“…Numerous investigators have drawn attention to quasiperiodic temporal structure in earthquake catalogs and the possibility of event triggering by time-dependent loading processes, from seasonal hydrologic loading (Ader & Avouac, 2013;Bettinelli et al, 2008;Bollinger et al, 2007;Johnson et al, 2017) to changes in Earth's rotation rate (Anderson, 1974;Levin & Sasarova, 2015a, 2015b or solid earth tides (e.g., Bodri & Iizuka, 1989;Cochran et al, 2004;Ide et al, 2016;Métivier et al, 2009). More broadly, quasiperiodic decadal fluctuations in global seismicity have been reported in many studies without a specific physical mechanism (Kanamori, 1977;Liritzis & Tsapanos, 1993;Milne, 1881;Pines & Shaham, 1973;Press & Briggs, 1975;Riguzzi et al, 2010;Shanker et al, 2001). Simulated earthquake catalogs also demonstrate emergent periodicity (Ader et al, 2014;Richards-Dinger & Dieterich, 2012;Sammis & Smith, 2013;Zahn & Shearer, 2015).…”