Fracking

Probably the hottest geologic topic right now is called "fracking", which is short for "hydrofracking", which is short for using water (hydro) pumped down wells at enormously high pressures to fracture (frack) so-called gas-rich "tight" rocks. The idea is that a huge formation found all over the north central and northeastern US, called the Marcellus Shale, is... well, shale. Shale is a rock formed from deeply rich, usually black muds at the bottom of swamps. These muds are loaded with carbon, because they are mostly organic in composition (e.g., "stinking swamp muck"), and carbon usually "matures" under heat and compression to a number of different forms ranging from coal through liquid hydrocarbons to different forms of carbon-based gas. A major component in the Marcellus is methane, a.k.a. natural gas. But shale itself looks typically like a dark gray to black, raggedy-edged yard stepping stone. It's just a gassy version of stepping stone.

This particular shale formation is widespread, extending from New York state (whose town of Marcellus is the type-locality) throughout much of Appalachia. It is OLD: around 400 million years old (Devonian age). It is also "tight", which oil drillers coined to refer to a rock that didn't let gas or fluid pass through it very easily. However, if you can break up the formation - fill it with fractures - then just the pressure of the overlying rock could potentially force trillions of cubic feet (the standard measurement of natural gas) out of your well. And guess what? The Marcellus is located strategically close to where it would be needed most: the northeastern US.

Fracking, however, means more than just water being injected. It also involves proprietary (e.g., secret) mixes  of solvents and lubricants and sand. Yes sand: after the hydraulic pressure is released, the particles of sand will keep those new fractures open so the natural gas trapped in the shale can get out. And the lubricants and solvents are designed to keep the fluids flowing - keep everything slick, not gooey. The theory, of course is that the top kilometer or so of the frack well is cased (lined with steel tubing) and that tubing is cemented into the hole to stop any potential leaks. This in most cases will extend beyond the groundwater being used by overlying communities and keep the fracking fluids and your drinking water separate.

The idea is that the solvents will sort of, you know, be nice, stay where you put them, and behave themselves. Here's a clue for you to think about however: the secret nature of those mixes. Why keep those chemicals secret unless you are trying to hide something? Another thing to think about: no underground system is "closed" - sealed off for eternity from everything else around it. Groundwater specialists know that there is always movement of groundwater through the sands and rock that it saturates. That movement can be as low as a few tens of centimeters per year, but is often far higher than that. So anything underground is not going to stay where it is - unless it's solid. Maybe you can see where this might lead to by now. There are whole communities in Appalachia, Colorado, South Carolina... and for that matter all over the world where the groundwater is poisoned for one reason or another. It could be mine waste leaching into the ground in West Virginia or Colorado. It could be a leaky tank beneath a service station in Illinois. It could be an abandoned landfill from a World War II Army base in Arkansas. It could be a plutonium-loaded and corroding tank on the Hanford nuclear facility near Pasco, Washington... leaking into the adjacent Columbia River that runs through Portland, Oregon. I kayak in that river, so it gets personal.

And "stuff" always moves.

Q:
I'm in the middle of a PhD in economics right now at University of _, and right now I'm working on possible dissertation projects. One project I've been thinking about is looking at gas drilling (specifically fracking), and looking at the economics of drilling. For example, I'm thinking of looking at the economic impact of drilling in the Marcellus Shale formation in Pennsylvania, where there's been a recent expansion of fracking.
I have a geological question for you that I haven't been able to figure out. Is there a way to determine a map that gives both (1) the depth of the top of the Marcellus formation and the (2) depth of the bottom of the Marcellus formation? When I look at standard geological maps, there doesn't seem to be a way to convey that information well in a 2D map, since the information I'm trying to figure out is 3D. I don't know how well this information is known. I imagine that mapping it would be tough, since it is expensive to take deep-earth samples.
Eric L.

