TIDAL DATUM PLANES 
Jan. .Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. 
Ketchikan, 1930-48 
Sitka, 1938-48 
Juneau, 1936-40; 1944-48 
Skagway, 1944-47 
Yakutat, 1940-48 
Adak, 1943-48 
Fic. 29.—Annual variation in sea level, Alaska. 
949995—51—_5 
