Volcano Deformation and Magma Migration in Galapagos Shield Volcanoes

盖斯特加拉帕戈斯盾火山是世界上最活跃的火山之一，是洋盆和其他星球上分布最广泛的火山类型之一。加拉帕戈斯型屏蔽火山的内部管道、岩浆迁移机制以及变形在演化中的作用都鲜为人知，特别是在它们所在的类型地区。将通过在费尔南迪纳和内格拉火山的51个站进行GPS大地测量和微重力测量，监测火山内部的应变状态和岩浆的就位情况。在初步部署后，GPS网络将在两年内每年重新使用，以测量地表对活跃的地下过程和任何喷发活动的反应。每年还将在相同的站点进行微重力测量，以探测与内部质量重新分配有关的重力信号的变化。这项综合调查将涉及：1)加拉帕戈斯型地盾的特征形态的起源，2)火山口坍塌的机制，3)与岩浆侵位有关的应变，4)反复岩脉侵入的长期空间容纳，以及5)火山口下方岩浆侵入的几何形状。这项研究的结果应该会提供有用的数据，有助于区分相互竞争和约束较差的火山演化模式，并将极大地增加我们对加拉帕戈斯火山活动的内部结构和活动过程的理解，这些结构和活动与加拉帕戈斯火山活动的形态和喷发方式有关

9814312GeistGalapagos shield volcanoes are some of the most active volcanoes in the world and constitute one of the most widespread volcano types in the ocean basins and on other planets. The internal plumbing, the mechanisms of magma migration, and the role of deformation in the evolution of Galapagos-type shield volcanoes are all poorly known, particularly in their type locality. The state of strain within the volcanoes and the emplacement of magma will be monitored through GPS geodetic and microgravity surveys at 51 stations at Fernandina and Sierra Negra volcanoes. After the initial deployment, the GPS networks will be reoccupied annually for two years to measure surface response to active subsurface processes and any eruptive activity. Microgravity measurements will also be carried out at the same stations each year, in order to detect changes in the gravity signal related to internal mass redistribution. This integrated investigation will address: 1) the origin of the characteristic morphology of Galapagos-type shields, 2) the mechanisms of caldera collapse, 3) the strain associated with emplacement of magma, 4) the long-term space accommodation from repeated dike intrusions, and 5) the geometry of magmatic intrusions underlying calderas. The results from this study should provide data useful in distinguishing between competing and poorly-constrained models of volcano evolution, and will greatly increase our understanding of the internal structure and active processes associated with morphologic and eruptive styles of Galapagos volcanism