A:
You have certainly picked a relevant (and highly politicized) subject - and one that will remain relevant for many, many years. Look forward to full employment for a long time! What you are searching for is an Isopach map - a map contouring the thickness of a particular sedimentary unit - of the Marcellus Shale. You can be absolutely certain that the Oil & Gas companies have these. These are what they base their drillstring-whipping efforts on: where to guide the drill (first downwards, then they "whip" it horizontally to follow a particular stratigraphic horizon). It's a 100% bet that if they DIDN'T have this information, their efforts would be a hugely expensive bust: it's not economic if a million-dollar drill-stem can't be contained within the producing horizon. The stratigraphic unit of interest can be quite thin, but spread over a large area - that's where the dollar value starts clocking in. The strata are almost never horizontal and rarely stay at the same depth over any significant distance, either, so you need to know where the top is and where the bottom is.

This inherently 3D information is generally obtained using 3D reflection seismic surveys... very expensive, but current technology has the capability of resolving layers as little as 5 meters thick when buried more than 2,000 meters down. It's really amazing where brains and (nearly) unlimited resources can bring technology these days.

One reason that this is not found much in modern geologic maps is that the graphic systems used to display and evaluate the unit(s) of interest are also 3D - the top and bottom of the Marcellus is inherently three dimensional so must be viewed that way to be meaningful. The display technology is handled using workstations costing $20,000 or more, with software that is far more costly still. Generally the people working with these data - and planning the drilling programs - are using 3D glasses and working off of multiple 50" plasma screens.

The problem facing YOU (and also the US Geological Survey) is that this information is highly proprietary: one oil company has very strong incentives to keep the information secret from competitors... AND from government entities that might want to tax and/or regulate them. I know some people in the Energy Program of the USGS these days... but their programs are more oriented towards doing large-scale resource estimates. THESE things are available in the public domain: http://energy.usgs.gov/. If you want more detailed information on the Marcellus Shale, my first recommendation is to get in touch with one of the "Minors" - smaller Oil & Gas companies working the Marcellus right now - and see if you can meet with one of their geologists. Explain what you are trying to do, and see if they might be willing to talk with you and share some of their data (perhaps even show their 3D data to you, after you sign a non-disclosure agreement).

~~~~~

A Desert vs a Tundra

Like all science fields, there have been arguments on what a particular word really means. In the example below, the question comes up: what is a desert? Would the Antarctic qualify? Does it have to be hot and sandy?

Q:

Hello!
I'm having an argument with a friend;
What is the largest desert? The Sahara or Antarctica?
Can Antarctica be considered a desert or a tundra?
What is the difference between a desert and a tundra?
Thank You,
Ashlee C.

A:

Hi, Ashlee,
Here's the dictionary.com definition of a Desert :
–noun
1. a region so arid because of little rainfall that it supports only sparse and widely spaced vegetation or no vegetation at all: The Sahara is a vast sandy desert.
2. any area in which few forms of life can exist because of lack of water, permanent frost, or absence of soil.
3. an area of the ocean in which it is believed no marine life exists.
4. (formerly) any unsettled area between the Mississippi and the Rocky Mountains thought to be unsuitable for human habitation.
5. any place lacking in something: The town was a cultural desert.

Here's the definition of a Tundra:
–noun
one of the vast, nearly level, treeless plains of the arctic regions of Europe, Asia, and North America.

Some Additional Information:
The Sahara covers about 8.6 million square kilometers; I have spent time there and it is pretty huge, but not a contiguous sand-dune desert like the smaller Empty Quarter in the Arabian Peninsula. You can at least drive across the Sahara and have a chance of getting to the other side.

Antarctica covers about 20 million square kilometers - quite a bit bigger.

From the definitions above, Antarctica is a Desert, but not a Tundra. The Sahara is a Desert, but not a Tundra. Antarctica is more than twice as big as the Sahara.

I hope this settles your argument.

~~~~~

Volcanoes, Earthquakes, and Plate Tectonics

Yes, they ARE connected.

With two notable exceptions, volcanoes are associated with (a) tectonic plates splitting apart (Iceland and east central Africa come to mind) or (b) tectonic plates that are coming together (the Pacific Ring of Fire comes to mind). In the former case, magma is simply rising into an opening gap between crustal plates that are being pulled apart - like the mid-Atlantic Ridge. In the latter case, an over-ridden oceanic plate, loaded with water and chemical sediments, heats up as it goes deeper into an increasingly-hotter-with-depth mantle. Something called partial melting takes place: the lighter materials like silica and water and CO2 segregate from the down-going slab and float up - Mount St Helens in the Pacific Cascades, Sheveluch in Russian Kamchatka, and Mount Fuji in Japan are examples of these.

