I don’t know (and doubt) my response is related to the explosions. I heard the same thing yesterday while hiking around Montara mountain, so possibly it’s related to the tunnel. I do know that I saw a highway patrol and sheriff’s vehicle combing the side of Hwy 1 in Moss Beach. Seems there were some home burglaries this morning and during the chase, the chasees were tossing articles out of the car along the highway, so the authorities were looking for evidence. Now, I heard this second hand, so my facts are probably vague at best, but it helps to explain the activity.