“泰山震”的震中在郯庐断裂带安丘地区的证据^*

Evidences that epicenter of ‘Taishan earthquake’ was located in Anqiu area of Tanlu fault zone

摘要

“泰山震”发生于公元前1831年,是中国史料记载的最早的历史地震。据《竹书纪年》记载: 夏帝发七年(公元前1831年),当名为“发”的皇帝正在登泰山时,发生了一次强地震。因这次地震使皇帝受到了惊吓,因此,被名之为“泰山震”而首次记载下来。显然,名为“发”的皇帝受地震恐吓的地理位置是泰山坡麓。由于在泰山及其附近,地震地质学家一直未找到“泰山震”的地震地质记录。因此,“泰山震”的震中和震级一直是个谜。重新观察已发现的地震地质遗迹,结合一系列的测试、实验与剖析,本研究为“泰山震”是震中处在郯庐断裂带内安丘地区的强烈的历史地震提供了证据。首先,在距泰山以东约200 km远的郯庐断裂带安丘—夏庄盆地内的全新世湖沼相软土层中,存有震陷向斜与同震微断层等宏观的地震事件遗迹,它们记录的震中烈度Ⅸ度、震级达M7.0;二是借助于¹⁴C同位素年龄测定结果,结合计算相关土层的沉积时间,而获得了极为接近公元前1831年的发震时间(公元前1827年);三是依据华北地震烈度衰减模型,计算出该地震在泰山的衰减烈度为Ⅵ度。中国地震烈度表显示,Ⅵ度烈度完全使人站立不稳或惊逃户外,这符合当年登山皇帝受地震惊恐的史料记录。

Abstract

The‘Taishan earthquake’ named after Mount Taishan,occurred in 1831 BC,which was the earliest historical earthquake recorded by writing-materials in China. Bamboo Annals recorded that the strong earthquake occurred,when the emperor named “Fa” was climbing the Mount Taishan in the seventh year of Xia Di Fa(i.e.1831 BC). The earthquake shocked the emperor at that time,so for the first time,it was written and named after Mount Taishan. Apparently,the geographical position that the emperor “Fa” was threatened by the earthquake was at the hillside of the Mount Taishan. However,seismic geologists have been unable to find any seismic-geological records or traces of the historical earthquake in the Taishan area and its surroundings. Therefore,the epicenter and magnitude of the “Taishan earthquake” have been a mystery. By reobserving the discovered seismo-geological remains,combined with a series of tests,experiments and analysis,the paper provides evidences that the “Taishan earthquake” was a strong and historical earthquake with its epicenter located in the Anqiu area within the Tanlu fault zone. First of all,in the Holocene soft soil layers of limnetic facies in the Anqiu-Xiazhuang Basin of the Tanlu fault zone about 200 km away from Mount Taishan,there are macroscopical seismic traces such as seismic-subsidence synclines and co-seismic micro-faults,which recorded epicenter-intensity for degree of IX ,seismic magnitude for M7.0. Second,by means of the results of dating¹⁴C isotope,combining with calculating the sedimention time of the related soil layer,the earthquake time(i.e.1827 BC)obtained is very close to 1831 BC. Third,based on seismic intensity attenuation model in North China,the attenuation intensity induced by the earthquake is calculated to the degree of VI near Taishan. The Chinese earthquake intensity table shows that the VI intensity completely makes people stand unstable or escape outdoors,which accords with the historical records that the mountaineering emperor was frightened by the earthquake.

关键词

泰山震 / 震中 / 安丘 / 震陷向斜 / 郯庐断裂带 / 证据

Key words

Taishan earthquake / epicenter / Anqiu / seismic-subsidence syncline / Tanlu fault zone / evidence

基金资助

*山东建筑大学博士基金项目(编号: XNBS1708)、国家自然科学基金项目(编号: 41272066)和国家科技支撑计划项目(编号: BAK19B04-01)联合资助