Get the Data. Don't get Killed.

There are different risk-factors that come with different life-callings:

• Fish for King Crab in the Barents Sea: unusually high risk of becoming crab food.
• Transport cocaine from Colombia to Texas: unusually high risk of being beheaded.
• Fight forest fires: unusually high risk of joining the Bar-B-Que and burning with the trees.
• Work as an accountant: Live Long and Prosper!

There have been several questions directed at us about safety while working as a geologist or geophysicist. These increased, as expected, during the 2004-2006 eruption of Mount St Helens. In a previous response to a question, I mentioned walking out the leading edges of moving lava flows in Hawai'i. This was not done casually, but to gain a clearer understanding of how these flows move - and why they suddenly can inundate towns like Kalapana. If we understand how lava creates its own new topography, perhaps we can predict where the Danger Zones are. 

This has non-trivial real-world consequences: if you build in Zone 1 or Zone 2 your home-owner's insurance will be phenomenally high, if you can get it at all.

In a larger sense, however, this opens the broader issue of inherent risk that comes with certain jobs - and how you can manage those risks.

In 1977 a young USGS geologist named Cynthia Dusel was part of a mapping team, surveying the Big Delta Quadrangle in east-central Alaska, when she was attacked and mauled by a bear. She survived, but lost both arms. Since then she has married, had a son, and even served as acting chief of the Western Mineral Resources team in Menlo Park, CA. She's something of an icon among us in the USGS: very matter-of-fact about her disability, very upbeat, great sense of humor - and epitomizes indomitable courage. 

The response to that attack within the USGS was probably predictable: everyone going up to work in Alaska started packing huge guns. Then the scientist in the Survey scientists stopped and many of them thought about it a bit more. Let's gather data about the real threats to geologists working in Alaska! they said. They did... and were surprised to learn that bear attacks came in as Number 7 on the list. Shooting yourself with your own weapon came in Number 3 - and this led to the development of a sophisticated 3-day weapons safety training course (informally called the "Bear Blasting" class) required of anyone planning to work in Alaska. Number 2 was helicopter accidents - my first USGS boss was killed in Ketchikan harbor this way. And this led to careful "carding" of pilots and mandatory training of geoscientists, so that none of us ever worked with a pilot with less than 5,000 hours of flight experience, for instance.

Number 1 was drowning. That's right: drowning. If you fall into deep water in Alaska (and southeast Alaska and the Aleutians are mostly islands, anyway), your arms will essentially stop working after about a minute unless you are wearing a Mustang suit. That's hypothermia for you. I came within a hairs-breadth of becoming one of those drowning statistics in Klawock in 1995.

It became a growing part of our scientific tradition: we all loved working in the field, but it carries with it different dangers. Soooo... how can we minimize these? How can we manage these risks?

Q:

That's a pretty crazy account.  It's particularly funny to think about your work when I think of it in comparison to our OHS (occupational health and safety) officers who come around to inspect our offices periodically to make sure that our chairs are properly aligned to make sure that we don't hurt our backs by sitting all day long.  Why in the world would you be stomping around an area of jungle amidst fresh-flowing lava?  - Lisa W.

A:

Throughout my professional career I've faced many rather disparate dangers. This wasn't done for the adrenaline thrill - it's the only way in most cases to acquire the crucial data that we need to solve real world problems. In the Continental US, this usually means working in really rugged terrain. I camped overnight with a geophysical crew inside the crater of Mount St Helens in 2007. I had helicoptered in with some geophysical equipment, but after several days had to get back to the office before the end-of-week scheduled helicopter flight. A case in point: I planned for it, and walked out. However, it proved to be far more rugged terrain than I had anticipated in my planning (which was done with 10-yr-old air-photos in a terrain that is unconsolidated, and evolving nearly every day). If I had not been carrying (and using) hiking poles with my pack, I wouldn't be wearing these front teeth today. I still sustained permanent damage to my left big toe and my right knee in the ~20 km walk-out (the knee is still swollen as I write this).

In Venezuela, my personal journals have WAY too many "I was nearly killed again today" entries. That was the first time I really looked at the full array of danger that comes with working in the deep jungle. Initially we went down for a three-year assignment to map the roadless, jungle-covered southern half of Venezuela thinking the the big risk was from snakes. In fact, I encountered a Bushmaster on my very first Entrada. It took awhile to recognize the more subtle, even hidden dangers: testosterone-poisoned pilots, poorly-maintained helicopters, Chagas disease, piranha in all the rivers, etc. The Number 1 killer? The Anopheles mosquito - the vector for Plasmodium Falciparum, also known as cerebral malaria, followed closely by drunk drivers. I lost two of my best friends in Venezuela, in separate incidents, to drunk drivers.

