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DIFFERENT BEHAVIOR Hubbard Glacier is advancing in a world (and a region) where most are retreating.  There is is, the front of it anyway, the white streak just above the water between the two land masses, in the picture to the right. To locate its position in Alaska, look at this map, which is in a US Geological Survey (USGS) web site.  I took the picture from Disenchantment Bay, somewhere in the the word "Disenchantment" on the map.  Russell Fjord (see map) is out of sight behind the land mass on the right.  The two smaller glaciers coming down on the left are out of sight behind the land mass on the left.  You will see Valerie Glacier on a couple of the pictues below.

Hubbard Glacier has retreated since the year 1130, as shown on the map, but has been moving ahead recently, as indicated by the arrow on the map.

That is a cruise ship called the "Summit" that belongs to the Celebrity Cruise Line up there.  It is still about six miles from the glacier, about at the last "t" in the word "Disenchantment" on the map.  Later, my ship, the "Volendam" of the Holland America Line, got up there that close. On the extreme left, there is Turner Glacier, the larger of the two small glaciers to the left of Hubbard.  It is now peeking around the land mass on the left.

A GIANT FLOOD

Refering to that USGS Map one more time, notice how close the front of the glacier is to cutting off Russell Fjord.  In fact, it did cut it off twice -- once in 1986, between May and October, and once in 2002.  Then the water running into Russell Fjord through various streams could not go anywhere.   In 1986 the dam it formed backed up the water in Russell Fjord to a height of about 80 feet above sea level before the dam broke.  Then the excess water emptied into the ocean a single day, the largest such outburst in North America in the last 10,000 years.  You probably didn't read about it in the disaster news, because the only thing to be flooded was the ocean itself.  In fact, there was more of a flood threat before the dam broke as the Russell Fjord lake threatened adjacent areas. The 2002 event was not quite as large, but the same process did repeat itself.  It will probably happen again, too.  Click here for more information and some great photos of the 2002 dam and outburst.  Here is a some information about the problems another closing of the Fjord might cause.

There is the front of Hubbard and Valerie Glacier coming down the mountain above it. Valerie Glacier has been known to "surge", or gallop ahead up to 100 times faster than normal,  which might be contributing to the advance of Hubbard.  But that is not the whole story.

Here is a closer look at the left side of Hubbard Glacier.  Turner Glacier is out of sight to the left in this picture.   Valerie Glacier is above Hubbard here, but there is a better picture of it to the right.

A close look at the front of Hubbard Glacier, which is a tidewater glacer, in fact the largest tidewater glacier in North America.  It is called that because it ends in an arm of the ocean, where there are tides.  There is part of Valerie Glacier above it, too. Did you notice all the floating ice in the water in these pictures?  These tidewater glaciers tend to loose mass by calving, a word which refers to chunks of ice falling off of a glacier.  I didn't get to see this one calve, though.  See my sections on Northwestern Glacier and Margerie Glacier for some pictures of calving.

Actually, I think that most of this floating ice came from Turner Glacier, the one to the left of Hubbard.  That's it in this picture.  The ship couldn't get as close as usual because of all that floating ice. Another small glacier, Haenke Glacier, the other small one next to Turner, does not reach the water and so is not visible here.  Go here and scroll for a picture of this. Notice the ice at the right side of this glacier is very dirty.  I was told that much of the front of it was that dirty not too long before my visit.  But the dirty ice broke off and filled the water.  Look just below for a couple of pictures of that dirty, floating ice.

So what is going on with this glacier, anyway?  Why would it be advancing when most others are retreating. (Only around 10 or so of Alaska's thousands of glaciers are advancing, and they tend to be the tidewater glaciers on or near Alaska's southern coast.) In general, many (but not all) tidewater glaciers that lose mass by calving are known to defy climate.  Here is a paper that discusses the matter while describing the 2002 closing of Russell Fjord. Among other things, it says that such glaciers "have unusually small ablation areas compared to their accumulation areas".  Just to interpret this, an "ablation area" is where the glacier is losing mass, and an "accumulation area" is where the snow is falling on the glacier to make new glacier ice.  That would allow it to make a lot of ice compared to what it loses. In the case of Hubbard, 95% of the area is accumulation area. Such glaciers also calve into unusually shallow water, which seems to make a difference.  The shallow water is often caused by the glacier's terminal moraine -- the sediment and junk dropped by the glacier as it loses its ice.   In general, the condition of the bottom of the fjord can govern how rapidly the glacier does or doesn't grow. This link takes you to the abstract of a similar paper. More discussion at this USGS site.