Open AccessTremor Activity Monitoring in Northern Cascadia
Author(s) -
Kao Honn,
Thompson Philip J.,
Shan ShaoJu,
Rogers Garry,
Dragert Herb
Publication year - 2008
Publication title -
eos, transactions american geophysical union
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.316
H-Index - 86
eISSN - 2324-9250
pISSN - 0096-3941
DOI - 10.1029/2008eo420001
Subject(s) - geology , subduction , seismology , north american plate , magnitude (astronomy) , plate tectonics , convergent boundary , moment magnitude scale , slab , margin (machine learning) , pacific plate , geodetic datum , episodic tremor and slip , oceanography , oceanic crust , paleontology , geodesy , tectonics , physics , geometry , mathematics , astronomy , machine learning , scaling , computer science
The Cascadia margin is characterized by a young (<8‐million‐year‐old) subducting slab stretching from British Columbia, Canada, to northern California, marking the convergent boundary between the North America plate and the oceanic Juan de Fuca and Explorer plates (Figure 1). Geodetic measurements over the past two decades have established that the shallow portion (depth <15 kilometers) of the interface between the subducting Juan de Fuca plate and the overriding North America plate is strongly coupled. The inevitable “unlocking” process can and will generate a megathrust earthquake with a magnitude as large as 9, as confirmed by the studies of paleoearthquakes in the region. Paleoseismic and tsunami data have indicated that the last Cascadia megathrust event (magnitude ∼9) occurred in 1700 [e.g., Satake et al. , 2003].