Universiteit Gent

Project Title: the Eroding Iceberg Lake Sediment: a Short-lived Opportunity to Obtain a Paleoseismic Record From the Eastern Edge of the Alaska Subduction Zoneproject Period: 3/1/2022 - 2/28/2023GEOLOGICAL Records of Past Earthquakes Are of Key Importance for Seismic Hazard Assessments. on and Around the Yakutat Terrance Such Paleoseismic Records Are Scarce. Currently, Only Coastal Records Exist Which Preserve Evidence of Land-level Change From Megathrust Earthquakes Such as the 1964 MW 9.2 Prince William Sound Earthquake. Lakes Have Proven to Provide Valuable Archives of Earthquake Shaking by Recording Different Types of Deposits Triggered by Earthquakes. Such Deposits Have Allowed to Estimate the Strength and Characteristics of Seismic Skahing. and by Providing Combining Such Results With So-call Ground-motion Prediction Equations (gmpes), It Is Sometimes Even Possible to Attribute Specific Seismic Sources and Fault Segments to Prehistoric Earthquakes. Here, We Study Iceberg Lake, Which Offers a Unique Opportunity to Obtain Paleoseismic Record for the Eastern Edge of the Alaskan-aleutian Subduction Zone Encompassing the Last 1500 Years. We Will First Examine Existing Datasets and Cores From Fieldwork Executed Between 2001 and 2003. Next We Plan Fieldwork to Iceberg Lake to Investigate Additional Outcrops Which Will Be Proceeded by Creating a High-resolution Digitil Terrane Model to Guide the Fieldwork Efforts. We Will Then Combine Detailed Sedimentological Descriptions, Photos, X-ray Computed Tomography (CT) Scans, Grain-size Data and Other Physical Parameters to Identify and Interpret Earthquakeinduced Deposits. We Date These Event Deposits by Counting Annual Laminations in the Sediments. Finally, We Will Merge All Gathered Data and Construct a Paleoseismic Record of Iceberg Lake.lastly, We Will Aslo Collect Shear-wave Velocity (VS) Profiles From Both Clayer and Sandy Sediments. These Will Be Used to Model How These Sediments Will React to Different Types of Earthquake Shaking. Using This Ground-motion Modelling, We Aim to Turn the Iceberg Lake Paleoseismic Record Into an Exceptionally Qualitative and Quantitative Record Which Will Refine Local Seismic Hazard Assessment and Push the Boundaries of Lake Paleoseismology. Local Communities and International Lake Paleoseismic Communities Will Benefit From the Results of This Project.