As volcanoes undergo unrest, understanding the conditions and timescales required for magma reservoir failure, and the links to geodetic observations, are critical when evaluating the potential for magma migration to the surface and eruption. Inferring the dynamics of a pressurized magmatic system from episodes of surface deformation is heavily reliant on the assumed crustal rheology, typically represented by an elastic medium. Here, we use Finite Element models to identify the rheological response to reservoir pressurization within a temperature-dependent Standard Linear Solid viscoelastic (“thermo-viscoelastic”) domain. We assess the mechanical stability of a deforming reservoir by evaluating the overpressures required to initiate brittle failure along the reservoir wall, and the sensitivity to key parameters. Reservoir inflation facilitates compression of the ductile wall rock, due to the non-uniform crustal viscosity, impacting the temporal evolution of the induced tensile stress. Thermo-viscoelasticity enables a deforming reservoir to sustain greater overpressures prior to failure, compared to elastic analyses. High-temperature (e.g., mafic) reservoirs fail at lower overpressures compared to low-temperature (e.g., felsic) reservoirs, producing smaller coincident displacements at the ground surface. The impact of thermo-viscoelasticity on reservoir failure is significant across a wide range of overpressure loading rates. By resisting mechanical failure on the reservoir wall, thermo-viscoelasticity impacts dyke nucleation and formation of shear fractures. Numerical models may need to incorporate additional processes that act to promote failure, such as regional stresses (e.g., topographic and tectonic), external triggers (e.g., earthquake stress drops), or pre-existing weaknesses along the reservoir wall.

中文翻译：

---

热粘弹性地壳中岩浆储层破坏的流变控制

随着火山经历动荡，在评估岩浆迁移到地表和喷发的可能性时，了解岩浆储层破裂所需的条件和时间尺度以及与大地观测的联系至关重要。从表面变形事件推断加压岩浆系统的动力学在很大程度上依赖于假定的地壳流变学，通常由弹性介质表示。在这里，我们使用有限元模型来识别温度相关的标准线性固体粘弹性（“热粘弹性”）域内对储层加压的流变响应。我们通过评估沿储层壁开始脆性破坏所需的过压以及对关键参数的敏感性来评估变形储层的机械稳定性。由于地壳粘度不均匀，储层膨胀促进了韧性围岩的压缩，从而影响了诱导拉应力的时间演变。与弹性分析相比，热粘弹性使变形的储层能够在失效前承受更大的过压。与低温（例如，长英质）储层相比，高温（例如，镁铁质）储层在较低的超压下失效，从而在地表产生较小的一致位移。热粘弹性对储层破坏的影响在很宽的超压加载率范围内都是显着的。通过抵抗储层壁上的机械故障，热粘弹性影响堤坝成核和剪切裂缝的形成。数值模型可能需要结合额外的过程来促进失败，