The notable exceptions are the volcanoes of the Hawai'ian Islands in the middle of the Pacific oceanic plate, and Reunion Island in the Indian Ocean. The generally accepted understanding for their existence is that a "hot spot" in the Mantle feeds up through a moving crust (the Pacific plate) and creates a string of volcanoes. In the Hawai'ian chain, the oldest are in the northwest, and the youngest are in the southeast on the Big Island. There's even a new one, called Loihi, that is forming on the ocean floor even farther southeast of the Big Island.

When we talk about moving tectonic plates, it's hard to come up with a reference point that everything is moving with respect to... Certainly the North American continent is moving westward over the Pacific and subsidiary plates, but Kamchatka is moving southeast over the same plate(s). If in fact there IS a "hot spot" in the middle of the Pacific plate - perhaps that is the one non-moving reference point on this entire planet.

Q:

With the increased recent activity around the "ring of fire", New Zealand, Japan and Gulf of California, is there an increased risk for earthquake in other areas of the ring of fire?
Thank you
David H


A:
Geologic events never happen according to a regular clock - sometimes things are quiet around the Ring of Fire, sometimes several events happen in relatively close succession. There is no recognized relation between the huge Tohoku earthquake in Japan and the much earlier Christchurch, New Zealand event - they are too far apart in both space and time. THAT said, there have been several cases observed where a large earthquake has "lit up" distant volcanic or earthquake-prone areas.  The large Denali fault earthquake of November 2002 apparently triggered swarms of small earthquake in Yellowstone, for instance. Nothing big happened, but there were a cluster of small earthquakes that correlate closely with the p-wave of the Denali event passing through.

The likelihood of other earthquakes around the Ring of Fire correlates much more closely with the rate of subduction - how fast the continental plate is over-riding and "smothering" the oceanic plate. This rate is much higher off the coast of Kamchatka, in eastern Russia for instance (about 8 cm/year), than the collision rate of the Pacific Northwest (moving only about 2.5 cm/year). For this reason the volcanoes in Kamchatka are historically much more active than those in the Cascades. In the 10 years that I've been receiving daily volcanic notices about Kamchatka, I'm at a loss to think of a time when a volcano in Kamchatka was not erupting. Whereas in the last century, here in the Pacific Northwest, we've only had Mount Lassen erupt (1915-17), then Mount St Helens in (1980-86).

Any plate motion will translate into earthquakes - the plates are scraping past each other - and the subduction (over-riding plate) earthquakes can be real doozies.

Slower tectonics translates to a quieter life: fewer earthquakes, fewer volcanoes.

~~~~~

Nuke it!

While I was serving as the chief scientist for volcano hazards of the US Geological Survey, Mount St Helens chose that particular window of time during 18 years of quiescence to erupt (October 1, 2004). At the time I was also still volunteering to answer questions for Ask-a-Geologist. Perhaps because of my calling at the time, I received not one but two AAG queries that went something like this (I couldn't find them in the archives or I would quote directly):

Why can't you drop an atom bomb on <Mount St Helens> to stop it from erupting?

A variant on this suggestion is to use a nuclear device to trigger a pending eruption at a time of your choosing.

There are several problems with this approach:
A. Highly radioactive debris scattered widely over a populated area.
B. You would need to get the device under the ground to open the ground.
C. The inherent energy of most volcanoes is far larger than any nuclear devices built by man.

"A" is, I hope, obvious. Nearly as many people died of radiation poisoning after the Hiroshima uranium bomb was dropped than died of the immediate blast itself. Half-lives for things like the unstable isotopes of strontium and cesium are looooong - thousands of years - and they are poisonous the whole time they are decaying. Plutonium is, gram for gram, far more deadly than botulinum toxin.

"B" is basic physics. A small stick of dynamite will blow OPEN a standing safe by over-pressuring it, but a cluster of dynamite sticks taped to the outside and detonated may or may not crush a safe door down onto the inner contents of the safe. Despite what you may have seen on Butch Cassidy and the Sundance Kid, safes don't blow up nicely.

Translation: you will need a very big, very expensive drill to place the nuclear device at a strategic place. Assuming it was powerful enough, that is.

When you come down to the many trade-offs, it's far easier to just (1) monitor the volcano, and (2) evacuate people when it's restive behavior starts accelerating and the seismometers start going ape on you.

"C" is just a numbers game. The Hiroshima uranium bomb and the Nagasaki plutonium bomb had estimated explosive yields between 12,000 and 20,000 tons of TNT. For you metric nerds out there, a metric ton of TNT equivalent is a bit over 4 gigajoules.  Mount St Helens' 1980 eruption was a VEI = 5 level blast. That's short for Volcano Explosivity Index, and a VEI 5 is about 10 times bigger than a VEI = 4; the values are approximate, and approximately logarithmic. The 1980 eruption of Mount St Helens released the equivalent of 20 million tons of TNT. That's between 1,000 and 30,000 times more energy released than the Hiroshima atom bomb.

The eruption of Yellowstone supervolcano about 640,000 years ago has been estimated as a VEI = 8 event, or 1000 times larger than the 1980 Mount St Helens eruption. That's between 1,000,000 and 30,000,000 times the power of a Hiroshima bomb.

Translation: a nuclear device is to a VEI 5 volcanic eruption, as a fly doing push-ups is to you doing push-ups. I may be exaggerating a bit with the fly, but you get the point. Volcanoes are BIG. That's why no one has ever seriously considered engineering around a volcanic eruption. Just get out of the way if you can.

If you want to open a can of spinach, ya gots ta squeeze it, to quote Popeye. No sissy atom bombs.

