USA: Alaska #24 Glaciers of Glacier Bay

Welcome back to this site after our diversion to www.dymusings.com for photos and stories of David’s treks and explorations of parts of China and Mongolia. We hope our regular readers have enjoyed those posts and thank you for joining David for his journeys.

He’s having a rest from travel at the moment and will be off again later in the year.

So to keep all of our armchair travellers out and about and exploring the world, we’ll now return to my journey with David through Alaska’s Inside Passage adventure in June 2015 with National Geographic/ Lindblad expeditions on our small ship Sea Lion. Of course, as I write this from the heat of an Australian summer, Alaska is in the midst of deep winter. But no matter; we can still enjoy more of this amazing part of the world together. I will be posting on Mondays, Wednesdays and Fridays for those who wish to follow these post.

In the last post that I published on this site, (#23 in this Alaskan series), we sailed north through Glacier Bay National Park towards the glaciers that give the park its name. In this post we’ll add photos of some of those majestic glaciers which can only be viewed from the ship… no landings are permitted within this National Park.

Glacier Map

Glacier Map

Glacier Bay needs a full day’s sailing to explore; it covers 3,280.198 acres and we only saw the part visible from our good ship as it meandered its way up through the mountains.

As we sailed, our National Park guide reminded us that when Capt. George Vancouver sailed the Alaska coast in 1794, Glacier Bay did not exist. It lay beneath a sheet of glacial ice several miles wide and thousands of feet thick. Since then, in one of the fastest glacial retreats on record, the ice has shrunk back the 65 miles of our sailing. As it has shrunk, it has unveiled new land and a new bay. It’s as if this area is returning to life after a long winter’s sleep.

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Approaching Margerie Glacier © DY of jtdytravels; P1110593

The first glacier we approached was the Margerie Glacier in the Tarr Inlet. This glacier is about 1.6 km (1 mile) wide and it’s height at the face is about 110m (350 ft) ; that includes the ice that extends underwater for a depth of 30m (100 feet). Although at this point the glacier still looked far away and not too large, it grew in grandeur as we approached. 

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Margerie Glacier © JT of jtdytravels; P1140228

Margerie Glacier extends up into the mountains for a length of 34 km (21 miles) to its source on the southern slopes of Mount Root.

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Margerie Glacier © JT of jtdytravels; P1110602

We were able to clearly see the black lines of moraine… the dirt and rocks that are carried down with the ice towards the terminus.

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Margerie Glacier © DY of jtdytravels; P1110605

We were able to get close enough to see the deep blues in the fissures in the ice.

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Margerie Glacier © JT of jtdytravels; P1140231

We were told that an iceberg’s colour often reveals its makeup; dense bergs are blue, while those filled with trapped air bubbles are white.

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Margerie Glacier © JT od jtdytravels; P1140235

There were many wonderful ice sculptures to hold our attention.

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Margerie Glacier © JT of jtdytravels; P1140253

Some seemed to be on the verge of breaking away to calve into the bay.

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Margerie Glacier © JT of jtdytravels; P1140255

Ice has been a major force in the Glacier Bay region for at least the last seven million years. However, the glaciers we gazed at with such awe, are remnants of ‘ The Little Ice Age”… a general ice advance that began about 4,000 years ago.  The ice here reached its maximum extent about 1750, when general melting began.

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Margerie Glacier © JT of jtdytravels; P1140219

This is a good example of the layering effect of a glacier… layer upon layer of ice with layers of moraine trapped in the ice for perhaps centuries.

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Margerie Glacier © JT of jtdytravels; P1140258

We were lucky enough to see several calvings of ice from the face of the glacier. It’s just difficult to get your timing right for photos! You can be watching one end of the face, when with a loud creak and crash, the ice falls from another part. But you always hear them. When the ice hits the water it sounds like a cannon shot. “White thunder,” the Tlingit called it, ‘the awesome voice of glacial ice’.

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Margerie Glacier © JT of jtdytravels; P1140252

The remains of a calving break up into various sized icebergs that float off down the bay. Blocks of ice up to 200 feet high sometimes break loose and crash into the water.

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John Hopkins Glacier © JT of jtdytravels; P1140294

Without doubt, the most majestic glacier in Glacier bay National Park is the John Hopkins Glacier. It’s 19 km (12 m) long and cannot be approached too closely by ships… the bergs that carve here are too large for safety. And, anyway, this is a favourite safe haul out for harbour seals… well away away from predators, especially when they are pupping.

