Exploring Mount St. Helens blast zone using Google Earth

May 18th marked the 44th anniversary of the 1980 eruption of Mount St. Helens. Over on Threads, someone started an account that posted pseudo-realtime updates leading up to the eruption and its aftermath. It’s been really fascinating to follow and it stoked my interest in learning more about the eruption (no surprise, given my past geology background, eh?).

Like most things that I start digging into, I ended up finding  a book!

Eruption: The Untold Story of Mount St. Helens by Steve Olson. It details events surrounding the eruption and explores how a number of victims ended up around the mountain on the fateful Sunday morning. Reading it sent me down a rabbit hole of Wikipedia entries, USGS reports and Google Earth sleuthing…

In the summer of 2009, I visited Johnston Ridge Observatory and was able to see the volcano first hand (see image below). Johnston Ridge Observatory is located on the site of the Coldwater II observation post — where volcanologist David Johnston famously radioed his last words before the lateral blast swept over the ridge, destroying his encampment (Johnston’s body was never found): “Vancouver, Vancouver! This is it!”

Source: Me

The lateral blast, the result of a M5.1 earthquake that triggered the largest landslide in recorded history (sheering 1,300 feet off the top of the mountain), sent a violent pyroclastic blast northward, scouring the landscape for miles. You can still see the results of the blast to this day.

When we visited in 2009 — 29 years after the blast, evidence of the lateral blast was evident in obvious signs of tree fall (below image) — gigantic trees snapped over in the direction of the blast as if they were toothpicks.

Source: Me

Johnston Ridge (and the site of the Coldwater II Observation Post) sit about 5 miles from the Mount St. Helens. Looking out over this grand vista, your sense of scale is completely messed up. The mountain is so huge that it looks like you can reach out and touch it — you swear to yourself that it’s just right there, a short hop and skip away.

“I’m going to go on a quick hike to the volcano. I’ll be back by lunchtime,” you say.

Everyone else: “lol”

The shockwave and pyroclastic blast that resulted from the lateral blast were estimated to have reached upwards of 670 miles per hour. At that speed, it would have taken 30 seconds to travel from the volcano to overtopping the ridge.

Looking at my own photos from the observation post, you can’t help but wonder what David Johnston was thinking as he saw the shockwave and pyroclastic blast rapidly spread across the valley below, approaching his location. It was probably an awesome sight to see, quickly followed by “Oh. Shit.”

Thanks to the wonders of modern technology, we have some fantastic exploration tools. I loaded up the Google Earth web app and set about exploring the area.

One of the first things I notice is how huge the mountain is (err… was?) and how small and insignificant Johnston Ridge seems, especially in the face of the resulting landslide and pyroclastic blast.

Via Google Earth

Zooming in on the Spirit Lake area, you can still see floating tree trunks grouped together, covering the northern part of the lake (I assume due to prevailing southerly winds in the area).

Via Google Earth

If we turn toward the west and look at Johnston Ridge, you can see deposits left over as the pyroclastic blast topped the ridge. They are the lighter grey outcrops you see around the map. (I’ve attempted to poorly outline them below).

Via Google Earth

Let’s pop over the the valley just to the north of Johnston Ridge (where Spirit Lake Highway runs). We can zoom in and see a mess of tangled tree trunks along the banks of South Coldwater Creek.

Via Google Earth

At the top of that valley, we can see more evidence of pyroclastic blast deposits. Like the image of Johnston Ridge above, look for the light grey outcrops and exposures.

Via Google Earth

Alright, let’s check out how far the effects of the lateral blast were felt. If we zoom out a bit and go to the top of the ridge (the next ridge north of Johnston Ridge — I am unsure of the name), we see more evidence of blast zone tree fall. At this point, we’re about 6.5 miles from the volcano.

Via Google Earth

If we skip north across the next valley that contains Coldwater Lake, we get to the third ridge we’re going to look at. Again, at the top, we see evidence of blast zone tree fall. This is 8 miles from the volcano.

