On a lighter note, a high tech ground penetrating radar was used to scan the foundation of the Hawaii Supreme Court building where I work. The radar was used to find a hollowed out time capsule cornerstone that was set by King Kamehameha V, a Freemason, in 1872. Although accounts of the day noted the laying of the capsule, and its contents, it was unclear exactly where it was placed. But using the radar, a geologist found it in about 10 minutes, surprising everyone as to how quickly it was found. Plans are to lay a commemorative plaque to mark the location of the capsule (which will be left sealed).
As an aside, King Kamehameha V died 10 months after laying the stone capsule. He passed on his birthday at the age of 42. It is not clear as to what he died of but it may have been heart or kidney disease. He was the last direct descendant of King Kamehameha I, the first king to rule over and unite all the Hawaiian Islands.