Inferred effects from future earthquakes^-Continued Ground shaking Continued Geologic units in category 1 (strongest expectable shaking)-^Continued Embankment fill (Qfe) overlying alluvial deposits (Qa) and modern delta deposits of the intertidal zone (Qi) Volcanic ash deposits (Qv) Geologic units in category 2 (intermediate expectable shaking) Modern beach deposits (Qb) Embankment fill (Qfe) overlying modern beach deposits (Qb), elevated shore and delta deposits (Qeb), and glacial drift deposits (Qd) Elevated shore and delta deposits (Qeb) Modified ground (Qfm) Geologic units in category 3 (least expectable shaking)-Glacial drift deposits (Qd) Bedrock of Sitka Group (KJs) Compaction Liquefaction Reaction of sensitive and quick clays Water-sediment ejection and associated subsidence and ground fracturing Earthquake-induced subaerial landslides-Earthquake-induced subaqueous landslides 70 Effects on glaciers and related features Effects on ground water and streamflow Tsunamis, seiches, and other earthquake-induced water waves Inferred future effects from geological hazards other than earthquakes Subaerial and subaqueous landslides Stream floods 78 High water waves Volcanic activity Recommendations for additional studies 82 Glossary 84 References cited 87 Appendix I Preliminary examination of volcanic ash and lapilli samples from near Sitka, Alaska 103 Recommended future geologic studies in the Sitka area could provide additional information needed for land-use planning. Detailed geologic mapping and collection of data on geologic materials, joints, faults, and stability of slopes are strongly recommended. Extensive offshore marine geophysical studies are needed to determine the position of nearby branches of the Fairweather fault; sensitive seismometers are needed to detect very small earthquakes in order to obtain an indication of activity along the fault branches. Naturally occurring volcanic ash apparently will not liquefy during earthquakes, but the ability of excavated ash to liquefy within a range of vibrational conditions suggests the need for further study. The program of volcanic surveillance being conducted on selected volcanoes elsewhere in Alaska should be expanded to include the volcanoes on Kruzof Island. Determination of the natural periods of oscillation of large lakes, fiords, bays, and sounds would assist in the prediction of heights of water waves caused by earthquake ground shaking. correspondence with Federal, State, and city-borough officials, private citizens, and personnel of engineering and construction companies that have worked at Sitka. Especially acknowledged is the help of Fermin (Rocky) Gutierrez, Administrator of the City and Borough of Sitka, and