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How does present glacier extent and sea level compare to the extent of glaciers and global sea level during the Last Glacial Maximum (LGM)?

The Last Glacial Maximum (LGM) occurred about 20,000 years ago, during the last phase of the Pleistocene epoch. At that time, global sea level was more than 400 feet lower than it is today, and glaciers covered approximately:

  • 8% of Earth’s surface
  • 25% of Earth’s land area
  • 33% of Alaska

Beginning about 15,000 years ago, continental glaciers retreated and sea level began to rise. Sea level reached its current height about 8,000 years ago and has fluctuated ever since.

Today, glaciers cover approximately:

  • 3% of Earth’s surface
  • 11% of Earth’s land area
  • 5% of Alaska.

Learn more: USGS Water Science School - Glaciers: Things to Know