Hey guize,
There are two areas on Pedo Island that seemed spoopy early on when we were digging: the temple and the area near the center of the island that has variously been some sort of ceremonial space, tennis courts, open concrete area with a berm around it.
It never occurred to me until today that the dirt for that berm must have come from somewhere on the island. We only recently started suspecting lower levels underneath the temple building. That type of excavation would result in earth that would need to go somewhere. The timing is about right because both were built between 2009 and 2013 (no other air photos available on Google Earth).
Berm dimensions = 525 feet length (circumference) by approx 30 feet wide. Approx triangular profile, so divide width by half (15 feet). Angle of berm slope = approx 45 degrees, so height would be roughly 15 feet. Total fill required = 525 x 30 x 0.5 x 15 = ~118,000 cu.ft.
The question is how wide the excavated area under the temple is. There is the actual building, a smaller forecourt, and a larger paved area. The overall paved area is around 5,550 sq.ft. To get 118,000 cu.ft. out of that, you would excavate around 21 feet. Maybe the footprint of the excavation is smaller and they went down deeper.
Maybe the numbers are off because I am guessing at a few things (exact cross-section of the berm, area of excavation under temple). But regardless, I am coming to the realization that the excavation for the temple was what provided the fill to create the berm around the ceremonial area.