Italian and Alpine three‐dimensional crustal structure imaged by ambient‐noise surface‐wave dispersion
Italian and Alpine three‐dimensional crustal structure imaged by ambient‐noise surface‐wave dispersion
复制标题
通过环境噪声表面波色散成像的意大利和阿尔卑斯山三维地壳结构
DOI：
10.1002/2015gc006176
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Andrea Morelli
中科院分区：
文献类型：
--
作者：
I. Molinari;J. Verbeke;L. Boschi;E. Kissling;Andrea Morelli
我们推导了意大利和阿尔卑斯地区地下的三维地壳结构（S波速度），扩展并利用了Verbeke等人（2012）的环境噪声瑞利波相位和群速度数据库。我们首先用一组密集的基于环境噪声的相速度观测数据来补充Verbeke等人（2012）的数据库。接下来，我们对相位和群速度数据进行了一套线性最小二乘反演，得到了周期在5到37秒之间的瑞利波相位和群速度的二维图。在相对较短的时间内，这些地图清楚地反映了该地区的地表地质情况，例如，波河平原的低速带；在较长时期，揭示了更深的构造，如阿尔卑斯山和亚平宁山脉下的莫霍地形和下地壳异常。接下来，通过邻域算法对我们的相速度和群速度模型进行反演，以确定一组一维剪切速度模型（每个相/群速度像素一个），从而得到一个新的剪切速度三维模型（vS），参数化方式与欧洲参考地壳模型EPcrust相同。我们还展示了vS如何很好地受到相和群色散曲线的约束。模型显示了波河平原和Molasse盆地下方的低速区；亚得里亚海地区的低速地壳和第勒尼安地区的高速地壳之间的对比清晰可见，以及阿尔卑斯带下几乎均匀的结晶地壳。我们的结果从地质/地球动力学的角度进行了讨论，并与其他跨学科研究的结果进行了比较。
We derive the 3‐D crustal structure (S wave velocity) underneath Italy and the Alpine region, expanding and exploiting the database of ambient noise Rayleigh‐wave phase‐ and group‐velocity of Verbeke et al. (2012). We first complement the database of Verbeke et al. (2012) with a dense set of new ambient‐noise‐based phase‐velocity observations. We next conduct a suite of linear least squares inversion of both phase‐ and group‐velocity data, resulting in 2‐D maps of Rayleigh‐wave phase and group velocity at periods between 5 and 37 s. At relatively short periods, these maps clearly reflect the surface geology of the region, e.g., low velocity zones at the Po Plain; at longer periods, deeper structures such as Moho topography under Alps and Apennines, and lower‐crust anomalies are revealed. Our phase‐ and group‐velocity models are next inverted via the Neighbourhood Algorithm to determine a set of one‐dimensional shear‐velocity models (one per phase/group‐velocity pixel), resulting in a new three‐dimensional model of shear velocity (vS) parameterized in the same way as the European reference crustal model EPcrust. We also show how well vS is constrained by phase and group dispersion curves. The model shows the low velocity area beneath the Po Plain and the Molasse basin; the contrast between the low‐velocity crust of the Adriatic domain and the high‐velocity crust of the Tyrrhenian domain is clearly seen, as well as an almost uniform crystalline crust beneath the Alpine belt. Our results are discussed from the geological/geodynamical standpoint, and compared to those of other, interdisciplinary studies.
影响因子：
3.9
作者：
Brueckl, Ewald;Bleibinhaus, Florian;Thybo, Hans
通讯作者：
Thybo, Hans