Yes...I was the one noodling around on LSJI a while back and pointed out how friggin’ weird that tennis court was due to what the elevation tool on GE was saying, and also how the court lines were bent visually signaling NOT FLAT.
A few here discounted what I was seeing. OK, but GE has always been dead nuts elevation-wise for known points back in my most lovely home state of Ohio. The ruler tool as well.
You have squarely hit the local fair bell ringer thingy: that tennis court is on a spoil pile...the spoil coming from UG excavation. That digging would generate a LOT of material, and on a 70-acre island there are not many options to scatter it around as to be unseen. The spoil pile thought I had not considered. Well done.
I will look again for a Gradall profile. Am quite familiar with them.
QOVFEFE™
Godspeed, find other islands in proximity that would need same tech to work the empty magma chambers.
OMG. Gradall profile. On weather SAT sites, there have been inexplicable brightish blue areas around coastlines and white effluvia washes. It’s tunneling artifacts.