High Resolution Seismic Imaging in Alpine Environment by Common Reflection Surface Method

Abstract

In alpine environment, alluvial fan architecture can reveal important information about the landscape geomorphic evolution and the climate change. The information about alluvial fan morphology and sedimentology can be obtained by a high-resolution geophysical approach. In this work, we acquired and processed a ∼4 km long high-resolution seismic reflection profile across a representative transect of Val Venosta, over the Gadria fan, Eastern Alps, Italy, using non-conventional acquisition and processing approaches. We tested Dense-wide aperture arrays (DWA) and Common Reflection Surface stack (CRS) in a complex environment, in order to obtain seismic data with a quality and resolution adequate to: 1) study the internal reflective configuration of the fan; 2) image both the pattern of the bedrock below the valley and thickness of the sediment accumulation above it; 3) evaluate the geometrical relationships between the Gadria Fan and the Adige River sediments. By the analysis of our results, we can deduce that DWA seismic data in combination with high-resolution CDP/CRS processing can provide complimentary and low-cost information to aid the study of alluvial fans in alpine environments.