In the southeast of Bosnia and Herzegovina, the Berkovići earthquake sequence started with the mainshock on 22 April 2022 21:07 UTC at focal depth 22 km with magnitude = 6.0 ( = 5.7). Our preliminary estimation of the mainshock's maximum intensity is VII EMS for Berkovići where 29% of buildings were damaged. We analysed the first nine months of this sequence, 22 April 2022–22 January 2023. The earthquakes were located using a guided grid-search algorithm with source-specific station corrections as a mean of solutions for 54 combinations of velocity models and program control parameters. The analysis of aleatory variation and epistemic uncertainty showed that they are very dependent on the station coverage, especially for focal depth. The event catalogue consists of 7217 earthquakes and can be considered complete for ≥ 1.3. Focal depths (15–30 km) are considerably larger than average for the Dinarides, but consistent within the zone of mid-crustal events where the earthquakes occurred. Focal mechanisms were determined with the first-motion polarity method for eight earthquakes: five of them, including the mainshock, were due to reverse faulting on faults striking in the Dinaric direction, with the preferred main fault gently dipping to the northeast. However, three events were due to normal faulting, unexpected for this area. We constructed a regional seismotectonic cross-section to delineate a potential seismogenic source of the mainshock, and it suggests that the mainshock occurred on the NE-dipping blind ramp of the basal thrust of the Dalmatian tectonic unit. Moreover, another NE-dipping and blind ramp of this basal thrust could be responsible for the Ston–Slano 1996 earthquake, located to the SW of the Berkovići mainshock hypocentre at the horizontal distance of c. 35 km.

中文翻译：

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2022 年 4 月 22 日 Berkovići (BIH) ML = 6.0 地震序列 – 地震学和地震构造分析

在波斯尼亚和黑塞哥维那东南部，贝尔科维奇地震序列始于世界标准时间 2022 年 4 月 22 日 21:07 的主震，震源深度 22 公里，震级 = 6.0 (= 5.7)。我们初步估计 Berkovići 的主震最大强度为 VII EMS，其中 29% 的建筑物受损。我们分析了该序列的前九个月，即2022年4月22日至2023年1月22日。使用引导网格搜索算法定位地震，并使用特定源台站校正作为速度模型和程序控制参数的54种组合的解的平均值。对偶然变化和认知不确定性的分析表明，它们非常依赖于站点覆盖范围，尤其是焦点深度。事件目录由 7217 次地震组成，对于 ≥ 1.3 可以认为是完整的。震源深度（15-30 公里）比迪纳里德斯的平均深度要大得多，但在发生地震的中地壳事件区域内是一致的。使用首次运动极性方法确定了八次地震的震源机制：其中五次（包括主震）是由于沿第纳尔方向断裂的逆断层作用造成的，首选主断层轻轻向东北倾斜。然而，三起事件是由于正常断层引起的，这对于该地区来说是意料之外的。我们构建了区域地震构造剖面，圈定了主震的潜在震源，表明主震发生在达尔马提亚构造单元基底逆冲的北东倾盲坡上。此外，该基底推力的另一个北东倾和盲坡可能是造成 1996 年斯通-斯拉诺地震的原因，该地震位于 Berkovići 主震震源的西南方向，水平距离为 c。35公里。