yoo 



1220 



Contour interval in meters-, 



heavier numerals are water 



heights in centimeters 



Figure 51. Tsunami runup at Hongo in Toni, Japan (after Nasu, 1934), 



runup was equal to (or sometimes less than) the height of the wave at 

 the shoreline. 



Tsunamis at a shoreline could be categorized into three types of 

 waves: nonbreaking waves (i.e., a tsunami which acts as a rapidly rising 

 tide); waves which break far from the shoreline and become fully developed 

 bores before reaching the shoreline; and waves which break near the shore- 

 line and act as partially developed bores which are not uniform in height. 

 In addition, there are some cases where reflected waves become bores after 

 reflecting from a shoreline. 



For the nonbreaking wave, the assumption that the runup height equals 

 the wave height at the shoreline may be reasonable and possibly even con- 

 servative. Field observations (e.g., Nasu, 1934) indicate that the runup 



151 



