Fjords (pronounced fee-YORDS) are typically long, narrow valleys with steep sides that are created by advancing glaciers. The glaciers leave deep channels carved into the earth with a shallow barrier, or narrow sill, near the ocean. When the glaciers retreat, seawater floods the deeply incised valleys, creating estuaries. Fjords tend to have a moderately high input of freshwater. In comparison, very little seawater flows into the fjord because of the sill. In addition, the sill prevents deep waters in the fjord from mixing with deep waters of the sea. This poor water exchange results in stagnant, anoxic (low oxygen) water that builds up on the bottom of the fjord.
Not surprisingly, fjords are found in areas that were once covered with glaciers. Glacier Bay in Alaska and the Georgia Basin region of Puget Sound in Washington State are good examples of fjords. Fjords are also found throughout Canada, Chile, New Zealand, Greenland, Norway, Siberia, and Scotland.
This satellite image of Glacier Bay Alaska shows many characteristic long narrow fjords that have been carved out of the surrounding terrain by advancing glaciers.