The use of a priori data for the construction of a seismic topographic model of the Khibiny massif

Abstract

The aim of the study is to construct the a priori constraints imposed on the model at the solving the inverse seismic problem. For the petrophysical materials are analyzed concerning the main classes of rocks distributed over the surface of the Khibiny massif and its surroundings. Shallow seismic tomography studies are performed on the basis of short (less than 2 km) first-arrivals curves of seismic waves. In the seismic tomography studies, the detailed seismic data of MOV (reflected wave method) are prepared and a static correction for LVZ (low-velocity zone) is calculated. Preliminary statistical analysis of seismic data is also carried out. Initial velocity models necessary for shallow seismic tomographic modeling are calculated. The criterion for stopping the iterative process and the optimal regularization parameter are searched. A detailed high-velocity model of the upper part of the studied medium (to a depth of 0.10÷0.15 km) is constructed as a result. The obtained values of the velocity of longitudinal waves are used as boundary conditions imposed on the 3D-model at the main stage of seismic modeling.