~~~~~

Deformation and GPS

We get a LOT of questions about volcanoes, including how to Know if they'll Blow. There are a number of ways we can track magma movement at depth, including deformation and "LP's" - long-period seismic tremor that is indicative of fluid movement. At late stages of unrest, we will start seeing "VT's" - short-period volcanic tremor that is indicative of shallow rock-breaking - and increases in CO2 and H2S gases. There is at least the possibility that we can detect early movement of magma at 30 - 40 km depths using magnetotelluric systems, but so far there hasn't been funding to try this. As I write this, deformation reaches out the longest time ahead of all these detection systems to give us warning of an impending eruption.

The term "deformation" is used by specialists in ground movement in the geosciences; these guys themselves are called "geodesists". Geodesists measure movement as a component of strain along an active fault, to try to get a sense of the energy accumulating that could lead to an earthquake. Deformation is used in volcanology to look for - and then track - inflation in a volcanic edifice. Deformation is done in several ways:

1. By surveying the ground with high precision. This has been done at Yellowstone since the mid-1920's, and those early data have helped us get a much better sense of how the huge caldera moves and breathes. 
2. By deploying tiltmeters. Originally these were long tubes of water laid out over the ground. If the ground under the flank of a volcano started tilting, it would show up in amplified movement of water in vertical tubes at the end of the long tube. Modern tiltmeters are ultra-sensitive cylinders placed in a vertical hole in the volcanic rock, then packed in with sand. The signal from these devices and all the following systems is generally telemetered back to a recording and monitoring system. 
3. By using radar satellites - this is called InSAR for Interferometric Synthetic Aperture Radar. If two images can be captured over the same volcano, they can be used to make interferograms. These are colored, Moire patterns - generated with enormous mathematical calculations to geometrically correct and ratio each pixel to another, called "rubber sheeting" - that will show inflation over the surface of a volcano and its environs. Each rainbow-colored ring-set represents one radar wavelength (typically 5 - 15 centimeters) of uplift. These often form a bulls-eye centered over an inflating volcano or deflating caldera, and I've seen several gorgeous examples at Ngiragongo volcano, in Central Africa; at Pavlof, Akutan, Okmok, Shishaldin, and many other volcanoes in the Aleutians, and at Mauna Loa and Kilauea volcanoes in Hawai'i. 
4. Gravity level-lines. This is like survey leveling, but is done by making repeat measurements with a gravity meter over a line of stations every six months or so. All other things (including the water table) being equal, an inflating volcano will show up as a decrease in the gravity field - the gravimeter is being moved farther away from the Earth's center, and the pull of gravity falls off as (1/radius distance squared). I did this to monitor magma moving into the Harrat Rahat volcanic field east of Madinah al-Munawarrah ("Medina") in Saudi Arabia. Seismic telemetry also showed small earthquakes associated with this magma movement at the same time. The events died out by 1995, causing a lot of people to breathe a collective sigh of relief, but this kind of one-again-off-again restive behavior is not at all unusual for a volcano.
5. Telemetered GPS. These use the same GPS satellites you and I utilize in our cars or when hiking, but the precision measurements made by geodesists (the formal name for the deformation guys) are made using different signals from the same satellites.
6. We also instrument volcanoes with sensitive analog, and ultra-sensitive broadband seismic sensors. Some of these data are telemetered, some are recorded and just stored in the instrument box on a small hard-drive until retrieval the following summer. That is, unless bears decide to play ball with one. One over-winter seismic network campaign at Katmai in Alaska found 5 of 11 very expensive stations had been trashed by bears before they could get back and retrieve them. 

