Alaska, Part II -- Glaciers

     Making our way down the coast, my wife and I had become just 2 of the 40,000 or so cruise passengers to travel the Alaskan coast that week, which is the average number of weekly cruise passengers during these summer months.  Throw in the freighters, trawlers, and the many smaller fishing boats we would occasionally see (for darkness at night was rare due to being so far north this time of year) and these waters seemed well used.  But then all of that was in the mind of the beholder because as with the forests and the horizon, the waters seemed (and were) vast.  And apparently warming, their surrounding temps now matched the outside air said our captain, a warm 60F degrees both in and out of the water as we neared Glacier Bay.  It had taken an entire day and night of sailing but the glaciers were now coming into view, and by the afternoon we would be closing in on North America's largest tidewater glacier, that of the Hubbard.*  

The "galloping glacier," as Hubbard is nicknamed, is one of the very few glaciers throughout the world which is actually growing in size, its caterpillar-like advance into the ocean hiding the fact that some 400 years earlier, that same ice now about to "calve" into the ocean started out as a mere flakes of snow that fell 76 miles further up on Mt. Logan, which is the 2nd tallest mountain in North America said Dr. David Ploud, marine biologist and the guest speaker for part of this cruise.  By reaching the ocean, that earlier snow had been compacted down by ever more layers of snowfall and was now so condensed and compressed that it had grown to a mammoth 40-story wall of blue-hued ice ready to give way to gravity and break off as it readied its return to its watery origins.  Along the way it had passed over mountains and rounded their tops, grinding the rocks and boulders into dust so fine (geologists call this glacial silt) that if you placed a cup of this "muddy" stirred up water from the water's edge it would take nearly a week for it to return to its normal gray-green color if set on your kitchen counter (the water is free of impurities and crystal-clear when captured at its top as meltwater).  As the ice grew denser and denser, air was forced out and thus left little room for light to reflect off of so its color changed from the airy white fluff one would ski down to an azure blue to, in the end, a chunk of almost-clear ice.  And by reaching the ocean, it had become a part of an elite group of glaciers that actually made it all the way to the sea for less than 1% do so and become tidewater glaciers.

    Here is how I described glaciers in a post some years ago: Alaska is home to over 100,000  glaciers (although just over 600 of those have been named), which sounds like a massive number but geographically those glaciers cover just 5% of the state.  And geologists have specific parameters for the qualifications and necessary ingredients which are needed for a glacier to form.  For one thing, a minimum of 150+ inches of snow must fall, all of which must transform itself from snowflakes to granules to a denser pack (which they term "firn") to even coarser grains...then ice, ice and more ice building layer upon layer onto itself.  And even though most of today's glaciers formed 10-15,000 years ago, what you see as you stare at their visible wall ahead is just the past 400 years of growth, despite their being 300-500 feet tall (which doesn't seem THAT tall until you see a kayak or small boat being buried by a wave when a piece of the glacier breaks off; that spectacular view those brave or foolish boaters took will all of a sudden turn into a rescue operation).

Lifeboats ready, in case...

     Ice, said Dr. Dave, floats...and sticks.  Reach into a freezer to grab a handful and you'll find a few stray cubes clinging onto your hand if the ice is dry, the same quality that allows glacial ice to pick up those rocks and boulders as it moves slowly downward over the centuries.  The ice continues to make it way to the top and it's a good thing that it does since the euphoric, or light zone of the sun only extends 100 to 200 meters (think deep blue sea); as the light diminishes, so too does the heat.  In other words, if ice sank to the bottom we would have vast areas which would never melt.  Have that tidewater glacier carve out a valley, one which soon flooded with seawater, and it would become a fjord, said the speaker (think Norway or places such as Milford Sound in New Zealand), adding that in Alaska only 616 of the glaciers have been named which leaves just over 93,000 other glaciers in the state awaiting names.  One final tidbit, he told us, an iceberg is but a small part of what floats out into the ocean (10% is all that is visible in an iceberg)...the rest of the floating pieces are called branches, growlers, and bergy bits (a small bit of trivia: when air begins to re-enter the compressed ice on those small floaters, it creates a fizzy sound appropriately called "bergy seltzer").  On an earlier cruise some years ago when we toured the southern half of the coast, we were able to get rather close to the Dawes glacier; but this time the threat of large floaters in the water was too risky so the captain felt it safer to stay a good half mile back (the lifeboats being out perhaps emphasized this to us passengers, at least those of us not wanting to reenact the Titanic scenario).

