THE GREAT ALASKA INVENTORY: GROUND FAILURE TRIGGERED BY THE 1964 GREAT ALASKA EARTHQUAKE

The M9.2 1964 Great Alaska earthquake is the second largest earthquake on record and involved nearly five minutes of shaking which generated extensive deep and shallow landsliding and widespread liquefaction. This significant event prompted a large number of studies, but due to its vintage, these publications have remained in the archives. This study pulls ground failure observations from dozens of publications and merges them into a single digital inventory with improved attribute fields. This new consolidated inventory contributes to the existing USGS-hosted earthquake-triggered ground failure inventory repository. Digital earthquake-triggered ground failure inventories for specific key earthquakes are needed to improve regional ground failure models. Such models are needed to calculate hazards and impacts from earthquakes in near real-time, to create scenario planning exercises, and for long-term mitigation strategies.

Ground failure observations have become more accurate and detailed with the advancement of technology; yet observations of earthquake-triggered ground failure have been documented for many decades. Data from consequential historic events like the Great Alaska earthquake are not only very valuable for understanding the extent of historic effects, but also for simulating the effects of potential analogous modern-day events.

There are complications to digitizing these historical data that we discuss, including large location uncertainties and inconsistency in data quality. Historical topographic maps and records were useful in confronting these challenges, and we added attribute fields to delineate different kinds of data as well as their accuracy. This study consolidates previously unavailable ground failure data into a digital inventory and presents new attribute fields for use in future inventories, both historical and modern, to improve comparability and ease use in future work.