Abstract. Modelling the seismic potential of active faults and the associated epistemic uncertainty is a fundamental step of probabilistic seismic hazard assessment (PSHA). We use SHERIFS (Seismic Hazard and Earthquake Rate In Fault Systems), an open-source code allowing to build hazard models including earthquake ruptures involving several faults, to model the seismicity rates on the North Anatolian Fault (NAF) system in the Marmara region. Through an iterative approach, SHERIFS converts the slip-rate on the faults into earthquake rates that follow a Magnitude Frequency Distribution (MFD) defined at the fault system level, allowing to model complex multi-fault ruptures and off-fault seismicity while exploring the underlying epistemic uncertainties. In a logic tree, we explore uncertainties concerning the locking state of the NAF in the Marmara Sea, the maximum possible rupture in the system, the shape of the MFD and the ratio of off-fault seismicity. The branches of the logic tree are weighted according to the match between the modelled earthquake rate and the earthquake rates calculated from the local data, earthquake catalogue and paleoseismicity. In addition, we use the result of the physics-based earthquake simulator RSQSim to inform the logic tree and increase the weight on the hypotheses that are compatible with the result of the simulator. Using both the local data and the simulator to weight the logic tree branches, we are able to reduce the uncertainties affecting the earthquake rates in the Marmara region. The weighted logic tree of models built in this study is used in a companion article to calculate the probability of collapse of a building in Istanbul.

中文翻译：

---

土耳其马尔马拉地区的地震发生率及相关不确定性建模

摘要。对活动断层的地震潜力和相关的认知不确定性进行建模是概率地震危险性评估（PSHA）的基本步骤。我们使用SHERIFS（断层系统中的地震危险和地震发生率）这一开放源代码，允许建立包括涉及多个断层的地震破裂在内的危害模型，以对马尔马拉地区北安那托利亚断层（NAF）系统的地震活动率进行建模。通过一种迭代方法，SHERIFS将故障的滑移率转换为遵循在故障系统级别定义的震级频率分布（MFD）的地震率，从而可以在研究潜在的多断层破裂和断层地震活动性时对其进行建模。认知不确定性。在逻辑树中，我们探索有关NAF在马尔马拉海的锁定状态的不确定性，系统中最大可能的破裂，MFD的形状和断层地震活动率。逻辑树的分支根据建模的地震率与根据本地数据，地震目录和古地震计算出的地震率之间的匹配进行加权。此外，我们使用基于物理的地震模拟器RSQSim的结果来通知逻辑树，并增加与模拟器的结果兼容的假设的权重。使用本地数据和模拟器对逻辑树枝进行加权，我们能够减少影响马尔马拉地区地震发生率的不确定性。本研究中建立的模型的加权逻辑树在随附的文章中用于计算伊斯坦布尔某建筑物倒塌的概率。