1 Inflammation of the gingiva, bone loss, and increased gingival recession may progress slower than with other forms of periodontitis.  Periodontitis Associated with Systemic Diseases - Systemic diseases, such as heart disease, diabetes, and certain forms of arthritis, may have a correlation with periodontitis.
Main Content. An earthquake is ground shaking caused by a sudden movement of rock in the earthâs crust. Such movements occur along faults, which are thin zones of crushed rock separating blocks of crust.
The common points where the plates touch one another is where the earthquake starts or the focus. As seen in the picture above, subduction zones are on the borders of each tectonic plate. As they crash together one plate moves below the other which causes subduction zone earthquakes. Earthquakes are one of the biggest natural disasters known to man. Earthquakes occur when there is a sudden release of energy below the earths crust at the focus.