Tuesday, August 29, 2017

Houston's Horrific Flooding: Thank Goodness It Can't Happen Here...Eh...Right? Think Again...

What's happening in Houston is beyond belief. And tragically, horrible flooding is happening now in southeast Asia as well, with at least 1,200 people dead. Although the extent of the damage in Houston is not yet known, meteorologists are already calling it unprecedented in American history. I can't begin to imagine experiencing feet of rain in the space of days, and it isn't over yet. My heart goes out to those in the midst of the disaster. It may take weeks for the waters to subside, and years for the region to fully recover.
This isn't Houston. It is our own much more modest flood a few months ago.

(I've abridged and adapted the following from a post in 2011)

Seeing events like this unfold on television or on the computer screen can provide a certain emotional distance from the full magnitude of what has happened. Thoughts develop along the lines of "Could it happen here?" and as we realize it might, we think "Are we prepared for an event like that?" Floods occur essentially everywhere, but the Central Valley (the GREAT Valley) is notable in the magnitude and frequency of its flooding. We had a experienced a few terrifying days in the early part of the year when it seemed that one of our largest dams, Oroville, was in danger of failing, and we have become aware that almost all our dams are aging, and need maintenance or replacement.  It makes one wonder how bad it could possibly get. Pretty bad, as it turns out.

Climate experts have been analyzing the possibilities that California could be hit by a devastating storm sequence that could leave much of the Central Valley as an inland lake. It sounds unlikely, at best a hypothetical model, but it has actually already happened. In 1861-62, a storm series dropped so much precipitation that a 300 mile long lake covered the valley, and forced the state capital to move operations from Sacramento to San Francisco for a time.
I mentioned Yellowstone in a while back, and it got me thinking once again about those things that are worth worrying about, those that are not, and those that are worth preparing for. Yellowstone last had an eruption 70,000 years ago, and the last major "supervolcano" (i.e. rhyolite caldera event) was more than 600,000 years ago. So how much should we worry about Yellowstone? It could happen, but not likely any time soon. But people are freaked out about the possibility if a quick internet search is any measure. They obsess about it, and even see strange conspiracies.

But what about a "superstorm"? People don't seem to worry about flooding so much, yet huge floods are a disturbingly common occurrence. Besides 1862, evidence has been uncovered of similar intense events in 212, 440, 603, 1029, 1418, and 1605 (sediments from storm runoff are preserved in ocean basins offshore of the state). That adds up to around a 0.3% possibility in a given year; not common, but enough that emergency providers are beginning to seriously consider the possible effects. A report from the US Geological Survey talks about the potential for an atmospheric river storm they have termed an ARkStorm (Atmospheric River Storm). The possible effects make California's expected "Big One" earthquake look, well, medium in comparison. From the USGS ARkStorm Report (PDF download here - 46 mb):
The storm is estimated to produce precipitation that in many places exceeds levels only experienced on average once every 500 to 1,000 years. Extensive flooding results. In many cases flooding overwhelms the state’s flood-protection system, which is typically designed to resist 100- to 200-year runoffs. The Central Valley experiences hypothetical flooding 300 miles long and 20 or more miles wide. Serious flooding also occurs in Orange County, Los Angeles County, San Diego, the San Francisco Bay area, and other coastal communities. Windspeeds in some places reach 125 miles per hour, hurricane-force winds. Across wider areas of the state, winds reach 60 miles per hour. Hundreds of landslides damage roads, highways, and homes. Property damage exceeds $300 billion, most from flooding. Demand surge (an increase in labor rates and other repair costs after major natural disasters) could increase property losses by 20 percent. Agricultural losses and other costs to repair lifelines, dewater (drain) flooded islands, and repair damage from landslides, brings the total direct property loss to nearly $400 billion, of which $20 to $30 billion would be recoverable through public and commercial insurance. Power, water, sewer, and other lifelines experience damage that takes weeks or months to restore. Flooding evacuation could involve 1.5 million residents in the inland region and delta counties. Business interruption costs reach $325 billion in addition to the $400 billion property repair costs, meaning that an ARkStorm could cost on the order of $725 billion, which is nearly 3 times the loss deemed to be realistic by the ShakeOut authors for a severe southern California earthquake, an event with roughly the same annual occurrence probability.
If that doesn't sound like events in Houston, you haven't been paying attention. This is serious stuff.
Flooding rarely gets the epic movie treatment. Volcanic eruptions and earthquakes are so sudden and devastating; rising water just doesn't cut it as a drama setting. I haven't seen a lot of Katrina movies yet. But life isn't a movie. If you live in California, think for a moment about getting hit with a superstorm, and the delta and Central Valley ending up like this:It is a real possibility and a sobering thought....

