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.
But earthquakes happen not only where plates collide. They also occur where two plates move away from each other in the so called spreading zones.. One of these zones is the Mid-Atlantic Ridge where Europe moves away from North America at the rate of about one inch per year.