Britannica
Sources used in this answer
- A Journey Through Time Since the Precambrian - Quaternary Period: 2.6 million years ago to the present
- paleoceanography
- Quaternary - Sea-level changes
- iceberg - Impacts on ice sheets and sea level
- Pleistocene Epoch - Tectonic and isostatic movements
- Pleistocene Epoch - Coastal environments and sea-level changes
- sea level
How did glaciers change sea level during the Quaternary Period?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
Quaternary
Distribution of landmasses, mountainous regions, shallow seas, and deep ocean basins during the Quaternary Period. Included in the paleogeographic reconstruction are the locations of the interval's subduction zones.
During the Quaternary Period, global sea levels fluctuated significantly in response to the growth and melting of massive continental glaciers. Because the water required to form these extensive ice sheets was drawn directly from the oceans, sea levels dropped substantially during glacial stages and rose during warmer interglacial periods.123
Key impacts of these changes include:
- Sea-Level Lowstands: During the peak of the most recent glacial stage approximately 18,000 years ago, sea levels were roughly 120 to 130 metres (about 390 to 426 feet) lower than they are today.32
- Exposed Landmasses: This drop in sea level exposed vast areas of the continental shelves, creating land bridges such as Beringia between Asia and North America, which facilitated the migration of plants, animals, and early humans.34
- Deglaciation and Flooding: As the climate warmed and glaciers melted, the return of meltwater to the oceans caused rapid sea-level rise, flooding low-lying coastal areas and transforming river valleys into estuaries.34
These fluctuations are recorded in marine sedimentation and the isotopic composition of foraminifera shells, which serve as a proxy for global ice volume.32