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Show 424 EARTHQUAKE IN CALABRIA, A.D. 1783. boundary cliffs were in great part vertical, it will readily be conceived that, amidst the various movements of the earth, the precipices overhat1ging the rivers, being with?ut support o~ one side, were often thrown down. We find, mdeed, that mun. dations produced by obstructions in river-courses are among the most disastrous consequences of great earthquakes in all parts of the world; for the alluvial plains in the bottoms of valleys are usually the most fertile and well peopled parts of the whole country, and whether the site of a town is above or below a temporary barrier in the channel of a river, it is exposed to injury by the waters either of a la~e or a flood. From each side of the deep valley or ravme of Terranuova, enormous masses of the adjoining flat country were detached and cast down into the course of the river, so as to give rise to great lakes. Oaks, olive-trees, vineyard~, and .corn! .were often seen ()'rowing at the bottom of the ravme, as httle InJUred as their c~mpanions from which they were separated in the plain above at least five hundred feet higher, and at the dis· tance of about three-quarters of a mile." In one par~ of this ravine was an enormous mass, two hundred feet lugh, and about four hundred feet in diameter at its basis, which had been detached by some former earthquak~. It is well atte~ted that this mass travelled down the ravme near four mtles, having been put in motion by th~ ~art?quake of. the 5th of February. Hamilton, after exammmg the locahty, decl~~ed that this phenomenon might be accounted for by the dechvtty of the valley, the great abundance of rain which fell, a?d t?e great weight of the alluvial matter which pressed behmd 1t. The momentum of the " terre movitine," or lavas, as the flowing mud is called in the country, is n? doubt very great; but the transportation of masses that m1ght ~e co~pared to small hills, for a distance of several miles at a bme, IS an effect which could never have been anticipated: and the fact sho~ld serve as a hint to those geologists who arc fon~ of .appeahn~ to alluvial phenomena as proofs of the superiOr vwlence 0 aqueous causes in former ages. . The first account sent to Naples of the two great shdes or lands1ips above alluded to, which caused a great lake n~ar Terranuova, was couc1 1 e d m. t 11 ese wor d s .. -" 'l'wo .m oun.t a.m asl on the opposite sides of a valley walked from their orJgm LANDSLlP OF FnA ROMOND, NEAR SORIANO. 425 .p o.s i.t ion untilh t hey met in the middle of the plain , and the t·e JOmmg toge~ er, they intercepted the course of a river, &c." The expressions here used resemble singularly those applied to phenomena, proba?ly very analogous, which are said to have ?ccurre~ at Fez, durmg the gt·eat Lisbon earthquake, as also m JamaiCa and Java at other periods. Not far from Soriano, which was levelled to the ground b the great shock of February the 5th a small valley cont · · y a beaut!' f.u 1 ol 't ve-grove, called Fra Ra' mondo, underw' ent aa mmmosgt extraordmary revolution. Innumerable fissures first traversed the riv:r-plain in all directions, and absorbed the water until the.argillaceous substratum became soaked, and a great part of It was reduced to a state of fluid paste. Strange alterati~ ns in the outline of the ground were the consequence, as the s01l.t? a great. depth was easily moulded into any form. In additiOn ~o. tlus ~hange, the ruins of the neighbouring hills were prec1p1tated mto the hollow; and while many olives were Cilang11 oj' the •urface at Fra J!amondo, ntar Soriano, in Calabria. 1. Portion of a hill covered with olives thrown down. 2. New bed of the river Caridi, 3. Town of Soriano. .u prro oted, others remained growinO' on the faJlen masses and o ' Inc ~n~d at various angles (see cut No. ~6). The small river Car1d1 .was enti1·ely concealed for many days; and when at length It reappeared, it had shaped for itself an entirely new channel. |
