Subsurface Imaging of a Mass Grave: An Investigation of the Former Old Jewish Cemetery of Riga, Latvia

Abstract

In Riga, Latvia many Jewish lives were executed by Nazi authorities and Latvian collaborators in World War II. More than 70,000 local and transported Jewish people from all around eastern Europe were exterminated in Latvia. The objective of the project is to find the unmarked mass graves of 800 to 1000 Jews who were murdered in the street of Riga Ghetto while being forced to march to a mass execution site in Rumbula on November 30, 1941. According to survivors’ testimonies, the Old Jewish Cemetery is the place were murdered Jews, that were not able to get to Rumbula, were buried. To find the mass graves within the Old Jewish Cemetery that is connected to Riga ghetto, ground penetrating radar (GPR) was utilized, by sending electromagnetic pulses into the ground to analyze soil contrast. A 10mx40m grid was laid down to examine the ground. A total of 160 lines were collected with a Sensors and Software Pulse EKKO Pro GPR system using an antennae frequency of 500 MHz and line spacing of 0.25m and step size of 0.02m which is triggered by an odometer wheel. The data was then processed through pulse EKKO_Project 5 software. Collection of topography using Topcon RL-H4C and light detection and raging (LiDAR) were used to examine the area. Based on electrical resistivity tomography (ERT) data there are anomalies that could be interpreted as trenches. To ensure that it a mass grave further studies are needed to confirm the content of the site.