By the way, not wanting to stir the pot (or maybe I do), if you are worried about Yellowstone erupting and you live in California, why aren't you giving more thought to our very own active rhyolite caldera, our "supervolcano"?

Maps and second photo from the USGS ARkStorm Report (PDF - 46 mb)

Monday, August 28, 2017

Hope and Willful Ignorance: Why I'm Going to Work This Week

There's road rage. There's rage tweeting. And I guess there is rage blogging. I know this because I'm doing it tonight. I'm filled with rage, and feeling somewhat helpless to do anything about it. And yet there is always something that can be done.

I'm watching the horrible events unfolding right now in the coastal region around Texas and Louisiana, where Hurricane Harvey is dropping rain at a rate that defies any kind of normal comprehension. Word is beginning to emerge that 100,000 homes, maybe more, have been destroyed. Even though we don't have a clear picture yet of the full extent of the damage, it's already clear that years will be needed before the region can return to some semblance of normal. It's a tragedy and the effects will extend far beyond the edge of the storm. Many of the nation's oil refineries are in the region, as well as important port facilities. My heart aches for those who have been injured or have died, and those who have lost their homes and businesses.

So why am I feeling so sick inside right now? It's tricky to explain...this was a so-called "act of God" event, one that might be expected to occur once every 500 or 1,000 years. They happen, and as occupants of this planet, we've had to deal events like this throughout our existence as a species. The problem is that these events are happening more often, driven in part by the warming of our planet. And willful ignorance is now killing people needlessly.

As has already been pointed out by many, no single event can be blamed on global warming, but warming is reinforcing the intensity of each event. A common analogy is that no home run in baseball can be pinpointed as the result of taking steroids, but an increase in the frequency and distance of home runs over time can be. Hurricane Harvey may very well have happened if global warming were not an issue, but the Gulf of Mexico was unusually warm. This caused additional evaporation, and helped to increase the intensity of the winds. Sea level is a few inches higher due to warming over the last century, and this intensified the effects along the coast. There are other factors, of course, including increased population and urban development, which destroyed wetlands that could have absorbed some of the storm waters.
Lives were saved this week because of science. Meteorologists and climatologists were able to use incredible technology to predict the trajectory and intensity of the storm days in advance, allowing people to prepare, and to evacuate if they could. Government agencies and emergency services were able to mobilize resources in advance of the disaster. We knew what was going to happen. Science told us.

But we now have people in charge of our government who are willfully ignorant of the extent and even the existence of global climate change. They are using their power to dismantle the very agencies that allowed us to predict the nature of Hurricane Harvey, and this leaves us vulnerable to hurricanes and tornadoes in the future. And it isn't just the climate agencies. Budgets are being cut at the Environmental Protection Agency, the Department of the Interior (except, of course, for oil and gas exploration), the Food and Drug Administration, the Centers for Disease Control, and the National Science Foundation. Science is under attack on many fronts. The reasons are many, involving politics, tax cuts, and outright fraud and lies. I read headlines every day, and sometimes I feel a deep sense of hopelessness.

Each of the pictures I've posted today is a place I've visited that is threatened by global warming. The first is Glacier National Park in Montana, where the glaciers are disappearing at an accelerated rate. When they are gone, the ecosystem of the park will be radically changed. The second is of Sequoia National Park, where an intense five-year drought, in all probability intensified by warming, has killed many millions of trees. The third photo is the Great Barrier Reef, which has been decimated by coral bleaching related to the warming of the oceans. And finally below, is Venice, a city threatened like almost no other by sea level rise. We are losing all of these precious places, and there are many more. Where is the hope?

