We present new 3D source fault representations for the 2019 M 6.4 and M 7.1 Ridgecrest earthquake sequence. These representations are based on relocated hypocenter catalogs expanded by template matching and focal mechanisms for M 4 and larger events. Following the approach of Riesner et al. (2017), we generate reproducible 3D fault geometries by integrating hypocenter, nodal plane, and surface rupture trace constraints. We used the southwest–northeast‐striking nodal plane of the 4 July 2019 M 6.4 event to constrain the initial representation of the southern Little Lake fault (SLLF), both in terms of location and orientation. The eastern Little Lake fault (ELLF) was constrained by the 5 July 2019 M 7.1 hypocenter and nodal planes of M 4 and larger aftershocks aligned with the main trend of the fault. The approach follows a defined workflow that assigns weights to a variety of geometric constraints. These main constraints have a high weight relative to that of individual hypocenters, ensuring that small aftershocks are applied as weaker constraints. The resulting fault planes can be considered averages of the hypocentral locations respecting nodal plane orientations. For the final representation we added detailed, field‐mapped rupture traces as strong constraints. The resulting fault representations are generally smooth but nonplanar and dip steeply. The SLLF and ELLF intersect at nearly right angles and cross on another. The ELLF representation is truncated at the Airport Lake fault to the north and the Garlock fault to the south, consistent with the aftershock pattern. The terminations of the SLLF representation are controlled by aftershock distribution. These new 3D fault representations are available as triangulated surface representations, and are being added to a Community Fault Model (CFM; Plesch et al., 2007, 2019; Nicholson et al., 2019) for wider use and to derived products such as a CFM trace map and viewer (Su et al., 2019).

中文翻译：

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2019 年加利福尼亚州里奇克莱斯特地震序列的详细 3D 断层表示

我们为 2019 M 6.4 和 M 7.1 Ridgecrest 地震序列提供了新的 3D 震源断层表示。这些表示基于通过模板匹配和 M 4 和更大事件的震源机制扩展的重新定位的震源目录。遵循 Riesner 等人的方法。(2017)，我们通过整合震源、节点平面和地表破裂痕迹约束来生成可重复的 3D 断层几何形状。我们使用 2019 年 7 月 4 日 M 6.4 事件的西南-东北走向的节点平面来限制南小湖断层（SLLF）在位置和方向上的初始表示。小湖东部断层 (ELLF) 受到 2019 年 7 月 5 日 M 7.1 震源和 M 4 的节点平面以及与断层主要趋势一致的更大余震的约束。该方法遵循定义的工作流程，为各种几何约束分配权重。这些主要约束相对于单个震源的权重较高，确保较小的余震作为较弱的约束应用。由此产生的断层面可以被认为是关于节点平面方向的震源位置的平均值。对于最终表示，我们添加了详细的、现场映射的破裂痕迹作为强约束。由此产生的断层表示通常是平滑的，但非平面且倾斜陡峭。SLLF 和 ELLF 以近乎直角相交，并在另一个角度交叉。ELLF 表示在北面的机场湖断层和南面的 Garlock 断层处被截断，与余震模式一致。SLLF 表示的终止由余震分布控制。这些新的 3D 断层表示可用作三角表面表示，并被添加到社区断层模型（CFM；Plesch 等人，2007 年，2019 年；Nicholson 等人，2019 年）中以供更广泛的使用和衍生产品，例如CFM 轨迹图和查看器（Su 等，2019）。