What are the thunderous sounds heard worldwide?

Around the world, unexplained thunderous sounds have been heard near coastlines, over land, and even in remote areas where human activity seems unlikely to be the cause. Depending on the region you are in, you may know them by a different name. Some people even call them “fog guns,” while the Japanese often call them “uminari,” which translates to “cries from the sea.” Despite modern technological advances in tracking sounds and geological activities, aerial earthquakes continue to baffle experts. What causes these mysterious sounds, and why do they occur with such regularity in different regions?