The NE‐trending Hinagu fault zone, length 81 km, is one of the major active faults in Kyushu, Japan. From north to south, it is divided into three segments based on geomorphic features and paleoseismic behavior: the Takano‐Shirahata, Hinagu, and Yatsushiro Sea segments. The 2016 Kumamoto earthquake produced a 6‐km‐long surface rupture with a dextral strike‐slip displacement on the northern part of the Takano‐Shirahata segment. Surface rupture, a faint east‐side‐up flexure with a vertical offset of less than 8 cm, was observed near the middle of the Takano‐Shirahata segment. To examine past surface‐rupturing earthquakes on the Takano‐Shirahata segment, including rupture frequency and timing, we conducted a paleoseismic study with boring and trenching at Yamaide. A trench across the surface rupture exposed multiple fault strands associated with multiple surface‐rupturing events that deformed several strata of fine‐grained sediments. By structural and stratigraphic interpretation, high‐density radiocarbon dating and tephra analysis, and Bayesian modeling, we constrained the timing of seven events, Events 1–7, to 0.84–1.25, 1.31–7.06, 9.99–11.0, 10.8–12.1, 12.0–13.0, 14.2–15.1, and before 14.8 kcal BP. Slip during Events 1–6 was obviously larger than the 2016 slip. The estimated average recurrence interval was about 2596–2860 years, but the interval between Events 2 and 3 was much longer than other intervals. Moreover, the vertical throw associated with Event 2 was larger than that of other events. This implies that the Takano‐Shirahata segment has a period with rare larger earthquakes and a period with frequent smaller earthquakes. Some events might have produced ruptures on both the Takano‐Shirahata and the northern part of the Hinagu segments simultaneously or in a short time. The variety of recurrence intervals suggests that the seismic activity has been affected by one or both activities of the Futagawa fault zone and the Hinagu segment.

中文翻译：

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通过2016年日本九州熊本地震表面破裂的高密度放射性碳测年和沟槽调查，揭示了Hinagu断层带的详细古地震历史

NE走向的Hinagu断裂带长81 km，是日本九州的主要活动断裂之一。从北部到南部，根据地貌特征和古地震行为将其分为三个部分：高野白滨，日牙谷和八代海部分。2016年的熊本地震在高野-白rah段的北部产生了6公里长的表面破裂，右旋走滑位移。在高野-白rah段的中部附近观察到表面破裂，这是一种微弱的东侧向上弯曲，垂直偏移小于8 cm。为了检查高野白rah段过去的地表破裂地震，包括破裂频率和时间，我们在山ide进行了钻孔和挖沟的古地震研究。贯穿地表破裂的沟槽暴露出多条断层股，这些断层股伴随着多次地表破裂事件，使数个细颗粒沉积物变形。通过结构和地层解释，高密度放射性碳测年和特菲拉分析以及贝叶斯模型，我们将七个事件的时间（事件1–7）限制为0.84–1.25、1.31–7.06、9.99–11.0、10.8–12.1、12.0 –13.0、14.2–15.1和14.8 kcal BP之前。1-6号赛事的滑点明显大于2016年的滑点。估计的平均复发间隔约为2596-2860年，但事件2和3之间的间隔比其他间隔长得多。此外，与事件2相关的垂直投掷比其他事件大。这意味着高野白rah段有一个罕见的大地震时期和一个频繁的小地震时期。某些事件可能同时或在短时间内在高野白Shi和Hinagu段的北部产生了破裂。重复间隔的变化表明，地震活动受到了二田川断裂带和Hinagu段的一项或两项活动的影响。