Mount St. Helens, glaciers, and climate change

This week is the 30^th anniversary of the 1980 eruption of Mount St. Helens, by far the 48 state’s largest eruption and including the largest landslide in Earth’s recorded history.  It was “the deadliest and most economically destructive volcanic event in the history of the United States.”  Many things about Mount St. Helens relate to all the Earth sciences including climate change, with several useful metaphors as well.

Our guest blogger is long-time commenter Richard Brenne.

Brenne is an award-winning screenwriter who teaches a NASA-sponsored on-line Global Climate Change class and serves on the American Meteorological Society’s Committee to Improve Climate Change Communication.

At 8:32 am on Sunday, May 18 I was summiting Mt. Whitney, the highest mountain in the 48 states and then skiing off with two climber friends who’d also climbed St. Helens many times.  We were 800 miles south in the Sierra and couldn’t have seen, heard or felt anything from Mt. St. Helens itself but felt as much shock as we could listening to radio accounts all the way home.

Volcanoes are central to our history and the history of all life on Earth.  During the largest extinction of life on Earth 251.4 million years ago during the Permian Extinction, one of Earth’s greatest mantle plumes led to a million years of volcanic eruptions in what are called the Siberian Traps (Swedish for steps) that could cover the 48 U.S. states in up to a mile of lava.  Volcanoes can release CO2 on their own, and also the lava from the Siberian Traps probably ignited coal seams that spiked CO2 and temperatures (the two are closely correlated) that only explosive volcanoes with particulates blocking the sun dropped.  Otherwise Earth’s climate could have run away toward that of Venus, which is the scenario that NASA’s Jim Hansen, the ultimate authority on both Venus’ and Earth’s atmospheres, fears we could be creating today.

At the bottom of page 236 of his 2009 book “Storms of My Grandchildren” Hansen says that if we burn all available fossil fuels including tar sands and oil shales,  he’s “Dead certain” that Earth’s climate would move toward that of Venus’ and create a dead planet.

The asteroid that exploded into Earth near the Gulf of Mexico’s shoreline with the Yucatan Peninsula 65 million years ago might have triggered the smaller but still significant Deccan Traps of India that could’ve covered the 48 states with 600 feet of lava.

More recently  about 73,000 years ago the super volcano Toba erupted with over 2300 times the power of the Mt. St. Helens eruption (though with minimal lava, nothing like the Siberian or Deccan Traps that are mostly immense oozes of lava, only punctuated by explosive eruptions).  Volcanologists, geneticists and anthropologists all feel that the resulting six-year particulate winter (similar to what a nuclear winter could bring) dropped the human population down from millions to only a few tens of thousands of people.

Our growth to a quarter of a million times that many people (meaning for every person alive 73,000 years ago there are around 250,000 alive today) means that we’ve gone from almost dying out as a species to maybe growing ourselves to death.

On April 10, 1815 Mt. Tambora erupted with over 100 times the force of Mt. St. Helens and like Toba (and unlike St. Helens and Iceland’s currently erupting volcano, which are also much smaller eruptions, when the eruption happens near the equator it can circulate more widely and have a global and not just regional impact) the resulting particulate winter caused 1816 to be called “The Year Without a Summer.”   Estimates are that over 200,000 Europeans died due to famines caused by the dramatic climate change that didn’t allow summer crops to grow in many places, and many New England farmers suffered similarly and the year without a summer helped accelerate migration into the Midwest.

Because of this lag time of over a year, I’ve never understood why those expecting to see the effects of the Pinatubo eruption in 1991 were expecting to see results within just a few months.  NASA’s Hansen attended a conference months later and famously said, paraphrasing Einstein, “I think this is a case where the models are correct and so far the Earth is not.”  After a few more months global temperatures came to closely mirror Hansen’s and NASA’s predictions, validating climate models accuracy as nothing else could.  (Hansen had wished for just such a volcanic eruption and got it within a short time of his asking, which makes me listen to him all the more since it sounds like he might have some fairly lofty connections.)