     So glaciers...turns out that there was a lot more too them and despite all of the mis-information out there, the National Park Service did its best to highlight the basics such as the question: Alaska was covered by glaciers during the Great Ice Age (Pleistocene)?  No - interior Alaska was a grassland refuge habitat for a number of plant and animal species during the maximum glaciation.  Or this one: What about the mammoths and giant bison found in ice?  The remains of prehistoric animals are indeed found in ice, but not glacier ice.  Or perhaps the most common question: Why are glaciers blue?  Because the red (long wavelengths) part of white light is absorbed by ice and the blue (short wavelengths) light is transmitted and scattered.  The longer the path light travels in ice, the more blue it appears.  So... why is snow white?  Light does not penetrate into snow very far before being scattered back to the viewer.  The US Geological Service dispelled a few more myths, such as: How much of the Earth's water is stored in glaciers?  About 2.1% of all of Earth's water is frozen in glaciers.  97.2% is in the oceans and inland seas...0.6% is in groundwater and soil moisture less than 1% is in the atmosphere less than 1% is in lakes and rivers less than 1% is in all living plants and animals. About three-quarters of Earth's freshwater is stored in glaciers.  And finally this surprising detail: Where are Earth’s glaciers located?  Glaciers exist on every continent except Australia.  Approximate distribution is:91% in Antarctica, 8% in Greenland, less than 0.5% in North America (about 0.1% in Alaska), 0.2% in Asia, less than 0.1% are in South America, Europe, Africa, New Zealand, and Indonesia.  So that last bit, in case you missed it: 1/10 of one percent of the world's glaciers are in Alaska (and didn't they just say Alaska had an estimated 100,000 glaciers?).  A graphic in Scientific American made it a bit easier to visualize the variety of glaciers in the world...

   

     Now about those light waves, all those photons and stuff taking 100,000 years to escape the gravity of our sun (I tried my best to explain a tiny bit of this in an earlier post), here's how Ed Yong explained light in the deep blue sea: To dive into the ocean is to enter the largest habitat on the planet -- a realm with over 160 times more living space than all the ecosystems on the surface combined.  Most of that space is dark.  At 10 meters down, 70 percent of the light from the surface has been absorbed.  If you were descending in a submersible, anything red, orange, or yellow on your person would now look black, brown or gray.  By 50 meters, greens and violets have largely vanished, too.  By 100 meters, there is only blue, at just 1 percent of its surface intensity, if that.  By 200 meters, the start of the mesopelagic or twilight zone, that intensity has fallen by another 50 times.  The blue is now almost laser-like -- eerily pure and all-encompassing.  Through it, silvery fish dart about.  Gelatinous jellyfish and siphonophores slowly snake past.  At 300 meters, it's as dark as a moonlit night, and getting darker....At 850 meters, the residual light is so faint that your eyes can no longer function.  At 1,000 meters, no animal eyes can...Depending on where you are in the world, there might be another 10,000 meters of ocean left to go.

