Geological field evidence and laboratory modelling indicate that volcanoes constructed on slopes slide downhill. If this happens on an active volcano, then the movement will distort deformation data and thus potentially compromise interpretation. Our recent GPS measurements demonstrate that the entire edifice of Mt. Etna is sliding to the ESE, the overall direction of slope of its complex, rough sedimentary basement. We report methods of discriminating the sliding vector from other deformation processes and of measuring its velocity, which averaged 14 mm year−1 during four intervals between 2001 and 2012. Though sliding of one sector of a volcano due to flank instability is widespread and well-known, this is the first time basement sliding of an entire active volcano has been directly observed. This is important because the geological record shows that such sliding volcanoes are prone to devastating sector collapse on the downslope side, and whole volcano migration should be taken into account when assessing future collapse hazard. It is also important in eruption forecasting, as the sliding vector needs to be allowed for when interpreting deformation events that take place above the sliding basement within the superstructure of the active volcano, as might occur with dyke intrusion or inflation/deflation episodes.

中文翻译：

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山的重力滑动。沿着倾斜的地下室的埃特纳火山

地质现场证据和实验室模型表明，在斜坡上建造的火山会滑下山坡。如果这种情况发生在活火山上，那么这种运动会扭曲变形数据，从而可能影响解释。我们最近的 GPS 测量表明，山的整个大厦。埃特纳火山正在滑向 ESE，这是其复杂、粗糙的沉积基底的整体斜坡方向。我们报告了将滑动矢量与其他变形过程区分开来并测量其速度的方法，在 2001 年至 2012 年的四个时间间隔内平均为 14 毫米年-1。众所周知，这是第一次直接观察到整个活火山的基底滑动。这一点很重要，因为地质记录表明，此类滑动火山容易在下坡侧发生毁灭性的扇形坍塌，在评估未来坍塌危险时应考虑整个火山的迁移。这在喷发预测中也很重要，因为在解释发生在活火山上层结构内滑动基底上方的变形事件时，需要考虑滑动向量，这可能发生在岩脉侵入或膨胀/通缩事件中。