Nothing about Mt. St. Helens is anywhere near as dramatic as any of these events globally or even locally, although it blew off its top 1300 vertical feet and most of a cubic mile, about as much as any Eastern ski area or say all the buildings in an immense city like New York.  It had the power of 100,000 Hiroshima bombs, and it was the massive landslide that not only filled the valley on the north side with up to 600 feet of debris, but sloshed Spirit Lake 800 feet up and then filled in 200 feet of land by the time it sloshed back, about half as deep but with twice the area (always remember volume vs. area when discussing glaciers or Arctic sea ice).

The landslide from the 9,677 foot summit to the 2000 foot valley below then climbed up 2000 vertical feet to kill volcanologist Dave Johnston, whose last words were ham-radioed to headquarters, “Vancouver, Vancouver, this is it!”  Johnston was such a true scientist that his fellow scientists who heard him on the radio that day told me his voice was more excited than fearful.  A 300 mph blast of searing hot gas reached him before the landslide did, and that blast exploded immense trees into kindling and toppled them up to 20 miles away, all because the landslide created more of a lateral blast to the north than volcanoes much more common vertical blasts.

This is what you call an act of God, with no human causes or triggering but with human infrastructure damaged because it was in harm’s way.  For Governor Perry of Texas to call the BP oil volcano an “Act of God” makes one imagine his TV-quality head of hair must’ve taken over his brain and be speaking for him.

Mt. St. Helens impacted a mostly wild or logging area along with a small resort area in one state.  The BP oil volcano could devastate the fishing grounds and coastlines of Louisiana, Mississippi, Alabama and Florida, with smaller impacts possible on even the east coasts of Florida, Georgia, South Carolina and North Carolina.  If thousands worked and played in the devastated area of Mt. St. Helens, myself included, millions work and play in these coastal waters.  Maybe my biggest fear is that the gentle and delicate eco-system of the Louisiana bayous that does more than anything to shelter New Orleans from hurricane storm surge could be devastated and much of the vegetation die off.  This would add to the Mississippi River levees not allowing silt to regenerate the bayous, the hundreds of miles of canals built to install and service oil and gas wells and pipelines, and the introduction of the non-native nutria from South America (the beaver-rat hybrid eats up to 25,000 acres of marshland a year) in creating open water at the expense of the bayous essential for New Orleans’ (at least temporary) safety.

Lewis and Clark imagined Mt. St. Helens to be America’s tallest mountain at 9,677 feet even though nearby Mt. Rainier (14,410), Mt. Adams (12,281) and Mt. Hood (11,249) tower over it.  But they paddled much closer to Mt. St. Helens and for much longer than the others as the Columbia curves around it.  Mt. St. Helens is even visible from much of the Astoria area where Lewis and Clark spent the winter of 1805-1806 camping and at Fort Clatsop (where I’ve given a talk about the very different climate Lewis and Clark encountered than the one we have today).

Storms come up the Columbia and slam into Mt. St. Helens, that has 1300 vertical feet less of orographic precipitation to encourage clouds to drop their moisture at the summit, but hundreds of feet were added to northern landscapes.  It gets much less snow in these northern areas than it used to because of the deforestation – forests recycle water far more efficiently than non-forested landscapes and also shade snowpack -  but also because the global climate has changed so much since 1980.  A degree and a half F global average temperature increase in the last hundred years – with more than half of that coming since 1980 – translates to almost a three degree increase at the latitude of Mt. St. Helens at 46 degrees north latitude.

Mt. St. Helens sterilized much of the immediately surrounding landscape and the nitrogen and phosphorus that are critical to productive soils has kept much of the landscape barren.  Interestingly the survivors were like our shrew-like mammal ancestors surviving the KT asteroid extinction event 65 million years ago, so I felt some vague, deep and dark ancestral memory as I gazed out at that landscape again last Saturday.  Also global agricultural experts are worried about the world reaching peak phosphorus, so hopefully that bleak landscape isn’t also a glimpse into our global future.  I’m afraid it might well be, because when an old-growth forest is replaced with even high desert, a positive climate feedback in addition to poor soil conditions can prevent forests from returning indefinitely.

