利用远震接收函数研究江西省地震台站下方莫霍面深度及泊松比分布

利用三分量远震记录资料,计算获得了江西省13个数字地震台下方的体波接收函数,利用H-kappa叠加方法反演得到这些台站下方的地壳厚度及泊松比。结果表明,研究区域东西向莫霍面起伏平缓,南北向地壳厚度变化稍大,全区域内地壳平均厚度为31 km,最大深度为九江的35 km,最小深度为赣州的28 km。泊松比的分布在研究区内从0.2到0.3之间变化,最大为会昌的0.27,最小为南昌的0.21。赣南各台站泊松比分布明显高于赣北,这可能与该区域地幔组分及地质演化过程有关。

Study on Moho Depth and Poisson's Ratio Distribution Beneath Seismic Stations in Jiangxi Province by Teleseismic Receiver Function

Based on three-component digital waveform data of teleseismic earthquake events, we calculate body wave receiver functions under the 13 stations in Jiangxi province , and obtain the crustal thickness and Poisson＇s ratio under these stations in this region by H-kappa stacking method.The results show that the crustal thickness with an average thickness of 31 km changes little from East to West and thickens from North to South.The maximum crustal thickness is 35 km beneath the station JUJ, and the crust thickness beneath the station GAZ is 28 km only. Poisson＇s ratio which may be related to material composition of earth interior and geological evolution in Jiangxi Province ranges between 0.2 and 0.3.Poisson＇s ratio in the South Jiangxi has distinctly higher values than that in the North Jiangxi.The results also show that the maximum Poisson＇s ratio in our study region is 0.27 beneath the station HUC, and the minimum Poisson＇s ratio beneath the station NNC is 0.21.