After a series of very close calls I took the Advanced Trauma Life Support training at the University of Maryland medical school (yes, it's supposed to be for medical doctors - but I have the certificate to prove it). I discussed the issues with some more experienced field geologists and began instituting some safety protocols for the mapping mission that I was in charge of - for instance we almost never used helicopters after the first year there. We wore light-colored clothes to minimize being targeted by Africanized bees. We always walked the picas (trails) in pairs. We always insisted on mosquito nets surrounding our hammocks, etc. One of my colleagues instituted one safety protocol himself: he bailed out, breaking his contract and leaving his commitments on my shoulders. I've never begrudged him for this by the way: he was one really, really frightened dude. A year later he even left the geosciences profession, abandoning his PhD training, to become a financial advisor. Live long and prosper.

But here's the thing: you CAN control the variables, you CAN push the statistical envelope far over to the likely-to-survive side of the Gaussian probability curve. 

I took some training last year that is a case in point. You can't study a volcano unless you can get a lot of equipment up INTO it. My sons will attest that just getting 300 kilos of gear up into the Pumice Plain (the Mount St Helens Blast Zone) for their mom's Masters Degree research project was a non-trivial exercise. It's much harder to do this in the upper edifice of the volcano - so we use helicopters.

Easy to say, technically hard to do.

The safest way to ensure the survival of the helicopter and pilot is NOT to have a lot of loose shovels, antennas, and batteries INSIDE the ship. This little nugget of wisdom was culled by carefully gathering reports of all helicopter crashes in the United States over 50 years. Instead, you *sling* all that loose, sharp-edged junk. There is an electrically-controlled hook on the belly of most helicopters. We took a full day to practice this routine on a level lawn:

• Gather all your gear in a pile, weigh it piece by piece. Give that manifest to the pilot - who will do a calculation to see if he can even lift it to the elevations you will work at AND have enough margin to carry you along with it.
• Load it into a net that itself weighs 25 kg. Try to balance that net, arrange it so things tilt inward, and especially be sure that nothing is sticking out of the net that could tangle with anything - like you, or the skids.
• Then call the helicopter in to you, holding your hands up and out in the direction of the wind (we usually dangle a strip of red flagging tape so the pilot can judge the local wind velocity).
• As the ship approaches, it comes in slowly at about 1.5 meters off the ground - remember that the thing is wobbling around in the wind as the pilot tries to control it against the volcano-heat-triggered turbulence, and it is SCREAMING SO LOUDLY that you can easily get rattled just by the 140-db sound (we wear helmets with ear protection, but it's still unnerving).
• You must then walk under this shuddering, screaming thing, hook your sling net to the belly, and then carefully back out (NOT turn around), without tangling your feet in the net, and keeping your footing amid the rocks and talus.
• Above all, if you stumble, you must NOT grab one of the skids to regain your balance. If you do, the ultra-light craft will flip, the blades will hit the ground, and all that angular momentum must go somewhere really, really fast – and you will both probably die. You have to trust the pilot, and he must trust you: if you hook the net wrong, or inadvertently tangle it in one of his skids, it could kill him. The craft is so fragile that you can literally push it around in the air above you with your hand... but those screaming turbines mean it is powered by 600 horses. Everything spinning is so finely balanced that if a blade nicks a branch it will chip a chunk off – and it then becomes hugely unbalanced. Then the angular momentum comes into play, and the aircraft will literally beat itself (and its occupants, and everyone within 20 meters) to death.

When a helicopter goes down, that's just the beginning of the bad stuff... think of the old high-school joke: What's red and green and goes round and round real fast? A frog in a blender. Now imagine doing this sling exercise on a steep ridge with 30-knot wind gusts.  THAT's why we practice and practice all day long on a lawn to do this right. So it's reflex.