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John Hopkins Glacier © JT of jtdytravels; P1140303

With a long distance lens, the ‘roads of moraine’ are clearly visible.

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John Hopkins Glacier © JT of jtdytravels; P1140299

John Hopkins is one of the several huge tidewater glaciers that flow out of from these mountains and down to the sea.

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A retreating glacier © JT of jtdytravels; P1140327

Our guide told us that scientists come here regularly to study glacial retreat; this area is called by some “a living laboratory for the grand processes of glacial retreat, plant succession, and animal dynamics. It is an open book on the last ice age.”

As we sailed between glaciers, we saw that much of the very rugged, more recently deglaciated land was beginning to host some vegetation.

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A retreating glacier © JT of jtdytravels; P1140324

Several glaciers were continuing their retreat back into the mountains.

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Lamplugh Glacier © JT of jtdytravels; P1140353

Lamplugh Glacier was my favourite of all the glaciers. It rises 45 to 55 m (150-180 ft) above the waterline and goes down 3 to 12 m (10-40 ft) below. The Lamplugh is immense; almost 1.2 km (3/4 ml) wide. It flows for 26 km (16 ml) from its source at a rate of 365 m (1200 ft) per year. They are pretty impressive statistics; but not as impressive as being there, right there… close up to such grandeur!

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Lamplugh Glacier © JT of jtdytravels; P1140335

While we were enjoying the spectacle of such a wonderful glacier, our guide gave us brief explanation of the formation of a glacier. Up in the high mountains, at the source of the glacier, it’s so cold that none of the snow melts even in the summer… so the snowfall exceeds snowmelt. Over time, that snow pack builds up until the weight of the upper, newer, layers of snow press down on previous layers of snow, deforming the flakes beneath and changing them into granular snow, like round ice grains. I was amazed to learn that individual crystals can sometimes grow the size of a football. Air trapped between the snowflakes is also frozen into the ice at this immense pressure.  Eventually the granular snow becomes solid ice, many, many meters thick.

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Lamplugh Glacier © JT of jtdytravels; P1140339

The ice near the bottom of the glacier is under such tremendous pressure that it flows almost like plastic over the rock beneath. Friction between the glacier and the bedrock produces meltwater which also allows the ice to slide. In places, you can see a cave like section under the glacier where the lowest layer of ice has melted away.

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Lamplugh Glacier © JT of jtdytravels; P1140349

It’s fascinating to watch large chunks of the ice calve off forming icebergs, some so large they might last a week or more as they deteriorate and melt way. Icebergs provide perches for bald eagles, cormorants, and gulls, as well as haul-outs for seals.

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Lamplugh Glacier © JT of jtdytravels; P1140352

We heard the mighty crash and splash as more ice fell into the bay. Spectacular! But it was also a timely reminder that icebergs are in retreat in many places around the world… and that’s not a good scenario for rising sea levels.

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Lamplugh Glacier © JT of jtdytravels; P1140359

Here, we were able to witness the start of an iceberg’s journey down towards the sea. Earlier in our journey, we’d had the privilege of getting up very close to icebergs in our inflatables. Then, we’d actually heard the crackles and pops as ancient, long-trapped air was released from the ice.

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Retreating Glacier © JT of jtdytravels; P1140314 2

Too soon, it was time to sail back south away from the glaciers. There, on slopes which had been deglaciated 50 to 100 years ago, we saw alder and willow growing in the moraine close down to the shore. Rocky areas and cliffs, exposed within the last 30 years, had patches of pioneering plant life such as mosses, mountain avens and dwarf fireweed. And on the crest of the view was the last vestige of yet another retreating glacier.

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Leaving the glacier zone © DY of jtdytravels; P1110591

The further down the bay we sailed, the more vegetation we saw. This new vegetation has created habitats for wolves, moose, mountain goats, black bears, brown bears, ptarmigan, and other wildlife; all in an environment less than 200 years old. Our park ranger guide told us stories of her camping trips in the wild here and of her contact with some of these animals… up close and personal! A little too close and personal for my liking!

The sea here also supports a wide variety of life; salmon, bald eagles, harbour seals, harbour porpoises, killer whales and humpback whales… and its the story of one particular whale that will be the centre of our next Alaska posting.

Jennie and David

All photographs copyright © JT  and DY  of  jtdytravels

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