Use of DInSAR techniques for the assessment of tide gauge measurements for long term past sea level evolution estimation reliability

Author(s):  
Daniel Raucoules ◽  
Poitevin Cyril ◽  
Le Cozannet Goneri ◽  
Woppelmann Guy ◽  
Marcello de Michele
2017 ◽  
Vol 7 (1) ◽  
Author(s):  
H. Bâki Iz ◽  
C. K. Shum ◽  
C. Zhang ◽  
C. Y. Kuo

AbstractThis study demonstrates that relative sea level trends calculated from long-term tide gauge records can be used to estimate relative vertical crustal velocities in a region with high accuracy. A comparison of the weighted averages of the relative sea level trends estimated at six tide gauge stations in two clusters along the Eastern coast of United States, in Florida and in Maryland, reveals a statistically significant regional vertical crustal motion of Maryland with respect to Florida with a subsidence rate of −1.15±0.15 mm/yr identified predominantly due to the ongoing glacial isostatic adjustment process. The estimate is a consilience value to validate vertical crustal velocities calculated from GPS time series as well as towards constraining predictive GIA models in these regions.


Ocean Science ◽  
2020 ◽  
Vol 16 (4) ◽  
pp. 997-1016
Author(s):  
Tal Ezer ◽  
Sönke Dangendorf

Abstract. A new monthly global sea level reconstruction for 1900–2015 was analyzed and compared with various observations to examine regional variability and trends in the ocean dynamics of the western North Atlantic Ocean and the US East Coast. Proxies of the Gulf Stream (GS) strength in the Mid-Atlantic Bight (GS-MAB) and in the South Atlantic Bight (GS-SAB) were derived from sea level differences across the GS. While decadal oscillations dominate the 116-year record, the analysis showed an unprecedented long period of weakening in the GS flow since the late 1990s. The only other period of long weakening in the record was during the 1960s–1970s, and red noise experiments showed that is very unlikely that those just occurred by chance. Ensemble empirical mode decomposition (EEMD) was used to separate oscillations at different timescales, showing that the low-frequency variability of the GS is connected to the Atlantic Multi-decadal Oscillation (AMO) and the Atlantic Meridional Overturning Circulation (AMOC). The recent weakening of the reconstructed GS-MAB was mostly influenced by weakening of the upper mid-ocean transport component of AMOC as observed by the RAPID measurements for 2005–2015. Comparison between the reconstructed sea level near the coast and tide gauge data for 1927–2015 showed that the reconstruction underestimated observed coastal sea level variability for timescales less than ∼5 years, but lower-frequency variability of coastal sea level was captured very well in both amplitude and phase by the reconstruction. Comparison between the GS-SAB proxy and the observed Florida Current transport for 1982–2015 also showed significant correlations for oscillations with periods longer than ∼5 years. The study demonstrated that despite the coarse horizontal resolution of the global reconstruction (1∘ × 1∘), long-term variations in regional dynamics can be captured quite well, thus making the data useful for studies of long-term variability in other regions as well.


1993 ◽  
Vol 156 ◽  
pp. 133-144
Author(s):  
W. E. Carter ◽  
D. S. Robertson

Very-long-baseline Interferometry (VLBI) has opened for study a broad new spectrum of geophysical phenomena including: direct observation of the tectonic motions and deformations of the Earth's crustal plates, observations of unprecedented detail of the variations in the rotation of the Earth, and direct measurement of the elastic deformations of the Earth in response to tidal forces. These new measurements have placed significant constraints on models of the interior structure of the Earth; for example, measurements of the variations in the Earth's nutation have been shown to be particularly sensitive to the shape of the core-mantle boundary. The VLBI measurements will allow us to construct a global reference frame accurate at the centimeter level. Such a frame will be essential to studying long-term global changes, especially those changes related to sea-level variations as recorded by tide gauge measurements.


Author(s):  
L. Rickards ◽  
A. Matthwes ◽  
K. Gordon ◽  
M. Tamisea ◽  
S. Jevrejeva ◽  
...  

