Rincón M, Márquez A, Herrera R, Alonso-Torres A, Granja-Bruña J L, van Wyk de Vries B
Universidad Rey Juan Carlos, Área de Geología, Móstoles, Madrid, Spain.
Hospital Rey Juan Carlos, Radiodiagnóstico, Móstoles, Madrid, Spain.
Sci Rep. 2018 Apr 18;8(1):6178. doi: 10.1038/s41598-018-24623-5.
Catastrophic volcanic eruptions triggered by landslide collapses can jet upwards or blast sideways. Magma intrusion is related to both landslide-triggered eruptive scenarios (lateral or vertical), but it is not clear how such different responses are produced, nor if any precursor can be used for forecasting them. We approach this problem with physical analogue modelling enhanced with X-ray Multiple Detector Computed Tomography scanning, used to track evolution of internal intrusion, and its related faulting and surface deformation. We find that intrusions produce three different volcano deformation patterns, one of them involving asymmetric intrusion and deformation, with the early development of a listric slump fault producing pronounced slippage of one sector. This previously undescribed early deep potential slip surface provides a unified explanation for the two different eruptive scenarios (lateral vs. vertical). Lateral blast only occurs in flank collapse when the intrusion has risen into the sliding block. Otherwise, vertical rather than lateral expansion of magma is promoted by summit dilatation and flank buttressing. The distinctive surface deformation evolution detected opens the possibility to forecast the possible eruptive scenarios: laterally directed blast should only be expected when surface deformation begins to develop oblique to the first major fault.
山体滑坡崩塌引发的灾难性火山喷发可以向上喷射或侧向爆发。岩浆侵入与山体滑坡引发的两种喷发情况（侧向或垂直）都有关，但尚不清楚如何产生如此不同的反应，也不清楚是否有任何前兆可用于预测它们。我们通过结合X射线多探测器计算机断层扫描的物理模拟建模来解决这个问题，该扫描用于跟踪内部侵入的演化及其相关的断层活动和地表变形。我们发现侵入会产生三种不同的火山变形模式，其中一种涉及不对称侵入和变形，早期发育的铲状滑塌断层会导致一个扇区出现明显滑动。这种以前未描述过的早期深部潜在滑动面为两种不同的喷发情况（侧向与垂直）提供了统一的解释。侧向爆发仅在侵入体上升到滑块中时才会在侧翼崩塌时发生。否则，岩浆的垂直而非侧向扩张会受到山顶扩张和侧翼支撑的促进。检测到的独特地表变形演化为预测可能的喷发情况提供了可能性：只有当地表变形开始向第一条主要断层倾斜发展时，才应预期会出现侧向爆发。