Oddly the leading ecologists and other scientists who’ve studied Mt. St. Helens the most aren’t yet factoring in how dramatically the climate has changed since 1980, something that surprised and disappointed me when I asked them about it recently.  In the current issue of National Geographic they have a timeline that concludes by saying, “Within 200 years everything will grow back the way it was before the eruption.”

How the National Geographic editors that usually do such a great job with climate change missed mentioning climate change here mystifies me.  Kevin Trenberth tells me he thinks hardly any trees living today will be alive in 200 years because the climate they grow up in will have changed so drastically.  This includes trees like the towering, shade-giving sycamore in our backyard that is supposed to have a 600 year life span.

Two hundred years from now an entirely different eco-system will have taken hold once soil productivity allows it, but I’m thinking it could be like what we see at the same elevations of mountains maybe a thousand miles south near the Mexican border or even two thousand miles south near the southern tip of the Baja Peninsula, which are high desert devoid of large trees or most other vegetation.

When my daughter Sarah was nine we climbed to the top of Mt. St. Helens and skied off, something we repeated last summer and hope to repeat every summer.  On July 2, 2002 during a good snowpack year Sarah skied all the way down to the trailhead (during an arid stretch above the forest she walked a mile and a half in Alpine ski boots when I avoid walking a foot and a half in my boots if I can help it) almost a vertical mile below the summit.

A hundred years ago the likelihood of doing of that would’ve been high.  Even before the 1980 eruption the likelihood of being able to do that would’ve been much higher than the likelihood today.   (The eruption blew out to the north, we ski the south side that had little volcanic impact.)  Last year in 2009 there was a good snowpack by current standards and we had to walk the last 1500 vertical feet on June 17.  This year despite a cool, wet spring there will probably be even less snowpack when we plan to do it with glaciologists and hydrologists June 6 (e-mail me at rabrenne@hotmail.com if you’re interested in joining us).

Since the eruption in 1980 transformed a symmetrical Fuji-like cone into a north-facing amphitheater, the world’s youngest and most rapidly-growing large glacier has taken dramatic hold, fighting the lava dome that has grown over 1300 feet in two stages since 1980.  Many parts of Mt. St. Helens gets 140 inches of precipitation a year, with most of that falling as snow up high, and most of the steep north-facing slopes feed the glacier with avalanches and rock fall, making the glacier 40% rock.  (At the summit on a warm summer day you hear almost continuous rock fall someplace into the crater.) Although the lava dome has pierced it (perceptive rangers could see changes in the lava dome often from one day to the next, rising or collapsing in the last eruptive period from 2004 to 2008), Crater glacier now circles the dome, with east and west arms meeting below the dome.

Crater glacier has grown by up to 50 feet in thickness and advanced 130 feet a year, averages 330 feet and at its thickest is 656 feet thick, close to that of the 48 states largest glacier, 5.7 mile-long Carbon glacier on Mt. Rainier 50 miles north.

While around 90 per cent of the world’s glaciers are retreating and about five per cent are stable, like Crater glacier about five per cent are advancing.  The largest of these are Alaska’s tidewater glaciers like the Hubbard glacier that’s 76 miles long and descends from up to 18,000 feet on Mt. Logan.  Calving glaciers are oddly immune to changes in climate, and like Hubbard some have been advancing over the last 100 or 150 years while most the world’s glaciers are retreating, and oddly they were retreating during the Little Ice Age.

The Cascade Mountains hold the world’s record for measured snowfall, with 95 feet of snow falling on Mt. Baker near the Canadian border in 1999, breaking the record at Paradise on Mt. Rainier in 1971-72, the time I started climbing these mountains.  On high mountains with average yearly temperatures far below freezing like the summit of 14,179 foot Mt. Shasta have increased in volume from 1951 to 2002, with two of them even doubling, and this despite an estimated 3.6 to 5.4 degree Fahrenheit local temperature increase during this time, because when someplace with sub-freezing temperatures has temperatures climbing toward freezing where greater snowfall takes place, snowpack and glacier-feeding from above can be increasing even while there’s significant melting from the bottom of the glacier up.

