GPS, Tectonic Geodesy

Constraints on the Slip Distribution of the 1938 MW 8.3 Alaska Peninsula Earthquake From Tsunami Modeling

“…The potential for future earthquakes can be assessed if we know the history of slip in past earthquakes and the distribution of slip deficit , where the slip deficit is the difference between the plate motion rate (and thus long‐term slip rate) and the short‐term slip rate of aseismic creep. To first‐order, slip that does not occur steadily by aseismic creep or as part of transient slow slip events is likely to occur at a later time as coseismic slip in an earthquake (e.g., J. T. Freymueller et al., 2008; Freymueller, 2020; Savage, 1983). The megathrust along the Alaska Peninsula was the location of a 1938 M W 8.2–8.3 earthquake (Figure 1), and shows strong along‐strike variations in slip deficit (Drooff and Freymueller, 2021; Fournier & Freymueller, 2007; Li & Freymueller, 2018), including the Shumagin seismic gap (Davies et al., 1981; McCann et al., 1979).…”