Live Long and Prosper. And still enjoy the Adventure!

~~~~~

Water - and Specific Heat Capacity

It's not a coincidence that about 80% of the human population lives within 60 miles/100 kilometers of an ocean margin. Spend a winter (or a summer) in an interior state like Kansas, or Kazakhstan, and you will understand why they are not crowded. Temperatures in Fairbanks, Alaska, can range from 86F/30C to below -60F/-50 between Summer and Winter - and that's above the Arctic Circle! I've personally experienced temperatures of 130F/50C in Arizona and 142F/61C while working in the interior of Saudi Arabia.

We would have occasional snows (and freeze rain) when we lived in Virginia. That wasn't so bad... But sometimes we do not even see snow during the winter in Vancouver, and it's notable when the temperatures get much above 75F/24C.

I could easily get used to this. I think I'll stay...

There's a downside to this, of course: populations close to a seashore are much more vulnerable to a tsunami from a seafloor fault rupture - or an asteroid impact. Volcanoes can even figure into the picture: the tsunami that resulted from the explosion of Krakatau in 1883 traveled more than 10 kilometers inland on neighboring Java and Sumatra... then swept everything it had picked up and took it all back out to sea. Contemporary accounts mention being able to walk across the Sunda Strait on logs and bodies.

There is a reason for that very human tendency to hug the coast, and it's not for the sandburgers and grit-flavored potato salad. It's because of the moderating effect of nearby oceans. The key to that effect is the specific heat capacity of water - it is more than 4 times greater than air. In other words, it takes more than four times as much energy to increase a unit mass of water by one degree C than it does to raise the same mass of air by one degree. That means that the oceans act like a thermal buffer - because they can absorb and release so much heat without much of a temperature change.

We notice the effects of water on temperature in a number of different ways, and the next series of questions raises an unusual issue:

Q:
Does an object traveling under water get colder as it increases it speed through the water? Similar to a wind chill factor. 
- Gaylord M.

A:

Yes - if the water is colder than the object moving through it.

Water has a specific heat capacity of 4.2 with respect to air. This means it can hold - and transfer - far more energy than air for just one degree of raised or lowered temperature. The faster you move through a medium (like water) that has a different temperature, the faster and more effective is the thermal exchange, all other variables constant.

Most people know that getting into cold water will affect them much faster than walking through air of the same temperature. I noticed when I lived near the Red Sea that if I went diving in temperatures below 82F/28C that I would quickly become hypothermic. This hugely different heat capacity is also why it is so important to wear clothing that keeps moisture away from the skin as much as possible.

Q: 

Thanks for the reply. I asked the question, as I was wondering if it could have had an effect on the Titanic's rivets to cause them to fail. I had watched a segment on the History channel where they had ran some tests and determined the rivets had not failed. However they were running their tests in what appeared to be a normal environment. Only one of the test rivets failed.


A: 

The possible effect of ice-temperatures on the Titanic's rivets is an interesting thought. I'm not a metallurgist, but have watched several back-and-forths in the semi-scientific literature about the possible "failing Titanic rivets" issue with some interest.

In this case I don't think the temperature would have made much difference, because North Atlantic water ranges between 0C and 22C, depending on the month.

That's not really much of a temperature difference, considering the temperature that the rivets were forged at, and the fact that the ocean temperature cannot go below the freezing point of ice. Because of water's large specific heat capacity, there really is not much of a temperature change in the North Atlantic.

There were literally thousands of steel-riveted ships plying the North Atlantic during that epoch, and it makes more sense to worry about metal impurities in a given production batch of rivets than in the narrow temperature range that they would operate under.

~~~~~

Infrasound

The Earth really is a living thing in many senses of the word. For instance, it is very active – it even makes sounds.

Q:
Hi, Wondering what kind of sounds the inner earth makes? Do you know where I might go to hear this?
Thank you 
-Nathan W.

A:
There are sounds from the "inner Earth", but they are generally at frequencies below what the human ear can detect - this frequency range is called "infrasonic". Occasionally these can be heard, but not normally.

I once heard a recording from a seismometer located on Tungurahua volcano in Ecuador - but it had been electronically speeded up about 400 times to bring the signal up into the audible range. It sounded like a large animal moaning and roaring. This of course would be normally inaudible to the human ear.

Here is one somewhat different, for volcanic gas venting: http://volcano.oregonstate.edu/vwdocs/videos/siocomm.mov 

Here is an example of the sounds of an actual surface eruption at Tungurahua: http://en.rian.ru/video/20101202/161596301.html

Note that if the volcano is not actually erupting at the surface, the sounds made are almost always inaudible (infrasonic).

More volcano sounds can be heard here: http://volcano.oregonstate.edu/book/export/html/385

In some volcanoes there is a seismic signal detected called "harmonic tremor" - it is generally thought to be caused by fluid movement through conduits deep below the volcano, and sometimes is a portent of an impending eruption (Mt Pinatubo in the Philippines in 1992, for instance). Harmonic tremor is typically in the 2 Hz frequency range - well below the lowest frequency that a human ear can detect (which is about 20 Hz).

