tuning appears to be such that they could develop appreciable amplitude 

 and persistence, nevertheless. 



Because of its nearness to the epicenter of the earthquake (near 

 Unakwik Inlet), Prince William Sound experienced more violent shaking 

 than most other places. Slides were numerous, and locally generated 

 effects were complex. From eyewitnesses' accounts about tsunamis in 

 the Prince William Sound area, it is difficult to obtain an integrated 

 concept of the wave sequences. 



Many places like Chenega, Sawmill Bay, and Thumb Bay (Figure 157) 

 were struck by high waves during the earthquake. These first waves were 

 seemingly of short period with the character of being locally generated 

 like the first slide-generated waves that struck Seward, Valdez, and 

 Whittier. However, there is no evidence of visible slides that could 

 have generated these waves. Glacial deposits such as those in which 

 the wave-generating slides took place at Seward, Valdez and Whittier 

 are apparently almost absent in the western and northern part of Prince 

 William Sound. However, such deposits probably occur locally under water 

 because depressed cirque levels in these areas indicate that shore lines 

 have been drowned since the last major glaciation (Plafker, 1965; von 

 Huene, et al, 196?) , and indeed a substantial invisible submarine slide 

 north of Latouche Island (Figure 157) has been reported by the U. S. 

 Coast & Geodetic Survey ship Surveyor (Coast & Geodetic Survey, 1965). 

 This slide probably generated the first waves that hit Port Ashton and 

 Thumb Bay. Other causes of local waves of uncertain origin may have been 

 local submarine faulting, and seiches generated by ground vibration. 



Figure I58 shows a generalized distribution in the Sound of larger 

 destructive local waves and known subaqueous slides as found by U. S. 

 Geological Survey (Plafker and Mayo, I965). Because available informa- 

 tion about possible wave origins at present is too scanty to justify 

 further speculation, only a description of the waves and the known damage 

 at the larger villages and Inhabited places, as reported by eyewitnesses, 

 will be included here. Reference to the location of these places may be 

 found in Figures 1 and 157- Valdez and Whittier will be discussed more 

 fully in later sections. An attempt has been made to infer marigrams 

 for some of the places; these are shown collectively in Figure 159- 



Chenega, on Chenega Island in Knight Island Passage, was one of 

 the places hit hardest. All houses were floated away and totally lost. 

 Twenty-five people were drowned. 



About 60 to 90 seconds after the earthquake started the first wave 

 came in like a fast-rising tide and reached half way up the beach. Some 

 people were drowned by this wave. As the water receded one minute later 

 to about 500 feet from the shore, it swept away some of the houses. A 

 second wave, arriving with a roar, struck the village about four minutes 

 after the quake started. This wave swept away all the remaining houses. 



248 



