近日，瑞士苏黎世联邦理工学院Huw J. Horgan团队研究了由偶发性水流塑造的南极西部陆域环境。2025年5月12日出版的《自然—地球科学》杂志发表了这一最新研究成果。
在南极洲的冰盖之下，一个观察不到的液态水网络连接着广阔的景观，并有助于覆盖冰层的运动。当冰下的水到达冰架下的海洋洞穴时，它会与海水混合，放大融化，并在冰层底部形成深通道。研究组展示了热水钻孔的观测结果，记录了冰下水进入坎布冰流和罗斯冰架接地带的海洋空腔。
观测结果表明，融化已经去除了大约三分之一的冰层厚度，但测量结果显示，浑浊羽流中的冰下排放率较低。从河道底部取芯的沉积物显示，发生了较大的流量事件，并偶尔沉积来自不同地质区域的物质。研究组量化冰下流量，并将该观测结果与上游集水区联系起来。最终得出结论，离散的排放事件可能会主导河道融化和沉积物输送，并导致坎布冰流下游广泛的冰架特征。
附：英文原文
Title: A West Antarctic grounding-zone environment shaped by episodic water flow
Author: Horgan, Huw J., Stewart, Craig, Stevens, Craig, Dunbar, Gavin, Balfoort, Linda, Schmidt, Britney E., Washam, Peter, Werder, Mauro A., Mandeno, Darcy, Marschalek, James, Hulbe, Christina, Holschuh, Nicholas, Levy, Richard, Hurwitz, Benjamin, Jendersie, Stefan, Johnson, Katelyn, Lawrence, Justin, Morgenstern, Regine, Mullen, Andrew D., Quartini, Enrica, Sauthoff, Wilson, Siegfried, Matthew, Still, Holly, Thorpe-Loversuch, Sam, van de Flierdt, Tina, Venturelli, Ryan, Whiteford, Arran
Issue&Volume: 2025-05-12
Abstract: Beneath Antarctica’s ice sheets, a little-observed network of liquid water connects vast landscapes and contributes to the motion of the overriding ice. When this subglacial water reaches the ocean cavity beneath ice shelves, it mixes with seawater, amplifying melt and in places forming deep channels in the base of the ice. Here we present observations from a hot-water-drilled borehole documenting subglacial water entering the ocean cavity at the grounding zone of Kamb Ice Stream and the Ross Ice Shelf. Our observations show that melt has removed approximately a third of the ice thickness, yet measurements reveal low rates of subglacial discharge in a turbid plume. Sediment cored from the channel floor shows larger discharge events occur and episodically deposit material from distinct geological domains. We quantify subglacial discharge and link our observations to the catchment upstream. We conclude that discrete discharge events are likely to dominate channel melt and sediment transport and result in the extensive ice-shelf features downstream of Kamb Ice Stream.
DOI: 10.1038/s41561-025-01687-3
Source: https://www.nature.com/articles/s41561-025-01687-3