     Unfortunately, life in those deep blue waters was emptying wrote The London Review: Oceans​ account for 96 per cent of all habitable space on Earth.  Scientists have mapped the surface of Mars and Venus more closely than they have the seafloor, with its as yet unnumbered trenches and seamounts.  Yet many marine species that once teemed in their millions have been harried close to extinction by nets, longlines and harpoons.  The scale of the loss is mind-boggling.  For every three hundred green turtles that swam the Caribbean before industrialised fishing, just one is left.  Ninety per cent of the world’s large fish and oyster beds have gone.  Seagrass meadows are disappearing at a rate of 7 per cent per year.  Only one in twenty blue whales remain.  This carnage required immense, dogged effort, and a blizzard of technology (from sonar to drones to so-called Fish Aggregating Devices), nets that could swallow a Boeing 747 and longlines that extend for a hundred kilometres, snagging everything in their path.  These nets and lines have been dragged through the sea by vast fishing fleets dominated by a dozen or so large corporations.  The operation has relied on an indulgent political class.  The fleets have been fuelled by huge public subsidies, even as they destroy coastal livelihoods.  They have largely avoided scrutiny over decarbonisation – an impressive feat, as Charles Clover observes in Rewilding the Sea, since bottom trawling alone releases as much carbon as the entire aviation industry.*  Fish are resilient and hugely fertile.  It took nearly a hundred years of industrialised fishing to dent their numbers.  Global catches have been dropping since the 1980s, a fact the industry has gone to some lengths to conceal.  The hunt goes on, reaping fewer and fewer rewards.  A typical wooden fishing boat in 1900 could catch sixteen times more fish in an hour than its contemporary equivalent...Carbon emissions on land are causing the oceans to acidify ten times faster than at any point in the last 65 million years.  As the oceans get warmer, heat stress causes coral polyps to expel the algae they depend on for nutrition.  Mass coral die-offs are becoming more common.  

Glacial silt stirred up from the boat turning

    Our polar regions protect life as we know it only as much as we protect them, wrote senior international climate and environment correspondent Aryn Baker in TIME.  A warming Arctic is not just a warning.  It has the potential to take us with it in its demise...A fundamental part of human nature is to want to pass something on to the next generation that symbolizes our values, be it a cultural tradition or material goods earned over a lifetime of labor. If my daughter inherits a damaged planet, racked by heat waves, befouled with a plastic tide, and witness to waves of climate migrants fleeing uninhabitable lands, what does that say about the values my generation cultivated in its dogged pursuit of perpetual growth?  

    As if symbolic of our own turning away, our ship did a 180 degree turn and churned up the silt (the waters were 720 deep below and still the silt stirred); we marveled at the surrounding mountains that had already been carved out, their ice long melted and the mountain bowls and valleys now acting as little more than reservoirs for next winter's snow.  This land was vast but it seemed obvious that the waters were even larger, more than ready to swallow everything with ease.  And yet somehow, it all still worked, a symbiosis that showed life on a grand scale.  For me, this was just the icy world, a small glimpse of a world we were leaving as we ventured further south.  Gazing at a map, it didn't seem much further south for we were heading down to Sitka, then back up to Skagway, then back down to Juneau (there must be a good reason for such routing).  But by heading into the protection of the many islands --the Inland Passage-- we would be venturing into the so-called banana belt where warmer temperatures would drop snowfall to less than a foot in most winters.  Our arrival had a forecasted temperature of 70F degrees, a far cry from the glacial chill we were leaving.  But nestled in a ship's cozy cabin, surrounded by food and sharply dressed attendants and crew, all highlighted by a dazzling array of lighting, one couldn't help but feel that little of this, outside or in, was real.  We were fortunate to be taking it in now, not only because the future climate may prove even more iffy, but so too our later years in life.  This (the land and the seas, not the cruises) had been here way before us and would likely be here long after.  In truth, humanity shared a lot with these glaciers, ebbing and flowing, carving down mountains and in the end, returning to our watery beginnings.  We were here and fortunate enough to be having a chance to see and absorb and learn.  This was the vastness of life out here, a form strikingly different from what we saw in Africa but it was life in its diversity...maybe all we had to do now was to hope that we could help future generations be able to see it as well.

Unfortunately, our ship couldn't get as close as we did to Dawes glacier some years ago...

*Hubbard glacier was named after Gardiner Hubbard, the first president of the National Geographic Society.  Also, I neglected to mention on the last post that the AlCan (Alaska/Canada) Highway was rushed through after the attack on pearl Harbor (really!) for the Japanese then went on to capture a small island in the Aleutian chain, one which surprised the U.S. in its vulnerability and cost them a year in fighting just to take back.  The result was the establishment of several large military bases throughout the chain, as well as the rapid building of the highway to connect Alaska itself to the rest of the United States.  The nearly 1400-mile long Alaska Highway was started and completed in a little over 8 months, along with the longest highway tunnel in north America, the Anton Anderson Memorial Tunnel (who's that, you ask?)...