GPS is a fascinating field, and applies far beyond the earth sciences. A brief run-down might be useful here.

The Global Positioning System was first envisioned by DARPA - the Defense Advanced Research Projects Agency of the Department of Defense - during the 1980's. Navigation at that time was complex and difficult, and getting any sort of location precision over vast distances including oceans was very important to some people. Like, the people targeting ballistic missiles, for instance.

In the late 1980's I worked in the Venezuelan jungle, where our main form of navigation was using 1:250,000-scale airborne radar (SLAR) maps. These were assembled by flight strips - and it was not unusual to find splice errors as large as 3 kilometers. Basically that means I could be standing on a rock - and half of the rock was 2 miles along the strip edge from the other half of the rock. I have been on a helicopter traveling for an hour over trackless forest using a half-meter-sized roadmap of the country (except there are no roads in the jungle) and crudely-penciled lines with the azimuth and distance for the site we wanted to visit. If that helicopter's fuel line had a single bug in it, we would have dropped down into the trees. Even assuming we had survived such a crash (the incident statistics gave me a 50% chance of this), how would you call in a rescue helicopter? How in the world would you tell them where you were?!?

I first began using a GPS device in the early 1990's in Saudi Arabia. In the northern reaches of the country there is a vast plain that is dead flat for hundreds of kilometers in all directions. Some of our guys had accidentally strayed across the Iraqi border because there is no way to know where the line arbitrarily drawn by the British a century earlier actually was. The first GPS units were incredibly slow, the size of a Betty Crocker cookbook, and didn't always work - but the idea fascinated me. With a radio, I could then precisely tell people where I was. 


Since then, hand-held GPS devices have shriveled to matchbox sizes, strap to your wrist, and have maps built in. You can program them, collect precise tracks... the list of bells and whistles goes on and on.

But how do they work? What actually is out (or up) there?

The American GPS constellation has at any given time about 24 active satellites and a few loitering spares, and each one transmits a very faint signal on two freqs - digital signal for hand held use and another digital carrier that is used for precision location acquisition - I'm talking centimeter-size precision here. BOTH frequencies are encrypted... they belong to the military, and for a long time the signals were deliberately "fuzzed" - this was called Selective Availability, or SA for short. If you had the key and a certain type of book-sized device, you could get very precise locations - within 10's of meters. But DOD didn't want someone else using those signals to pop an artillery round on top of one of their military outposts. Even to this day, if you try to use a receiver and go faster than a commercial airliner (as in: a ballistic missile) it won't work. It has a built-in fail-safe.

In the meantime, the rest of the world has become incredibly dependent on the GPS constellation. I could never summarize adequately all the ways and places where it is used right now.

If you are surveying - or trying to see if two points on the opposite sides of a volcano are moving apart from other (uh-oh), then you need great precision. It can now be as good as a bit over a centimeter horizontally and 2-3 centimeters vertically. In part this difference in precision is because for horizontal solutions you can subtract the atmosphere effect from two different near-horizon satellites - and triangulate better. For vertical elevations, you have only satellites in one direction (not beneath your receiver).

GPS signals all use the same frequency, but the signals are encoded to separate the satellites. Both transmitted signals from each are encoded, so you can't use one for a ballistic missile guidance system unless you own the codes. As I said, above a certain aircraft speed, GPS won't work.

