Subsurface Mapping of Holocaust Execution Sites at the Lighthouse in Liepāj, Latvia

Abstract

During the early stages of the Holocaust in 1941, over 5,470 people were shot by bullets within the city limits of Liepāja, Latvia. Near the Liepāja Lighthouse, a film recorded by Reinhard Wiener captures the scene of active killings while a 1945 Soviet Commissions Map illustrates four execution trenches. The map and film present geographic reference points that suggest trench locations near the Lighthouse. The research aims to build upon prior research to map the continuation of execution trenches. The primary method, ground penetrating radar (GPR), a non-invasive technique that transmits high-frequency electromagnetic pulses into the subsurface. Seven grids were laid out using survey tapes with a 0.25m line spacing and ranging from 4.5-29m in length and 12-33m in width. All seven grids used an antennae frequency of 500MHz with an odometer wheel triggered step size of 0.02m. The data was processed using Sensors and Software pulseEKKO Pro V6 software. Pairs of erosional truncation reflections are interpreted as trench outlines within local subhorizontal semicontinuous coastal aeolian sediments. Two possible trenches extend in grids 1 and 5. The project builds an understanding of how to detect mass burial sites worldwide and help the Liepāja Jewish community identify memorial locations for execution trenches.