Gum disease generally develops because of improper brushing and flossing habits, although underlying medical conditions may have a correlation to greater incidence. The bacteria that are found in the mouth as a result of these poor habits begin to affect the surrounding bone and tissues below the gumline.
Most earthquakes occur at the boundaries where the plates meet. In fact, the locations of earthquakes and the kinds of ruptures they produce help scientists define the plate boundaries. There are three types of plate boundaries: spreading zones, transform faults, and subduction zones.
Where do tsunamis happen most? A: Tsunamis occur with the most frequency in the Pacific Ocean and around Indonesia. This is because of the properties of the Pacific Rim; it has a high number of active submarine earthquake zones, which are a major factor in the occurrence of tsunamis. However, it is also possible for tsunamis to occur in other places.