256 HOVEY— EARTHQUAKES : [April 24, 



Messina there runs a fault with thousands of feet of throw, the 

 upHft being upon the Calabrian side of the Strait. Movement ap- 

 pears to be still going on along this and other fault zones, resulting 

 in repeated earthquakes. Furthermore, the slopes into the sub- 

 marine depths on both sides of the " toe " of Italy are very steep 

 and therefore unstable. 



Toward the end of 1908 the seismic activity of the region was 

 evidently on the increase, and noteworthy shocks were felt No- 

 vember 5 and December 10, while F. A. Perret^^ reports that at 

 5 :20 A. M., December 27, just twenty-four hours before the occur- 

 rence of the great shock, the seismograph at the Messina observa- 

 tory registered an important earth movement. The observatory 

 was wrecked by the great earthquake, but the instruments had been 

 installed in its cellar and Dr. E. Oddone^" of the seismographic 

 service found them intact and the records intelligible, when he 

 reached the place January i. These records showed that the quake 

 began at 5:21 :i5 o'clock A. M., December 28, with a gentle move- 

 ment the force of which increased during ten seconds and then 

 diminished during ten seconds. After two minutes of calm came 

 the great shock, lasting 30 to 35 seconds, which was recorded by 

 seismographs all over the world. This was followed by com- 

 paratively light shocks at 5:45, 5:53 and 9:05 o'clock A. M. of 

 the same day, and by noteworthy quakes at 2:51 and 7:30 o'clock 

 P. ]M. of the following day. For several days and even weeks 

 minor shocks continued to occur. Some of these " after-shocks " 

 were strong enough to add to the damage caused by the principal 

 quake. According to Mr. Perret-^ the intensity within the mega- 

 seismic area was between the ninth and tenth degree of the Mercalli 

 scale decreasing rapidly with increasing distance from the epi- 

 centrum, and the centrum was not deeply located, being possibly 

 fifteen kilometers (9I miles) beneath the surface. 



Messina was a beautiful city stretching for miles along the 

 shore of a magnificent harbor. Lying in an advantageous position 

 on the short cut from the Eastern Mediterranean to the Tyrrhene 



^Mjn. Jour. Sci., IV., xxvn., p. 321, April, 1909. 

 ^ La Nature, XXXVII., 103, January 16, 1909. 

 ^ Loc. cit., p. 321. 



