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：密集的阿尔卑斯阵地震台网(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性质。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，但只有在西部阿尔卑斯山才达成了一定程度的共识。然而，对于东阿尔卑斯山的构造和构造过程导致的造山仍有争议的讨论。汉迪等人讨论的东阿尔卑斯山的构造革命。在第二阶段的介绍中，SPP必须在地壳中找到它的表达，最显著的是作为大尺度地壳脱钩的层位；然而，它们的位置和范围还不受地球物理图像的限制。此外，东阿尔卑斯山俯冲可能发生的极性反转仍存在激烈的争论，但如果存在的话，应该伴随着莫霍面跳跃。在这一提议中，我们将使用局部地震层析成像(LET)来成像P波和S波的速度以及相应的泊松比(Vp/Vs)，以及阿尔卑斯山地壳和地幔岩石圈的精确地震震中，从而提供必要的地球物理图像和约束来揭示构造革命所涉及的过程。对于波形数据的分析(拾取/识别相位)，我们将使用与人工智能和机器学习相关的方法。我们将直接讨论主题1：通过描绘地壳内结构和莫霍面地形，在造山过程中岩石圈的重组。我们的综合速度模型还将处理主题2：通过将所调查的MB4D表面结构与目前地震学界正在讨论的地幔过程的高分辨率图像(例如板片极性反转)联系起来，处理山体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运动的一系列建议中的一部分，这些建议具有互补的目标和方法。这个集群将提供阿尔卑斯山地质学、数值模拟和地震学方面的必要补充专业知识，以揭示东阿尔卑斯山的造山过程。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·上地幔断层成像研究的地壳校正·全面的波形数据库和事件数据库(包括旅行时间)，以供进一步分析

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