i9°9-] THEIR CAUSES AND EFFECTS. 255 



the ground waters enter the harbor left caverns into which the 

 overlying material was shaken by the quake (Brown). No sea 

 wave of importance accompanied or followed the shock. 



(A series of lantern slides was used to show the destruction 

 caused in the city, the sinking of Port Royal point and the faulting, 

 fissuring and formation of craterlets along the PaHsadoes.) 



The Messina-Reggio Earthquake. 



Time after time during the historic period Italy has suflfered 

 from the effects of serious earthquakes, but never before so severely 

 as from that which occurred in Calabria and Sicily on December 

 28. 1908, when 200,000 human beings are supposed to have lost 

 their lives. The cities of Messina in Sicily and Reggio in Calabria 

 were completely wrecked, and many other villages and towns were 

 laid in ruins or damaged throughout an irregularly elliptical district 

 85 miles long by 50 miles wide, extending from Pizzo, Calabria, 

 on the northeast to Riposto, Sicily, at the sea base of Mt. Etna, on 

 the southwest. The epi focal area was the Strait of Messina, with 

 the epicentrum at or near the northern end of the Strait. More 

 precisely, the longer axis of the ellipse of greatest destruction 

 (from Ali to Palmi, about 35 miles), as shown by isoseismals, lies 

 in the strait and runs N.N.E.-S.S.W. 



Calabria and northeastern Sicily form a district of extreme 

 seismicity that has been visited by several disastrous earthquakes, 

 among which those of 1783, 1785 and 1905 stand out with prom- 

 inence on account of their destructiveness to human life and prop- 

 erty. Volcanic quakes have been associated with eruptions of Mt. 

 Etna, but they have been strictly local in effect, and their influence 

 has not been seriously felt across the Strait. All the severe shocks 

 have originated in Calabria or under the Strait of Messina are of 

 tectonic character, the geological structure being particularly favor- 

 able to the production of such quakes. Forming the backbone of 

 Calabria and extending beyond Messina in Sicily there is an 

 elongated area of Archean gneisses and mica schists. Along this 

 axis there occur nearly horizontal beds of Miocene age up to an 

 altitude of 3,300 feet above the sea, while along the Strait of 