Earthquakes (shifting, sliding crustal plates) also generate seismic waves, but like those under a volcano they tend to be mostly at frequencies well below what a human ear can readily detect.

~~~~~

Geoengineering

Geoengineering is a very broad topic – in fact, no one group of people can actually agree what the word actually encompasses. One thing for sure, however: the word carries with it a lot of emotion already, not unlike Fracking.

Q: What is geoengineering and why do people say it is bad?

- Byron S.

A:

The term “geoengineering” (or environmental engineering, depending on who you are listening to) can encompass a lot of very different things: 

• Stratospheric Particle Injection for Climate Engineering (SPICE). This experiment this Spring in the Europe envisioned injecting water into the atmosphere at a 1-kilometer altitude. However, there have been proposals to inject vast quantities of sulfates into the stratosphere to reduce global warming. The theory underlying these is that Mt Pinatubo already did this in 1993 – and lowered the Earth’s average temperature by more than a degree C for two years.
• Injecting large volumes of iron sulfates into the Southern Ocean in 2009. This was done to test a theory that adding iron to the ocean would encourage phytoplankton growth, leading to an increase in zooplankton growth with concomitant oxygen release and carbon dioxide sequestration all at the same time. The fear, of course, was that the exercise would trigger a massive, toxic algal bloom.
• Injecting water from a hose maintained at a 1-kilometer altitude to test if this could cause more reflectance of solar radiation, and thereby reduce global warming effects.
• All the Walmart parking lots in the world contribute to large-scale diversion of water from the Earth and unusual absorption of solar radiation, creating unnatural microclimates (“heat islands”) that will affect local and even regional weather. In fact, one can watch any local regional weather radar, and readily see that clouds will often form donut holes over large, paved metro areas like Portland, OR.
• Groundwater depletion and other anthropogenic (man made) changes in terrestrial water usage were responsible for about 42% of the 8-cm rise in global sea level observed between 1961 and 2003.
• Ethinyl Estradiol (EE2) is the active ingredient in birth-control pills. More than 100 million women worldwide use contraceptive pills, and the products make their way through waste-water treatment systems into rivers and lakes, where they have caused widespread disruption of aquatic environments. It has done this by disrupting endocrine systems in wildlife (for example, irreversible development of eggs in the testes of male fish, a condition called “intersex”). EE2 introduced into a Canadian lake in 2001, at a level of only 5 parts per trillion, caused the population of one fish species to completely collapse.

There are other potential kinds of geoengineering, limited only by the creativity of people who worry about the Earth we live on - and who DON’T worry about where funding for their proposals might possibly come from.

These mega-scale engineering changes all sound like good ideas – they promise potentially great (and highly leveraged) rewards. The problem with geoengineering, according to a lot of people, is that if we play with our ecosystem on broad scales like these, we can never be sure of the consequences.  We may very well, with the best of intentions, create a spiraling-out-of-control disaster. We could just be asking for it.

An extreme example of this fear was the concern that when the Large Hadron Collider in Europe went online, its huge particle beams would create a tiny Black Hole - that would burrow to the center of the Earth and destroy our planet from inside out. The most compelling argument against this, of course, is that far greater particle energies are generated daily in our upper stratosphere by cosmic rays… without any noticeable harm having been done over the past 4.5 billion years or so.

Another example of mega-scale engineering is the massive use of DDT to solve a perceived insect problem – to save crops and mitigate human disease by eliminating dangerous insect vectors. We now know, of course, that the extensive use of DDT did solve, at least temporarily, some crop and human disease problems. However, it had huge unforeseen downrange consequences like plummeting bird populations and possible birth defects.

Some people might call the massive use of antibiotics another example of a well-intended global effort to deal with a human problem – but one that has in fact led to a growing disaster. We now see explosive growth of Multiply-Resistant Staphylococcus Aureus (MRSA, or the terrifying “flesh-eating bacteria” increasingly in the news). Indiscriminate antibiotic use has also led to a world-wide resurrection of resistant tuberculosis, Bubonic Plague, and other once-curable diseases.

Perhaps even more terrifying is the research into genetic engineering: what if something unforeseen gets loose into the world’s environment, with disastrous and irreversible consequences, like Zebra Mussels, lampreys, and Asian Carp getting into the Great Lakes? Or Kudzu being introduced into the southeastern US? Or Africanized bees introduced into the Western Hemisphere? Or cases of incurable cerebral malaria exploding in areas where unregulated hydraulic mining is rampant?

In 2010, a gathering in Oxford, UK, came up with some guiding principles for geoengineering:

-          Geoengineering should be regulated as a public good

-          There should be public participation in decision-making

-          Research should be openly published

-          There should be independent assessments of potential impacts

-          Decisions to deploy any new technology should be managed within a “robust governance framework.”

All of these principles sound great – but are terminally vague. Furthermore, they will probably never be implemented on an international scale. It takes just one nation ignoring the International guidelines on something as far-reaching (and frontier-crossing) as geoengineering to abrogate the whole effort for the rest of the international community.

If there is a lesson here from the pesticides, antibiotics, and biological introductions, it is that nothing is consequence-free. However, many people feel that they are forced to just stand by and helplessly watch things unfold - decisions made by just a few people. That may be why there are such vociferous demonstrations to something as innocuous-sounding as SPICE.

