New low frequency rumble in the Turnpike Lane area

There seems to be a new low frequency rumble in the Turnpike Lane area.

It has been present for the last week or maybe two. It also seems to be fairly constant, day and night but more noticeable during nighttime. It does sometimes stop for a while. Perhaps there are some local works taking place in the area but I haven’t seen anything in the immediate area.

Does anyone have an idea of what the cause is?