Application of Geophysical Methods for mapping the buried archaeological heritage from the 13th Century in Aceh Sultanate of Lamuri, Indonesia

Abstract

Kuta Lubok is one of the archaeological heritage sites of the Lamuri Sultanate in Aceh, dating back to the 13th century. The site has experienced significant damage over time, primarily due to the Indian Ocean tsunami and natural erosion, which has led to the partial destruction and burial of structural remains. To support preservation and reconstruction efforts, a non-destructive geophysical approach was deemed necessary to locate and map the buried features of this historical site. Geophysical methods, including magnetic, VLF-EM, and EM induction techniques, were applied to investigate the subsurface conditions and identify the distribution of archaeological remains. A total of 22 survey profiles, each ranging from 60 to 80 meters in length, were conducted across the fort and adjacent areas of archaeological interest. Fraser’s analysis of VLF-EM data revealed the distribution of archaeological traces, with high tilt values on the west side indicating the location of the Kuta Lubok fort. Measurements between 80 and 400 meters suggest the presence of a road leading to the fort. VLF-EM data also show that archaeological remains are buried at depths between 0 and 5 meters, a range consistent with the Euler Decomposition results obtained from magnetic data collected along the same profiles. In the form of apparent conductivity, EM induction data identified the fort’s distribution, albeit with lower resolution. Magnetic susceptibility data from EM induction confirmed similar findings. The excavation results in the fort area have found several archaeological objects such as pottery, stoneware, ceramics, charcoal, and bones, indicating that the Kuta Lubok building was once a community settlement area. This research demonstrates the value of integrating multiple geophysical methods to enhance archaeological investigations and preservation planning in coastal heritage sites. Overall, the combined geophysical and archaeological analysis suggests that the Kuta Lubok fort extends approximately 400 meters eastward, parallel to the coastline, from the remaining visible structure.