That would make them safe until the next earthquake, which is probably a lot better than "until the coming summer" but you never know. Digging is expensive tho

That would make them safe until the next earthquake, which is probably a lot better than "until the coming summer" but you never know. Digging is expensive though. At home a similar problem is solved by having someone walk along the cables every few months, clearing undergrowth and felling trees as necessary. Also expensive, but the electricity network is reliable (and and as a side effect, so is the supply of Christmas trees).