Catastrophic eruptions of rhyolitic super volcanoes require large volumes of silicic magma to be extracted from a crystal-rich mush at high rates. However, fast melt extraction is thought to be difficult because of the low permeability of mushes and the high viscosities of silicic melts. Here, we show that induced ephemeral high permeability pathways in the mush may be critical. During uniaxial compression of the mush, driven by the impingement of recharging magmas from below, melt within the mush can be redistributed preferentially into vertical melt pockets. This redistribution of melt can increase vertical permeability by a factor of 10-100 times, which leads to rapid expulsion of melt. As melt is expelled, the permeability rapidly declines. The end result is a fast, short-lived pulse of melt extraction that can grow a 1 km thick silicic magma reservoir in 10 kyr. Our analysis shows how the incursion of deep-seated magmas into the base of a crystal-rich mush in the crust can trigger the expulsion of silicic melts that may lead to an eruption.

流纹质超级火山的灾难性喷发需要从富含晶体的糊状物中高速提取大量硅质岩浆。然而，由于糊状物的低渗透性和硅熔体的高粘度，快速熔体提取被认为是困难的。在这里，我们表明在糊状物中诱导的短暂高渗透性途径可能是关键的。在糊状物的单轴压缩过程中，受来自下方补充岩浆的冲击驱动，糊状物内的熔体可以优先重新分布到垂直的熔池中。熔体的这种重新分布可使垂直渗透率增加 10-100 倍，从而导致熔体快速排出。随着熔体被排出，渗透率迅速下降。最终结果是快速，熔体提取的短寿命脉冲，可以在 10 kyr 中生长 1 公里厚的硅质岩浆储层。我们的分析表明，深层岩浆侵入地壳中富含晶体的糊状物底部是如何触发硅熔体的排出，从而导致火山喷发。