Publication Date:
2017-04-04
Description:
Observations from the global array of tide gauges show that global sealevel
has been rising at an average rate of 1.5-2 mm/yr during the last
~150 years [Douglas 1991, Spada and Galassi 2012]. Although a global
sea-level acceleration was initially ruled out [Douglas 1992], subsequent
studies [Douglas 1997, Church and White 2006, Jevrejeva et al.
2008, Church and White 2011] have coherently proposed values of ~1
mm/year/century [Olivieri and Spada 2013]. More complex non-linear
trends and abrupt sea-level variations have now also been recognized.
Globally, these could manifest a regime shift between the late Holocene
and the current rhythms of sea-level rise [Gehrels and Woodworth 2013],
while locally they result from ocean circulation anomalies, steric effects
and wind stress [Bromirski et al. 2011, Merrifield 2011]. Although isostatic
readjustment affects the local rates of secular sea-level change
[Milne and Mitrovica 1998, Peltier 2004], a possible impact on regional
acceleration has been so far discounted [Douglas 1992, Jevrejeva et al.
2008, Woodworth et al. 2009] since the process evolves on a millennium
time scale [Turcotte and Schubert 2002]. Here we report a previously unnoticed
anomaly in the long-term sea-level acceleration of the Baltic Sea
tide gauge records, and we explain it by the classical post-glacial rebound
theory and numerical modeling of glacial isostasy. Contrary to previous
assumptions, our findings demonstrate that isostatic compensation plays
a role in the regional secular sea-level acceleration.
Description:
Published
Description:
S0432
Description:
1T. Geodinamica e interno della Terra
Description:
JCR Journal
Description:
open
Keywords:
Sea-level change
;
Glacial isostatic adjustment
;
Rheology
;
04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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