There is hope, and that's what this week is about.  I have a classroom, and this week I get to start the adventure of my 33rd year of teaching science in the community college system. In my own small way, I am privileged to light a candle to help fight the darkness that threatens our future. I am always encouraged at this time of year that logic and science can win out over ignorance and rancid politics. I may be naïve in that thought, but I'll take it. I am proud beyond all words of my former students who are themselves now teachers and researchers. I am proud of my former students who went on in other fields, but who have continued to do their part as knowledgeable members of society to seek the best science-based solutions to the problems that bedevil us.

I know that ignorance can in fact be overcome. We managed as a society to pass the Clean Air Act, the Clean Water Act, formed the Environmental Protection Agency, and expanded our protected areas as parks, monuments, and wilderness areas. We dealt as a world community with ozone depletion. And nearly all the world's nations agreed to the Paris Climate Accords. I am confident that saner minds will ultimately prevail in Washington so that the United States will also participate. The ignorance cannot stand in the light of knowledge and evidence. Our world is worth fighting for.
Am I being too naïve and idealistic? Maybe. Time will be the judge, I suppose. But I find it interesting that I still go into the classroom each new semester with a sense of hope and renewal. It's been that way when times were good, and it seemed like we as a society were on the right track, and it's been that way in the darkest of times, when fools and criminals have held the reins of power. The hope for a better future hasn't been beaten out of me. Not yet. And if it ever is, I will fight on anyway.

Thursday, August 24, 2017

The Amazing Disappearing (and Very Dangerous) Mountain: Mt. Rainier

Yes, disappearing. In two senses, one rather personal. Mt. Rainier is actually one of the most obvious, most visible mountains on planet Earth. At 14,411 feet (4,392 meters), it towers over western Washington, and in clear weather can be seen from more than a hundred miles away in some directions. In clear weather, that is...

I was in Washington just a week ago, part of my eclipse-related journey, but in four days, I saw not one little bit of the mountain. It was mostly overcast, or I was in one of those spots where the peak simply wasn't visible. The peak had disappeared and it was kind of frustrating!
And then there was our summer field studies trip back in June. We had plans for exploring the Mt. Rainier area then as well, but the heavy snows of last winter had not yet melted much, so we only managed a single stop within Mt. Rainier National Park (near Chinook Pass), with only a single view, and no trails that we could explore (although there was an epic snowball fight). That stop makes up the first two pictures of this post. I had to dig into the photo archives to find some other views of the mountain. The one below is from our 2014 exploration of Canada that included a short stop at Rainier along Sunrise Ridge (below).
Mt. Rainier is the tallest volcano in Cascades Range, and is exceeded in volume only by Mt. Shasta. Because it is by far the tallest mountain in the Pacific Northwest, it is completely covered by the largest mass of glacial ice in the lower 48 states, about a cubic mile (I read somewhere that it contains half of the all the glacial ice in the lower 48, but I can't find the source and would welcome any corrections from those who know such things). Aside from the "normal" threats that volcanoes might present to a given region (lava flows, ash flows, and that sort of thing), the snow makes the mountain far more dangerous. It's not hard to imagine why: any small eruption would melt a vast amount of ice, forming volcanic mudflows called lahars that are capable of flowing for many tens of miles, and threatening many of the cities along the southern part of the Puget Sound. The entire city of Tacoma is built on a mudflow that thundered down the mountain 5,000 years ago. The last major eruption occurred around a thousand years ago, although minor activity was noted several times in the 1800s.

The reason I mentioned "disappearing" in two senses has to do with the effect of the ice on the mountain. The volcano is being dismantled. Glaciers are a major force of erosion, especially when the underlying rock has been weakened by chemical weathering related to the hot acidic fluids that circulate and attack the mountain from below (hot springs exist around the summit where the steam has excavated miles of ice caves). The glaciers have scraped away the rock around the original summit, which has also collapsed in several large debris avalanches. In other words, the mountain once stood as high as 16,000 feet, which would have made it the highest mountain in the lower 48 states by far.

My favorite pictures of Mt. Rainier both involved flights. I was returning from a geology trip in Italy a number of years ago, and our flight path took us right over Rainier, giving me the awesome perspective seen in the picture above.

