Every year there are seismic disturbances, and though Santiago is the point of most frequent visitation, they occur in all parts of the island, in 1880 affecting the entire western end.
Apparent proof has been obtained that the shocks occurring in the Pacific districts originate at the bottom of the sea the Tuscarora Deep is supposed to be the centre of seismic activity and they are accompanied in most cases by tidal waves.
Notable seismic disturbances in Cuba have coincided with similar activity in Central America so often as to make some connexion apparent.
Professor Suess, to whom the above description is due, finds that the Mediterranean forms no exception to the rule in affording no evidence of elevation or depression within historic times; but it is noteworthy that its present basin is remarkable in Europe for its volcanic and seismic activity.
All this country was comprised in classical times under the title of the Phlegrean Fields, and was certainly then more actively volcanic than it now is, although the severe shock of earthquake which occurred in the island of Ischia in 1883 completely destroyed Casamicciola, and did serious damage to Forio, Lacco Ameno and Serrara Fontana, shows that there is great seismic activity in the locality.
In depths beyond the reach of wave motion, and apart from suspension across a submarine gully, which will sooner or later result in a rupture of the cable, the most frequent cause of interruption is seismic or other shifting of the ocean bed, while in shallower waters and near the shore the dragging of anchors or 40 fishing trawls has been mostly responsible.
If the calculation be carried farther backas has been done by the seismic disaster investigation committee of Japan, a body of scientists constantly engaged in studying these phenomena under government auspices,it is found that, since the countrys history began to be written in the 8th century AD,, there have been 2006 major disturbances; but inasmuch as 1489 of these occurred before the beginning of the Tokugawa administration (early in the 17th century, and therefore in an era when methods of recording were comparatively defective), exact details are naturally lacking.
The earthquake occurred early in the morning of December 28, and so far as Messina was concerned the damage was done chiefly by the shock and by the fires which broke out afterwards; the seismic wave which followed was comparatively innocuous.