Abstract Located near Japan's most densely populated and industrially active region, the Nankai Trough subduction zone has long been highlighted as a high-risk area for damaging earthquakes and tsunamis. In contrast, less attention has been paid the adjacent Ryukyu Trench because historical and geological records are scarce. In order to develop better quantitative estimates of the timing and size of the earthquakes and tsunamis generated along these subduction zones, comprehensive studies using geological, seismological and historical methods have been conducted. Since the 1990s, studies of tsunami deposits in this region have contributed to our current understanding of the history of tsunamis over the last 6000 years. Following the 2011 Tōhoku earthquake and tsunami, paleotsunami research has especially focused on guiding and enhancing tsunami disaster management and mitigation measures. The last nine years have seen a rapid increase in paleotsunami data from the Nankai Trough and Ryukyu Trench coasts. These recent studies reveal that there are significant differences in the size and recurrence pattern of earthquakes and tsunamis along these subduction zones. For instance, large earthquakes have repeatedly occurred along the Nankai Trough every 100–200 years. On the other hand, large earthquakes and tsunamis may not have occurred over the last few thousand years at the junction between these subduction zones. There is also no evidence for the occurrence of large earthquakes along the northern and central Ryukyu Trench over this time period. Large earthquakes and tsunamis may have occurred every few hundred years at the southern end of the Ryukyu Trench. Nevertheless, data on the occurrence of these earthquakes are still insufficient, both in quantity and quality, to estimate the maximum size or recurrence pattern.

中文翻译：

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南海海槽和琉球海沟俯冲带古海啸研究——当前成就与未来挑战

摘要 南海海槽俯冲带位于日本人口最稠密、工业最活跃的地区，长期以来一直被强调为破坏性地震和海啸的高风险区域。相比之下，由于历史和地质记录稀少，对邻近的琉球海沟的关注较少。为了更好地定量估计沿这些俯冲带产生的地震和海啸的时间和规模，使用地质、地震和历史方法进行了综合研究。自 1990 年代以来，对该地区海啸沉积物的研究有助于我们目前对过去 6000 年海啸历史的了解。在 2011 年东北地震和海啸之后，古海啸研究特别侧重于指导和加强海啸灾害管理和减灾措施。在过去的九年中，南海海槽和琉球海沟沿岸的古海啸数据迅速增加。这些最近的研究表明，沿着这些俯冲带的地震和海啸的规模和复发模式存在显着差异。例如，南海海槽每隔100-200年就会反复发生一次大地震。另一方面，在过去的几千年里，这些俯冲带之间的交界处可能没有发生过大地震和海啸。也没有证据表明在这段时间里琉球海沟北部和中部发生了大地震。琉球海沟南端每隔几百年就会发生一次大地震和海啸。尽管如此，关于这些地震发生的数据在数量和质量上仍然不足以估计最大规模或复发模式。