A 2012 test excavation and archaeoastronomical analysis at one of the most notable sites — the roughly 40-meter-square walled structure pictured below — concluded that the site was likely associated with the annual Makahiki harvest season.
Read about those findings in this article published in 2015 by the Journal of the Polynesian Society.
Then, in February 2014, Dr. Scott Byram performed a Ground Penetrating Radar (GPR) survey with assistance from Dr. Timothy Gill and Andrea Gill. Scott Bryam and Timothy Gill are affiliated with the University of California, Berkeley Archaeological Research Facility.
The equipment, which resembles a small sled, was towed by hand across the interior of the Pa stone enclosure in measured transects.
Geophysical radar data are generated with GPR by sending pulses of radar energy into the ground at specific time intervals. The energy reflected off buried objects, features or strata is detected as the waves return to a receiving antenna. The GPR mapping appeared to show buried stone concentrations, but subsequent excavation in 2017 did not find any structures or features of interest.
Another test excavation in February 2018 obtained additional charcoal for dating from the walled structure and a nearby site featuring an alignment of standing stones. Read about the findings in this article published in 2019 in the Journal of Pacific Archaeology.
In January 2020, a team of archaeologists associated with the University of California, Berkeley completed additional excavations, removing soil samples for micromorphology analysis. Lab work was delayed by the COVID-19 pandemic but is underway as of early 2021.
An example of a GPR image from the survey.
Dr. Scott Byram, assisted by Dr. Timothy Gill, gather GPR data at the Pa archaeological site.
Pre-contact walled structure.
Dr. Pat Kirch recording archaeological features.
Dr. Pat Kirch utilizing a plane table to map archaeological sites.
Dr. Pat Kirch inspecting soil removed from a test pit.
Dr. Timothy Gill supervising the location of test pits.
Student researchers examining soil in an excavated test pit.