Well, the Russians certainly didn't want to be dependent on something that the Americans could fuzz - or even turn off. So despite their crushing economic difficulties, they turned the best Russian minds onto building their own constellation. This is called GLONASS, and the signal is not encoded, the energy transmitted is greater, so the signal-to-noise ratio is 5 times or 15 db better. Because of this, the signal penetrates tree canopy, so I could use it in the jungle! Woo-HOO! The GLONASS system also uses 3 different frequencies, so you can reduce ambiguities and calculate better differential atmospheric corrections.

These GNSS (Global Navigation Satellite Systems) are so precise that they routinely calculate and correct for relativistic effects! There are also huge atmosphere effects that must be compensated for - dense air masses here and and ionized layers there. GLONASS even works on new American and European hand-held devices when the GPS signals are poor due to a poor view of the constellation - if you've ever been in steep canyons in Utah or New York City, you will know what I mean here.

Not to be outdone, the European Union is now experimenting with their own GNSS (Global Navigation System) called GALILEO. This is a purely civilian system with three frequencies, and is scheduled to come online in 2015 - they are testing 2 satellites in orbit right now.

For the same reasons, the Chinese have started their own COMPASS satellite GNSS system, and it likewise is coming on line rapidly - there are 6 satellites in orbit already, and thee would have been more if a recent Russian rocket system hadn't crashed. Not to be left behind, the American version of GNSS - the only one that should technically be called "GPS", is being upgraded.

All four of these GNSS systems use L-band frequencies to resolve ambiguities and increase precision - and penetrate the ionosphere. What does L-band mean? Look at your personal GPS system and the smallest dimension on it will give you an idea of the wavelength for L-band.

The navigation problem is more than just triangulation - three satellites near the horizon would serve for this; two would give you two possible location solutions, three would mean only one possible solution. But there are four unknowns, since you are measuring how long a stretch of space and air that your signal must travel. The precision of your timing thus becomes utterly critical, the speed of light being so huge (300,000 km/second), and hand-held GNSS devices cannot carry $100,000 maser clocks. Thus, you must use a 4th satellite to help solve for the 4th unknown: 3 for position, 1 for a clock reference for your receiver

There are a few more complications. You really need to use a reference ground station to get really good differential distance calculations - to do good back-corrections for the changing satellite orbits, the complex and varying atmosphere, snow cover, etc... However, during the Tohoku earthquake in early 2011, all of Japan jerked eastward, so geodesists couldn't see the whole shift with really great precision because their reference station also moved.

So how does this help volcanologists? As I said earlier, if two telemetered GNSS receivers are moving away from each other, and there is a volcano in between them (this is happening right now with Mauna Loa, the largest volcano on Earth), then you are being given a warning that something is coming.

In 1989 we didn't have such a warning before Redoubt volcano in Cook Inlet of Alaska erupted. A KLM Boeing 747 flew right into the ash cloud - and lost all four engines in rapid succession. I've got a recording of the captain's voice as she tries to guide her flight crew in Dutch and talk with flight control in Anchorage in English. Her voice rises steadily a full octave before she finally yelled "Anchorage we have lost all four engines, we are in a fall. We can use all the help you can offer." They managed to restart two of the engines, and made a rough landing at Anchorage International airport. No lives were lost - but the repairs to that Boeing 747 cost $80 million.

To put that in perspective, when I served as chief scientist for volcano hazards for the US Geological Survey, my entire science team budget was less than $20 million.

There was another interesting GNSS application that you will find fascinating - I sure did. When Mount St Helens erupted on 1 October, 2004, we had just a week of accelerating seismic racket on our network beforehand for a warning. The extrusion was first seen on October 12 - and by pure luck I got the first photo of the new "spine" from a helicopter orbiting the steaming and fractured Crater Glacier. The dacite extrusion - 700 degrees C at where it was coming up from the talus slope at its base - came out like a tube of squeezed gray toothpaste. It resembled the back of a whale, so that became its name: The Whale. It moved south through crumbling talus and ice until it hit the remaining south rim of the 1980 eruption. The geodesists wondered when it actually reached the wall - When Did The Whale Hit the Wall? A check of a GPS station on the other side, on the outside south slope of the volcano, answered the question. On November 17, 2004, that station suddenly started moving south. Was it an effect of snow on the antenna? No, because the only direction it moved was south - by about 10 cm. The entire crater wall was shoved southward by 4 inches.

