SEE GLACIERS THOUSANDS OF YEARS OLD
There are several tidal glaciers in Glacier Bay, Alaska. The glaciers are around 4,000 years old, but the ice in them is about 100 years old – that’s the time it takes for snow and ice to move through the entire glacier. John Hopkins Glacier is about one mile wide, two hundred fifty feet tall above sea level and another two hundred feet deep below sea level.
You can’t appreciate their size until you are close up right next to them – then their enormity hits you. Recent estimates are that these magnificent glaciers could vanish by the end of this century as the climate changes.