Marine Transgression in Modern Times

Area of Science:

• Earth and Environmental Sciences
• Coastal Geomorphology
• Climate Change Impacts

Background:

• Global sea-level rise is accelerating coastal erosion and landscape change.
• Marine transgression, the landward movement of the sea, significantly impacts coastal zones.
• These changes necessitate understanding different transgression dynamics for effective coastal management.

Purpose of the Study:

• To differentiate and describe the two primary forms of marine transgression: active and passive.
• To analyze the geomorphological processes and spatial extents of each transgression type.
• To explore the implications of these processes for coastal ecosystems and human populations under rising sea levels.

Main Methods:

• Comparative analysis of coastal geomorphological responses to sea-level rise.
• Distinguishing between wave-driven erosion on open coasts and ecosystem translation in low-energy margins.
• Assessment of sediment-delivery rates versus accommodation creation.

Main Results:

• Active transgression is rapid, visible, and localized, characterized by wave erosion and landform translation on open coasts.
• Passive transgression is slow, subtle, and widespread, marked by ecosystem migration along low-energy, inland margins.
• The interplay between active and passive transgression influences coastal zone dynamics.

Conclusions:

• The distinct mechanisms of active and passive transgression dictate the future of coastal zones.
• Anthropogenic interventions can exacerbate or mitigate the impacts of sea-level rise on coastal ecosystems.
• Understanding these processes is crucial for addressing the often inequitable displacement of human populations due to coastal changes.