法国克莱蒙奥弗涅大学Kelfoun, Karim和Proao, Antonio提出，稀释火山碎屑密度流引起大规模火山沉积物流态化。该研究于2023年5月22日发表于国际一流学术期刊《自然—地球科学》杂志上。

研究人员使用实验室实验和数值模拟证明，稀释的火山碎屑密度流通过后的减压，可以在几乎几平方公里的范围内和几十厘米的深度造成快速的沉积物流化。原沉积的沉积物的再移动，使得流化沉积物的量可以大于触发火山碎屑异重流沉积的量，流化的沉积物甚至可以在低度的斜坡上流动。沉积物的再移动能力受到其颗粒内聚力的限制，而颗粒内聚力会随大气湿度的增加而增加。这种流态化机制提醒人们，要注意这种未被充分认识的火山危险事件，即火山碎屑流的长期溢出，这种火山碎屑流可能是由非常迅速且没有征兆的再移动产生的。

据悉，越来越多的证据表明，火山碎屑流中的细粒沉积物可以大规模重新移动，并引发集中流动。这些集中流动事件存在重大风险；例如的，1997年在苏弗里埃尔火山（蒙特塞拉特)的细粒沉积物重新移动，越过了指定的危险区，流动到人类的居住区域。尽管这些流具有潜在的危害，但人们对这些流的规模和形成机制知之甚少。

附：英文原文

Title: Large-scale volcanic deposit fluidization by dilute pyroclastic density currents

Author: Kelfoun, Karim, Proao, Antonio

Issue&Volume: 2023-05-22

Abstract: There is increasing evidence that fine-grained deposits of pyroclastic density currents can be remobilized on a large scale, resulting in concentrated flows. These flows can be a major hazard; for example, at Soufrière Hills Volcano (Montserrat) in 1997, some travelled beyond the designated danger zone to inhabited areas. Despite their hazard potential, the scale and generation mechanism of these flows are poorly understood. Here we demonstrate using laboratory experiments and numerical modelling that decompression following the passage of dilute pyroclastic density currents can cause rapid deposit fluidization over areas of several square kilometres and to depths of tens of centimetres. The fluidized volume can be substantially greater than that deposited by the triggering pyroclastic density current because of remobilization of previously emplaced deposits, and the fluidized volume can flow even on slopes of a few degrees. The capacity for remobilization of a deposit is limited by its particle cohesion, which rapidly increases with atmospheric humidity. This mechanism of fluidization should alert us to an under-appreciated volcanic hazard of long-run-out pyroclastic flows that can be generated by remobilization very rapidly and with little warning.

DOI: 10.1038/s41561-023-01190-7

Source: https://www.nature.com/articles/s41561-023-01190-7