A comprehensive high resolution 3D P- and S-wave velocity model for the Alpine mountain chain using local earthquake data: Constraining crustal structure, lithologies and mountain-building processes

描述：密集的AlpArray地震网络（AASN）首次能够以高分辨率成像阿尔卑斯山下地壳和地幔岩石圈的地震特性。虽然已经进行了大量的研究和地震实验来破译阿尔卑斯山的造山过程，但只有在西阿尔卑斯山才达成了一定程度的共识。然而，对于东阿尔卑斯构造和构造过程导致的造山作用仍有争议。Handy等人在SPP第二期的导言中所讨论的东阿尔卑斯山的构造革命必须在地壳中找到它的表达，最明显的是作为大尺度的地壳解耦层；然而，它们的位置和范围还不受地球物理图像的约束。此外，东阿尔卑斯地区可能存在的俯冲极性翻转仍有争议，但如果存在，应该伴随着莫霍跳变。在这一建议中，我们将使用局部地震层析成像（LET）对阿尔卑斯地壳和地幔岩石圈的纵波和横波速度和相应的泊松比（Vp/Vs）以及精确的震源进行成像，为揭示构造革命所涉及的过程提供必要的地球物理图像和约束。对于波形数据的分析（挑选/识别相位），我们将使用与人工智能和机器学习相关的方法。我们将通过描绘地壳内部结构和莫霍地形来直接解决主题1：造山过程中岩石圈的重组。我们的综合速度模型还将通过将MB4D研究的地表结构与目前在地震学界争论的地幔过程（例如板块极性翻转）的高分辨率图像联系起来，解决主题2：山脉结构变化的地壳响应。这项工作是研究阿尔卑斯山新近纪造山革命的一系列建议的一部分，这些建议具有互补的目标和方法。该集群将提供必要的高山地质学、数值模拟和地震学方面的专业知识，以解开东阿尔卑斯山脉的山脉建设过程。交付成果：•阿尔卑斯山的3d高分辨率P波和s波速度（和泊松比）模型•高分辨率地震位置和相关不确定性•用于上地幔断层扫描研究的地壳校正•用于进一步分析的综合波形数据库和事件数据库（包括旅行时间）

Description:The dense AlpArray Seismic Network (AASN) allows for the first time to image in high resolution the seismic properties of the crust and mantle lithosphere beneath the Alps. Although numerous studies and seismic experiments have been conducted to decipher the mountain building processes in the Alps, only in the Western Alps some degree of consensus has been reached. However, for the Eastern Alps structure and tectonic processes leading to mountain building are still controversially discussed. The tectonic revolution in the Eastern Alps as discussed by Handy et al. in the introduction to the second period of the SPP must find its expression in the crust, most notably as large scale crustal decoupling horizons; however, their location and extend are not constrained yet by geophysical images. Additionally, the possible polarity flip of subduction in the Eastern Alp is still hotly debated, but if existent should be accompanied by a Moho jump.In this proposal we will use Local Earthquake Tomography (LET) to image the P- and S-wave velocities and corresponding Poisson ratio (Vp/Vs) and precise earthquake hypocenters in the Alpine crust and mantle lithosphere providing essential geophysical images and constraints to unravel the processes involved in the tectonic revolution. For the analysis of the waveform data (picking/identification of phases) we will use methods related to artificial intelligence and machine learning. We will directly address Theme 1: Reorganisations of the lithosphere during mountain building by delineating intra-crustal structures and Moho topography. Our comprehensive velocity model will also address Theme 2: crustal response of changes in mountain structure by linking the investigated surface structures in MB4D with high resolution images of mantle processes that are currently debated in the seismological community (e.g. slab polarity flip). The work is part of a cluster of proposals with complementary goals and approaches to investigate the Neogene Orogenic Revolution of the Alps. This cluster will provide the necessary complimentary expertise in Alpine geology, numerical modelling, and seismology needed to unravel the mountain building processes in the Eastern Alps. Deliverables:• 3D high resolution P- and S-wave velocity (and Poisson ratio) model of the Alps• High resolution earthquake locations and associated uncertainties• Crustal corrections for upper mantle tomography studies• A comprehensive waveform database and event database (including travel times) for further analysis