~~~~~

Black Holes & Super Novas & Geology

Here is a continuing question from 3-yr-old Samantha. It actually goes to the heart of why we have geology in the first place: black holes and supernovas of earlier suns have led to a cyclic mix of fusion-created heavy element products like oxygen, carbon, iron, and silicon - major constituents of our rocky Blue Marble, water-covered planet. A world like ours could not have existed in the early life of the universe.


Q:
Thank you so much for your reply. She (Samantha) still talks about you from time to time. Then out of the blue she asks "Mommy, what are black holes made of?" I don't know! :)
--Jo L.

A:
Well, the short answer is a LOT of mass. There are actually at least two different kinds of Black Holes.

A Stellar Black Hole starts with the collapse of a very large star - a star much bigger than our Sun. As the star uses up its hydrogen by fusing it to helium, it starts converting helium to carbon - these stars are a deep red, almost garnet color in a visible light telescope. Rather quickly on a cosmic time-scale, it will start converting carbon and helium into a number of other life-critical elements, all the way up to iron. The fact that the Earth's crust contains elements up into the uranium range suggests other processes, too. All the material we find on our own Earth has come from this thermonuclear process - probably from many ancient stars that reached old age and blew up long ago.

In two words, we are “Star Stuff.”

Somewhere in this winding-down process for this very large, earlier star, there is an initial collapse of the outer blanket of hot gas material down to the star's core, and a "bounce" causing an initial huge blow-out of the outer envelope. This is called a nova, or in some cases a super nova. It produces prodigious, short-lived amounts of radiation from visible light all the to X-Ray energies and beyond. In a distant galaxy, a supernova can look temporarily like a nearby star in our own galaxy.

This outer shell ejection process creates something called a Planetary Nebula - a glowing shell of gas that almost looks like a planet in a cheap telescope. Finally, there is a huge terminal collapse and all the remaining matter, without thermonuclear heat to hold it up, collapses into what becomes a Black Hole. It's called a Black Hole because there is so much mass in such a tiny volume that it bends light. It bends light so strongly - this is an essential part of Einstein's General Theory of Relativity - that light can't get out of a certain volume outside the central concentrated mass. This "edge" where light can't escape from is called the Schwarzschild radius, or the Schwarzschild discontinuity. You can guess who suggested this idea first. If the original star isn't big enough, the mass will collapse back into a White Dwarf - or if there is more mass, it will collapse into a neutron star, a teaspoons of which would weigh tons on Earth (if you could get it here or even weight it).

This is a description of a multi-stellar-mass Black Hole. 

There are other, far larger Black Holes. Galactic Core Black Holes are found in the centers of most galaxies including our own – and they form for different reasons and are HUGE. These Black Holes result from too many large stars in the crowded center of the galaxy being in too small a confining space - and they coalesce into each other forming a Black Hole that grows ever larger with time as it gobbles other nearby stars spiraling into it from tidal orbital collapse. In some science fiction books this is called "The Eater" or the Black Monster. We know there is a Galactic Core Black Hole in the Sagittarius constellation - the center of the Milky Way galaxy - because astrophysicists can see huge Doppler shifts in radiated light over a very small angular separation in a tiny area. This zone was originally named "Sagittarius A" - for the first apparent brightest star classified in that constellation by early astronomers. Sensitive satellite detectors indicate that the center of this interesting area radiates light all the way up into the X-Ray range of energies. On one side the Doppler shift indicates that material is rotating TOWARDS us (the absorption bands are blue-shifted), and close by on the other side there is a red shift telling us that it is rotating AWAY from us. The latest indirect calculations suggest this area, called Sagittarius-A* (Sagittarius-A-Star, or "Sgr-A*" for short) is about the diameter of Mercury's orbit around our Sun - but holds a mass equivalent to at least 44 million Suns in that relatively tiny volume. It's hard to see this, as the whole mess is about 26,000 light years away from us, so it's taken some very clever astrometrics by some very smart astrophysicists to get these numbers.

~~~~~

This seems like more than a normal 3-yr-old might be able to absorb. I am struck, however, that this 3-yr-old of yours has such a wide-ranging interest in scientific things. She could not get there without a highly supportive parent who will spend the time at least trying to answer her questions. You must have some rather eclectic conversations with your daughter.

~~~~~

Age Dating - and Why it is VERY Important

We have received many queries that implicitly ask a question about how old something is – typically the odd rock that they found in their backyard. A review of age dating, and why it can be critically important, seems appropriate here. 

