woodworth: geological expeditiox to brazil and chile. 37 



great disaster which had but four months previous led to the destruc- 

 tion of San Francisco, has received such scant attention in North 

 American scientific journals that the following notes taken largely 

 from local accounts and the paper of Dr. H. Steffen of the University 

 at Santiago are deemed worthy of record. 



In Valparaiso the immediate loss of life was estimated at 3,000 

 persons and the wounded at 20,000, some of whom subsequently died 

 in consequence of their injuries. Several hundreds of lives were 

 lost in surrounding towns and villages. (Rozas y Cruzat, 1906.) 



Owing to the lack of seismographs in Chile in 1906, the exact time 

 of the earthquake is a matter of some uncertainty. At Santiago where 

 there is an astronomical observatory the first sensible shock appears 

 to have taken place 7h. o8m. 36s. P. M., August 16th, local time. 

 Taking the longitude of Santiago as 4h. 42m. 46.4s. west from Green- 

 wich, the initial shock was felt there at Oh. 41m. 22s. Greenwich 

 mean time, midnight to midnight, August 17th. At \'alparaiso 

 whose time is 3m. 50s. later, the first shock is placed at 7h. oom and at 

 7h. 56s. by several different time-keepers. The mean of the times 

 at Valparaiso, 7h. 55m. 30s. makes the apparent time of the first 

 shock at Valparaiso 44 sees, earlier than that at Santiago. The 

 earthquake from various studies appears to have originated in a 

 fault plane off Coquimbo about 228 miles north of Valparaiso. The 

 seismographic indications as to the time of origin point to Oh. 40 m. 

 as the probable moment of the primal great shock. 



From the varied estimates of observers, it appears that in the 

 central tract along the coast extending north and south of \'alparaiso 

 between the parallels of 28° and 39° S. L. there were two series of 

 shocks separated by an inter\al of relative quiet. The first strong 

 shock of exceptional duration, lasted from four to five min., while 

 the second equal to or perhaps stronger than the first one had a dura- 

 tion of 1 min. or less. Outside of the epicentral region but one 

 continuous series of shocks seems to have been noticed. (Steft'en, 

 1907, p. 23). A vertical movement was distinctly recognized at 

 isolated points between 38° and 36° S. L. with greater distinctness and 

 precision on the north as far as the river Mante. IMost observers 

 judged the primal movement to be upward. Dr. Steffen obtained 

 testimony to the effect that heavy objects in Illapel, Santiago, Talca, 

 etc., within the central tract were thrown upward to a certain height 

 above the base on which they stood, contradicting as he notes the 

 statement of Dutton (1904, p. 148) that there never has been observed 

 an acceleration sufficient to overcome the force of gravity. It may 