Via Google Earth

Now that we’re getting a sense of the scale of the blast, we can zoom out and start putting things together. Wherever this sort of tree fall exists, it almost looks like the landscape was scoured (it was!).

Let’s see if we can find anything else interesting. We zoom out and see some scour marks on ridges way off to the north.

Via Google Earth

The area I circled looks interesting. It’s called Goat Mountain and it’s nearly 12 miles from the volcano. Let’s zoom in… ah, yes. There is the distinct “hash mark” pattern we keep seeing, that represents the blast zone tree fall.

Via Google Earth

From our computer screen, it’s hard to get a proper sense of scale. If we use Google Earth to measure the length of one of these “match sticks” (a big dead tree!), we get about 33 feet!

Via Google Earth

A USGS report on the lateral blast showed evidence of 100 foot tall trees knocked over that were located 19 miles from the volcano! Try as I might, I am unable to find evidence of this via Google Earth, as the margins of the blast zone seem to merge with areas where loggers have clear cut the forest.

Below is an example of a clear cut logging area about 30 miles away from the volcano (this was not affected by the blast zone).

Via Google Earth

“But Dave,” I hear you say, “how do you know some of those are from the blast and some are from logging?”

You’re right! In a way, I don’t.  However, one potentially easy way to tell is by the presence of logging roads. In my example from Goat Mountain above (12 miles from the volcano), the tree fall was located on a ridge, away from any sort of easily accessible logging road.

There was one section of Steve Olson’s book that I found particularly fascinating, especially because I hadn’t heard about it before. At the exact time the mountain erupted, a small plane was flying overhead with two geologists as passengers — Keith and Dorothy Stoffel.

They were on their fourth pass over the north rim of the crater, flying west to east, when Keith noticed something moving. “Look,” he said, “the crater.” Judson tipped the Cessna’s right wing so they could get a better view. Some of the snow on the south-facing side of the crater had started to move. Then, as they looked out the plane’s windows, an incredible thing happened. A gigantic east-west crack appeared across the top of the mountain, splitting the volcano in two. The ground on the northern half of the crack began to ripple and churn, like a pan of milk just beginning to boil. Suddenly, without a sound, the northern portion of the mountain began to slide downward, toward the north fork of the Toutle River and Spirit Lake. The landslide included the bulge but was much larger. The whole northern portion of the mountain was collapsing. The Stoffels were seeing something that no other geologist had ever seen.

A few seconds later, an angry gray cloud emerged from the middle of the landslide, and a similar, darker cloud leapt from near the top of the mountain. They were strange clouds, gnarled and bulbous; they looked more biological than geophysical. The two clouds rapidly expanded and coalesced, growing so large that they covered the ongoing landslide. “Let’s get out of here,” shouted Keith as the roiling cloud reached toward their plane.

Excerpt From Eruption by Steve Olson

Now, wait a minute! You’re telling me that at the exact time the volcano erupted, there were people flying overhead? I know this happened in 1980, but there just has to be photos of this, right?

Yes, there are photos!

Via Dorothy Stoffel

Via Dorothy Stoffel

Via Dorothy Stoffel

Via Dorothy Stoffel

The photos correlate well to a famous series of images captured by Gary Rosenquist as the initial moments of the landslide and eruption unfolded.

Via USGS / Gary Rosenquist

Here’s a fun aside (if you can call something related to an epic natural disaster “fun“). A YouTuber took the series captured by Rosenquist and ran some magical AI frame interpolation on them (essentially — an AI tries to generate content to fill in missing information between frames of a video). The result is a near real-time simulation of what those initial moments of the blast may have looked like.

After taking the photos, Rosenquist and his fellow friends correctly decided it was time to leave. Immediately.

He took one last photo (this is another one I don’t remember seeing before).

Via Gary Rosenquist

Do you like geology? Want more? Here’s a post I wrote in 2010 that took a deep dive into earthquake frequency.

