Evolution of a Near-Surface Model In an Area of Complex Topography

This paper describes a case study of the evolution of the near-surface statics model for an area of complex topography giving large velocity contrasts in a short distance. The 2D lines were modeled with a single layer velocity model and local anomalies investigated. This technique is inadequate for the later 3D acquisition. A twolayer model was built using existing upholes; however local anomalies were still evident. This initial two-layer model was further refined by adding extra contol points to define the near-surface geology much more accurately than before. While this model defined the regional trends better than previous models, further work was to be done to confirm the structure.