This study presents and discusses horizontal and vertical geodetic velocities for a low strain rate region of the south Alpine thrust front in northeastern Italy obtained by integrating GPS, interferometric synthetic aperture radar (InSAR) and leveling data. The area is characterized by the presence of subparallel, south-verging thrusts whose seismogenic potential is still poorly known. Horizontal GPS velocities show that this sector of the eastern Southern Alps is undergoing ∼1 mm a⁻¹ of NW–SE shortening associated with the Adria–Eurasia plate convergence, but the horizontal GPS velocity gradient across the mountain front provides limited constraints on the geometry and slip rate of the several subparallel thrusts. In terms of vertical velocities, the three geodetic methods provide consistent results showing a positive velocity gradient, of ∼ 1.5 mm a⁻¹, across the mountain front, which can hardly be explained solely by isostatic processes. We developed an interseismic dislocation model whose geometry is constrained by available subsurface geological reconstructions and instrumental seismicity. While a fraction of the measured uplift can be attributed to glacial and erosional isostatic processes, our results suggest that interseismic strain accumulation at the Montello and the Bassano–Valdobbiadene thrusts it significantly contributing to the measured uplift. The seismogenic potential of the Montello thrust turns out to be smaller than that of the Bassano–Valdobbiadene fault, whose estimated parameters (locking depth equals 9.1 km and slip rate equals 2.1 mm a⁻¹) indicate a structure capable of potentially generating a M_w>6.5 earthquake. These results demonstrate the importance of precise vertical ground velocity data for modeling interseismic strain accumulation in slowly deforming regions where seismological and geomorphological evidence of active tectonics is often scarce or not conclusive.

中文翻译：

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垂直大地速度对意大利南部阿尔卑斯山活跃构造和震源潜力的新见解

这项研究提出并讨论了通过整合GPS，干涉合成孔径雷达（InSAR）和水准仪数据获得的意大利东北部南部高山逆冲锋面低应变率区域的水平和垂直大地速度。该地区的特点是存在次平行的，南下的逆冲，其成震潜力仍知之甚少。GPS的水平速度表明，南阿尔卑斯山东部的这一部分正在经历〜1  mm a ^-1NW-SE缩短的过程与Adria-Eurasia板块的收敛有关，但是横跨山前的水平GPS速度梯度对几个次平行推力的几何形状和滑移率提供了有限的约束。就垂直速度而言，这三种大地测量方法可提供一致的结果，显示出约 1.5 mm a ^-1的正速度梯度，横跨山脉，这很难仅通过等静压过程来解释。我们开发了一种地震间错位模型，其几何结构受可用的地下地质构造和仪器地震活动性的约束。虽然测得的隆起的一小部分可归因于冰川和侵蚀的等静压过程，但我们的结果表明，蒙特洛和巴萨诺-瓦尔多比亚德烯之间的地震应变累积推动了它对测得的隆起做出了显着贡献。蒙特洛逆冲断层的发震潜力小于巴萨诺－瓦尔多比亚德涅断层，其估计参数（锁定深度等于9.1 km，滑移率等于2.1 mm a ^-1）表明该结构有可能产生M _w> 6.5级地震。这些结果表明，精确的垂直地面速度数据对于建模缓慢变形区域中的地震间应变累积非常重要，在这些区域中，活动构造学的地震学和地貌学证据通常很少或没有定论。