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推断导致地震触发的永久和动态(瞬时)应力变化常比地震本身释放的应力数量级小,这意味着触发发生在应力处于临界状态的断层上(Hill et al,1993;Gomberg et al,2000;Huc and Main,2003;Belardinelli et al,2003)。所以,触发的地震活动速率增加可能出现在加载速率最高以及可能由高温流体引起孔隙压力升高,使摩擦力减小促使断层破裂的区域(Cocco and Rice,2002;Streit and Cox,2001;Sturtevant et al,1996)。本文说明2002年阿拉斯加州迪纳利M=7．9级地震在整个不列颠哥伦比亚省和美国西部触发了广泛的地震活动速率增加。地震波引起的动态触发应该沿着辐射能集中的破裂方向增加,我们利用迪纳利主震的地震波和新的高精度GPS记录证实了这个结论。这些观测结果和1992年加利福尼亚州兰德斯M=7．4级地震(Hill et al, 1993)引起的触发仅在震级上具有可比性,并说明兰德斯地震的触发没有反映该地区的特性和地震活动性。可是,由迪纳利地震触发的地震活动速率增加的地区构造活动并不明显,意味着即使在周围应力加载速率低的地区,断层可能仍然处于应力临界状态,动态的触发很可能是普遍存在和无法预测的。
It is inferred that the permanent and dynamic (transient) stress changes that cause earthquakes to trigger are often orders of magnitude smaller than those released by the earthquakes themselves, which means that the triggering occurs on a stress-critical fault (Hill et al, 1993; Gomberg et al, 2000; Huc and Main, 2003; Belardinelli et al, 2003). Therefore, an increase in the rate of triggered seismic activity may occur at the area where the loading rate is highest and pore pressure may increase due to the high-temperature fluid, reducing the friction force to rupture the fracture (Cocco and Rice, 2002; Streit and Cox, 2001; Sturtevant et al, 1996). This article shows that the 2002 M = 7.9 earthquake in Denali, Alaska triggered a wide range of seismic activity increases across British Columbia and the western United States. The dynamic triggering caused by seismic waves should increase along the direction of the rupture where the radiant energy concentrates. This conclusion is confirmed by the seismic waves of the Denali main shock and the new high-precision GPS records. These observations are only comparable in magnitudes to those triggered by the 1992 M = 7.4 M = 7.4 (Hill et al., 1993) earthquake in Landes, California, and suggest that the trigger of the Landers earthquake did not reflect the characteristics of the area And seismicity. However, the tectonic activity in the region triggered by the Denali earthquake with an increased rate of seismic activity is insignificant, implying that the fault may remain stress-critical even in regions with low ambient stress loading rates and that dynamic triggering is likely to be ubiquitous Unpredictable.