On a different flight from Seattle, we took off just after sunset and I didn't expect to see anything, but the faint twilight allowed the mountain to glow blue, and I got the rather ethereal other-worldly view seen below. The color is the way the camera recorded it (I didn't play with the contrast or color).
Mt. Rainier is a place I would very much like to get to know better.

Monday, August 21, 2017

Just Barely Through the Fog Banks: The Eclipse from Ground Zero, the Oregon Coast

Yeah, I was really taking a chance, choosing to stay on the Oregon Coast for the 2017 eclipse. The reason? The fog. And there was a lot of it. To make the long story short, it never really lifted, but we could still see most of the sights through the clouds. I didn't get to see much of the corona, but there were lots of Solar prominences to compensate. It was an awesome experience in the end, but my nails are bitten down to the nubs!
We started out from Florence at 4:40 AM, not wanting to miss a parking spot. There was not a lot of traffic, and we were absolutely thrilled to see parking spaces at Seal Rock State Park. The fog was a concern, though, and the sun was still not at all visible at 8:30.
The crew at Seal Rock was stubborn though. There was some discussion of trying a different spot, but most everyone stayed, hoping for a break in the clouds. It never happened, but the clouds thinned enough that the Sun shown through. I suspect that made things a bit more dangerous, because the clouds made the eclipse glasses almost useless, and UV light could still damage people's eyes. I trusted my cameras to filter things for me (I was shooting with two Panasonic Lumix DMZ FZ70 with a 60x zoom; one on a tripod, the other handheld). I started snapping photos.
At the beginning, the Sun was the show with a couple of sunspots visible, one almost dead-center, and the other near the lower left quadrant.

More of the Sun's surface was covered, and it was becoming difficult to focus on the crescent sun in the rapidly dimming light.
Despite the warnings, I realized I could get pictures at this point without the filter, so the next couple of pictures are the true color of the Sun: white.
The discontinuities on the right edge of the crescent below are mountains on the Moon splitting up the sunlight.
The crowd at Seal Rock had been chattering away throughout most of the buildup to totality, but there was a sudden hush of shock and awe as the Sun suddenly disappeared, and it was as dark as night.
The Solar prominences glowed pink around the margins of the disk. As noted before, the corona was not visible through the fog.
There was an audible gasp in the crowd as the first streaks of light appeared on the other side of the Moon. The prominences quickly disappeared in the bright shinning light.
And then totality was over as the sky began to lighten up after 1 minute and 25 seconds of darkness. We didn't get to see the stars and planets, but I was not going to complain. What we saw was simply awe-inspiring. I understand that not everybody can drop everything and go across an entire country to see a shadow for less than two minutes, but if you ever have an opportunity, don't pass it up! It's a common experience of humanity to see the Sun blotted out by the Moon, and witnessing one in person can help one understand the myths and legends that grew around eclipses. I literally felt like shouting for the dragon to let the Sun back out of its mouth.

Update: Very pleased that EarthSky posted one of my pictures! http://earthsky.org/todays-image/photos-aug-21-2017-total-solar-eclipse

Sunday, August 20, 2017

Notes From the Eclipse Trail (with apologies to Ken Burns)

{Note: This may not work right unless as you read you hear the voices narrating a Ken Burns documentary, like the Civil War, or Baseball...}

Dearest Ones...

It is August 20, 2017. I pray that our missive arrives intact from the hinterlands of the Oregon Territory. Our journey has been long and arduous, and the outcome remains a great uncertainty. As you no doubt recall, we left the familiar fields and cities of our Central Valley home a week ago, but the time might as well have been a year. We are tattered and dirty, but we remain resolute in our goal of witnessing a total Solar eclipse.

