Battlefield archaeology

Earthwork surveys are the search for manmade modifications to the environment or ground such as trenches or holes.[2] Depending on the time period of the battlefield being studied, earthwork surveys will exhibit varying degrees of success.  Before modern history such as medieval history, open battlefields were the primary battlegrounds.  Within the last two centuries, trench warfare has become increasingly popular allowing earthwork surveys to become far more useful. These time dependent characteristics on battlefields can typologically identify and date earthworks.  This will help remove any confusion such as placing trench warfare with Egyptian warfare tactics.

Battlefield archaeologists utilize a variety of geophysical instruments.  These instruments have the ability to identify the irregularity (artifact, bone, wall) and omit any other background material such as dirt or naturally occurring elements.

The metal detector is the most common instrument used within battlefield archaeology.  The location of fragments on metal are located by using an induced magnetic field within a certain proximity to the head of the detector.[2]  The quality of the instrument varies allowing for a range of depth quality.  A metal detector generally works to a maximum depth of between 20–30 cm deep for smaller objects.  Battlefield archaeologists are most successful with metal detectors when using them in large groups.  Novice users of metal detectors can easily miss or record misleading data.  

A fluxgate gradiometer records anomalies in the Earth’s magnetic field across a specific area.  These detectors are especially useful when detecting ferrous items.  They detect ferrous spikes when a piece of ferrous metal is close to the instrument.[2]  These instruments are most useful the more recent the site’s artifacts have existed. Since iron has a natural tendency to change over time, fluxgate gradiometers have a tendency to fail in identifying locations where iron is present.  These devices are very successful when locating mass graves on battlefields.  Depending on the strength of the magnetic anomaly, a fluxgate gradiometer can have various degrees of success.  They generally work at a depth of around 50 cm.  

An electrical earth resistance meter records differences in the electrical conductivity or water content within soil.  These instruments are very effective at depths of less than 50 cm deep.  Electrical Earth resistance meters are very successful at located recent graves because recent grave fills often exhibit different moisture content compared to surroundings.[2]  

Ground penetrating radar sends out electromagnetic radiation pulses to detect and then reflect signals from subsurface structures.  The electromagnetic conductivity can drastically affect the limit of the device although they are usually effective up to several meters deep.  In order to be effective, the anomaly being investigated needs to be distinct from the background material.  

Field walking surveys are done by walking across a field looking for artifacts on the surface.  A grid system is employed so as to mark the specific location an artifact was found and to map out the remaining artifacts in relation to each other.  This process requires little expertise and minimal equipment as long as grid mapping is very effective and accurate.  Depending on the circumstances, the artifacts are either collected or analyzed on site so their historical context is placid.[2]  

Desk-top assessments are performed by searching through text based documents pertaining to the site in question.  These can include maps, photographs, primary sources, and secondary sources.  The issue with desk-top assessments is that depending on the historical context, certain international conflicts can vary in accuracy.[2]

Excavations on the Western Front often occur for humanitarian reasons, namely the recovery and identification of human remains and the disposal of unexploded ordnance. The unique conditions of Western Front excavations often pose a threat for archaeological excavations. For example, during the first five hours of the Kaiserschlacht ('Spring Offensive'), over one million shells were fired by the Germans into the Allies' lines across the entire 150-mile front.[9] The million shells fired during the beginning of the Spring Offensive are only a small sample of the total used during the war. Most of the shell casings were dumped on the battlefields and a considerable number of shells did not detonate upon impact. Archaeologists conducting excavations at World War I sites are often at risk not just from the unexploded ordnance but from the environmental pollution caused by the deterioration of ordnance, shell and bullet casings, and various other forms of battlefield debris. A study conducted at the Ypres battlefield in 2008 concluded that the highest level of copper contamination of the soil was over 200 mg/kg, which was higher than the background threshold of 17 mg/kg.[10] The large area in France, where the levels of heavy metals from battlefield debris can negatively impact the health of flora and fauna is labeled by the French government as Zone Rouge (Red Zone). The French Government created Département du Déminage for the purpose of collecting and detonating unexploded ordnance in the Red Zone.

The majority of artillery shells recovered during archaeological excavations or by demining operations are from World War I. This is due to a revolution in shell design that occurred between the First and Second World Wars. In World War I, artillery shells were designed to detonate upon impact. Many times, the detonator would not activate, resulting in the large number of duds.[11] By the time of the Second World War, the detonator for artillery shells was hooked up to a timer. The intention was for the shell to explode over the enemy, raining shrapnel on them.[12]

Archaeological excavations on the Western Front (World War I) have also helped to identify a unique soil condition that is only found in the context of battlefield archaeology. This unique soil condition is known as bombturbation. Intense artillery barrages, and airstrikes cause large amounts of deforestation. Additionally, bombardment creates large craters and mixes the soil layers together in unique ways.[13] As a result, methods of stratigraphic analysis must take into account this unique phenomenon when analyzing a site related to World War I.

A noteworthy burial site contains the remains of thirty-one British soldiers at Le Pont de Jure. It is thought that these soldiers died in April 1917 during successful British assaults on the German trenches in the area.[14] The burials for the soldiers were carefully prepared. The distance between each body was roughly equal, showing that time was taken to carefully measure the locations of each. The bodies were buried with their arms placed across their chests. Two bodies show evidence of having been victims of artillery or other high explosives, with only one arm, one leg, and half a skull between the two of them. The two victims were also buried alongside two pairs of empty boots. When these soldiers died, these may have been the only recognizable body parts lefts to bury.[15]

Mass grave sites sometimes reuses preexisting trenches or artillery craters. One example would be the German mass burials at Gavrelle. It contained twelve German soldiers of the 152nd Infantry Regiment of the 48th division.[16]