Tsunami coastal hazard along the US East Coast from coseismic sources in the Açores convergence zone and the Caribbean arc areas

Modeled Flooding by Tsunamis and a Storm Versus Observed Extent of Coral Erratics on Anegada, British Virgin Islands—Further Evidence for a Great Caribbean Earthquake Six Centuries Ago

“…Grilli et al. (2022), using orthogonal convergence of 6–7 mm/yr, estimated return periods of 250, 550, and 1,000 years for Puerto Rico Trench earthquakes of M8.3 (slip 1.5 m), M8.7 (slip 3.7 m) and M9.0 (slip 7.1 m), respectively. But the fault loading depends on interplate coupling, which has been shown geodetically to be weak (ten Brink & Lin, 2004; ten Brink, 2005; ten Brink & López‐Venegas, 2012; Symithe et al., 2015), A combinatorial optimization method gave a seismic slip rate along the Puerto Rico Trench of 2 ± 1 mm/yr, along with a mean return time greater than 1,000 years for earthquakes of M > 8.1 (Geist & ten Brink, 2021).…”

“…There, Mesozoic lithosphere of the North America plate converges obliquely, at 2 cm/yr, with the Caribbean plate. The resulting megathrust has been posited as a source of tsunami hazards not just in the Caribbean near‐field but also on the Atlantic seaboard of the United States and Canada (ten Brink & Lin, 2004; Grilli et al., 2022). But no Puerto Rico Trench earthquake, back to about 1500 C.E., has a confirmed size of M8.0 or larger (ten Brink et al., 2011); the plate convergence is highly oblique; and this part of the megathrust is weakly coupled (DeMets et al., 2010; ten Brink & López‐Venegas, 2012; Symithe et al., 2015).…”