Ash production and dispersal from sustained low-intensity Mono-Inyo eruptions
Ash production and dispersal from sustained low-intensity Mono-Inyo eruptions
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DOI：
10.1007/s00445-016-1053-0
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发表时间：
2016-08-01
影响因子：
3.5
通讯作者：
Andrews, Benjamin
中科院分区：
文献类型：
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作者：
Black, Benjamin A.;Manga, Michael;Andrews, Benjamin
最近的流纹岩火山作用表明，长时间的低强度火山灰喷发可能伴随着热流穹顶的形成。我们研究了在加利福尼亚州东部流纹岩的Mono-Inyo链上发生延长的、微弱的火山灰喷发的可能性和一些后果。我们描述了最年轻的穹顶之一帕纳姆陨石坑内充满火山灰的裂缝，它提供了穹顶渗出期间火山灰排放的质地记录。我们使用基于同步加速器的X射线计算机断层摄影术来表征这些凝灰岩中的颗粒。分选好的凝灰岩层中的颗粒大小与蒙特塞拉特南菲尔山火山弱火山灰喷发过程中观察到的颗粒尺寸分布很好地吻合，并给出了这些层形成期间气体速度和质量通量的近似上下限。我们用Ash3d模拟火山灰的扩散，以评估长期的单一因约火山灰喷发对火山灰沉积和随之而来的火山灾害的影响。我们的结果突出了火山喷发的大规模结果对小规模过程的敏感性。
Recent rhyolitic volcanism has demonstrated that prolonged low-intensity ash venting may accompany effusive dome formation. We examine the possibility and some consequences of episodes of extended, weak ash venting at the rhyolitic Mono-Inyo chain in Eastern California. We describe ash-filled cracks within one of the youngest domes, Panum Crater, which provide a textural record of ash venting during dome effusion. We use synchrotron-based X-ray computed tomography to characterize the particles in these tuffisites. Particle sizes in well-sorted tuffisite layers agree well with grain size distributions observed during weak ash venting at Soufricre Hills Volcano, Montserrat, and yield approximate upper and lower bounds on gas velocity and mass flux during the formation of those layers. We simulate ash dispersal with Ash3d to assess the consequences of long-lived Mono-Inyo ash venting for ash deposition and the accompanying volcanic hazards. Our results highlight the sensitivity of large-scale outcomes of volcanic eruptions to small-scale processes.