Seismicity trends and potential for large earthquakes in the Alaska-Aleutian region
Seismicity trends and potential for large earthquakes in the Alaska-Aleutian region
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DOI：
10.1007/bf00875969
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发表时间：
1994-03
影响因子：
2
通讯作者：
C. Bufe;S. Nishenko;D. Varnes
中科院分区：
文献类型：
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作者：
C. Bufe;S. Nishenko;D. Varnes
阿拉斯加俯冲带在这十年内发生填隙逆冲地震的可能性很高，这是由两种独立的方法表示的：历史地震复发数据分析和应用于近几十年仪器数据的故障时间分析。最近（1993年5月）舒马金群岛缺口的地震活动与以前预测的地震释放量增加是一致的，这表明这一部分，沿着阿拉斯加半岛部分，正在接近失败。基于这种地震加速释放的模式，我们预测1994-1996年期间舒马金-阿拉斯加半岛地区将发生一次或多次M ≥7.3地震。阿拉斯加-阿留申地震带的不同区段在前十年或前二十年的大地震中表现不同，一些区段显示地震释放加速（“A”型区），而另一些区段显示地震释放减速（“D”型区）。最大的阿拉斯加-阿留申地震-在1957年，1964年和1965年-起源于表现出D型行为的区域。目前显示加速释放的A型区域是舒马金、阿拉斯加半岛、德拉罗夫和科曼多尔斯基段。失效时间分析表明，大地震可能在未来几年内发生在这些地区。
The high likelihood of a gap-filling thrust earthquake in the Alaska subduction zone within this decade is indicated by two independent methods: analysis of historic earthquake recurrence data and time-to-failure analysis applied to recent decades of instrumental data. Recent (May 1993) earthquake activity in the Shumagin Islands gap is consistent with previous projections of increases in seismic release, indicating that this segment, along with the Alaska Peninsula segment, is approaching failure. Based on this pattern of accelerating seismic release, we project the occurrence of one or moreM≥7.3 earthquakes in the Shumagin-Alaska Peninsula region during 1994–1996. Different segments of the Alaska-Aleutian seismic zone behave differently in the decade or two preceding great earthquakes, some showing acceleration of seismic release (type “A” zones), while others show deceleration (type “D” zones). The largest Alaska-Aleutian earthquakes—in 1957, 1964, and 1965—originated in zones that exhibit type D behavior. Type A zones currently showing accelerating release are the Shumagin, Alaska Peninsula, Delarof, and Kommandorski segments. Time-to-failure analysis suggests that the large earthquakes could occur in these latter zones within the next few years.