CHARACTERIZATION OF SURFACE-WAVES IN THE CENTRAL SWAMP DEPOBELT IN THE NIGER DELTA, NIGERIA

Abstract

This paper presents a detailed study on refraction survey carried out in the Central Swamp Depobelt of the Niger Delta in order to compute the characteristics of the surface waves. Twenty-seven (27) boreholes were each drilled in the Central Swamp Depobelt of the Niger Delta to 66m. The borehole data were acquired using Seismograph McSeis-160MX Recorder, hydrophone detector and electric detonator as the source. Analysis of the results shows two-layer refractors. The consolidated-layer velocities range between 1580 and 1906ms-1with an average of 1737.78ms-1. Weathered-layer (surface) velocities range between 213 and 781ms-1 with an average of 504.81ms-1. Air-blast low velocities range between 213 and 377ms-1 with an average of 307.33ms-1. Depths from refracting surfaces range between 2.25 and 6.12m with an average of 4.58m. Dominant surface wave frequencies range between 5 and 10Hz. The layer thickness and velocity parameters can be applied in static correction in the processing of seismic reflection survey data. The dominant frequency information can also be integrated with the other parameters in detector and source arrays design necessary for attenuating the ground roll noise in the study area.