰川的速度。在山体滑坡后约 9 个月形成三角洲时，阿玛利亚冰川的南部冰锋减慢了 40%，其终点站的一部分成为陆地终端。自 2021 年 11 月起，阿玛利亚冰川继续向前推进，自 2020 年初以来，其崩解通量一直保持在其滑坡前值的三分之二左右。总而言之，我们将阿玛利亚冰川的速度变化归因于三个来源：(1) 地形引起的变化在冰川应力场中，与冰下滑坡侵位和冰面抬升有关；(2) 与更有效的融水疏散和随之而来的冰下水文系统减压相关的底滑减少；(3) Amalia Glacier 冰锋的前冰期三角洲形成和部分接地。我们的研究结果突出了遥感在了解偏远地区冰川动态变化方面的潜力，尽管现场数据对于更好地评估冰川基础过程和应力变化很有价值。阿马利亚冰川对大型滑坡的反应的某些特征让人想起冰川涌动。在典型的浪涌型冰川中，冰会逐渐积聚在水库区，直到达到临界水平，然后在浪涌期间使冰川不稳定并迅速排出（Eisen et al., 2001, 2005）。在阿玛利亚冰川，滑坡侵位瞬间形成“储层带”，抬升冰面，带动下冰川迅速增厚和加速（图 2 和图 3）。长期（2 年以上）锋面减速和前冰期三角洲形成更让人联想到潮水冰川的推进阶段，浅的前冰期浅滩减少了正面消融并使冰川前进（Post et al., 2011）。需要对阿玛利亚冰川进行未来研究，以评估破坏是暂时的还是冰川已转变为新的稳定状态。由于地处偏远，与阿玛利亚冰川的这种冰川反应相关的危害很小。然而，在人口较多的地区，冰川动力学的大规模、快速和长期变化可能会引起关注（例如，Gardner 和 Hewitt，1990；Deline 等，2015）。我们的研究结果强调了与冰川相关的滑坡监测的重要性，包括滑坡与冰川动力学之间的相互作用如何将滑坡的影响扩大到其滑坡区以外数公里。2019 年 4 月 26 日，262 ± 77 × 106 m3 的滑坡影响了阿玛利亚冰川。不同寻常的是，这次滑坡在冰川表面几乎没有沉积碎片，而是移动了冰川边缘，通过脆性断层和侵蚀冰碎片的堆积使冰川变厚，并留下了强烈的脆性收缩断裂模式。遥感冰川表面速度和 DEM 显示，阿玛利亚冰川加速了 100-400 m yr-1，增厚了 10-50 m，并在滑坡后推进了 1 km 以上。这种加速被冰川范围内的减速所取代，首先以滑坡跳动区为中心，然后是阿玛利亚冰川的崩解前沿。我们将冰川速度的这种复杂的时空变化归因于三个因素：（1）驱动应力的变化，与冰面和基底地形的改变有关；(2) 冰川基础水文的转变，随着滑坡增加基础排水管网效率；(3) 由于前冰期三角洲的形成和冰锋的接地，增加了冰川锋的稳定性。滑坡两年后，锋面速度和产犊通量仍然受到抑制。这些结果表明，预计随着气候变暖，滑坡的频率会增加，甚至可以改变非常大的冰川的动态。Van Wyk de Vries 得到了明尼苏达大学科学与工程学院和博士论文奖学金的支持。这项工作得到了美国国家科学基金会向 Wickert、E. Ito 和 A. Noren 以及首席首席研究员 MB Magnani 授予的 EAR-1714614 的支持。图片由欧洲航天局提供（提案 N57129）。K. Cuffey、F. Beaud 和 M. 的评论