Archaeology of the Holocaust

Study of the Holocaust is particular within archaeology as it covers an event of the modern period, and began when persons with direct experience of the events studied were still alive. Although Nazi extermination camps were captured and liberated by the Soviet Red Army in 1943-1945 on the Eastern Front of World War II, the full extent of the Holocaust was obscured by attempts to hide and disguise evidence of mass murder.

Judicial investigations linked to the trials for crimes against humanity of Nazis and collaborators studied material evidence of the Holocaust in the 1940s. However these were not performed using archaeological methods and techniques. While some sites linked to the Holocaust and Nazi war crimes have been designated memorials or museums, Caroline Sturdy Colls estimated in 2011 that "the majority [of sites of the Holocaust] have not been examined archaeologically".^[2]

In the late 1980s, archaeological methods were applied at the site of the Chelmno extermination camp by museum curator Pawlicka-Nowak. These studies identified previously unknown human remains of victims which were not cremated during the camp's destruction. These findings led to similar research being performed at other extermination and concentration camps starting in the 1990s, as well as the archaeological study of sites related to Jewish life and culture during World War II.

The archaeology of the Holocaust presents unique challenges as a study of a recent event with significant historical and judicial record. In this field, ethical practice requires conducting scientific investigations in a manner that takes into consideration the needs and wishes of diverse stakeholders, including survivors, relatives of the victims, religious groups, and governments.^[4]

A primary ethical challenge within Holocaust archaeology involves respecting Halakha (Jewish law), which prohibits the disturbance of Jewish graves unless it is under threat, centering on the belief that a grave is eternally tied to the soul of the deceased. This religious law applies to all graves, regardless of whether they were created legally or illegally as was the case in the Holocaust. Because Halakha also prohibits scientific analyses of the deceased, researchers often face limitations in their abilities to investigate many Holocaust sites, leading to disagreements between archaeologists, religious groups, governments, survivors, and family members of the deceased.^[5] Further, since archaeological practices often center on excavation, new archaeological methods were developed for Holocaust archaeology. These prioritize non-invasive techniques (as described in the next section), allowing archaeologies to thoroughly investigate Holocaust sites while still adhering to Halakha.^[6][7][8]

Beyond religious considerations, archaeologists have the ethical obligation to treat victims of violence and all deceased persons with dignity. At sites of mass atrocities, archaeologists are also responsible for helping to uncover evidence of crimes and informing their surviving relatives, ensuring the victims are remembered with respect. Holocaust archaeology also provides a means of public education, documenting crimes against humanity to ensure they are recognized by the world.^[9]

Holocaust archaeology employs an interdisciplinary approach with a focus on non-invasive methods, which offer the potential to examine large areas at high levels of detail and serve as a valuable precursor to excavation when it is needed.^[10] Methods are selected on a case-by-case basis, based on the nature of the site under investigation and the specific circumstances in which the work is being undertaken. Prior to any fieldwork, researchers integrate archival research, historical maps, survivor testimony, and Geographic Information Systems (GIS) to reconstruct site layouts and identify areas of interest. These approaches allow archaeologists to correlate physical evidence with documentary sources and better understand the spatial organization of extermination and concentration camps.^[6]

On site, a variety of above-ground, non-invasive methods are used. Walkover surveys are typically conducted prior to other in-field survey methods to identify and record visible features, often leading to the discovery of previously unrecorded features in Holocaust sites. Light Detection and Ranging (LiDAR) is used to generate high-resolution digital terrain models, allowing archaeologists to rapidly identify surface features such as depressions associated with buried remains or remnants of former camp infrastructure that may not be visible at the ground level, even in densely vegetated sites. Unmanned Aerial Vehicles (UAVs, or drones) are a cost-effective means of collecting aerial imagery and monitoring Holocaust site conditions over time and are frequently used in conservation strategies.^[7]

Other above-ground methods include forensic archaeological search techniques, adapted from crime scene investigation practices, are used to locate mass graves, cremation pits, and other body disposal areas in Holocaust sites. Global Positioning System (GPS) and total station surveys are used for precise spatial recording, while laser scanning and the less-expensive multi-photo photogrammetry are used to record above-ground remains by creating detailed three-dimensional models of landscapes, structures, and artifacts found at Holocaust sites. Building recording further documents Holocaust structures that remain fully or partially standing, preserving information about the building’s function and providing the opportunity to identify evidence concealed within the construction.^[7]

After a thorough assessment of above-ground evidence utilizing the non-invasive methods described, a series of below-ground methods may be employed where appropriate. Because a lot of the evidence of the Holocaust was deliberately concealed or altered, it is crucial to assess buried remains while adhering to ethical and religious considerations. This often begins with geophysical surveys instead of excavation, which are considered the more practical and ethical approach for investigating Holocaust sites since they are non-invasive and thus do not disturb human remains. Geophysical surveys include ground penetrating radar (GPR), electrical resistivity tomography (ERT), resistance survey, and magnetometry.^[8][11] These methods measure variations in subsurface physical properties to identify anomalies such as graves, structural remains, pits, and other forms of disturbances.

GPR allows archaeologists to generate three-dimensional images of buried features and estimate their depth beneath the surface.^[8] ERT uses an electrical charge in the soil to also creates an image of what is below the surface, but at a higher level of detail than GPR, distinguishing between materials such as stone, bone, ceramic, metal and glass.^[11] Similarly, resistance survey detects differences in the electrical resistance of soils, allowing archaeologists to identify and differentiate between buried features and the surrounding soil. Magnetometry identifies variations in the Earth’s magnetic field caused by buried objects or disturbances such as excavation or burning. In the rare case that excavation is undertaken, it is typically limited and carefully controlled, often stopping once the presence of graves is confirmed and leaving most remains where they were found to respect ethical and religious constraints. Geochemical testing can also be used in targeted areas to analyze soil for chemical indicators of human decomposition or to detect residues such as Zyklon B or carbon monoxide in gas chamber remains.^[8]