Still other glaciers have been in equilibrium or advancing. Some, like the Johns Hopkins, have stopped their retreat and have advanced during the period covered by the satellite record. Also, the Lamplugh, Reid, Margerie and Grand Pacific glaciers are all advancing at this time. And the nearby Brady Glacier has been advancing since 1794. Tidewater glaciers, like the Muir and the Margerie, terminate in the sea.
Tidewater glaciers follow their own cycles that are independent of short-term climate changes.
There are also non-tidewater glaciers near Glacier Bay, many of which are receding. Recession of non-tidewater glaciers in the area is probably due to amelioration of the regional climate. Meteorological data from the nearby stations at Juneau, Sitka and Yakutat show a tendency toward an increase in average summer air temperature since about 1940 when the meteorological record began. Carl Benson measuring snow density Combining the extensive records of explorers beginning in the late 18th century, with more recent efforts of glaciologists and computer scientists, a wealth of information has been obtained about the deglaciation of Glacier Bay, Alaska. And many of the non-tidewater glaciers are excellent indicators of regional climate and climate change.