I'll never forget the elation of scientists using GPS technology to answer a real question about an erupting volcano. But GNSS systems provide us more than just answers to our scientific curiosity.

In 2006 a sharp-eyed geodesist in Anchorage, Alaska, was routinely checking data from several GPS units installed on Augustine volcano in the middle of Cook Inlet, south of Anchorage. This had erupted in 1979 and nearly killed David Johnston, one of our brightest young geologists who was later killed during the 1980 lateral blast, the opening eruption salvo of Mount St Helens.

In August 2006 this geodesist noticed some differential movement apart - the first subtle inflation was starting - and notified the Scientist-in-Charge. A close checking and monitoring effort was triggered - and sure enough, the signal was real, showing above all the background noise - and it was continuing. Federal and State Emergency entities, along with the FAA, were put on notice. In Late December the first VT's started appearing on the seismometers. As they accelerated in frequency and amplitude, the USGS issued a warning: an eruption is imminent in hours or days. One day later, on January 16, 2007, Augustine erupted, and dusted Anchorage with ash. International flights were cancelled or re-routed for three days - but not a single aircraft was damaged, not a single life was lost.

Yeah! This stuff works!

~~~~~

Lava Tubes

If you've never walked through a lava-tube, you are in for a Bucket List experience. There are many in Hawai'i (of course), but there are others in the Pacific Cascades of America and even in Idaho. I have a permanent dent in my forehead, a trophy obtained while climbing through Upper Ape Cave, on the south side of Mount St Helens, in Washington, State.

WEAR HELMETS. Do as I say, not as I did.

Q:

I’m writing a sci‐fi novel and would like to know what kind of rock makes up a lava tube? As far as I can tell with my feeble mind, it’s basaltic rock, is this right? I’ve tried searching the internet and can’t find a definite answer. Can you help me?
Thanks ahead, J.R.M.


A: Yep, you're right. Higher-silica lava like rhyolite and dacite don't make tubes - but crusty domes instead. It helps if you understand how lava tubes are formed. I've walked through lava-tubes in Hawai'i and Mount St Helens, and you can see that everything - even the "bathtub rings", is basalt. At Pu'u O'o, part of the East Rift Zone of Kilauea, a friend used a police speed-gun to clock the yellow-glowing basalt magma at 40 kph (25 miles per hour) as it shot through the active tube past a skylight. As lava pours down a slope, it finds the natural drainages (or makes its own) and follows them. The lava on the edges of these flowing, yellow-red rivers starts to cool, and then starts to crust over. When the cover is complete, you have a lava-tube that is now insulated from the (relatively) cold air, and liquid lava can now maintain its heat and travel farther. After the the hydraulic pressure stops from above, the tube drains, empties out, and cools off. The inside isn't perfectly smooth, either; there are lots of irregularities, and these are fascinating. They give subtle insights on how magma flows - and "paints" and drips and leaves "bathtub rings" in the walls of the tube.

The roof can be up to 7 meters tall, and boulders and cold lava in the hot lava path get incorporated into the flow or partially dam it. There are parts of the roof that break off - exposing skylights - and these slabs travel down as solid chunks (at least for awhile) in the lava. I have a permanent dent in my right forehead from making a right turn into one of these lava "blades" hanging out of a roof in the Ape's Cave lava tube at Mount St Helens. In my office I have a USGS cap soaked in dried blood from this experience: sort of a trophy, and a reminder to be more careful.

~~~~~

CME Events - How They Affect Your Life

Let's switch briefly to the interface between Earth and Space. Specifically, the probably-novel-for-most-people idea of "space weather."

Two days ago, something not unknown, but not commonplace either, happened on the surface of the Sun. Something called a Coronal Mass Ejection (CME) event took place. These are complex phenomena, still rather poorly understood, but involve the Sun's powerful magnetic field and the huge energy being generated by hydrogen fusion. The result is a huge ball of ionized material shooting off into space. This particular one was aimed at Earth and Mars. It is the space equivalent of a Category 5 hurricane.