Q:  

How old is this rock?

- various 

In 1979, a young USGS geologist named Rick H. was mapping flows on the north flank of a beautiful, glacier-covered, symmetric volcano in southwest Washington State. He had some idea of how old the Goat Rock Dome was that he stood on – textures and some sparse historical information suggested that it was very young. He had no idea that in a year the huge outcrop he stood on would be moved many miles to the north – that the spot he then stood on would be more than a thousand feet up in the air. The 1980 eruption of Mount St Helens killed 59 people – that is, that authorities are certain of. The death-toll could have been greater by more than 800 people. By a miracle of governance, those people were being held back at a roadblock until 9am on May 18^th. However, 45 minutes before the gate would have been opened - to allow in people who had property around the volcano - the monster blew up catastrophically with a lateral blast. Authorities were certain of 57 people killed, but speculate that there were more caught in the blast that no one knew about. Gray dacite dust fell on cars in Atlanta a day and a half later. 

As the new chief scientist for volcano hazards, I made a point of visiting - and spending time listening to - every single staff member scattered over six different centers. This was not a trivial exercise; it meant lots of airport time and lots of listening. I made a point of spending the same amount of time with the technicians as I did with the senior scientists, and this helped me get a better view for how things were really working within the organization that I had just inherited. In one case, techs clued me in that one of our observatories was no longer functioning, due to a perfect storm of very human conflict starting with a management failure.

The experience was not all grief, however. One of the people I spent time listening to was Andy C., a brilliant young PhD geologist/geochemist who had decided to specialize in age-dating. I also talked with Jim S., a smart, furiously hard-working tech who worked with him. After listening to them, I travelled to the USGS national headquarters in Reston, VA, and tin-cupped around the building. I mean this literally – I carried around a tin cup with me to help break down resistance by disarming people with humor. I was looking for “spare change” in people’s budgets that I could divert to Andy’s laboratory. Spare change in my little 120-person volcano science team usually meant a few thousand dollars from my cost center budget. Two thousand dollars would pay for a young scientist to attend a science meeting, where he would not only learn what was going on in his field, but connect with people he could cooperate with. This meeting attendance had the effect of leveraging our meager funds to accomplish quite a bit more with them by getting others to help us accomplish our objectives.

To put this in perspective, a Stryker combat vehicle costs about $1,500,000. For the Department of Defense, however, I was looking for funding down in their noise-level. For them, our needs were what Sherrie G., a DOD executive, dismissed as “decimal dust.”

But Andy had both energy (he frequently worked 60-hour weeks) and a vision. His vision was to create a center of excellence: a laboratory for high-precision dating. I found and funded him with $250,000 to develop the world’s best state-of-the-art ⁴⁰Ar/³⁹Ar age-dating laboratory. This has allowed him to steadily refine the ages of very young volcanic rocks, which in turn allows us to put better and better parameters on the eruptive frequency of volcanoes – so we know what we may or may not have to worry about.

In the 10 years that followed, Andy had accumulated a sufficient number of very good age-dates that he was able to start looking in broad brush at the eruptive history of the entire Cascades range - and he can now see episodic pulses of eruptive activity in the past 500,000 years. Importantly, this includes the first hints that we are entering into an unusual period of volcanic activity right now.

In the past 5 years, Andy refined his +/- errors on an age-date from several thousand years to just 400-500 years. He did this by gaining precise control on the atmospheric Argon component in rocks, but also by refining his sample-collecting techniques. He sought the centers of lava flows, parts that were “platy” because they were shearing as they cooled while still flowing. He also avoided porphyries, because the internal crystals formed under different circumstances than the fine-grained that had extruded out onto the Earth’s surface. Other things he avoided included air-vesicles and glass: that is, water-quenched lava that inevitably had an Argon contribution from the water. How did he sort these out? By licking the rock with his tongue. If his tongue stuck slightly to the rock, experience showed that he would get a low-precision date on it. Since he was working long hours to deal with a huge back-log of samples, this kind of “pre-sorting” had gone a long way toward narrowing down his error-bars on dates.

So..... How Does Age-Dating Work?

Wait, you ask, how does age-dating work?  In the pre-radioactive isotope days, crude dating could be done by measuring how fast sediments accumulated in a lake-bottom, measuring the thickness of a stack of those sediments, and noting which sedimentary units lay above (were younger than) another layer. But while you could easily get the relative ages with stratigraphy, you couldn’t get good absolute ages – there were too many variables, like water levels, wind influences, and changing sedimentation rates.

