Thesis Defences

Brandon Nasr

Thesis Defence for the degree of Master of Science in Earth Sciences

Date: Friday, September 11, 2026
Time: 10:00 AM - 1:00 PM
Location: WAC 2020, Library Thesis Defence Room, SFU Burnaby

Zoom link: https://sfu.zoom.us/j/89042347354?pwd=yGNF6kFlseRIINtJZ6vbCMudjtf1dG.1 

Title: "High-resolution sedimentary archives of Western North Pacific tropical cyclone activity over the past six centuries and their linkages to climate change"

Examining Committee

Senior Supervisor: Dr. Jessica Pilarczyk, Associate Professor (School of Environmental Science)
Committee Member: Dr. Davin Wallace, Adjunct Professor (Department of Earth Sciences) and Professor (University of Southern Mississippi Ocean Science & Engineering)
Examiner: Mr. Dave Huntley, Geological Survey of Canada
Chair: Dr. Gwenn Flowers, Professor (Department of Earth Sciences)

Abstract: Western North Pacific tropical cyclones (TCs) are among the world's most destructive natural hazards, yet instrumental observations are too short to resolve whether recent increases in the most intense storms exceed natural climate variability. This MSc thesis reconstructs 630 years of intense TC activity from submerged reef hole sediments offshore Bohol, central Philippines, within one of the most active typhoon regions on Earth. The thesis uses an innovative combination of high-resolution grain size and geochemical analyses, integrated with Bayesian age-depth models that are constrained by 210Pb and radiocarbon dating, to identify storm deposits using an objective statistical framework calibrated to the sedimentary signature of Super Typhoon Haiyan (Category 5+). The TC reconstruction reveals pronounced centennial-scale variability, with elevated activity during parts of the Little Ice Age, reduced activity through much of the nineteenth and early twentieth centuries, and an unprecedented increase during the Current Warm Period. Four Typhoon Haiyan-scale TCs affected the region during the past 50 years, whereas no earlier 50-year interval contains more than two comparable events. Comparison with published paleotempestology records from across the western North Pacific indicates that centennial-scale TC activity was spatially heterogeneous, consistent with shifts in TC tracks driven by El Niño–Southern Oscillation and Intertropical Convergence Zone migration. Coupled with sea-surface temperature reconstructions from the same field site, results of the TC reconstruction suggest that atmospheric circulation determines where extreme TCs occur, whereas warming of the western Pacific warm pool amplifies their occurrence where storm tracks are already focused, providing long-term context for increasing typhoon hazard in the central Philippines.

For more information on this thesis defence, please contact the Graduate Program Assistant in the Department of Earth Sciences at easc_grad_secretary@sfu.ca.