4 Technologies Gives New Life to Archaeology
Movies such as “Indiana Jones” and “Tomb Raider” may have forever imprinted on the collective psyche the idea of the archaeologist as a swashbuckling rogue adventurer. The popular image of archaeological tools may be shovels and brushes and knives and maybe even a whip, but what are archaeologists today actually using as they rediscover and interpret the past? There may be no shootouts, ancient traps, or mummies come to life, but archaeological researchers have their own high tech set of tools to ensure they can both preserve and analyze artifacts of civilizations past. From innovative forms of radar to laser mapping and space archaeology, here are the top four tools of the modern archaeological field.
Radar is a staple of archaeological research, used to make enormous discoveries and clear-up historical mysteries. Most recently, Bek’s chapel, one of England’s most important medieval buildings, was rediscovered, and radar was used to reimagine what it once looked like, aiding in reconstruction of the site’s unearthed masonry, stained glass, and black plaster floor — all of which was destroyed with gunpowder in the mid-seventeenth century. Another recent discovery? A previously undiscovered chamber in King Tut’s tomb: a possible location of the still-missing remains of Queen Nefertiti.
So how were these discoveries made? Used across a number of fields including environmental studies and civil engineering, ground-penetrating radar (GPR) is a system that performs a type of geophysical study which can scan, map, and record information about the Earth’s subsurface. The most significant benefit of this type of study, when it comes to archaeology, is that it’s entirely non-intrusive and nondestructive.
GPR employs high-frequency (usually polarized) radio waves at UHF/VHF frequencies, which are emitted into the ground. The pulses are reflected, refracted, or scattered back to the surface when encountering the differing permittivities of buried objects or boundaries between materials; a receiving antenna records the variations in the return signal. This works very similarly to seismology but employs electromagnetic energy rather than acoustic energy. As GPR can be used from above the ground, it’s excellent for use-cases like the unearthed medieval chapel, where the exact location has been lost, and where researchers may need to scan a broad area for traces.
The Maya flourished more than 1,000 years ago, and our knowledge of how exactly the civilization lived has been limited. Modern technology is uncovering information at a rapid pace, however. There is perhaps no more clear illustration of how technology has outpaced the intrepid, bushwhacking archaeological archetype: these discoveries are structures hidden by jungle greenery that scientists in the field over the last hundred years never detected, and might not have even if given another hundred.
While it does not penetrate to sub-surface layers, light detection and ranging (LiDAR) offers even broader mapping capabilities than an air-launched GPR system. In the case above, Guatemalan scientists used aircraft equipped with this high-tech mapping tool to remotely identify ruins, farms, and irrigation channels — in fact, this was the largest dataset ever recovered using LiDAR, scanning 800 square miles and uncovering thousands of unknown Maya structures.
One of the greatest strengths of LiDAR is its accuracy: the systems can pinpoint tiny surface anomalies that may indicate sunken artifacts beneath the surface. By firing rapid pulses of laser light at the Earth’s surface and measuring the time each pulse takes to bounce back, researchers can accomplish large-scale mapping and analysis used to uncover points of interest and plan archaeological digs. This tool has the capability to trigger a paradigm shift in the field and enable incredible efficiency.
GIS software turns data into knowledge and perspective.
Sending out pulses and taking measurements gets you a lot of raw data, not a map. Luckily, software solutions can turn data arrays into visual maps ready for analysis. A geographic information system (GIS) allows researchers to manage and display all types of geographic and spatial data. As a field, archaeology was an early adopter of GIS mapping, and as geospatial tools have become more powerful, the software has only allowed archaeology to evolve.
GIS is the software component to LiDAR technology that allows for efficient use of remote sensing technologies to map areas of archaeological interest, but it can also be used for predictive mapping and to provide new perspectives on well-researched sites. In predictive applications, researchers can incorporate data from multiple sources — historical maps, current landscape, and known information about past inhabitants — to predict sites that may have held cultural, historical, or agricultural relevance.
Using software tools can also shed new light on previously collected and analyzed data. To understand more of the complex Maya civilization, researchers have used GIS to aggregate known data — on which structures were built and on their selected locations — in order to analyze why choices may have been made. With a little prior knowledge and data, GIS software can be just the tool to shed new light on ancient civilizations.
Want to broaden the scope of what we can scan and map even further? Let’s get satellites involved. Space archaeology, or satellite remote sensing, stands to revolutionize archaeological techniques by searching the Earth’s surface for hints of buried features from orbit. The origins of this technique can be traced from early-twentieth-century aerial photography, used to identify features from a distance. Beyond visual imaging, it also employs multispectral and hyperspectral scanners, which obtain the electromagnetic spectrum for each pixel in an image, thermal infrared multispectral scanners (TIMS), microwave radar, and color infrared film.
Currently, resolution for satellite imagery is capped at approximately one foot, but resolutions down to one centimeter are in development. To aggregate data in an easily parsed image, scientists often assign “false color” to different types of features. Scanning methods such as LiDAR and radar are currently employed in satellite mapping, and there are only more developments to come.