SEEA STAR is a U.S. National Science Foundation–funded ocean-bottom seismology experiment along the eastern Aleutian subduction zone. It is a collaborative project led by Helen Janiszewski at the University of Hawaiʻi at Mānoa and by S. Shawn Wei at Michigan State University, in collaboration with Aaron Wech at the Alaska Volcano Observatory. In summer 2028, we plan to deploy 40 broadband ocean-bottom seismometers on the seafloor from Sanak Island to the western tip of Unalaska Island, a span chosen to straddle the along-strike transition in the overriding plate from continental to oceanic crust. By seismically imaging the structure of the subduction zone and its megathrust fault, we aim to test whether that transition explains the marked variations in earthquake behavior along this margin. Great earthquakes on the Aleutian megathrust have sent tsunamis across the Pacific to Hawaiʻi, and threaten coastal communities across the region. SEEA-STAR will improve our understanding of what controls these processes.

NSF awards: Award 2618356 to UHM and Award 2618357 to MSU