And always remember that with glaciers or Arctic sea ice melting, the volume is more important than the surface area.  Crater glacier on Mt. St. Helens encompasses only 20 per cent of the previous surface area of all the mountain’s pre-1980 eruption glaciers, but because of such ideal glacier-making conditions matches those glaciers in total volume.

Of course there will always be good snow years and bad snow years relative to the average for the current decade, but my guess is that there will be few times anyone could think of skiing all the way down to the trailhead on July 2 in any foreseeable future.  Just as it would’ve been likely a century ago, it will probably be extremely unlikely a century from now, probably even laughable to consider.  In fact any consistent snowpack might rarely reach that 3800 elevation at any time of year a hundred years from now.

When Mt. St. Helens experienced its first large (4.2) earthquake March 20, 1980 and volcanologists rushed to study it more closely, they closed the mountain and surrounding area as the harmonic tremors signaling the rise of lava in its throat increased.  The owner of Spirit Lake Lodge was an 83-year-old curmudgeon oddly named Harry Truman like the president born a decade earlier.  When sheriffs listening to the best knowledge and advice of scientists evacuated the area, Truman refused to leave, saying the threat of the mountain was “over-exaggerated” and “The mountain’s not gonna hurt me, boy,” invariably with one of a seemingly endless supply of rum and cokes in his hand.  Truman’s refusal to leave helped prevent sheriffs from closing the area to others and so Truman’s stubbornness (sheriffs had said that his rum-inspired bravado – evidently he’d been a rum-runner during Prohibition – for cameras was countered by their finding him cowering and weeping in fear in his basement) contributed to some of the other 56 deaths.

I’m reminded of all this because the former (largely self-proclaimed) State Climatologist of Oregon George Taylor is a vocal and consistent climate change denier.  He debated then-Washington State Climatologist Phil Mote about climate change but to me it was a very uneven debate, like a dentist debating a noted heart specialist about the link between smoking and heart disease.  Taylor knows weather well but climate change hardly at all, while Dr. Mote is a PhD in atmospheric science who publishes and is thus subject to peer review and was a respected lead author of the IPCC Report.  Taylor has no PhD and doesn’t publish and so is not subject to peer review and thus has no relation to the IPCC Report process.

So listening to Taylor about climate change not being a problem would be like listening to someone with a master’s who studies only Hawaiian shield volcanoes that only produce lava flows and rarely if ever explode saying that Mt. St. Helens was no danger.  I’d rather listen to Dr. Mote and all top climate scientists who’d developed a strong consensus about the human-caused climate change, just as I’d listen to all the top volcanologists who study explosive volcanoes when they warned about the great danger of an imminent explosive eruption.

And so when Phil Mote replaced George Taylor as Oregon’s top climatologist, I introduced him at an event as “Washington’s greatest gift to Oregon since their topsoil during the Missoula Floods.”  (This is funny to an audience of geologists who’ve studied one of Earth’s two greatest floods that flooded the Columbia up to 1200 feet deep and 400 feet deep up the now-fertile as a result Willamette Valley to Eugene, at flows exceeding by 10 times all the rivers of the world.)

My partner in our NASA-sponsored Global Climate Change class Toby Dittrich has also studied the Juneau Icefield for 40 years and is a patent-holding nuclear engineer as well who likes to get things done and can see me as something of a pessimist.  So in one of our on-line classes banter he quoted president Harry Truman saying something like “Optimists get everything done while pessimists get nothing done” and then asked me whether I was an optimist or a pessimist and I answered, “There was another Harry Truman at Spirit Lake Lodge in 1980 who was an optimist.  He said, ‘The mud stops here’ but it didn’t, and now he’s under hundreds of feet of it.  Sometimes optimism isn’t as relevant as realism.”

– Richard Brenne.

Related Post:

• De-Icer: USGS report details “recent dramatic shrinkage” in U.S. glaciers, matching global decline