CHIRP Imaging in Extant Lakes and Reservoirs: Selecting Source Parameters for Optimal Depth and Resolution Objectives

ABSTRACT Compressed high-intensity radiated pulse (CHIRP) acoustic reflection data acquired in lakes and other shallow water bodies can provide detailed imaging that is valuable for environmental and engineering geology applications well below the sub-bottom floors. However, it is often unclear to non-specialists which acquisition settings should be considered to achieve optimal imaging quality when beginning a new survey, particularly in an unfamiliar environment. We review fundamental concepts for optimizing signal design using coincident CHIRP lines from two extant glacial lakes in the eastern Sierra Nevada of California: Convict Lake and June Lake. As part of the optimization process, seismic data were recorded with different source acquisition parameters, including sweep bandwidth and length, in pre-production testing to determine the most effective acquisition parameters for satisfying survey depth and resolution objectives. We offer recommendations for best practices based on these results.