Some things are better left unsaid

(I’m currently on a plane, en route to Florida for the STS-134 NASA Tweetup.)

A British couple behind me are looking out the window and ask a flight attendant if that’s the Grand Canyon below us and to our left. She says yes, so I look out and see that it’s actually Valley of the Gods in Southern Utah (neeeeerd). I turn around to say something, right as the husband says, “Oh, that is so great! I’ve always wanted to see the Grand Canyon!”

Alright then. Just smile and turn around, Dave. 🙂

Good grief, we geologists can (nearly) be assholes sometimes!

Insane geological coincidence at Lotta’s Fountain

Lotta’s Fountain, originally uploaded by Dave Schumaker.

Today marks 105 years after the great earthquake and fire ravaged San Francisco in 1906. I decided to take a stroll downtown and pay my respects at Lotta’s Fountain.

I took this photo at 2:54PM. Three minutes later, a magnitude 3.8 earthquake hit the Bay Area. It was located on the San Andreas fault and was just southeast of where the 1906 epicenter was thought to be. What?!

Christchurch – Then and Now

EDIT: The Big Picture is featuring powerful and scary photos of the damage.

We’re just starting to find out how bad today’s M6.3 earthquake in Christchurch, New Zealand was.

A former professor of ours when we were in New Zealand in 2006 dropped us an email this evening and let us know that it was going to be bad. He also informed us that the iconic Christchurch Cathedral in the center of the city was destroyed.

It was an absolutely beautiful building – originally built in mid-1800’s and completed in 1904.

As we saw it in 2006:

Christchurch Cathedral - 2006

Christchurch Cathedral - 2006


And as it lays today:

Chch Cathedral 2011 Quake

[via TwitPic]

My heart goes out to everyone in Christchurch. This is going to be fairly bad.

Earthquakes in 2010 – A final update

Back in March of 2010, I wrote a post looking at the frequency of earthquakes occurring around the world and examined whether or not there were more earthquakes occuring than normal. Specifically, I chose to look at earthquakes between M6.0 and M6.9, as they are sufficiently large enough to be detected by seismometers around the world and they seem to be well documented in recent history.

So, what were the final numbers for 2010? Using the global earthquake search tool on the USGS website, we can see that there were 151 M6.0 – M6.9 earthquakes detected last year.

FILE CREATED: Mon Jan 3 19:59:37 2011
Global Search Earthquakes = 151
Catalog Used: PDE
Date Range: 2010/01/01 to 2010/12/31
Magnitude Range: 6.0 – 6.9
Data Selection: Historical & Preliminary Data

According to recent USGS data, an average of ~134 earthquakes happen in this range every year. Yes, we had 151, but does that mean it’s time to freak out?


It falls well within what we would expect. In fact, there were more earthquakes within this magnitude range in 2007 (178) and 2008 (178)! What? Crazy!

A few more data points:
M7.0 – M7.9 eq’s in 2010: 21 (avg: ~17)
M8.0 – M8.9 eq’s in 2010: 1 (avg: ~1)

Here’s a handy table from the USGS [via]:


So, to sum things up, the world is not ending, despite what crazy folks say, earthquakes are not increasing, and there’s probably a number of other things more important to worry about.

Cheers and happy new year!

“This is my church…”

Owens River Gorge overlook

Overlooking the Owens River Gorge near Bishop, California

Finally have a chance to fully check out Ken Burns’ wonderful documentary, “The National Parks: America’s Best Idea.”

In the first episode, they document the discovery of Yosemite Valley and a quote by Lafayette Bunnell.

“None but those who have visited this most wonderful valley can even imagine the feelings with which I looked upon the scene that was there presented.

The grandeur of the scene was but softened by the haze that hung over the valley-light as gossamer-and by the clouds which partially dimmed the higher cliffs and mountains. This obscurity of vision but increased the awe with which I beheld it, and as I looked a peculiar exalted sensation seemed to fill my whole being, and I found my eyes in tears with emotion.
…for I have seen before me the power and glory of a Supreme being.”

