EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Common Era sea-level budgets of North America

Jennifer Walker1,2, Robert Kopp1,2, Timothy Shaw3, Geoff Richards3, and Benjamin Horton3,4
Jennifer Walker et al.
  • 1Department of Earth and Planetary Sciences, Rutgers University, New Brunswick, USA
  • 2Rutgers Institute of Earth, Ocean and Atmospheric Sciences, Rutgers University, New Brunswick, USA
  • 3Earth Observatory of Singapore, Nanyang Technological University, Singapore
  • 4Asian School of the Environment, Nanyang Technological University, Singapore

A sea-level budget improves understanding of driving processes and their relative contributions. However, most sea-level budget assessments are limited to the 20th and 21st centuries and are global in scale. Here, we estimate the sea-level budget on centennial to millennial timescales of the Common Era (last 2000 years). We expand upon previous analysis of sites along the U.S. mid-Atlantic coast (Walker et al., 2021) and produce site-specific sea-level budgets for all of the eastern and western North American coastlines and Gulf coast. This broader scope further improves understanding of the temporal evolution and variability of driving processes of sea-level changes in the past and present, and which will shape such changes in the future.

To produce the sea-level budgets, we use an updated global database of instrumental and proxy sea-level records coupled with a spatiotemporal model. Using the unique spatial scales of driving processes, we separate relative sea-level records into global, regional, and local-scale components. Preliminary results along the eastern North American coastline reveal that each budget is dominated by regional-scale, temporally-linear processes driven by glacial isostatic adjustment until at least the mid-19th century. This signal exhibits a spatial gradient, ranging from 1.0 ± 0.02 mm/yr (1σ) in Newfoundland to a maximum of 1.6 ± 0.02 mm/yr in southern New Jersey to 0.5 ± 0.02 mm/yr in Florida. Non-linear regional and local-scale processes, such as ocean/atmosphere dynamics and groundwater withdrawal, are smaller in magnitude and vary temporally and spatially. The most significant change to the budgets is the increasing influence of the global signal due to ice melt and thermal expansion since ~1800 CE, which reaches a 20th century rate of 1.3 ± 0.1 mm/yr, accounting for 43-65% of each budget.

How to cite: Walker, J., Kopp, R., Shaw, T., Richards, G., and Horton, B.: Common Era sea-level budgets of North America, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6530,, 2022.