Pulse-like and crack-like ruptures in experiments mimicking crustal earthquakes
Pulse-like and crack-like ruptures in experiments mimicking crustal earthquakes
复制标题
模拟地壳地震实验中的脉冲状和裂缝状破裂
DOI：
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发表时间：
2007
影响因子：
11.1
通讯作者：
A. Rosakis
中科院分区：
文献类型：
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作者：
Xiao Lu;N. Lapusta;A. Rosakis
理论研究表明，破裂模式的问题对断层本构关系、断层上的应力条件、地震能量分配和发热、尺度规律以及断层滑动的时空复杂性具有重要意义。早期的理论模型将地震视为裂隙状破裂，但地震反演表明，地震破裂可能以自我修复的脉冲状模式传播。对于滑移脉冲的存在，已经提出了许多解释，并继续进行激烈的辩论。这项研究提供了模拟地壳地震的均匀线弹性环境中自发脉冲状破裂的实验观察；揭示了如何根据断层预应力水平选择不同的破裂模式；证明了这两种破裂模式都可以转变为超剪切速度；并根据与理论研究的比较，主张速度减弱摩擦对地震动力学的重要性。
Theoretical studies have shown that the issue of rupture modes has important implications for fault constitutive laws, stress conditions on faults, energy partition and heat generation during earthquakes, scaling laws, and spatiotemporal complexity of fault slip. Early theoretical models treated earthquakes as crack-like ruptures, but seismic inversions indicate that earthquake ruptures may propagate in a self-healing pulse-like mode. A number of explanations for the existence of slip pulses have been proposed and continue to be vigorously debated. This study presents experimental observations of spontaneous pulse-like ruptures in a homogeneous linear-elastic setting that mimics crustal earthquakes; reveals how different rupture modes are selected based on the level of fault prestress; demonstrates that both rupture modes can transition to supershear speeds; and advocates, based on comparison with theoretical studies, the importance of velocity-weakening friction for earthquake dynamics.