Our progress slowed as we entered the great forests of what the local inhabitants call the "Redwood Trees". The trees were immense, and the forest dark. It was hard at most times to even know the location of the Sun in the sky above. We pressed on, looking for some kind of shelter or inn that would take us in for a night. We found accommodation at an outpost called Albee Creek, in the deep forest of Humboldt Redwoods State Park. We found ourselves surrounded by wagons once known to us as VW Microbuses. It was an uncomfortable and worrisome night in the dark forests, as we listened to the sounds of men, beasts, and air-cooled four stroke engines.
We explored this strange new environment following the mere traces of human pathways, which we found to be covered with potholes and twisting and turning through the forest in confusing fashion. Navigation by the sun or the stars was well-nigh impossible, as we could not see them through the forest canopy above. We did our best with tattered maps provided by the local constabulary called "park brochures".
We have been set upon by the beasts of the forest, who seem to track our every move. The night was filled with the rustlings of animals large and small. There was the snap of branches, the snuffling of noses, and the munching sound of apples being consumed nearby. We even witnessed one of the behemoths high in an apple tree, stripping it of its bounteous fruit.
It was becoming clear to us that the eclipse would never be visible to us in the deep forests of Northern California, and so we set forth with few provisions and even less knowledge over the borders of the land called Oregon. At first little seemed to have changed, but as we continued further into the wilds, we saw that the inhabitants of the land of Oregon were different. As we stopped to refuel our conveyance, we were not allowed to handle the mechanism for pumping the petrol. It was done for us, but not out of human kindness. It was because of statutory decree. What kind of tyrant controls these poor inhabitants?
Still, we pressed on deeper into the land of Oregon. We realized that our hope of witnessing an eclipse would require more open lands, so we worked our way down to the coastline where the restless waves lashed at the solid rock in a mighty conflict. Eventually we arrived at a small village called Florence, where we found shelter with some of the locals. They are a kind people, and generous in their sharing of their meager resources of ribs and Chinese cuisine. We have benefited from their generosity and have regained strength for the journey ahead.
There are rumors passed around the local peoples of the days ahead of giant crowds, clogged highways, and high costs of parking. We fear for the future, yet we face it with a steadfastness that grows from our intense desire to see the incredible event high in the morning sky of August 21st. From our base camp, we sent an exploratory party in search of potential viewing sites, and there is a discovery of potential spots in the coastal areas with such names as Waldport, Seal Rock and Forfar. Our strategy and only hope for success is that we can arise before the sun itself and set out for these choice viewing localities. And so it shall be done, and only Providence knows whether success can be had.
As for myself, dear ones, I press on. I am covered with scrapes and bruises, as I may have misinterpreted the advice of the sages, and put on the eclipse glasses a bit soon. I have been walking into trees and walls at a horrendous rate and our medical supplies are running low.

But through our trials and troubles, the goal remains true and we hope attainable. It is known that no American can hope to see such a spectacle on American soil again before 2024, no matter their bravery and skill. We can only hope to press on with fortitude and stubbornness born of being earth scientists and astronomers.

Yeah, we'll let you know if we make it...

Monday, August 14, 2017

What do Bears Do in the Redwood Forest? They Eat Apples...

California is the only state whose state designated mammal is extinct. The last California Grizzly Bear died in the 1920s. But we do have bears, but they just aren't quite as terrifying as an angry Grizzly. The only bears native to California today are the Black Bears, a species found all across North America. Those in the east tend to actually be black in color, but out west there tends to be more variation, from black to almost blond.
It's usually terrifying for people to see a bear for the first time when they are out camping or hiking, but California bears are fairly benign. They got kind of a fearsome reputation as car destroyers in Yosemite Valley, but an intense effort by rangers to train tourists has largely brought the problem under control. The bears are certainly a nuisance in some environments where natural food is scarce (especially during the recent drought). But my understanding is that Black Bears haven't killed anyone in California in a century, although I'm always open to correction (I've heard of one or two deaths in Wyoming or Montana). We unfortunately kill bears instead, either on purpose or by accident. If you are driving in Yosemite National Park and see a temporary sign that says "Speeding kills bears", it means that a bear died at that spot.
I'm out on my last journey of the summer, headed towards Oregon hoping to see the eclipse, and we spent a few nights camping at Albee Creek in Humboldt Redwoods State Park. It's a nice campground, too small for large RVs, and off the main highway. It's next to a meadow that was a homestead a century ago, and a large apple orchard still survives. The bears not too surprisingly love apples, and actually ignored the campground in favor of a few tasty treats from the apple trees. They've already stripped away the low-hanging fruit, so getting some required climbing into the trees. Most of the campers weren't even aware that there was a bear only a few hundred feet from their campsite. It was a pleasant way to spend the evening, watching bears be bears.

