Facts about glaciers

Malaspina GlacierMalaspina Glacier in Alaska is the world's largest piedmont glacier. The glacier's massive lobe is clearly visible in this aerial photograph taken by Austin Post in 1959. —Credit: Austin S. Post photograph/NSIDC

  • Presently, 10% of land area on Earth is covered with glacial ice, including glaciers, ice caps, and the ice sheets of Greenland and Antarctica.
  • Glaciers store about 75% of the world's freshwater.
  • Glacierized areas cover over 15 million square kilometers (5.8 million square miles).
  • Antarctic ice is over 4.2 kilometers (2.6 miles) thick in some areas.
  • In the United States, glaciers cover over 75,000 square kilometers (30,000 square miles), with most of the glaciers located in Alaska.
  • During the last ice age, glaciers covered 32% of the total land area.
  • If all land ice melted, sea level would rise approximately 70 meters (230 feet) worldwide.
  • Glacier ice crystals can grow to be as large as baseballs.
  • The land underneath parts of the West Antarctic Ice Sheet may be up to 2.5 kilometers (1.6 miles) below sea level, because of the weight of the ice.
  • North America's longest glacier is the Bering Glacier in Alaska, measuring 204 kilometers (127 miles) long.
  • Glacial ice often appears blue when it has become very dense. Years of compression gradually make the ice denser over time, forcing out the tiny air pockets between crystals. When glacier ice becomes extremely dense, the ice absorbs all other colors in the spectrum and reflects primarily blue, which is what we see. When glacier ice is white, that usually means that there are many tiny air bubbles still in the ice.
  • The Kutiah Glacier in Pakistan holds the record for the fastest glacial surge. In 1953, it raced more than 12 kilometers (7.5 miles) in three months, averaging about 112 meters (367 feet) per day.
  • In Washington state alone, glaciers provide 1.8 trillion liters (470 billion gallons) of water each summer.
  • Antarctic ice shelves may calve icebergs that are over 80 kilometers (50 miles) long.
  • Almost 90% of an iceberg is below water—only about 10% shows above water.
  • The Antarctic continent has has been at least partially covered by an ice sheet for the past 40 million years.
  • From the 17th century to the late 19th century, the world experienced a "Little Ice Age," when temperatures were consistently cool enough for significant glacier advances.