Some residents of Silver Spring Township in southcentral PA began to experience booming noises days after heavy rain deluged the area in September 2021. Township officials consulted geological experts who concluded that the sounds originated underground but were not related to earthquakes. Instead, the karst system was actively moving the water and debris in the subsurface.
A representative of the PA Geological Survey said: “That’s probably the root of these strange sounds we’re having, water moving through this conduit system, washing some soil around, moving some things, possibly something like water hammering like in your pipes, possibly a rock somewhere down in this maze falling down and shaking things a little bit.”
Other local karst areas had similar sounds in the past related to heavy rainfall in a short span.
Source: The Sentinel.