Improving the characterization of overdeepened Alpine valleys by combining seismic reflection imaging and waveform inversion

在过度加深的阿尔卑斯山谷的沉积序列中隐藏着什么样的小型第四纪构造？过度加深的山谷的基岩地形有多不均匀？为什么阿尔陶塞湖底到处都是直立的树木？国家的最先进的地震方法努力回答这些和其他开放的问题中出现的ICDP项目钻探过度加深阿尔卑斯山谷（DOVE）。特别是在Schäftlarn（德国）和巴德奥塞（奥地利），参数测定的分辨率和准确度的局限性阻碍了对这些问题的回答。因此，我们打算提高过深阿尔卑斯山谷的沉积序列的表征相结合的高分辨率地震反射成像（HRSR）和全波形反演（FWI）。我们的概念包括一个方法的发展（1）两种方法的相互作用，将限制FWI与来自HRSR的信息，并使复杂的处理与速度从FWI。(2)工作流程将克服FWI的先决条件，即通常由爆炸源激发的低频内容，这受法律的规定的约束。它将使相互作用的其他网站，只有振动数据存在。最后，我们将（3）测试这一概念在其他DOVE场址的适用性，并确保DOVE场址的特征具有可比性。在该项目中，我们将在Schäftlarn和巴德奥塞站点使用振动源和爆炸源采集P波地震数据，并使用振动源采集S波地震数据。国家的最先进的HRSR处理的振动数据和FWI的爆炸数据将提供第一个洞察到沉积内部的两个过度加深的山谷，在那里没有高分辨率的地震数据存在至今。在这些结构中，我们将发展和实现我们的概念。该项目的合作伙伴是巴伐利亚和奥地利地质调查局以及维也纳自然资源和生命科学大学。

What types of small-scale Quaternary structures are hidden within the sedimentary succession of the overdeepened Alpine valleys? How heterogeneous is the bedrock topography of overdeepened valleys? Why are upright standing trees distributed all across the bottom of Lake Altaussee? State-of-the-art seismic methods struggle to answer these and other open questions that arose within the ICDP-project Drilling Overdeepened Alpine Valleys (DOVE). In particular at the sites Schäftlarn (Germany) and Bad Aussee (Austria), the limitations in resolution and accuracy of parameter determination hamper answering these questions. Therefore, we intend to improve the characterization of the sedimentary succession of overdeepened Alpine valleys by combining high-resolution seismic reflection imaging (HRSR) and full waveform inversion (FWI). Our concept comprises a methodological development of (1) an interplay of both methodologies that will constrain the FWI with information from the HRSR, and enables sophisticated processing with velocities from FWI. (2) A workflow will overcome prerequisites of FWI, i.e. the low frequency content that is usually excited by explosive sources, which are subject to legal regulations. It will enable the interplay to other sites, where only vibratory data exist. Finally, we will (3) test the applicability of the concept at other DOVE sites and ensure a comparable characterization of the DOVE sites. Within the project, we will acquire P-wave seismic data using vibratory and explosive sources as well as S-wave seismic data using vibratory sources at sites Schäftlarn and Bad Aussee. State-of-the-art HRSR processing of the vibratory data and FWI of the explosive data will give the first insight into the sedimentary interior of the two overdeepened valleys, where no high-resolution seismic data exist so far. At these structures, we will develop and realize our concept. Partners within the project are the Bavarian and Austrian Geological Surveys as well as the University of Natural Resources and Live Sciences Vienna.