Almost everyone in the world knows of the TerraCotta warriors. Legendary soldiers meant to guard the tomb of China’s first emperor, Qin Shi Huang. These statues were first discovered in march of 1974 by peasants digging a well, and were later explored and excavated by archaeologists. What many people dont know is that the pits housing the warriors are but one small portion of a much larger necropolis, a tomb city built to be the final resting place of the man who first unified the warring states of China. 

     Located in a massive burial mound near the city of Xi’an China, the vast tomb covers over 20 square miles. It contains an inner city, an outer wall, and miles of various structures built around it. The pits from where the terraCotta warriors were recovered are just one of these structures. They were built to the east of the tomb, to defend it from enemies. Despite the vast wealth of knowledge uncovered from these outer relics, the tomb proper has yet to be fully excavated or explored, due to concerns for the safety of the artifacts still lying within. When the terracotta warriors were first uncovered, a lack of proper conservation techniques combined with the dry air of Xi’an led to rapid damage to the colorfully painted coatings the statues once had. The Chinese government has stated that it will not open up the rest of the mausoleum to excavation until it can be guaranteed that similar damage will not occur to the rest of the tomb. Despite this reluctance, a number of novel archaeology techniques have allowed Chinese historians to gain some level of understanding of what lies inside. For example, analysis of the soil around the tomb has managed to back up the claims of ancient Chinese historian Sima Qian in regards to the massive amount of mercury used within the tomb.

     In ancient China, the element mercury was believed to be an elixir of life. It is even theorized that the death of the first emperor was due to consumption of mercury in the hopes of prolonging his life. As such, mercury played a major role within his tomb complex. According to historical records from Sima Qian written approximately 80 years after his death, the tomb contained massive rivers and lakes of mercury in a facsimile of major Chinese bodies of water at the time. This was backed up by Chinese scientists Guangyu Zhao, Weixing Zhang, Zheng Duan, Ming Lian, Ningbin Hou, Yiyun Li, Shiming Zhu & Sune Svanberg in 2020. The scientists used laser radar scanning of mercury emissions in the soil to determine approximately the amount of mercury lost in the form of vapor over the years. “We obtain a total loss of mercury to air of the order of 1 ton of liquid mercury.” (Zhao et. al 2020). This helps back up the ancient historical claims about the massive amount of the element contained within the tomb.

     Another new method being discussed to increase our understanding of the tomb lies in utilizing cosmic rays. When cosmic rays impact earth’s atmosphere, they break down into smaller subatomic particles known as muons. Similarly to x-rays, muons pass through objects, however they pass through heavier objects like stone and metal slower than dirt or air. Yuanyuan Liu, a scientist working at Beijing Tsinghua university was the one to propose the idea of using these cosmic particles to study the emperor’s tomb. By placing muon detectors underneath the tomb complex, a kind of x-ray can be taken of the inner caverns. While this idea is still theoretical, it shows promise as a non harmful way of seeing the inside of this magnificent construction. The tomb necropolis of Qin Shi Huang is a treasure trove of archaeological and historical knowledge waiting to be uncovered. While many traditional methods of excavation are unusable due to concerns over damage, this provides a wonderful opportunity for new and innovative methods of survey to be used.

Further reading

https://www.scmp.com/news/china/science/article/3159821/china-mulls-planting-cosmic-ray-detectors-tomb-qin-shi-huang

https://www.nature.com/articles/s41598-020-67305-x

References

Zhao, G., Zhang, W., Duan, Z., Lian, M., Hou, N., Li, Y., Zhu, S., & Svanberg, S. (2020, June 26). Mercury as a geophysical tracer gas – emissions from the emperor Qin tomb in xi´an studied by Laser Radar. Nature News. Retrieved September 23, 2022, from https://www.nature.com/articles/s41598-020-67305-x 

Chen, S. (2021, December 30). Could cosmic rays unlock the secret tomb guarded by China’s Terracotta Army? South China Morning Post. Retrieved September 23, 2022, from https://www.scmp.com/news/china/science/article/3159821/china-mulls-planting-cosmic-ray-detectors-tomb-qin-shi-huang 

Encyclopædia Britannica, inc. (n.d.). Qin Tomb. Encyclopædia Britannica. Retrieved September 23, 2022, from https://www.britannica.com/place/Qin-tomb