Physical Sciences and Mathematics Commons^™

Testing Potential Triggering Mechanisms Of Long-Runout Catastrophic Rock Avalanches In The Nooksack River Basin, Whatcom County, Washington, Eric R. Brown

WWU Graduate School Collection

The Nooksack basin contains five large Holocene long-runout rock avalanche deposits. Similarities and spatial proximity of the deposits suggest that they may share a common triggering mechanism. Two of the deposits, Van Zandt Landslide Complex (VZLC) and Church Mountain Sturzstrom (CMS) have published ages that overlap with prehistoric earthquakes, suggesting seismicity may be the cause. To further test this idea, I mapped and dated the remaining three deposits, Racehorse Creek (RHC), Middle Fork (MFN), and Maple Falls (MF). To establish ages for the slides, I combined radiocarbon dating of organics in sediment cores from bogs in the debris fields and …