Yes, I got a bit of video too....

Friday, August 11, 2017

After the Disasters that Formed the Crater Lake and Crooked River Calderas, St. Helens was Hardly a Blip...Right? Uh, Right?

Yup, perspective is everything. I've been going on for several posts about prehistoric volcanic eruptions that were pretty much unimaginable in their violence and destructiveness. The Crater Lake eruption took place 7,700 years ago, and put 15 cubic miles of ash into the atmosphere, covering much of the western North America. The Crooked River Caldera dwarfed the Crater Lake event, with something like 200 cubic miles of ash. A repeat of either event would result in a huge death toll, and a serious threat to civilization. Luckily, such events are relatively rare in the time frame of human history.

Which brings us to the next destination from our field studies journey through the Pacific Northwest last June: Mt. St. Helens in southern Washington. Every school child for the last 37 years knows the familiar profile of the mountain as it exists today, and vaguely knows that it looked much different prior to 1980. It appears in pretty much every science textbook in the United States, being the last volcano to erupt in the lower forty-eight states.
Mt. St. Helens prior to the May 18, 1980 eruption. Source: U.S. Geological Survey

The problem these days is that for many people, St. Helens is ancient history. It is a geological event that took place years before they were born, and as such there is a disconnect regarding the reality and intensity of the events that took place in 1980 and the years following. I'm even guilty of belittling the event by comparing it to the prehistoric eruptions that happened in the region thousands and millions of years ago
Mt. St. Helens in 2002. Note the lava dome in the crater interior
The eruption of Mt. St. Helens may not have been on the scale of Crater Lake or the Crooked River events, but it was a huge event, almost beyond imagination, by any kind of human standard. What had once been a mountain nearly 10,000 feet high was reduced to a smoldering crater 1,300 feet shorter. The trigger that led to the disastrous explosion was the largest mass wasting (landsliding) event ever witnessed by human beings. And many people lost their lives, despite the evacuation and relative remoteness of the mountain.

The eruption began in March of 1980 when a moderate 4.1 magnitude earthquake shook the mountain, the largest ever recorded. Geologists were concerned and wired the mountain with whatever sensors they could think of. The rising mass of magma began to interact with groundwater and ice within the mountain, and a series of ash eruptions tore away at the summit of the volcano. The magma began to push outwards on the north flank of the mountain producing a 600 foot high bulge. Geologists were concerned about slope stability, but what happened was far beyond what they expected, or could even imagine. On May 18, 1980 at 8:32 in the morning, a magnitude 5.1 earthquake shook the bulge loose in a titanic debris avalanched that dwarfed any ever seen by humans. It thundered down the north flank, partly into Spirit Lake, with the remainder shooting down the Toutle River valley for 12 miles. Twelve miles.

The loss of the bulge meant that there was no longer any pressure holding back the gas-rich magma chamber, and it exploded with the power of hundreds of atomic bombs. The main blast was directed north and west, again towards Spirit Lake, and down the Toutle River valley. The ash was moving so fast (around 300 mph) it actually passed the fast-moving debris avalanche, so that in places the ash layer is actually covered by the avalanche deposits.
Mt. St. Helens in 2006, during the eruption that began in 2004. Note the second dome in the crater, behind the first.
The ash traveled north at hurricane speeds, up and over the intervening ridges, ultimately traveling around fifteen miles. The heavy dust-laden air downed nearly every tree in its path, stripping away branches and bark. Unless they were already underground in burrows, no animals survived in the main blast zone. The total area of devastation was around 150 square miles.

USGS geologist David Johnston, monitoring the volcano from an observation station on the ridge that now bears his name was one of the first people killed by the blast. Despite the evacuation orders (which were not far enough away from the volcano anyway), 57 people died.

