GRACE era secular trends in Earth rotation parameters: A global scale impact of the global warming process?

Roy, Keven; Peltier, W. R.

doi:10.1029/2011gl047282

Cited by 44 publications

(77 citation statements)

References 26 publications

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“…This decrease in oblateness was attributed to viscous adjustments of the solid Earth to past deglaciations, which move solid Earth mass toward the polar regions (Mitrovica and Peltier, 1993). This long-term decline reversed itself in the mid-1990s (Roy and Peltier, 2011), presumably because melting of the Greenland and Antarctic ice sheets began to move mass away from the poles at rates fast enough to increase Earth's oblateness (Nerem and Wahr, 2011). An imbalance between the rates of melting in the Northern and Southern Hemispheres causes a net southward or northward motion of water mass, which must be compensated by an equivalent translation of the solid Earth in the opposite direction (Conrad and Hager, 1997).…”

Section: Elastic Deformation and Anthropogenic Sea-level Changementioning

confidence: 99%

The solid Earth's influence on sea level

Conrad

2013

Geological Society of America Bulletin

173

180

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Because it lies at the intersection of Earth's solid, liquid, and gaseous components, sea level links the dynamics of the fl uid part of the planet with those of the solid part of the planet. Here, I review the past quarter century of sea-level research and show that the solid components of Earth exert a controlling infl uence on the amplitudes and patterns of sea-level change across time scales ranging from years to billions of years. On the shortest time scales (10 0 -10 2 yr), elastic deformation causes the ground surface to uplift instantaneously near deglaciating areas while the sea surface depresses due to diminished gravitational attraction. This produces spatial variations in rates of relative sea-level change (measured relative to the ground surface), with amplitudes of several millimeters per year. These sea-level "fi ngerprints" are characteristic of (and may help identify) the deglaciation source, and they can have signifi cant societal importance because they will control rates of coastal inundation in the coming century. On time scales of 10 3 -10 5 yr, the solid Earth's time-dependent viscous response to deglaciation also produces spatially varying patterns of relative sea-level change, with centimeters-per-year amplitude, that depend on the time-history of deglaciation. These variations, on average, cause net seafl oor subsidence and therefore global sea-level drop. On time scales of 10 6 -10 8 yr, convection of Earth's mantle also supports long-wavelength topographic relief that changes as continents migrate and mantle fl ow patterns evolve. This changing "dynamic topography" causes meters per millions of years of relative sea-level change, even along seemingly "stable" continental margins, which affects all stratigraphic records of Phanerozoic sea level. Nevertheless, several such records indicate sea-level drop of ~230 m since a mid-Cretaceous highstand, when continental transgressions were occurring worldwide. This global drop results from several factors that combine to expand the "container" volume of the ocean basins. Most importantly, ridge volume decrease since the mid-Cretaceous, caused by an ~50% slowdown in seafl oor spreading rate documented by tectonic reconstructions, explains ~250 m of sea-level fall. These tectonic changes have been accompanied by a decline in the volume of volcanic edifi ces on Pacifi c seafl oor, continental convergence above the former Tethys Ocean, and the onset of glaciation, which dropped sea level by ~40, ~20, and ~60 m, respectively. These drops were approximately offset by an increase in the volume of Atlantic sediments and net seafl oor uplift by dynamic topography, which each elevated sea level by ~60 m. Across supercontinental cycles, expected variations in ridge volume, dynamic topography, and continental compression together roughly explain observed sea-level variations throughout Pangean assembly and dispersal. On the longest time scales (10 9 yr), sea level may change as ocean water is exchanged with reservoirs stored by hydrous minerals within the...

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Section: Elastic Deformation and Anthropogenic Sea-level Changementioning

confidence: 99%

The solid Earth's influence on sea level

Conrad

2013

Geological Society of America Bulletin

173

180

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“…These estimates are much earlier than detected in observational analyses (e.g. Hanna et al 2008;Roy and Peltier 2011).…”

Section: The Empirical Modelmentioning

confidence: 99%

“…Nevertheless, all datasets with un-smoothed data covering the end of the twentieth century warm dramatically beginning in the 1990s. This is consistent with a marked change in Greenland surface ice load beginning in this period inferred from a sharp change in the Earth's rotational state (Roy and Peltier 2011). Furthermore, all datasets exhibit warming during the 1920s followed by a gradual cooling leading into the 1990s.…”

Section: Data Characterizationmentioning

confidence: 99%

Attributing observed Greenland responses to natural and anthropogenic climate forcings

Andres

Peltier

2015

Clim Dyn

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“…Smaller deviations have also been reported to have occurred in the early 1990s (Roy & Peltier 2011). By convention, the deformation associated with such deviations in polar motion from its longer-term path is not corrected through the pole tide model which addresses only periodic deviation away from a time variable reference pole position.…”

Section: Introductionmentioning

confidence: 99%

Geodetic vertical velocities affected by recent rapid changes in polar motion

King

Watson

2014

Geophysical Journal International

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S U M M A R YSecular motion of Earth's rotation pole results in large-scale secular deformation of Earth. Here, we investigate the magnitude of the deformation that has resulted from the rapid motion of the rotation pole to the east since ∼2005. We show that geodetic (GNSS, DORIS, VLBI and SLR) estimates of vertical velocity since ∼2005 have been biased by up to ±0.38 mm yr -1 relative to the longer-term deformation pattern. The largest signals occur within regions that include the U.S. Pacific Coast, Europe and South Pacific islands where geodetic measurements provide essential measurements of tide-gauge vertical movement and important constraints on models of glacial isostatic adjustment. Consequently, geodetic vertical velocities based on recent data should not be interpreted as being identical to centennial or longer term vertical land movement. Since 2010 the effect is further amplified by the overprediction of the IERS polar motion model relative to the ongoing secular change in pole position-during this time geodetic vertical velocities based on the IERS pole tide model are not just biased relative to the long-term rates but also from actual post-2010 Earth deformation. For geophysical or reference frame studies seeking geodetic vertical velocities that are representative of decadal timescales, where interannual variation is considered noise, the correction for this non-linear effect is straightforward, requiring an elastic computation using a reference rate of polar motion that is linear over the timescales of interest.

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GRACE era secular trends in Earth rotation parameters: A global scale impact of the global warming process?

Cited by 44 publications

References 26 publications

The solid Earth's influence on sea level

The solid Earth's influence on sea level

Attributing observed Greenland responses to natural and anthropogenic climate forcings

Geodetic vertical velocities affected by recent rapid changes in polar motion

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