Paleoseismicity of the Ovindoli‐Pezza fault, central Apennines, Italy: A history including a large, previously unrecorded earthquake in the Middle Ages (860–1300 A.D.)
Paleoseismicity of the Ovindoli‐Pezza fault, central Apennines, Italy: A history including a large, previously unrecorded earthquake in the Middle Ages (860–1300 A.D.)
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意大利亚平宁山脉中部奥文多利-佩扎断层的古地震活动：一段历史，包括中世纪（公元 860-1300 年）发生的一场此前未记录的大地震
DOI：
10.1029/95jb03213
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发表时间：
1996
影响因子：
--
通讯作者：
F. Cinti
中科院分区：
文献类型：
--
作者：
D. Pantosti;G. D'Addezio;F. Cinti
沿着Ovindoli-Pezza断层的地貌和挖沟调查表明，该正断层是亚平宁山脉中部的主要发震断层之一。我们在这条断层上发现了三次全新世地表断层地震的明确地质证据：最近的一次地震发生在公元860年至1300年的中世纪，倒数第二次地震发生在公元前1900年或之后不久，最古老的地震可能发生在公元前3300年至5000年之间。尽管最近的地表断层地震发生在历史时期，但在历史记录中没有发现证据。单次滑动范围为2 ~ 3 m，破裂长度至少为12-20 km，古地震震级为6.5-7.0级。从挖沟确定的倾斜滑动速率为0.7-1.2毫米/年，与从位移地貌特征获得的长期滑动速率0.9-2.5毫米/年（优选较低值）一致。海沟数据与长期滑动率估计相结合，表明复发间隔超过一千年，可能长达3300年。最近一次地震发生的时间是700-1130年。Ovindoli-Pezza断层的地震行为与亚平宁山脉中部和南部其他著名的地震断层一致。在过去两千年的历史记录中，奥温多利-佩扎断层上最近发生的事件没有被提及或被错误定位，这主要是因为中世纪的文化和社会条件不稳定，经济状况不佳，特别是在人口稀少的地区，如亚平宁山脉中部。这个例子突出了历史数据的内在局限性，并提出了一种可能性，即根据长期历史记录被认为地震平静的其他地区实际上可能发生了没有记录的大地震。
Geomorphic and trenching investigations along the Ovindoli-Pezza fault show that this normal fault is one of the major seismogenic faults in the central Apennines. We found clear geological evidence for three Holocene surface-faulting earthquakes on this fault : the most recent earthquake occurred in the Middle Ages between 860 and 1300 A.D., the penultimate occurred about 1900 B.C. or shortly after, and the oldest probably occurred between 3300 and 5000 B.C. Although the most recent surface faulting earthquake occurred during historical time, no evidence for it have been found in the historical record. Slip per event ranges between 2 and 3 m, and the length of the rupture is at least 12-20 km, suggesting M 6.5-7.0 for the paleoearthquakes. The dip-slip rate determined from trenching is 0.7-1.2 mm/yr and is consistent with the long-term slip rate of 0.9-2.5 mm/yr (lower values preferred) obtained from displaced geomorphic features. Trench data combined with long-term slip rate estimates suggest the recurrence interval is longer than a millennium and possibly as long as 3300 years. The time elapsed since the most recent earthquake is 700-1130 years. The seismic behavior of the Ovindoli-Pezza fault is consistent with other well-known seismogenic faults of the central and southern Apennines. The lack of mention or mislocation of the most recent event on the Ovindoli-Pezza fault in the historical record of the past two millennia should be attributed mainly to the unsettled cultural and social conditions and poor economic state that characterized the Middle Ages, especially in thinly populated regions such as the central Apennines. This example highlights an intrinsic limit of the historical data and raises the possibility that other regions considered seismically quiet on the basis of a long historical record may in reality have had large earthquakes that were not recorded.