GPS监测慢滑移信号的双曲正切函数建模

Hyperbolic Tangent Function Modeling of GPS Monitor Slow Slip Signals

以日本房总半岛2011年、2013~2014年、2018年3次慢滑移事件(slow slip event, SSE)为例,利用自主研发的GPS坐标时序分析(GPS coordinate time series analysis, GTSA)软件批量处理该半岛多个GPS站点2009~2019年共10 a的坐标时序数据,构建包含周期性SSE的坐标时序模型。结果表明:1)双曲正切函数的数学特性与SSE的运动规律十分吻合,表现为缓慢加速-快速滑动-缓慢减速,最后恢复至稳态;2)函数对SSE的精准建模可有效确定SSE发生时间的中心、持续时长和地表位移;3)2011年SSE持续时间最长可达50 d, 2013~2014年和2018年的SSE持续时间最长为25 d;4)3次SSE的水平位移均朝东南方向,高程位移量均表现为下沉,2018年SSE最大水平位移达5.2 cm, 2013~2014年最大高程位移达3.8 cm。

Taking the nearly three slow slip events(SSE)in Boso Peninsula in Japan in 2011,2013-2014,and 2018 as examples,we use the independently developed GPS coordinate time series analysis(GTSA)software to batch process the coordinate time series data of multiple GPS stations in the peninsula for a total of 10 a from 2009 to 2019,and build a coordinate time series model containing periodic SSE.The results show that:1)The mathematical characteristics of the hyperbolic tangent function are very consistent with the motion law of SSE.At the initial stage,the hyperbolic tangent function accelerates slowly,then slides rapidly,and finally decelerates slowly to return to the steady state;2)The precise modeling of SSE by the function can effectively determine the center of SSE occurrence time,duration,and surface displacement;3)The duration of SSE in 2011 can reach 50 d at most,and in 2013-2014 and 2018 can reach 25 d at most;4)The horizontal displacement of the three SSE is toward the southeast,and the elevation displacement is shown as subsidence.The maximum horizontal displacement of the SSE in 2018 was 5.2 cm,and the maximum elevation displacement in 2013-2014 was 3.8 cm.