The after-shocks in 1883 were much more numerous than in 1881.
Method of representing the Distribution of After-shocks in Space.
It is difficult to form any estimate of the total number of after-shocks.
Even in those which visit this country, after-shocks are seldom absent.
The most important of all these after-shocks was one felt about an hour after the principal earthquake.
From this time, after-shocks occurred almost daily until the end of May, after which they became much less frequent.
The small shocks which follow an initial large disturbance are known as after-shocks.
The decreasing frequency with which after-shocks occur may be represented by a curve.
To the energy by which this result was accomplished, we owe our most valuable registers of the after-shocks of a great earthquake.
It is evident, from Figs. 54-57, that a similar law governs the area within which the after-shocks originated.