鄂豫皖交界地区地震地质背景与中强地震复发特征的研究

Study on seismological background and recurrence behaviors of moderate earthquake in the border area among Hubei, Henan and Anhui province

鄂豫皖交界地区位于东大别山西部,历史中强地震(M≥43/4)主要发生在土地岭-落儿岭及商城-麻城断裂带上,且“互动”和“连动”的特征较为显著。根据这一特征,在研究东大别山区域地质、地壳结构、断裂活动及地震构造应力场特征的基础上,可将鄂豫皖交界地区的中强地震作为秦岭-大别山活动地块中的次级地块的整体活动来看待。该区历史地震活动整体表现为丛集特征,而主要发震断层(土地岭-落儿岭断裂)的历史地震活动则具有相对较好的准周期性。地震复发周期研究提示,该地块近期发生M≥5.0左右地震的危险性较大,而霍山-六安地区为未来发生中强地震的主要危险区。

The border area among Hubei, Henan and Anhui province lies on the west of East-Dabie Mountain. Historical earthquakes (M ≥53 /4) mostly occurred on Tudiling-luoerling fault and Shangcheng-Macheng fault zones, and had some characters of correlative and consecutive earthquake. Based on the east Dabie geotectonic elements, crustal structure, fault activity and seismotectonic stress field, we think that moderate earthquakes of the area are one of entirety activities, belong to the second-class active land block of Qinling-Dabie. In this block, the recurrence behavior of entirety earthquakes have clustering characters, but history earthquakes activity on the strong shock fault (Tudiling-Luoerling fault) have some quasi-periodic characters. The earthquake recurrence period studying suggests that a M ≥ 5.0 earthquake will occur in Huoshan-Liu'an area at this block in recently.