Department of Earth Sciences, Dickinson College, Carlisle, Pennsylvania 17013, USA.
Institute of Volcanology and Seismology, Petropavlovsk-Kamchatsky, Russia.
Nat Commun. 2014 Dec 16;5:5666. doi: 10.1038/ncomms6666.
Understanding interactions between volcanic eruptions and the cryosphere (a.k.a. glaciovolcanism) is important for climate reconstructions as well as for hazard mitigation at ice-clad volcanoes. Here we present unique field observations of interactions between snowpack and advancing basaltic lava flows during the 2012-13 eruption at Tolbachik volcano, Kamchatka, Russia. Our observations show that lava-snow heat transfer is slow, and that styles of lava propagation control snowpack responses. 'A'a and sheet lava flows advance in a rolling caterpillar-track motion on top of the rigid, snowpack substrate with minor lava-snow interaction. In contrast, pahoehoe lava propagates by inflation of lobes beneath/inside the snowpack, producing rigorous lava-snow interaction via meltwater percolation down into the incandescent lava causing production of voluminous steam, rapid surface cooling and thermal shock fragmentation. The textures produced by pahoehoe-snowpack interactions are distinctive and, where observed at other sites, can be used to infer syn-eruption seasonality and climatic conditions.
了解火山喷发与冰冻圈（又称冰火山作用）之间的相互作用，对于气候重建以及覆盖冰层的火山的灾害缓解都很重要。在这里，我们呈现了俄罗斯堪察加半岛托巴尔恰克火山 2012-13 年喷发期间独特的雪包与前进玄武岩熔岩流相互作用的实地观测结果。我们的观测表明，熔岩与积雪的热传递非常缓慢，熔岩的流动方式控制了积雪的响应。块状熔岩和流状熔岩在坚硬的积雪基底上以滚动的毛毛虫状运动前进，与积雪的相互作用很小。相比之下，绳状熔岩通过在积雪下/内部膨胀的流舌进行传播，通过融化水渗透到炽热的熔岩中产生大量蒸汽，导致快速的表面冷却和热冲击碎裂，从而产生强烈的熔岩与积雪的相互作用。绳状熔岩与积雪相互作用产生的纹理具有独特性，在其他地方观察到这些纹理时，可以用来推断喷发季节和气候条件。
