90 



cocciN BKoYVN: TI1K BURMA EARTHQUAKES OF MAY L912. 



common. The same is true for Burma probably to a greater 



degree still. 



" Wooden houses by reason of their greater elasticity, arc 

 usually orach better adapted to withstand the wracking movement 



of an earthquake shock than arc brick ami masonry walls. The 

 intensity as inferred from a region of wooden buildings, would 

 therefore, in genera] appear to be less than that for a region ol 

 brick or masonry structures. Even among the latter, and among 

 the brick chimneys of wooden houses, which are so generally used 

 as indicators of intensity, there is a great variation in strength 

 due to the variation chiefly in the character of the mortar used 

 in their construction.'^ 1 ) 



The prevailing custom in the district towns of Burma is to 

 build houses with wooden frames, the panels of which are tilled 

 in with brick-work. This adheres to the wooden framing with 

 greater or lesser cohesion depending upon the character of the ori- 

 ginal structure and the age of the work. Now although intensity 

 inferred from damage to wooden buildings appears to be less than 

 that computed from the partial destruction of hrick structures, 

 it must not be forgotten that panels of fairly loose brick nogging. 

 especially those tilling in the frames of high parts of end or parti- 

 tion walls, do not require much shaking to bring them down. 



Another point to which the Californian Commission draws atten- 

 tion and which is of interest to us in Burma, 



Fissures in the ground deals with the question of fissures in the 

 as a measure of tnten -, , , f .1 1 • 1 , 



Bit ground, taken as a criterion ol the highest 



grade of intensity and placed in grade X of 

 the llossi-Forel scale. As a matter of fact the value of such a 

 criterion entirely depends on the circumstances under which such 

 a fissure is formed. Those which are dur to actual rupture on a 

 fault-plane are significant of the highest degree of disturbance, but 

 cracks which occur in the bottoms of alluvium-tilled valleys, or 

 near a stream, or cracks which are associated with earth or rock- 

 slides, when the slide was imminent and merely precipitated by 

 the shock, are superficial phenomena and do not actually indicate 

 so high a degree of intensity as \ on the Rossi-Fore! scale. The 



subject will lie referred to in a later paragraph in connection 



with llSSUreS caused by the Burma quake near Kvauksc. Again, 



1 The California Earthquake <>i 18th April 1906. Reportol the. state Earth- 

 quake Investigation Commission. Vol. I. Ft. I, p. 161. 