It’s a great quote (and a great geology related quote at that) and reminds me of something a friend said to me on a backpacking trip in the Sierra Nevada a number of years ago.

While eating lunch on an outcrop overlooking a forested valley, he said, “I may not believe in much, but this right here, this is my church.”

Agreed, my friend. Agreed.

My biggest environmental consulting fear

More drilling
My old office

In what seems like another lifetime, I used to be a geologist for an environmental consulting company here in the Bay Area. One of my biggest fears was drilling through a gas line.

We were often in the field, supervising remediation projects or gathering data in preparation for a remediation project. This often involved gathering soil and rock samples while drilling a series of boreholes that ranged anywhere from 3 feet in depth to around 100 feet in depth.

Before we ever drilled on a site, we consulted numerous maps and hired a company to carry out a USA (underground service alert) survey. The objective of a USA survey was to detect any utilities (gas, water, electricity) and mark them on the ground so that any drilling or excavation work wouldn’t impact said utilities.

This is what all the crazy markings you see all over a sidewalk or on a street mean.


While working on a project in Ukiah a few years ago, we marked a series of spots to drill and had a survey company make sure our spots were clear of any subsurface obstructions. Then we had a drill rig come out and start putting down boreholes.

Midway through the first day of drilling, we were sitting at our logging table when we heard a loud rushing sounds followed by frantic shouts. We looked up in time to see a 30 foot geyser of water shoot up through the top of rig’s tower and the workers scrambling away from the site.

We promptly contacted one of the property owners who turned off the water. After surveying the mess (a lot of muddy ground and a very wet drill rig), it turns out we had drilled right through the middle of an old asbestos cement water main about 6 feet below the surface. It never appeared on any site maps nor did the company conducting the USA survey detect it.

Since the pipe contained asbestos, special care had to be taken to clean up and repair the main, which involved masks for air filtration and disposable Tyvek suits.

Fortunately, it was only a water main (and not a very big one, at that), but it’s something that I was extremely paranoid about in future drilling operations that we conducted.

What if, through sloppy work, unmarked maps, or some other coincidence, it was a gas main? It’s a thought that still scares me today.

Dislike for Corona saves geologist from death.

I’m sure Corona’s marketing department is thrilled about this.

[H]e returned to his residence in Kabul to find it had been burgled. The intruder took money from a drawer and left behind a bottle of Corona beer. The Corona bottle sat on his counter for the next two weeks Yeager says, because Corona is one of his least favorite beers. He finally opened it during a going away party as the other drinks began to run low.

“I pulled it out and when I popped it there was no fizz and the cap was loose,” says Yeager. “Because this one didn’t have fizz you wonder if it went rancid or not, and I just kind of sniffed it and I went ‘Oh, that doesn’t smell like beer.’ “

Yeager, a geochemist familiar with acids, realized it smelled like sulfuric acid – otherwise known as battery acid. He called a friend over who had the same reaction to the smell. Yeager poured the “beer” into the toilet and it foamed and fizzed, leaving “no question” in his mind it was sulfuric acid.

Have there really been more earthquakes than average?

Update: January 3rd, 2011 – A final update on 2010 numbers posted right here.


Damage in Santiago, Chile. Photo by Reuters/Marco Fredes

After the massive earthquake this past weekend in Chile, MSNBC published a sensationalistic piece entitled, “Is nature out of control?” The Wall Street Journal asked if three massive earthquakes around the world in two months are related and a cause for alarm. The mainstream media, always searching for sensationalistic or fear mongering news, has latched onto the question; are we seeing more earthquakes than normal?

Well, not really.

To better understand why, let’s take a look at how many earthquakes occur each year on average. The USGS has a fascinating page of earthquake facts and statistics, with the following table:

Magnitude Average Annually
8 and higher 1 ¹
7 – 7.9 17 ²
6 – 6.9 134 ²
5 – 5.9 1319 ²
4 – 4.9 13,000
3 – 3.9 130,000
2 – 2.9 1,300,000

¹ Based on observations since 1900.
² Based on observations since 1990.