Abstract. The PSMSL was established as a “Permanent Service” of the International Council for Science in 1958, but in practice was a continuation of the Mean Sea Level Committee which had been set up at the Lisbon International Union of Geodesy and Geophysics (IUGG) conference in 1933. Now in its 80th year, the PSMSL continues to be the internationally recognised databank for long-term sea level change information from tide gauge records. The PSMSL dataset consists of over 2100 mean sea level records from across the globe, the longest of which date back to the start of the 19th century. Where possible, all data in a series are provided to a common benchmark-controlled datum, thus providing a record suitable for use in time series analysis. The PSMSL dataset is freely available for all to use, and is accessible through the PSMSL website (www.psmsl.org).


2012 ◽  
Vol 9 (5) ◽  
pp. 3049-3070
Author(s):  
Joanne Williams ◽  
Christopher W. Hughes

Abstract. Studies comparing tide gauge measurements with sea level from nearby satellite altimetry have shown good agreement for some islands, and poor agreement for others, though no explanation has been offered. Using the 1/12° OCCAM ocean model, we investigate the relationship between sea level at small, open-ocean islands, and offshore sea level. For every such island or seamount in the model, we compare the shallow-water sea level with the steric and bottom pressure variability in a neighboring ring of deep water. We find a latitude-dependent range of frequencies for which off-shore sea level is poorly correlated with island sea level. This poor coherence occurs in a spectral region for which steric signals dominate, but are unable to propagate as baroclinic Rossby waves. This mode of decoupling does not arise because of island topography, as the same decoupling is seen between deep ocean points and surrounding rings.


2014 ◽  
Vol 71 (4) ◽  
Author(s):  
Othman A.H. ◽  
Omar, K. ◽  
Othman. R ◽  
Mat Som Z.A ◽  
Opaluwa, Y.D

The present vertical datums in Sabah and Sarawak (East Malaysia) are based upon various tide gauge measurements of mean sea level over certain period defined locally, are manifested by a physical framework of vertical reference point i.e benchmarks. An effort to establish a unified vertical network in Sabah and Sarawak has undergone very tedious survey operation, lack of access routes to connect levelling network due to geographical setting constraint, and it is too costly to be fully implemented. This paper discussed the current status of vertical datum in East Malaysia as well as the concept of realizing new vertical datum based on gravimetric geoid model.


2020 ◽  
Vol 42 (4) ◽  
pp. 411-424
Author(s):  
Aleksandr KHOLOPTSEV ◽  
Sergey PODPORIN

The paper aims to investigate basic features of modern long-term variations of the Okhotsk Sea level in its coastal areas and establish feasibility of certain retrospective analysis databases usage for determination of mean rates of the above processes. The reanalysis databases considered include Global Ocean Physics Reanalysis GLORYS12v.1 by the Copernicus Marine Environment Monitoring Service and ICDC-reanalysis supported by the Integrated Climate Data Center, which provide coverage of the sea in question. The raised problem is of significant interest for physiographers, oceanographers and involved in coastal shipping and marine safety in the Sea of Okhotsk. Long-term sea level variations are most accurately monitored by tide gauge stations, which, however, are scarce along the coast of the sea in question. Less accurate and not uniformly available through easier to use and collect data is the satellite monitoring by radar altimeters. Global retrospective analyses based on mathematical modelling are considered to be an effective instrument to assess sea levels at any given time at any point.


2020 ◽  
Author(s):  
Marta Marcos ◽  
Bernat Puyol ◽  
Angel Amores ◽  
Begoña Pérez Gómez ◽  
M. Ángeles Fraile ◽  
...  

<p><span>A set of historical tide-gauge sea-level records from two locations in Santander (Northern Spain) and Alicante (Spanish Mediterranean coast) have been recovered from logbooks stored in national archives. Sea-level measurements have been digitised, quality-controlled and merged into three consistent sea-level time series (two in Alicante and one in Santander) using high precision levelling information. The historical sea-level record in Santander consists of a daily time series spanning the period 1876-1924 and it is further connected to the modern tide-gauge station nearby, ensuring datum continuity up to the present. The sea-level record in Alicante starts in 1870 with daily averaged values until the 1920s and hourly afterwards, and is still in operation, thus representing the longest tide-gauge sea-level time series in the Mediterranean Sea. The long-term consistency and reliability of the new records is discussed based on the comparison with nearby tide gauge time series.</span></p>


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