Seismic imaging of the newly discovered Sub-Lithospheric Discontinuity (SLD) in the larger Alpine region

Kind等人（2016，见附件）在中欧约100公里深的岩石圈-软流圈边界（LAB）以下用地震接收函数发现了一个新的迄今未知的负（向下速度减少）不连续面，他们称之为亚岩石圈不连续面（SLD）。SLD位于潘诺尼亚盆地约150公里深，到达波希米亚地块300公里以下，并突然向上跳跃至德国北部盆地和东欧克拉通下方200公里处。到目前为止，对SLD还没有普遍接受的地质解释。Kind等人（2016）在东阿尔卑斯山以下观测到的LAB深度约为150公里，但无法分辨俯冲方向。总的来说，我们和其他人的观察表明，s -接收函数技术可能是上地幔不连续面分辨率最高的方法。高寒地区的SLD仅是利用现有常设台站的低分辨率观测到的。AlpArray台站的大密度应该能够解决中欧SLD是与东欧克拉通相连还是与南部吸积地体相连的问题。特别是，我们将研究大阿尔卑斯地区以下的SLD和其他上地幔不连续体的地形，这对研究地球动力学关系很重要。此外，我们还将借助理论地震记录研究地震不连续的清晰度，这对岩石学解释很重要。最后，我们计划将接收函数速度模型与表面波层析成像观测到的速度模型进行比较，以确保模型的正确性。这些项目符合第一个研究主题RT1“造山过程中岩石圈的重组”和数据收集活动领域：AF-A (UNIBRAS/DSERBA), AF-B (LOBSTER), AF-C （Swath C：从亚平宁到阿尔卑斯山）AF-D （Swath D：横跨阿尔卑斯中部和东部）。

Kind et al. (2016, see attachment) discovered with seismic receiver functions below the in central Europe about 100 km deep lithosphere-asthenosphere boundary (LAB) a new so far unknown negative (downward velocity decrease) discontinuity which they called Sub-Lithospheric Discontinuity (SLD). The SLD is in the Pannonian Basin about 150 km deep, reaches below the Bohemian Massif 300 km and jumps abruptly upward to 200 km below the north German Basin and the east European craton. So far there exists no generally accepted geological interpretation of the SLD. Kind et al. (2016) observed below the eastern Alps the LAB down to about 150 km depth without being able to resolve the subduction direction. On the whole our observations and others show that the S-receiver function technique is probably the method with highest resolution for upper mantle discontinuities. The SLD under the Alpine region has been observed only with low resolution with the existing data of the permanent stations. The large density of the AlpArray stations should be able to resolve the question if the central European SLD is connected to the east European craton or to the from the south accreting terranes. In particular we will study the topography of the SLD and other upper mantle discontinuities below the larger Alpine region which is important for studies of the geodynamic relations. In addition we will study the sharpness of the seismic discontinuities with the help of theoretical seismograms, which is important for the petrological interpretation. Finally we plan to compare receiver function velocity model with such observed with surface wave tomography to ensure correctness of the models.These projects fit into the first Research Theme RT1 'Reorganisation of the Lithosphere during Mountain Building'and in the data collecting Activity Fields: AF-A (UNIBRAS/DSERBA), AF-B (LOBSTER), AF-C (Swath C: From Apennines to Alps) AF-D (Swath D: across central and easter Alps).