It’s not hard to get the radioactive decay rates of anything if you have something like a Geiger counter: a certain number of atoms are “popping” every minute, and you could measure how many atoms were in the sample to begin with using some relatively straight-forward chemistry.

Once you have decay rates, age dating - in principle at least - is pretty straightforward.  A mineral solidifies out of a magma mush somewhere with uranium in it. By early in the 20^th Century, the decay-process of uranium was well known… there were intermediate “daughter products” with different half-lives, but they all ended up at stable lead, where the decay process ended. All you really needed to do was measure the lead-to-uranium ratio precisely, and with the rate of decay you could get a handle on how long it had been sitting there since the last melt solidified. This wouldn’t work if the rock had been metamorphosed (or “stewed and cooked” as old miners would say it) since the initial solidification. In that case, the age you got was the last re-melt. 

All is not lost, however. Some really smart people eventually worked out how to get something of a handle on even this. It required some good geology, some good chemistry, and some clever statistics… but you could at least get an idea if something had been messed with since original formation.

There were other problems, however. The half-life of uranium-235 is 704 million years. Also, the precision was not that hot when you measure micrograms of uranium and lead in a mass spectrometer - and try to divide that up into 704 million years. In the best of circumstances, you get a rather large plus-or-minus – many thousands, even hundreds of thousands of years. In many situations that didn’t matter all that much. For instance when we were trying to figure which rocks arrived before which in truly ancient southern Venezuela – then 500,000 years or 5,000,000 years one way or the other didn’t matter all that much.

If you have two volcanoes, and one erupts every 20,000 years and the other erupts every 200 years, then this precision doesn’t help you at all. Unless you know the eruption frequency, you have no easy way to know how dangerous the volcano is.

THIS is why age-dating volcanic rocks is so important. Do we pour our meager annual instrumentation budget into Mount St Helens, or into (literally) Crater Lake?

There are other radioactive decay series, of course: rubidium-strontium, carbon-14 (which we use with volcanoes if we can find some fried vegetation under a flow), and the argon series. You can’t always find uranium-hosting minerals, and you usually can’t find rubidium-hosting minerals. If you find something burned under a lava flow, it can’t be older than a few tens of thousands of years, or the ¹⁴C is already all gone. But ⁴⁰Ar has a more useful half-life, and argon is also a significant constituent of the atmosphere. It can be found just about anywhere in volcanic rocks – which came from a subducted ocean floor once exposed to the atmosphere.

Rats. There is yet ANOTHER problem: all that argon in the atmosphere is also going to pollute any measurement you make. Like carbon-14, which is “made” in the upper atmosphere by cosmic rays transmuting nitrogen molecules, Argon-40 comes from atmospheric Argon-39 – which is everywhere, and seeps into just about everything. If you want real numbers – true age dates – you must find a way to get clean and unsullied samples.

Where there’s a smart person, there’s a way. Believe it or not, it comes down to something as low-tech as putting your tongue on a rock. Andy - by trial and error - found that the best rocks to date were the ones in the "platy" middle section of a solidified lava flow. The final test was to see if your tongue sticks to the sample that you hammered out. Does it stick? Chuck it and look for another sample, because it won't give you a reliable age-date.

Bottom line:

It comes down to this: if we are being shot at, it’s important to know how OFTEN we are being shot at. You can plan. You can set up many forms of disaster mitigation to keep a crisis from becoming a catastrophe. Rock-dating information is crucially necessary in order to have even half a chance of predicting the volcano’s future behavior – and roughly calculating the risk it carries. High-risk volcanoes then claim the larger share of our very limited instrumentation budget. Crater Lake (the former Mount Mazama) last erupted catastrophically over 7,000 years ago. Mount St Helens has erupted more frequently than almost all the other Cascades volcanoes combined… the last period of repose was just 24 years. So with good age-dates, we invested the lion’s share of instrumentation on this critical, very-high-risk volcano.

We were relieved that we had done so when the 2004 eruption started with just over a week’s seismic warning. We had seismic and GPS “eyes” already in place and with them we could ”see” what was going on under the volcano. With a huge experience base acquired by studying hundreds of volcanoes in the US, Kamchatka, Japan, Indonesia, and Latin America, the scientists at the Cascades Volcano Observatory could predict (sometimes to within hours) when the next eruptive pulse was coming – and on 1 October 2004 they called for the evacuation of hundreds of people from the Johnston Ridge observatory.

They could not have made that emergency call if the geologists had not already carefully mapped its past eruptive products. And the eruptive history would not have been deciphered without precision age-dating. The 2004 eruption was not nearly as violent as the one in 1980. But even if it had been, the disaster of 1980 would likely not have been repeated. By 2004 we had dates and knew what this volcano was likely to do.

