scholarly journals Inferring regional vertical crustal velocities from averaged relative sea level trends: A proof of concept

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.

Author(s):  
Julian D Orford ◽  
Joanne Murdy ◽  
Robert Freel

Tide-gauge records from the north of Ireland have been digitized to generate annual estimates of both mean-sea-level (MSL) position from Malin Head (1958–1998), and mean tidal level (MTL) from Belfast Harbour (1918–2002). Both sites exhibit substantial annual variation, but show overall long-term shallow rates of falling relative sea-level change (RSLC) that are very similar at −0.2 mm a −1 (±0.37 mm a −1 ) for Belfast and −0.16 mm a −1 (±0.17 mm a −1 ) for Malin. Using these rates as constraints, plus other constraints of inferred RSLC rates from the mid-Holocene, an approximation of the likely profile of RSLC rates for the northeast of Ireland since 6 ka ago is presented.


2019 ◽  
Vol 11 (3) ◽  
pp. 277 ◽  
Author(s):  
Suresh Palanisamy Vadivel ◽  
Duk-jin Kim ◽  
Jungkyo Jung ◽  
Yang-Ki Cho ◽  
Ki-Jong Han ◽  
...  

Vertical land motion at tide gauges influences sea level rise acceleration; this must be addressed for interpreting reliable sea level projections. In recent years, tide gauge records for the Eastern coast of Korea have revealed rapid increases in sea level rise compared with the global mean. Pohang Tide Gauge Station has shown a +3.1 cm/year sea level rise since 2013. This study aims to estimate the vertical land motion that influences relative sea level rise observations at Pohang by applying a multi-track Persistent Scatter Interferometric Synthetic Aperture Radar (PS-InSAR) time-series analysis to Sentinel-1 SAR data acquired during 2015–2017. The results, which were obtained at a high spatial resolution (10 m), indicate vertical ground motion of −2.55 cm/year at the Pohang Tide Gauge Station; this was validated by data from a collocated global positioning system (GPS) station. The subtraction of InSAR-derived subsidence rates from sea level rise at the Pohang Tide Gauge Station is 6 mm/year; thus, vertical land motion significantly dominates the sea level acceleration. Natural hazards related to the sea level rise are primarily assessed by relative sea level changes obtained from tide gauges; therefore, tide gauge records should be reviewed for rapid vertical land motion along the vulnerable coastal areas.


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).


2019 ◽  
Vol 36 (11) ◽  
pp. 2205-2219 ◽  
Author(s):  
Li Zhai ◽  
Blair Greenan ◽  
Richard Thomson ◽  
Scott Tinis

AbstractA storm surge hindcast for the west coast of Canada was generated for the period 1980–2016 using a 2D nonlinear barotropic Princeton Ocean Model forced by hourly Climate Forecast System Reanalysis wind and sea level pressure. Validation of the modeled storm surges using tide gauge records has indicated that there are extensive areas of the British Columbia coast where the model does not capture the processes that determine the sea level variability on intraseasonal and interannual time scales. Some of the discrepancies are linked to large-scale fluctuations, such as those arising from major El Niño and La Niña events. By applying an adjustment to the hindcast using an ocean reanalysis product that incorporates large-scale sea level variability and steric effects, the variance of the error of the adjusted surges is significantly reduced (by up to 50%) compared to that of surges from the barotropic model. The importance of baroclinic dynamics and steric effects to accurate storm surge forecasting in this coastal region is demonstrated, as is the need to incorporate decadal-scale, basin-specific oceanic variability into the estimation of extreme coastal sea levels. The results improve long-term extreme water level estimates and allowances for the west coast of Canada in the absence of long-term tide gauge records data.


2003 ◽  
Vol 59 (3) ◽  
pp. 300-309 ◽  
Author(s):  
Roman J. Motyka

AbstractApplication of dendrochronology and geomorphology to a recently emerged coastal area near Juneau, Alaska, has documented a Little Ice Age (LIA) sea-level transgression to 6.2 m above current sea level. The rise in relative sea level is attributed to regional subsidence and appears to have stabilized by the mid 16th century, based on a sea-cliff eroded into late-Pleistocene glaciomarine sediments. Land began emerging between A.D. 1770 and 1790, coincident with retreat of regional glaciers from their LIA maximums. This emergence has continued since then, paralleling regional glacier retreat. Total Juneau uplift since the late 18th century is estimated to be 3.2 m. The rate of downward colonization of newly emergent coastline by Sitka spruce during the 20th century closely parallels the rate of sea-level fall documented by analysis of local tide-gauge records (1.3 cm/yr). Regional and Glacier Bay LIA loading and unloading are inferred to be the primary mechanisms driving subsidence and uplift in the Juneau area. Climate change rather then regional tectonics has forced relative sea-level change over the last several hundred years.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Juan D. Restrepo-Ángel ◽  
Héctor Mora-Páez ◽  
Freddy Díaz ◽  
Marin Govorcin ◽  
Shimon Wdowinski ◽  
...  

AbstractCartagena is subsiding at a higher rate compared to that of global climate-driven sea level rise. We investigate the relative sea level rise (RSLR) and the influence of vertical land movements in Cartagena through the integration of different datasets, including tide gauge records, GPS geodetic subsidence data, and Interferometric Synthetic Aperture Radar (InSAR) observations of vertical motions. Results reveal a long-term rate (> 60 years) of RSLR of 5.98 ± 0.01 mm/yr. The last two decades exhibited an even greater rate of RSLR of 7.02 ± 0.06 mm/yr. GPS subsidence rates range between − 5.71 ± 2.18 and − 2.85 ± 0.84 mm/yr. InSAR data for the 2014–2020 period show cumulative subsidence rates of up to 72.3 mm. We find that geologically induced vertical motions represent 41% of the observed changes in RSLR and that subsidence poses a major threat to Cartagena’s preservation. The geodetic subsidence rates found would imply a further additional RSLR of 83 mm by 2050 and 225 mm by 2100. The Colombian government should plan for the future and serve as an example to similar cities across the Caribbean.


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