Optimal locations of sea-level indicators in glacial isostatic adjustment investigations

Abstract:

Knowledge of the Glacial Isostatic Adjustment (GIA) process allows us to understand mantle rheology and dynamics, ice sheet thickness history and climate change. In order to further constrain GIA models and improve our current knowledge of GIA, more observations (e.g. relative sea-levels (RSL), GPS, gravity measurements, tide-gauges) are desirable to resolve the following parameters of GIA:

1.Ice thickness,

2.Lithospheric thickness,

3.Radial viscosity profile (background viscosity profile for modeling),

4.Lateral viscosity changes in view of thermal versus chemical origin of the 3D structures in the mantle.

We discuss global sensitivities of RSL data of the last 18,000 years. This also includes indicative RSL-like data (e.g., lake levels) on the continents far off the coasts. We present detailed sensitivity maps for the four parameters above for up to nine dedicated times. Assuming an observational accuracy of 2 m of RSL data of all ages (based on analysis of currently available data), we highlight areas (or optimal locations) around the world where, if the environmental conditions allowed its deposition and survival until today, RSL data of at least this accuracy may help to quantify the GIA modeling parameters above.