What was the main source of meltwater that caused sea levels to rise after the last Ice Age?

According to the study, the majority of global sea level rise between 9,000 and 7,000 years ago resulted from the melting of ice sheets in North America, not Antarctica as previously believed.

How did Tulane University researchers make this discovery?

Tulane geologist Lael Vetter found deeply buried marsh sediments off the coast of New Orleans, which allowed the researchers to chart sea level changes over the past 10,000 years with high resolution. An ex-Tulane PhD student, Udita Mukherjee, then matched this data with records from Europe and Southeast Asia, revealing that the Northern Hemisphere was the primary contributor of meltwater.

What are the implications of the North American ice sheets being the main source of sea level rise?

The massive influx of freshwater from the melting North American ice sheets could have disrupted the critical Atlantic Meridional Overturning Circulation, potentially triggering sudden cooling events like the one around 8,200 years ago. This new understanding of the past has important implications for forecasting how future ice sheet melting could impact global climate and ocean circulation.

Home / Science / North American Ice Sheets, Not Antarctica, Fueled Sea Level Rise After Last Ice Age

North American Ice Sheets, Not Antarctica, Fueled Sea Level Rise After Last Ice Age

12 Oct, 2025

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Summary

Majority of sea level rise 9,000-7,000 years ago came from North American ice sheet melt
Newly discovered sediment records in Mississippi Delta provide high-resolution data
Findings require "radical reworking" of ice melt history during this critical period

North American Ice Sheets, Not Antarctica, Fueled Sea Level Rise After Last Ice Age

According to a study published in 2025, the majority of global sea level rise between 9,000 and 7,000 years ago was driven by the melting of ice sheets in North America, not Antarctica as scientists had long believed. The research, led by a team from Tulane University, overturns decades-old assumptions about the sources of meltwater that flooded the oceans as the planet warmed at the end of the last Ice Age.

The key evidence comes from deeply buried marsh sediments discovered off the coast of New Orleans by Tulane geologist Lael Vetter. By radiocarbon dating these sediment layers, the researchers were able to chart sea level changes over the past 10,000 years with unprecedented detail. An ex-Tulane PhD student, Udita Mukherjee, then matched this high-resolution Mississippi Delta record with data from Europe and Southeast Asia, revealing a clear global trend: the pace of sea level rise varied significantly across different locations, indicating the Northern Hemisphere was the primary contributor of meltwater.