Regional variations in relative sea-level changes influenced by nonlinear vertical land motion

Area of Science:

• Earth and Environmental Sciences
• Geophysics
• Oceanography

Background:

• Absolute sea level is monitored by satellite altimetry, but vertical land motion (VLM) is less observed.
• VLM is often modeled linearly, despite evidence of nonlinearities from tectonics, loading, or groundwater changes.
• The temporal evolution and impact of VLM on sea-level rise projections remain uncertain.

Purpose of the Study:

• To reconstruct probabilistic vertical land motion from 1995 to 2020.
• To assess the impact of regional and nonlinear VLM on relative sea-level projections up to 2150.
• To quantify the uncertainty introduced by nonlinear VLM in sea-level change projections.

Main Methods:

• Probabilistic reconstruction of vertical land motion using observational data from 1995-2020.
• Integration of VLM into relative sea-level change models.
• Analysis of nonlinear VLM effects on regional sea-level projections.

Main Results:

• Regional variations in projected coastal sea-level changes are equally influenced by VLM and climate-driven factors.
• VLM can drive relative sea-level changes of up to 50 cm by 2150.
• Accounting for nonlinear VLM increases projection uncertainty by up to 1 meter regionally.

Conclusions:

• Nonlinear vertical land motion significantly influences regional sea-level change projections.
• Accurate sea-level rise predictions require incorporating nonlinear VLM.
• Understanding VLM is critical for assessing future coastal impacts and adaptation strategies.