Using ShakeMap to Improve Awareness of Seismic Hazard and Risk in Alaska

Abstract:

As part of the Alaska Earthquake Center’s effort to create customized and relevant products to diverse Alaskan communities, we have embarked on a process to take results from ShakeMap and tailor them to state needs. We have created customized ShakeMaps, produced shaking estimates for small communities that may not be obvious on large-scale maps, and greatly expanded a suite of earthquake scenarios throughout the state for use in hazard assessment and disaster preparation. These efforts have the combined goal helping Alaskans better prepare for the possibility of a damaging earthquake in their community. ShakeMap is a well-regarded system created by the U.S. Geological Survey (USGS) to produce maps of measured and predicted ground-motions for real and scenario earthquakes; many seismic networks throughout the world use it operationally. The Earthquake Center routinely uses ShakeMap to provide general information about recent earthquakes to stakeholders and the public. Customized ShakeMaps are produced for notable earthquakes near the Trans-Alaska Pipeline and made available to Alyeska, the pipeline operator. These ShakeMaps are part of a larger system to alert Alyeska of any strong motions that could cause damage to the pipeline infrastructure to help minimize economic and environmental issues. However, despite being the most seismically active state in the United States, limited work has been done to assess possible earthquake scenarios in much of the state and even fewer of the end products are known to residents, many of whom live in small towns and villages, isolated both in distance and in infrastructure from the rest of the population. ShakeMap scenarios are visual representations of earthquake data that have tremendous outreach value as a stand-alone product. For many of the scenarios, we have used earthquake parameters pulled from the numerous notable earthquakes in the history of the state, from the well-known (2004 M7.9 Denali Fault, 1964 M9.2 Good Friday), to the unexpected (M5.7 near the village of Noatak in 2014). Many of these earthquakes occurred before a true seismic network existed in the state, limiting what data products are available. Working with partner local, state, and federal agencies, these scenarios form the initial framework for assessing hazards and loss modeling throughout the state.