The ubiquitous creeping segments on oceanic transform faults
The ubiquitous creeping segments on oceanic transform faults
复制标题
DOI：
10.1130/g49562.1
复制
发表时间：
2021-11
期刊：
影响因子：
5.8
通讯作者：
P. Shi;M. Wei;R. Pockalny
中科院分区：
文献类型：
--
作者：
P. Shi;M. Wei;R. Pockalny
海洋转换断层是全球板块边界系统的重要组成部分，众所周知，它产生的地震比预期的要少和小。对少数几个地点的详细研究支持这样一种假设，即大量的蠕动段是这些断层上观察到的大多数地震不足的原因。我们在全球范围内检验这一假设。我们重新定位了全球138个海洋转换断层上的Mw1.5级地震，并确定了这些断层上的蠕动段。我们发现，几乎所有的大洋转换断层上都存在蠕动段，这可以解释其地震活动的不足。我们还发现，大多数蠕动段不与任何大规模的地质结构，如断层阶跃，这表明沿走向变化的断裂带属性可能是它们存在的主要原因。
Oceanic transform faults are a significant component of the global plate boundary system and are well known for generating fewer and smaller earthquakes than expected. Detailed studies at a handful of sites support the hypothesis that an abundance of creeping segments is responsible for most of the observed deficiency of earthquakes on those faults. We test this hypothesis on a global scale. We relocate Mw ⩾5 earthquakes on 138 oceanic transform faults around the world and identify creeping segments on these faults. We demonstrate that creeping segments occur on almost all oceanic transform faults, which could explain their deficiency of earthquakes. We also find that most of the creeping segments are not associated with any large-scale geological structure such as a fault step-over, indicating that along-strike variation of fault zone properties may be the main reason for their existence.