以2015—2023年格尔木地震监测中心站流体观测井井下40 m和井下90 m处水温日均值数据为研究对象,利用小波分析方法在时、频域具有较高分辨率的特性,选取db5小波基提取水温异常。结果表明:利用小波分析方法可更直观、高效地提取格尔木流体观测井水温震前异常信息,其日均值数据异常在小波细节2阶上表现更为显著;井下40 m处水温异常通常出现在临震前4个月内,井下90 m处水温异常则多出现在震前3—8个月内,而在强震、大震发生前,水温异常信息出现时间更早。在青海南部地区部分地震发生前,水温原始数据也会出现异常变化。通过综合分析2套不同深度水温观测仪的数据异常,并与原始曲线进行对比,发现水温异常对格尔木周边400 km内5级及以上地震及其发震地点有一定指示意义。
Taking the daily average data of water temperature at -40 m and -90 m of Golmud Seismic Monitoring Central Station from 2015 to 2023 as the research object, and using the characteristic of high resolution in time and frequency domain of wavelet analysis method, the db5 wavelet basis is selected to extract water temperature anomaly. The results show that the anomaly of water temperature data on the second-order wavelet detail is obvious. Through wavelet analysis, the abnormal water temperature information in Golmud before earthquakes can be extracted more intuitively and easily. The abnormal water temperature at -40 m mostly occurs from imminent earthquakes to four months before earthquakes, and the abnormal water temperature at -90 m mostly occurs from three to eight months before earthquakes. The abnormal information before strong and major earthquakes occurs even earlier. Before some earthquakes in southern Qinghai, abnormal changes also occurred in the original water temperature data. Combining the anomalies of two sets of water temperatures at different depths and comparing them with the original curves has certain indicative significance for earthquakes above magnitude 5 within 400 kilometers around Golmud and their location.
2025,46(2): 131-138 收稿日期:2024-8-30
DOI:10.3969/j.issn.1003-3246.2025.02.015
基金项目:青海省地震局地震科技基金(项目编号:2024-12)
作者简介:周瀚琳(1989—),女,甘肃榆中人,本科,工程师,主要从事地震监测工作。E-mail:274692542@qq.com
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