For our analysis, let’s take earthquakes based in the magnitude 6.0 – 6.9 range. Why am I picking earthquakes in the M6 range? It’s arbitrary. You can repeat this process for earthquakes of any range. Based on data recorded since 1990, we’d expect to see an earthquake within this magnitude range occur every 2.7 days or so.

So here we are, on March 1st, 2010, the 60th day of the year. How many earthquakes in the M6.0 – M6.9 range have we had this year? According to this handy search tool from the USGS, there have been 25 earthquakes of M6.0 – M6.9 in 2010.


That works out to roughly one earthquake in the magnitude 6 range every 2.4 days. That doesn’t seem totally unreasonable or a reason for alarm, but we should do some further work to put it in context.

We can plot up the number of earthquakes per year and come up with a standard deviation, assuming a normal distribution of earthquakes in any given magnitude range.


Total results: 21
Mean (average): 2.67143
Standard deviation: 0.41732

So, the number of magnitude 6 earthquakes that we’ve had in 2010 falls within one standard deviation of the mean. If we were to plot up a graph, it’d look like this. The error bars represent one standard deviation.



Awesome! Well, what about those ranges of values that fall outside of one standard deviation from the mean? For those that don’t understand how statistics works, check out the following bell curve from Wikipedia.

File:Standard deviation diagram.png

This shows roughly the percentage of values that you’d expect to fall within a specific standard deviation away from the mean value.

Dark blue is less than one standard deviation from the mean. For the normal distribution, this accounts for about 68% of the set (dark blue), while two standard deviations from the mean (medium and dark blue) account for about 95%, and three standard deviations (light, medium, and dark blue) account for about 99.7%.

So, if we modify our graph to show an error bar of 2 standard deviations, you’ll notice that every result since 1990 fits inside this model! Statistically speaking, you would expect to find 95% of all results falling within two standard deviations of your average. Simply put, there is absolutely nothing strange happening.


In fact, thanks to this normal curve you can basically predict, with a 99.7% chance of success (three standard deviations), that an earthquake of equal to or greater than M6.0 will occur somewhere around the world within the next 3.5 days. Update: Proven correct! A M6.4 earthquake occurred in Taiwan on March 3rd.

Alright, so what’s with all the coverage on earthquakes? It sure seems like a lot is happening, right? We can attribute this to observer bias. The massive devastation in Haiti warranted a large amount of news coverage. Because this is so fresh in everyone’s mind, people are more likely to notice any news or information related to earthquakes anywhere in the world. An earthquake of M6.0 or greater, usually garners international attention.

It’s the same principle that happens whenever you acquire some new toy, gadget, or piece of clothing. Suddenly, you notice that particular item around all the time. It’s like everyone has it.

So, bottom line, the Earth isn’t becoming more active, more dangerous, or even “out of control.” Despite the fear mongering and what esteemed mainstream media networks would have you believe, the simple reality is that the numbers prove things are happening at an expected rate. Keep that in mind the next time a large earthquake happens and everyone is wondering why the Earth seems so active!

Update (April 21, 2010): Chris Rowan at Highly Allochthonous has a great post on yearly earthquake averages and variability with larger magnitudes.

In the last 28 years, there have been on average around 13 such ‘significant’ earthquakes a year, with a magnitude 8 occuring about every year and a half. This average rate is marked by the grey line on the plot: if we extraplolate the six major earthquakes recorded in the first four months, 2010 is on course to experience 18 major earthquakes, a little above average but well within the variability shown by the whole dataset (and it’s actually closer to the centennial average of 16 major quakes a year reported by the USGS above).

Water vapor and climate change


Just saw this absolutely ridiculous article posted on Digg, by way of the Guardian: “Water vapour caused one-third of global warming in 1990s, study reveals.”

