EVIDENCE FOR STATIC DISPLACEMENTS FROM THE JUNE 9, 1994 DEEP BOLIVIAN EARTHQUAKE

The 1994 Bolivian Earthquake (M(W)=8.3) was recorded on-scale by 8 very-broadband stations deployed approximately 600 km south of the epicenter. When these seismograms are carefully converted to ground displacement, there appears to be a static offset which is on order of 2 cm. We have modeled the waveforms with a synthetic waveform method that contains near-, intermediate- and far-field terms. Although the synthetics are only calculated for an elastic half-space, they compare favorably with the observed waveform in terms of shape. However, the theoretical amplitude is 1/2 of the observed static offset, which probably reflects the limitations of a homogeneous half-space model and/or the instabilities in deconvolution.