On Sea-Level Change in Coastal Areas

Abstract

Variations in sea-level, based on tide gauge data (GSLTG) and on combining tide gauges and satellite data (GSLl) are subjected to singular spectrum analysis (SSA), to determine their trends and periodic or quasi-periodic components. GLSTG increases by 90 mm from 1860 to 2020, a contribution of 0.56 mm/yr to the mean rise rate. Annual to multi-decadal periods of ∼ 90/80, 60, 30, 20, 10/11, and 4/5 years are found in both GSLTG and GSLl. These periods are commensurable periods of the Jovian planets, combinations of the periods of Neptune (165 yr), Uranus (84 yr), Saturn (29 yr) and Jupiter (12 yr). These same periods are encountered in sea-level changes, motion of the rotation pole RP and evolution of global pressure GP, suggesting physical links. The first SSA components comprise most of the signal variance: 95% for GSLTG, 89% for GSLI, 98% for GP, 75% for RP. Laplace derived the Liouville-Euler equations that govern the rotation and translation of the rotation axis of any celestial body. He emphasized that one must consider the orbital kinetic moments of all planets in addition to gravitational attractions and concluded that the Earth's rotation axis should undergo motions that carry the combinations of periods of the Sun, Moon and planets. Almost all the periods found in the SSA components of sea-level (GSLl and GSLTG), global pressure (GP) and polar motion (RP), of their modulations and their derivatives can be associated with the Jovian planets. It would be of interest to search for data series with longer time spans, that could allow one to test whether the trends themselves could be segments of components with still longer periodicities (e.g. 175 yr Jose cycle).

On the external forcing of global eruptive activity in the past 300 years

“…Such a link would not be favored, as illustrated by various interpretations suggested in the past (e.g., Lyons, 1899;Jensen, 1902;Schneider and Mass, 1975;Mazzarella and Palumbo, 1988;1989;Stothers, 1989;Strestik, 2003;Herdiwijaya et al, 2014;Vasilieva and Zharkova, 2020). Dumont et al (2022) have identified a link between global volcanic eruptions and the global mean sea level, which is known to exhibit planetary-scale periodicities (Le Courtillot et al, 2022a). Such a link can be understood in the case of insular, submarine and coastal magmatic plumbing systems, which are the most abundant (Dumont et al, 2022): stress variations can be induced by pressure changes imposed by oceanic water mass transport at different timescales.…”

“…Similarly to short-term timescales and tidal periodicities, these multi-annual to centennial variations are present in other geophysical parameters. Most of them record both tidal and solar periodicities, as illustrated by the magnetic field (e.g., Bartels, 1932;Le Mouël, 1984;Courtillot and Le Mouël, 1988;Jault, 1990;Le Mouël et al, 2019), polar motion (Lopes et al, 2017;Lopes et al, 2021a;Lopes et al, 2022a), sea level observed from local and global data (e.g., Chambers et al, 2012;Wahl and Chambers, 2015;Le Mouël et al, 2021a;Courtillot et al, 2022a), global surface air temperatures (e.g., Courtillot et al, 2013;Le Mouël et al, 2020b;Scafetta, 2021), and more generally, climate (e.g., Wood and Lovett, 1974;Schlesinger and Ramankutty, 1994;Scafetta, 2010;Courtillot et al, 2013;Scafetta, 2016;Le Mouël et al, 2019c;Le Mouël et al, 2021b). Moreover, these links also seem to exist 1) on much longer timescales of millennia, governed by astronomical configurations and impacting climate and sedimentation (e.g., Milanković, 1920;Kutterolf et al, 2013;Coussens et al, 2016;Kutterolf et al, 2019;Lopes et al, 2021b;Satow et al, 2021); and 2) also for earthquakes, as suggested by numerous studies (e.g., Tamrazyan, 1968;Mazzarella and Palumbo, 1988;Marchitelli et al, 2020).…”