CRUSTAL ADJUSTMENT — Reason for recent relative sea-level fall/rise in Canada & Scandinavia The process that explains modern changes in relative sea level along the coasts of eastern/northern Canada and Scandinavia (due to post-glacial uplift) is:

Introduction / Context:During the last glacial maximum, thick ice sheets depressed the lithosphere. After deglaciation, removal of the ice load triggered a slow, continuing rebound of the crust that changes relative sea level along affected coasts.

Given Data / Assumptions:

• Regions: eastern/northern Canada and Scandinavia.
• Phenomenon: ongoing crustal uplift and relative shoreline change.
• Cause: removal of former ice load and viscous mantle flow response.

Concept / Approach:Isostasy describes gravitational equilibrium between Earth’s lithosphere and asthenosphere. Post-glacial isostatic adjustment (glacio-isostatic rebound) raises formerly glaciated crust while surrounding forebulges may subside, altering relative sea level.

Step-by-Step Solution:Identify load removal (melting ice) → reduced lithospheric depression.Viscous mantle flows back, pushing crust upward over millennia.Observed effect: raised shorelines, changing tidal datums, and relative sea-level trends.This is isostasy in action.

Verification / Alternative check:Raised paleo-shorelines and GPS geodesy document uplift rates of several mm/year in Fennoscandia and parts of Canada.

Why Other Options Are Wrong:Continental drift/plate tectonics — plate motions occur, but the described coastal changes are dominated by glacio-isostatic rebound.None of the above/orographic rebound — not the correct terminology.

Common Pitfalls:Confusing eustatic (global) sea-level change with local relative sea-level change due to vertical land motion.

Final Answer:isostasy