Synchronous retreat of Thwaites and Pine Island glaciers in response to external forcings in the presatellite era
Synchronous retreat of Thwaites and Pine Island glaciers in response to external forcings in the presatellite era
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卫星前时代思韦茨和派恩岛冰川响应外部强迫的同步退缩
DOI：
10.1073/pnas.2211711120
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发表时间：
2024
期刊：
影响因子：
--
通讯作者：
Clark R
中科院分区：
文献类型：
--
作者：
Clark R
今天，相对温暖的环极深水正在融化思韦茨冰川的冰架底部和接地带，造成了显著的冰退缩。自20世纪70年代以来，已经观察到加速的冰损失；然而，目前尚不清楚这一阶段的显著融化是何时开始的。通过对海相沉积记录的分析，重建了斯韦茨冰川从全新世早期至今的历史。沿着浮动冰架边缘进行了海洋地球物理调查，以确定不同地貌背景下的核心位置。我们使用沉积学数据和物理性质来确定七个芯点的沉积相。冰川期海洋沉积物表明，在大约9400年前，阿蒙森海海湾的接地冰已经退缩到距离现代接地带约45公里的范围内。过去100+ y内沉积的沉积物记录了环境条件的突变。在海底高处，这些变化记录了至少早在20世纪40年代就开始的冰架变薄。从深盆地中恢复的沉积物反映了从冰近端到远端条件的转变，表明自20世纪50年代以来，接地带正在持续退缩。斯韦茨冰川冰架从海底脱落的时间与邻近的松岛冰川的类似记录相吻合。我们的工作提供了强有力的新证据，表明阿蒙森海的冰川退缩始于20世纪中叶，可能与气候变化有关。
Today, relatively warm Circumpolar Deep Water is melting Thwaites Glacier at the base of its ice shelf and at the grounding zone, contributing to significant ice retreat. Accelerating ice loss has been observed since the 1970s; however, it is unclear when this phase of significant melting initiated. We analyzed the marine sedimentary record to reconstruct Thwaites Glacier’s history from the early Holocene to present. Marine geophysical surveys were carried out along the floating ice-shelf margin to identify core locations from various geomorphic settings. We use sedimentological data and physical properties to define sedimentary facies at seven core sites. Glaciomarine sediment deposits reveal that the grounded ice in the Amundsen Sea Embayment had already retreated to within ~45 km of the modern grounding zone prior to ca. 9,400 y ago. Sediments deposited within the past 100+ y record abrupt changes in environmental conditions. On seafloor highs, these shifts document ice-shelf thinning initiating at least as early as the 1940s. Sediments recovered from deep basins reflect a transition from ice proximal to slightly more distal conditions, suggesting ongoing grounding-zone retreat since the 1950s. The timing of ice-shelf unpinning from the seafloor for Thwaites Glacier coincides with similar records from neighboring Pine Island Glacier. Our work provides robust new evidence that glacier retreat in the Amundsen Sea was initiated in the mid-twentieth century, likely associated with climate variability.
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影响因子：
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作者：
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DOI：
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发表时间：
2021
期刊：
影响因子：
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作者：
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通讯作者：
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DOI：
--
发表时间：
2022
期刊：
影响因子：
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作者：
Sproson Adam D.;Pogge von Strandmann Philip A.E.;Selby David;Jarochowska Emilia;Frida Jiri;Hladil Jindrich;Loydell David K.;Slavik Ladislav;Calner Mikael;Maier Georg;Munnecke Axel;Lenton Timothy M.;Southern Hemisphere pacing of global climate during the Late Pleistocene;Holocene Ice Loss in the Amundsen Sea Embayment Linked to Tropical Pacific Warming
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南极洲西部阿蒙森海海湾近期沉积物和冰期沉积物之间的物源变化：粘土矿物组合证据
影响因子：
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作者：
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通讯作者：
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