...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Geophysical Research. Biogeosciences >Recent seismicity and tomographic modeling of the Mount Etna plumbing system
【24h】

Recent seismicity and tomographic modeling of the Mount Etna plumbing system

机译：埃特纳火山管道系统的近期地震和层析成像建模

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The monitoring of seismic activity in eastern Sicily (southern Italy) has been recently improved, in the framework of the Poseidon Project, to investigate both tectonics and volcanic processes of Mount Etna. This effort has produced a homogeneous and complete data set which we use to image the deep structure of the volcano and to define the space and time distribution of the recent seismicity, encompassing the 1995 eruption, diffuse eruptions between 1995 and 1997, a further magma intrusion started in 1997, and an increase of volcanic activity in July 1998. We inverted P wave arrival times from 307 selected local earthquakes to obtain a three-dimensional velocity model of the volcano; With a. Simultaneous inversion for hypocenters and velocity parameters. The new tomographic images permit us to define the structure beneath the volcano from the surface down to 18 km depth. The main structural feature revealed by our inversion is a high-velocity body located beneath the central craters whose lateral extent increases from similar to 6 km between 18 and 9 km depth to similar to 12 km between 9 and 3 km depth. Near the surface the fast anomaly branches in two separate high-V-p regions, which are located below the summit craters sad the eastern flank (Valle del Bove), respectively. The high-velocity features are interpreted as high-density cumulates of solidified magma that intruded the shallow crust. We hypothesize that magma ascends the crust within the relatively small high-velocity conduit (below 9 km depth) and is stored at depth shallower than 9 km within the broad high-velocity region, as also suggested by petrological data. A sharp increase of seismicity in 1997, with earthquakes occurring at the border of the high-velocity body, suggests that Mount; Etna sustained recent episodes of intrusions, which possibly herald future eruptions;. No large low-velocity anomaly interpretable as a melted magma chamber is imaged in the upper 18 km of the crust, while a broad low-velocity anomaly in the uppermost mantle, revealed by regional seismic data, possibly indicates the magma source region at depth. Earthquake occurrence from the deep source to the shallow intrusive area helps to trace the magma migration and the feeding of the volcanic system. [References: 47]
机译：在波塞冬项目的框架内，西西里岛东部（意大利南部）的地震活动监测最近得到了改进，以调查埃特纳火山的构造和火山过程。这项工作已经产生了一个均质而完整的数据集，我们可以用来对火山的深层结构进行成像，并确定最近地震活动的时空分布，包括1995年的喷发，1995年至1997年之间的弥散喷发，进一步的岩浆侵入。从1997年开始，到1998年7月增加了火山活动。我们反转了307次局部地震的P波到达时间，从而获得了火山的三维速度模型。用。震源和速度参数同时反演。新的断层图像使我们能够定义从表面一直到18 km深度的火山下面的结构。我们的反演揭示的主要结构特征是位于中央火山口下方的高速物体，其横向范围从深度在18至9 km之间的约6 km增加到深度在9至3 km之间的约12 km。在地表附近，快速异常分支出现在两个单独的高V-p区域，分别位于山顶陨石坑下方的东部侧面（Valle del Bove）。高速特征被解释为侵入浅地壳的凝固岩浆的高密度累积。我们假设岩浆在相对较小的高速导管（深度小于9 km）内使地壳上升，并且在宽广的高速区域内的岩石深度小于9 km，这也得到岩石学数据的提示。 1997年地震发生率急剧上升，地震发生在高速物体的边界。埃特纳火山最近遭受入侵，可能预示着未来的爆发;在地壳的上部18 km中没有成像到可解释为融化的岩浆腔的大的低速异常，而区域地震数据显示，在最上地幔中的一个广泛的低速异常可能表明了深处的岩浆源区。从深源到浅侵入区的地震的发生有助于追踪岩浆的运移和火山系统的供给。 [参考：47]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号