Research Components
“Will a Cascadia earthquake cause damage where I live?”
My recent research evaluates the use of lake sediments as paleoseismic recorders of ground motion from a Cascadia earthquake. I hope my work will eventually lead to a better understanding of shaking intensity and duration throughout the Pacific Northwest, especially for inland locations where most people live. My recently published works have three components:
1) Observations of similarities in timing and frequency of event deposits from lake sediments and the marine record of Cascadia earthquakes (Morey et al., 2013 (published paper) and 2011 (conference poster)).
2) Do southern Cascadia lakes contain disturbances from Cascadia earthquakes? If so, are they different from the deposits from other types of events such as floods? What mechanisms and lake processes are involved in deposition? Recent publication: Morey et al., 2024.
3) Development of a southern Cascadia earthquake chronology using lake sediments. Recent publication: Morey and Goldfinger, 2024.
Ongoing additional research research areas include estimating ground motions at Acorn Woman Lakes, Oregon, in response to the ~M9 1700 CE Cascadia subduction earthquake and the ~M7 1873 CE Brookings crustal earthquake, investigating crustal faults using lake sediments in Cascadia, and using lake sediments to confirm the linkage between Cascadia and San Andreas fault earthquakes.
The timing and frequency of disturbances recorded in the sedimentary records from southern Oregon and northern California lakes suggest a link to Cascadia earthquakes.
Morey et al., 2013, describe disturbance event sequences from southern Cascadia lakes, and compare event timing and frequency to the marine record of Cascadia earthquakes. The locations of the sedimentary sequences used in this study are shown in Figure 1 (shown to the right). Three of the lakes, Bolan, Sanger and Acorn Woman Lakes (previously called Squaw Lakes), are located in the Klamath Mountains near the California/Oregon border.
Fig 1. Lake and marine core locations used in this study. Modified from Fig. 1 of Morey et al., 2013.
Conclusions
“The similarities between downcore magnetic susceptibility and associated radiocarbon data from both lake and marine cores over great distances and multiple depositional environments supports synchroneity and therefore earthquake triggering. Lithologic characteristics of the disturbance event deposits suggest instantaneous deposition, and include many of the features of turbidites found in the marine record with some differences based on sediment supply and setting. The presence of earthquake-triggered deposits in forearc lakes may provide important information useful for hazard assessment from the coast inland to more populated areas. In addition, the analysis of these deposits from lakes throughout Cascadia may provide insight as to subduction zone characteristics, such as rupture lengths and segmentation.”
NEW! Drafts of Morey et al., 2024 and Morey and Goldfinger, 2024, can be found below, in addition to links to posters I’ve presented at annual conferences since 2011: