New insights from analysis of historical texts on the 1568 Northeast Xi'an earthquake, Shaanxi, China
New insights from analysis of historical texts on the 1568 Northeast Xi'an earthquake, Shaanxi, China
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DOI：
10.1016/j.ijdrr.2019.101417
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发表时间：
2020-04
影响因子：
5
通讯作者：
J. Ma;X. Feng;G. Y. Li;X. Li
中科院分区：
文献类型：
--
作者：
J. Ma;X. Feng;G. Y. Li;X. Li
公元1568年5月25日，陕西省西安市东北部发生了一场毁灭性的地震，造成了大量人员伤亡、严重的财产损失和严重的生计中断。这次地震被选为计算渭南及其周边城市地震情景的合理依据。先前的研究一致认为这次地震的震级为6又3 / 4，但得出了不同的震中位置和等震烈度图。我们将历史地震报告的文本研究与实地调查相结合，以减少不确定性，并对如果此类地震再次发生将经历的地面震动施加限制。我们发现靖阳县、高陵县和咸宁县是地震中受灾最严重的县，永乐镇、会军镇、皮沙镇和丰正镇（今天的高庄和张布镇）可能位于这次地震的中震区。通过对历史文献的重新解释，结合现场观测，认为此次地震的震中位于北纬34°28′和东经108°59′，震中强度为Ⅸ+，震级估计为7级。等震等值线的主要轴向为WNW-ESE，与早期历史文献研究推断的更多的NS走向相反。烈度为VIII+的等震线包围了渭南-靖阳活动断层，其主轴平行于渭南-靖阳活动断层，我们推断该断层是1568年5月25日地震中发生滑动的断层。
A destructive earthquake occurred in Northeast Xi'an, Shaanxi province, on May 25th, 1568 AD, causing many casualties, severe damage to property, and significant disruption to livelihoods. This earthquake has been chosen as a plausible basis for calculating a seismic scenario for the modern city of Weinan, and its surrounding urban areas. Previous studies agreed in assigning a magnitude 6 ¾ to the earthquake but yielded differing epicentral locations and isoseismal intensity maps. We combine textual research on historical earthquake reports with field investigations to reduce the uncertainties, and to place constraints on the ground shaking that would be experienced if such an earthquake were to recur. We show that the counties of Jingyang, Gaoling, and Xianning were the worst hit by the earthquake, with the townships of Yongle, Huijun, Pisha, and Fengzheng (present-day Gaozhuang and Zhangbu township), likely being in the mesoseismal area of this earthquake. Reinterpretation of the historical texts, combined with field observations, indicates that the epicenter of the earthquake was at about 34°28′N and 108°59′E, with an epicentral intensity of Ⅸ+ and an estimated magnitude of 7. The isoseismal contours have major axes-oriented WNW-ESE, in contrast to the more NS alignment inferred from the earlier study of the historical documents. The isoseismal of intensity VIII+encloses, and has its major axis parallel to, the active Weinan-Jingyang fault, which we infer to be the fault that slipped in the May 25th,1568 earthquake.