That’s gotta be one of the more sensationalist titles ever written in the climate change debate, which will help fuel and legitimize claims made by climate change deniers. Anyway, the article does have some interesting nuggets and things that should be discussed.

Scientists have underestimated the role that water vapour plays in determining global temperature changes, according to a new study that could fuel further attacks on the science of climate change.

The research, led by one of the world’s top climate scientists, suggests that almost one-third of the global warming recorded during the 1990s was due to an increase in water vapour in the high atmosphere, not human emissions of greenhouse gases. A subsequent decline in water vapour after 2000 could explain a recent slowdown in global temperature rise, the scientists add.

Basically, scientists need to do a better job modeling how water vapor plays a role in climate change. That said, there are few interesting things to consider, that this article fails to mention:

  • Examples of common greenhouse gases are CH4 (methane), CO2 (carbon dioxide), N2O (nitrous oxide), and H2O (water!).
  • The atmospheric concentration of CO2 and CH4 *is* increasing, mainly due to anthropogenic causes (burning coal, oil, and natural gas).
  • In general, the concentration of H2O in the atmosphere varies (but is dependent on atmospheric temperature), however there is a complex relationship between increased H2O -> increased cloud cover -> increased albedo.

The second thing to consider is the relative impact each of these gases have on trapping heat. In general, all greenhouse gases are compared to CO2 (which has a value of 1.0). This is called the global warming potential.

Methane is 25x stronger at trapping heat than carbon dioxide! Again, the atmospheric concentration of both of these gases is increasing. What is water vapor’s effect on trapping heat?

A GWP is not usually calculated for water vapour. Water vapour has a significant influence with regard to absorbing infrared radiation (which is the green house effect); however its concentration in the atmosphere mainly depends on air temperature. As there is no possibility to directly influence atmospheric water vapour concentration, the GWP-level for water vapour is not calculated.

Anyway, how do we know that concentrations of carbon dioxide and other greenhouse gases are increasing? I wrote an article about that on the Geology News Blog awhile ago. Check it out.

Last full day in NZ

Alright, it’s my last full day in New Zealand! How quickly the last 6 weeks have gone by. I’m quite sad to be leaving actually. Though at the same time, I’m anxious to get home, see my friends and share stories. We’re in Rotorua all day today and will be trying to catch the Super Bowl somewhere in town. My flight leaves here tomorrow at 7pm!

I arrive back in San Francisco on Tuesday at 10:15AM! (Interestingly enough, while I was having lunch on Mt. Ngauruhoe, another couple came by who were also from San Francisco. Small world!)

Anyway… internet use here is incredibly expensive! Time to go.

So long New Zealand.

Best Hike *EVER*

About after about 9 and a half hours of hiking today, we completed the Tongiriro Crossing. It’s the best hike I’ve ever done. I took *200* pictures today and have no way to upload them. Grr!

Anyway, I am quite wiped out. It’s currently 10:43 PM and we got back about an hour ago. Time for bed.

(3 more days in New Zealand!!)

Lake Taupo and Tongariro Crossing

Alright, we’re currently staying outside of Tongariro National Park at the backpackers hostel located there. It is quite an awesome place. We played volleyball with a few people earlier this evening and then did some rock climbing (this place has it’s own rock climbing gym! Awesome!).

Tomorrow we are going to hike the world famous Tongariro Crossing, which is roughly 20 kilometers in length. Among the highlights will be climbing Mount Ngauruhoe (famously known as Mount Doom from the Lord of the Rings movies). Apparently, we actually have a beautiful shot of it from our bedroom window. Unfortunately, it’s been cloudy! (Supposed to be cloudy tomorrow too! Grrr!).

Also, I haven’t been able to upload photographs I’ve taken lately due to the fact that most computers I’ve encountered have lacked the proper USB connections. So I might just have to wait until I get home next week.

Anyway, things are going swell! I’ll write more soon.