Earthquakes hit urban centres in Europe infrequently, but occasionally with disastrous effects. Obtaining an unbiased view of seismic hazard (and risk) is therefore very important. In principle, the best way to test probabilistic seismic hazard assessments (PSHAs) is to compare them with observations that are entirely independent of the procedure used to produce PSHA models. Arguably, the most valuable information in this context should be information on long-term hazard, namely maximum intensities (or magnitudes) occurring over time intervals that are at least as long as a seismic cycle. The new observations can provide information of maximum intensity (or magnitude) for long timescale as an input data for PSHA studies as well. Long-term information can be gained from intact stalagmites in natural caves. These formations survived all earthquakes that have occurred over thousands of years, depending on the age of the stalagmite. Their ‘survival’ requires that the horizontal ground acceleration (HGA) has never exceeded a certain critical value within that time period. Here, we present such a stalagmite-based case study from the Little Carpathians of Slovakia. A specially shaped, intact and vulnerable stalagmite in the Plavecká priepast cave was examined in 2013. This stalagmite is suitable for estimating the upper limit of horizontal peak ground acceleration generated by prehistoric earthquakes. The critical HGA values as a function of time going back into the past determined from the stalagmite that we investigated are presented. For example, at the time of Jókő event (1906), the critical HGA value cannot have been higher than 1 and 1.3 m/s² at the time of the assumed Carnuntum event (∼340 AD), and 3000 years ago, it must have been lower than 1.7 m/s². We claimed that the effect of Jókő earthquake (1906) on the location of the Plavecká priepast cave is consistent with the critical HGA value provided by the stalagmite we investigated.The approach used in this study yields significant new constraints on the seismic hazard, as tectonic structures close to Plavecká priepast cave did not generate strong earthquakes in the last few thousand years. The results of this study are highly relevant given that the two capitals, Vienna and Bratislava, are located within 40 and 70 km of the cave, respectively.

中文翻译：

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使用来自斯洛伐克小喀尔巴阡山脉的 Plavecká priepast 洞穴 (Detrekői-zsomboly) 的原位完整且脆弱的石笋估算史前峰值地面加速度的上限，这是首次结果。


欧洲城市中心很少发生地震，但偶尔也会造成灾难性影响。因此，获得对地震危害（和风险）的公正看法非常重要。原则上，测试概率地震危险评估 (PSHA) 的最佳方法是将其与完全独立于生成 PSHA 模型程序的观测结果进行比较。可以说，在这种情况下最有价值的信息应该是有关长期灾害的信息，即在至少与地震周期一样长的时间间隔内发生的最大强度（或震级）。新的观测结果也可以提供长时间尺度的最大强度（或幅度）信息，作为 PSHA 研究的输入数据。可以从天然洞穴中完整的石笋中获得长期信息。这些构造在数千年来发生的所有地震中都幸存下来，具体取决于石笋的年龄。它们的“生存”要求水平地面加速度（HGA）在该时间段内从未超过某个临界值。在这里，我们提出了一个来自斯洛伐克小喀尔巴阡山脉的基于石笋的案例研究。 2013年，人们对Plavecká priepast洞穴中一处形状特殊、完整且脆弱的石笋进行了检查。该石笋适合估算史前地震产生的水平峰值地面加速度的上限。给出了我们研究的石笋确定的临界 HGA 值作为时间函数的回溯到过去的函数。例如，在 Jókő 事件（1906 年）发生时，临界 HGA 值在假设的 Carnuntum 事件（公元 340 年）发生时不可能高于 1 和 1.3 m/s ² ，而 3000 年前，它必须已低于1。7 m/s ² 。我们声称 Jókő 地震（1906 年）对 Plavecká priepast 洞穴位置的影响与我们研究的石笋提供的临界 HGA 值一致。本研究中使用的方法对地震危险产生了重要的新限制，因为构造普拉韦卡普里帕斯特洞穴附近的建筑在过去几千年里没有发生强烈地震。鉴于维也纳和布拉迪斯拉发这两个首都分别距离洞穴 40 公里和 70 公里，这项研究的结果具有高度相关性。