In volcano gravimetry, when analyzing residual spatiotemporal (time-lapse) gravity changes, the accurate deformation-induced topographic effect (DITE) should be used to account for the gravitational effect of surface deformation. Numerical realization of DITE requires the deformation field available in grid form. We compute the accurate DITE correction for gravity changes observed at the Laguna del Maule volcanic field in Chile over three nearly annual periods spanning 2013–2016 and compare it numerically with the previously used free-air effect (FAE) correction. We assess the impact of replacing the FAE by DITE on the model source parameters of analytic inversion solutions and apply a new inversion approach based on model exploration and growing source bodies. The new inversion results based on the DITE correction shift the position of the mass intrusion upwards by a few hundred meters and lower the total mass of the migrated fluids to roughly a half, compared to the inversion results based on the local-FAE correction. Our new Growth inversion results indicate that vertical dip-slip faults beneath the lake, as well as the Troncoso fault play active roles in hosting migrating liquid. We also show that for the study period, the DITE at Laguna del Maule can be accurately evaluated by the planar Bouguer approximation, which only requires the availability of elevation changes at gravity network benchmarks. We hypothesize that this finding may be generalized to all volcanic areas with flatter or less rugged terrain and may modify interpretations based on the commonly used FAE corrections.

在火山重力法中，当分析残余时空（时移）重力变化时，应使用精确的形变引起的地形效应（DITE）来说明表面形变的重力效应。DITE的数值实现需要网格形式的变形场。我们计算精确的DITE校正，以校正在2013-2016年的三个近一年期间在智利Laguna del Maule火山场上观察到的重力变化，并将其与以前使用的自由空气效应（FAE）校正进行数值比较。我们评估了用DITE替换FAE对解析反演解决方案的模型源参数的影响，并基于模型探索和不断增长的源体应用了一种新的反演方法。与基于局部FAE校正的反演结果相比，基于DITE校正的新​​反演结果使侵入体的位置向上移动了几百米，并将迁移流体的总质量降低了大约一半。我们的新的生长反演结果表明，湖下的垂直倾滑断层以及特隆科索断层在容纳正在迁移的液体中起着积极的作用。我们还表明，在研究期间，可以通过平面布格逼近法准确评估Laguna del Maule的DITE，这仅需要在重力网络基准处获得高程变化即可。我们假设，这一发现可能会推广到地形平坦或不那么崎all的所有火山地区，并且可能会根据常用的FAE修正修改解释。