Díaz-Moreno A, Barberi G, Cocina O, Koulakov I, Scarfì L, Zuccarello L, Prudencio J, García-Yeguas A, Álvarez I, García L, Ibáñez J M
Department of Earth, Ocean and Ecological Sciences, School of Environmental Sciences, Jane Herdman Building, 4 Brownlow Street, Liverpool, Merseyside L69 3GP UK.
2Instituto Andaluz de Geofisica, University of Granada, 18071 Granada, Spain.
Surv Geophys. 2018;39(1):57-97. doi: 10.1007/s10712-017-9425-3. Epub 2017 Sep 15.
In the Central Mediterranean region, the production of chemically diverse volcanic products (e.g., those from Mt. Etna and the Aeolian Islands archipelago) testifies to the complexity of the tectonic and geodynamic setting. Despite the large number of studies that have focused on this area, the relationships among volcanism, tectonics, magma ascent, and geodynamic processes remain poorly understood. We present a tomographic inversion of P-wave velocity using active and passive sources. Seismic signals were recorded using both temporary on-land and ocean bottom seismometers and data from a permanent local seismic network consisting of 267 seismic stations. Active seismic signals were generated using air gun shots mounted on the Spanish Oceanographic Vessel 'Sarmiento de Gamboa'. Passive seismic sources were obtained from 452 local earthquakes recorded over a 4-month period. In total, 184,797 active P-phase and 11,802 passive P-phase first arrivals were inverted to provide three different velocity models. Our results include the first crustal seismic active tomography for the northern Sicily area, including the Peloritan-southern Calabria region and both the Mt. Etna and Aeolian volcanic environments. The tomographic images provide a detailed and complete regional seismotectonic framework and highlight a spatially heterogeneous tectonic regime, which is consistent with and extends the findings of previous models. One of our most significant results was a tomographic map extending to 14 km depth showing a discontinuity striking roughly NW-SE, extending from the Gulf of Patti to the Ionian Sea, south-east of Capo Taormina, corresponding to the Aeolian-Tindari-Letojanni fault system, a regional deformation belt. Moreover, for the first time, we observed a high-velocity anomaly located in the south-eastern sector of the Mt. Etna region, offshore of the Timpe area, which is compatible with the plumbing system of an ancient shield volcano located offshore of Mt. Etna.
在中地中海地区，化学性质多样的火山产物（例如来自埃特纳火山和伊奥利亚群岛的火山产物）的生成证明了构造和地球动力学背景的复杂性。尽管已有大量研究聚焦于该地区，但火山活动、构造运动、岩浆上升和地球动力学过程之间的关系仍知之甚少。我们利用主动和被动震源进行了P波速度的层析成像反演。使用陆上临时地震仪和海底地震仪以及由267个地震台站组成的永久性本地地震网络的数据记录地震信号。主动地震信号由安装在西班牙海洋学船只“萨尔米恩托·德·甘博亚号”上的气枪激发产生。被动地震源来自4个月期间记录的452次本地地震。总共对184,797个主动P波震相和11,802个被动P波震相的初至进行了反演，以提供三种不同的速度模型。我们的结果包括西西里岛北部地区（包括佩洛里塔 - 卡拉布里亚南部地区以及埃特纳火山和伊奥利亚火山环境）的首个地壳地震主动层析成像。层析成像图像提供了详细且完整的区域地震构造框架，并突出了空间上不均匀的构造格局，这与先前模型的结果一致并有所扩展。我们最重要的结果之一是一幅深度延伸至14千米的层析成像图，该图显示了一条大致呈西北 - 东南走向的间断面，从帕蒂湾延伸至陶尔米纳角东南部的爱奥尼亚海，对应于伊奥利亚 - 廷达里 - 莱托亚尼断裂系统，这是一个区域变形带。此外，我们首次在埃特纳火山地区东南部、廷佩地区近海观测到一个高速异常，这与位于埃特纳火山近海的一座古老盾形火山的管道系统相符。