These are just numbers, and numbers can't always describe the totality of the destruction of this volcanic eruption. You pretty much have to stand in the middle of it, and walk it. My first exposure to the devastation came about dozen years after the main blast (smaller-scale eruptions continued through 1986). I drove to the Windy Ridge Observation Point on the east side, which at the time was the only real viewpoint. The mountain was socked in by clouds (I had one brief glimpse of the outline of the volcano), but mile after mile of downed forest drove home the magnitude of the devastation.
I began bringing my students to the volcano in the 1990s once the road to the Johnston Ridge Observatory was opened. It provides an almost terrifying view into the maw of the gigantic crater, as well as a 360 degree view of the devastation. Tree trunks still litter the landscape, and only a few spindly conifers have begun to replace those that were blown away in 1980. The mountain ecosystem is well underway towards recovery however. Areas that were gray and dusty during my first visit are now green and covered by shrubs and wildflowers.
The mountain erupted again in 2004, and of course all the networks and cable new outlets converged on the mountain to report on the death and devastation. They hung around for a week or so and no one died, so they got bored and went back to their breathless coverage of missing white women (yes, that was a thing for months, and both stories involved Modesto in one way or another). The eruption continued for four more years, and a new 900 foot high dome appeared behind the 1986 dome.
The last time we tried to explore St. Helens with students was in 2011. The day was rainy and fog-bound, and we saw literally nothing of the volcano or the devastation, wasting hours of valuable time in the attempt. That was on my mind last June as we sized up the weather reports for the day of our expected visit... they called for rain. Mrs. Geotripper suggested we might skip a few "minor" stops the day prior to our scheduled visit, and catch the mountain in the late afternoon. It turned out to be a great idea, and all we missed was a view of the crater rim, due to the advance clouds from the coming storm.
The hummocky surface of the debris flow is still very evident in the valley of the Toutle River. The brush has had a harder time covering the small hillocks because soils can't readily develop on the steep slopes. Hundreds of new trees can be seen on the slopes beyond the valley floor however. Two new lakes formed in 1980 because the debris flow blocked some of the side canyons. Ecosystems are developing in these new environments as well.
The forest belt of Washington is not necessarily know for wildflower shows, but the slopes around the Johnston Ridge Observatory are for the time being vast meadows. Until the forest recovers, wildflowers will be part of the visitor experience.
As we traveled down the highway towards our camp, we noted a striking difference in the forest as we left the national monument and entered onto private lands owned by lumber companies. The forest was as uniform as a cornfield. The companies lost a great deal of timber during the eruptions, and it made sense to replant trees as quickly as possible. It's a bit disconcerting to see what amounts to monoculture going on. One hopes that these trees aren't vulnerable to the boring tree beetles that have destroyed forests across the western United States.
We headed down the hill to our camp at Seaquest State Park at Silver Lake. We had been privileged to see most of the volcano, and gained a perspective of the devastation from the ground. I wished I could have shown my students even more, and was reminded of a flight I took to Seattle a number of years ago. It happened to be one of those rare perfectly clear days, and the flight was only half full. The stewards gave me some dirty looks as I gleefully jumped from one side of the plane to the other snapping pictures of Cascades volcanoes (I got great shots of every volcano north of Crater Lake to Mt. Rainier). And I got pictures of Mt. St. Helens from the air for the first time.
We flew on the west side of Mt. St. Helens which provided me a view of Mt. Adams in the distance, and the Toutle River valley in the foreground. The gray strip of flood plain reveals the location of the debris avalanche, providing a perspective on the size of the flow.

In the big picture of Earth history, the eruption of Mt. St. Helens will barely register as a blip. Unless future researchers find the debris avalanche deposits, the record of the eruption in most places will be a thin layer of ash, at most a few inches thick. It would be an unremarkable eruption. But the eruption happened in modern times. We had accurate records of the volcano as it existed before, and excellent documentation of the events of May 18, 1980 (had the day been cloudy, we would be confused by some of the deposits). And we know what the volcano looks like today. The changes by any human standard were huge, and the effects on society very large. There was nothing small about the eruption of Mt. St. Helens.

If you are interested in the St. Helens story, may I recommend an excellent series on the eruptions by fellow geoblogger Dana Hunter at Rosetta Stones (click here for the index). She did a stellar job of bringing the volcano to life, along with the stories of those who were affected by the disaster.