GEOSCAN, résultats de la recherche


TitreRelative and absolute sea level rise in western Canada and northwestern United States from a combined tide gauge-GPS analysis
AuteurMazzotti, S; Jones, C; Thomson, R E
SourceJournal of Geophysical Research vol. 113, C11019, 2008, 19 pages, (Accès ouvert)
Séries alt.Secteur des sciences de la Terre, Contribution externe 20070616
Documentpublication en série
Mediapapier; en ligne; numérique
ProvinceRégion extracotière de l'ouest; Colombie-Britannique
Lat/Long OENS-136.0000 -120.0000 58.0000 40.0000
Sujetschangements du niveau de la mer; variations du niveau de la mer; milieu côtièr; analyse environnementales; etudes de l'environnement; effets sur l'environnement; changement climatique; géologie de l'environnement; géologie marine; Nature et environnement
Illustrationslocation maps; tables; plots
ProgrammeRenforcer la résilience face aux changements climatiques
Diffusé2008 11 21
Résumé(disponible en anglais seulement)
Empirical studies and climate models suggest large variations of absolute sea level (ASL) changes between oceanic basins. Such potential variations raise concern on the applicability of global mean ASL predictions to specific regions and on estimates of relative sea level (RSL) hazards. We address this issue for the western Canada and northwestern United States coastline by estimating the 20th century ASL rate using a combination of 34 colocated tide gauge and Global Positioning System (GPS) stations. The tide gauge data are quality controlled and corrected for spatially and temporally correlated sea level transients in order to derive robust RSL trends and standard errors. Reference frame and other GPS-specific issues are considered as part of the error budget in absolute GPS vertical velocities. Our combined tide gauge-GPS analysis, aligned to the International Terrestrial Reference Frame 2000, indicates a northeast Pacific ASL rise of 1.8 ± 0.2 mm/a through the 20th century, which is similar to accepted rates for the global eustatic mean. For the period 1993 - 2003, we find a regional ASL rate of -4.4 ± 0.5 mm/a consistent with satellite altimetry. On the basis of the Intergovernment Panel on Climate Change Assessment Report 4 mean scenario and our assessment of coastal motions from GPS and tide gauge data, we derive a map of predicted 21st century RSL rise in western Canada and the northwestern United States. Variations in coastal uplift strongly affect spatial RSL patterns. Subsidence of southern Puget Sound may significantly increase RSL rise in the Seattle-Tacoma metropolitan area. Conversely, tectonic uplift along parts of the outer west coast may reduce future RSL rise by up to 50 - 100%.