Читать книгу A Study of Recent Earthquakes - Charles Davison - Страница 34

The limited depth of the focus is also evident from the nature of the shock. It was only within the actual meizoseismal band that the shock was subsultory or vertical throughout; at a short distance from the epicentre, the movement was both subsultory and undulatory; while near the third isoseismal, and in most of the region outside, the movement was entirely undulatory or lateral. An observer at Perrone (which lies 1–⅔ miles east of the epicentre) gives the following account of the shock:—"I was standing on my balcony (this faces Casamicciola) admiring the scene … when I felt the house rock, feeling at the same time as if something was rolling along beneath the ground. This movement was accompanied by a sound like this, Boob, boob—boob—— boob———boob———— boob. Both noise and movement seemed to come from Casamicciola. … In a few seconds, in the distance over the town arose a terrific cloud of white dust, so that I imagined the town on fire. … I felt hardly any, if any, subsultory movement, but as I leant upon the balcony rails, I was alternately pressed against them and then drawn away."

At Fontana, however, the undulatory shock was replaced by a vertical one. This was the universal experience, though one or two persons felt a slight lateral movement immediately after. At Valle (near Barano) and Piejo, both places about a mile from Fontana, the vertical component was also perceptible.