Relative sea level rise

Definition

Relative sea level rise refers to the change in the height of sea levels in relation to a specific point on land, taking into account factors such as land subsidence and ocean dynamics. This concept is crucial for understanding how different regions experience varying degrees of sea level changes due to both global sea level rise and local geological conditions.

5 Must Know Facts For Your Next Test

1. Relative sea level rise can vary significantly from one location to another, influenced by local geological processes and human activities.
2. Regions that experience significant land subsidence, like deltas or coastal cities, may see higher relative sea level rise compared to global averages.
3. In areas undergoing isostatic rebound, relative sea level may actually fall despite global increases in sea level.
4. The combination of global eustatic changes and local land movements makes monitoring relative sea level rise complex and essential for coastal planning.
5. Relative sea level rise poses a substantial risk to coastal ecosystems, infrastructure, and communities, requiring tailored responses based on local conditions.

Review Questions

• How does relative sea level rise differ from eustatic sea level rise in terms of measuring changes in sea levels?
  • Relative sea level rise focuses on the changes in sea levels in relation to a specific point on land, considering local factors like land subsidence or uplift. In contrast, eustatic sea level rise measures global changes due to factors like thermal expansion and melting ice without accounting for local geological movements. This distinction is important for accurately assessing risks and impacts in different regions affected by rising seas.
• Discuss the implications of land subsidence on relative sea level rise and its impact on coastal communities.
  • Land subsidence directly contributes to relative sea level rise by causing the ground to sink, which can make coastal areas more vulnerable to flooding and erosion. In regions where subsidence is prominent, such as urban areas built on reclaimed land or river deltas, the effective increase in sea levels can be much greater than the global average. This presents challenges for infrastructure, water supply, and ecosystem health, necessitating proactive management strategies.
• Evaluate the relationship between isostatic rebound and relative sea level changes in a given region after a glacial period.
  • Isostatic rebound occurs when land that was previously compressed under heavy ice sheets begins to rise as the ice melts. This process can lead to a decrease in relative sea level in those areas despite overall global sea levels rising. Evaluating this relationship helps understand how different regions can experience contrasting effects from global warming, highlighting the importance of localized studies in managing coastal resilience and planning for future changes.

Related terms

Eustatic sea level rise: Eustatic sea level rise refers to the global change in sea level due to factors such as thermal expansion of water and melting ice sheets, without considering local land movement.

Land subsidence: Land subsidence is the gradual sinking of land due to natural processes or human activities, contributing to relative sea level rise in certain areas.

Isostatic rebound:

Isostatic rebound is the rise of land masses that were previously compressed by the weight of ice sheets during glacial periods, affecting local sea level measurements.