摘要
本文推导了速度与密度网格大小不同时的交叉梯度计算公式,并实现了二维重震联合反演。新方法考虑了重力和地震数据分辨率不同的情况,可以避免由于观测重力异常含有噪音以及密度网格划分过小而引起的过拟合现象。分别使用理论模型数据和实测资料对本文提出的二维重震联合反演方法进行测试,结果表明,新方法通过采用较大的密度网格和较小的速度网格进行重震联合反演,能够获得比地震或重力单独反演更准确的地下速度和密度模型。
By simultaneously using seismic travel time and gravity anomaly data,joint inversion under structural similarity constraints can effectively reduce the non-uniqueness of inversion and improve its accuracy.The resolution of gravity anomaly inversion density model is often lower than the resolution of seismic travel time inversion velocity model,so it is more reasonable to use different size of velocity and density grids in the joint gravity-seismic inversion.The authors derive the cross-gradient calculation formula when velocity and density grid sizes are different,and implement the two-dimensional joint gravity-seismic inversion.The new method considers the different resolutions of gravity and seismic data,and can avoid overfitting caused by noise in the observed gravity anomalies and excessively small density grids.The proposed two-dimensional joint inversion method is tested using both theoretical model data and real measurement data.The results show that the new method,by using larger density grids and smaller velocity grids for joint inversion,can obtain a more accurate subsurface velocity and density model compared to using seismic or gravity inversion alone.
作者
吕鲁元
张建中
黄忠来
Lv Luyuan;Zhang Jianzhong;Huang Zhonglai(Key Laboratory of Submarine Geosciences and Prospecting Techniques,Ministry of Education,College of Marine Geos-ciences,Ocean University of China,Qingdao 266100,China)
基金
国家自然科学基金项目(42174154)资助。
关键词
地震
重力
交叉梯度
联合反演
seismic
gravity
cross-gradient
joint inversion
作者简介
吕鲁元(1996-),女,硕士生,研究方向:地球物理信息技术。E-mail:lvluyuan32@163.com;通信作者:张建中,男,博士,教授,研究方向:地震及重力数据正反演。E-mail:zhangjz@ouc.edu.cn。