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Snowball Earth - the Faint Young Sun Paradox

Here’s a detective story for you, and it doesn’t involve a murder.

Astronomers studying young stars like ours have realized that as a Main Sequence star evolves over time, the inner core becomes denser and the fusion rate of hydrogen to helium increases. In other words, our own Sun must have grown brighter and brighter during its first 5 billion years of existence.

Careful astrometric studies have even placed some numbers on this: the energy output of the Sun 2 billion years ago is inferred to be about 70% - 85% of what it is today. This would not be enough to warm the Earth above the freezing point of water. The Earth 2 billion years ago should have been a frozen ice-ball, like Mars today. Mars is more distant from the Sun than Earth is and correspondingly cooler.

There is a problem with this conclusion, however: it doesn’t agree with ancient evidence gleaned from geology. There are sedimentary rocks in South Africa with ripple-marks and mud-cracks. These rocks are derived from volcanic ash - and therefor easily dated at about 2 billion years old. Other rocks dated at 2.7 billion years ago show fossilized rain-drop imprints. I have personally handled ripple marks and pillow-lavas (lava that is fast-quenched in water) dated at about 1.7 billion years ago in southern Venezuela. Ancient stromatolytes - blue-green algal clumps and  mats - have been found in rocks over 3 billion years old in Australia.

The evidence is everywhere: the atmosphere may have been different, but there was liquid water on the Earth’s surface as far back as we can test.

What gives?  The arguments used to explain this so-called “Faint Young Sun Paradox” fall into three main groups:

- The young Earth may still have had a lot of residual heat left over from potential energy accumulated during the accretion process. However, the surface of the Earth would have equilibrated quickly with energy received from the Sun, and the existence of solid cratons back at least 3.4 billion years ago argues for a solid crust. Energy released from the Earth’s interior has actually ramped up with the onset of mantle convection and plate tectonics, now thought to have started about 2.5 billion years ago.

- The Earth’s atmosphere retained heat more efficiently than it does now - for instance, by containing more greenhouse gasses like carbon dioxide and methane. Sufficient nitrogen can also act as a greenhouse gas under a phenomena called nitrogen broadening. There are a few questionable gas inclusions in ancient rocks, but scientists argue over how pristine the gasses in these inclusions actually are - or if they have diffused (either into the rock or out) over time.

- The Earth’s albedo, or surface reflectance, was lower in the past. Lower surface albedo could have been due to less continental area (more dark, absorbing ocean), or perhaps by the lack of biologically induced cloud condensation nuclei. How would you ever obtain evidence for something like cloud cover 2.5 billions years ago, however?

There are other suggested explanations out there. One is the modulating effect of a stronger Solar Wind in Archean times (i.e., greater than 2.5 billion years ago). Another is that due to orbital mechanics and tidal effects, the Earth’s orbit was once closer to the Sun.

This last explanation is treated skeptically by most astronomers because of some bad science propagated in several books by Immanuel Velikovsky a generation ago. The Earth-Moon distance varies depending on where the Moon is in its orbit. Lunar laser ranging experiments show that in general the Moon is receding from the Earth at a rate just under 4 centimeters per year. This is due to tidal energy being transferred to the earth (and converted to heat) via the seas, and the deformation of the Earth’s crust along with the tides. It is a logical step to infer that the Earth’s orbit around the Sun could increase for the same reason over time.

There is a major problem with all these theories: with time, the evidence for anything becomes increasingly fragmentary, increasingly suspect. It’s like a Cold Case murder - only 2.5 billion years cold.

Scientists are clever folk, however - and they keep thinking, keep looking for other ideas. Recently some of them have gone back to the fossil imprints of ancient rain-drops onto volcanic ash, and have conducted comparison experiments to estimate the density of the Earth’s ancient atmosphere. There are many variables to deal with, however, including how big will rain drops be, and how much moisture was in the volcanic ash? Careful calibration has at least allowed scientists to put a range on the ancient Earth’s atmosphere: it was between 50% and 105% as dense as it is today. This immediately calls into question the greenhouse gas argument.

We also know from other geological evidence that the Earth’s atmosphere began to fill with freed-up oxygen around 2.5 billion years ago. Rounded pyrite grains found in ancient South African sandstones, which could not have occurred in the presence of oxygen, is one proof of this. The Great Oxygenation Event came at the expense of methane and carbon dioxide, which biological processes were already starting to sequester in the form of carbon accumulating in the bottoms of ancient swamps. 

You recently drove your car to the grocery store using gasoline - some of that sequestered carbon. That same trip thus released more of a greenhouse gas to the Earth’s atmosphere.

And so the Earth grows hotter and hotter...

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