The Solar Dynamics Observatory satellites first picked up this solar flare erupting from the sun on January 22, 2012. Almost immediately there was a large burst of radiation, higher levels than have been measured since 1989. The highly energetic ionized particles erupted from the sun as part of this CME traveled well above the speed limit - at roughly 2,200 kilometers per second - and hit Earth on January 24 around 10am US Eastern Time.

Why would you possibly care?

Because there are some amazing side effects from one of these events that can directly affect you.

The huge ion bomb, when it strikes Earth's protective magnetic field, is partially deflected towards the poles. Auroras sometimes reach the mid-continental United States during these events. They set up huge telluric currents in the Earth's surface - these are short-circuited by the oceans, but the shallow continental crust is resistive to varying degrees. Basic physics says that if current is flowing, there must be a voltage difference causing it. Electrical power grids generally transmit electrical energy at very high voltages (in the 100,000 range and higher) in three "phases" - in other words, the power on each of the three lines held up by transmission towers is at 60 Hz (in North America; 50 Hz in Europe and the British Commonwealth), and each line's alternating signal is out of phase from the other two by 120 degrees. Think of a wheel turning through 360 degrees for each cycle, then each cycle will peak at 4 o'clock, 8 o'clock, and 12 o'clock in sequence.

But the power transmission system is never perfectly insulated - electrical charge inevitably "leaks", and for this reason each tower and power substation has a fourth electrical line called a "ground" to take care of that leakage. This is the fat round opening on the bottom of most electrical sockets. In our homes, we only "see" two phases and a ground after the voltage is stepped down by transformers to 220 volts and 110 volts. The assumption underlying all grounds is that the Earth is all at the same base voltage - the same reference point. However, if there is a large telluric current (this word means an electrical current flowing through the ground), then the voltage of each tower's "ground" and each substation's "ground" is going to be different. Inevitably something will become unstable - a ground-loop is set up - and an excessive voltage at some point is going to lead to an "arcing" or jump of current to someplace where it shouldn't be going. It's not unusual for transformers the size of a car or an SUV to explode violently when this happens. This is commonly seen in video of a city skyline as a tornado approaches: the transformers "pop" with a flash, one by one.

How could this affect you? The Canadian provinces of Quebec and Ontario experienced a huge and long-lasting blackout due to a CME event back in 1989. In mid-winter, if electricity is your source of heat, this could be a life-threatening event. If you survive, your water pipes will freeze and burst, and you will have heck to pay when it warms up again.

What else happens? The huge telluric currents overwhelm the carefully-designed electrical corrosion protection on oil and gas pipelines. Most readers are aware of the fiery inferno that happened in San Bruno, California two years ago when a corroding pipeline leaked natural gas that somehow ignited. Whole neighborhoods were consumed in a raging fire that took hours to subdue.

Death by fire, death by flood.

Do you use GPS in your car? You can expect that the GPS satellites, which are designed to withstand this sort of event up to a point, might malfunction. Some satellites can go off-line for awhile or even permanently if the damage is too severe. I hope you are aware that any commercial airliner you fly in depends on GPS. Same holds for weather and communication satellites. American Idol? You may miss an episode, but that may not necessarily be a bad thing...

Death by boredom. Are you starting to feel a pinch now?

Large and turbulent changes in the ionosphere during geomagnetic storms triggered by these CME events interfere with high-frequency radio communications... just what your pilot is using to communicate with the control tower. As of today (24 January) Delta Airlines has started re-routing pole-crossing international flights away from the poles, where the dipolar nature of the Earth's magnetic field allows these huge ion-storms to penetrate deeply into our Earth's protective atmosphere. This is why the auroras will be so bright and far-reaching tonight.

What about our astronauts in the International Space Station? They have a protective "safe room" to retreat to, but this is a partial mitigation at best. As I write this, all six astronauts in the ISS are being severely irradiated. The highly energetic particles during solar events like this cause temporary operational anomalies, damage critical electronics, degrade solar arrays, and blind optical systems such as imagers and star trackers. The latter are necessary to keep the solar arrays correctly oriented, and to keep one side of the ISS from broiling while the other side freezes.

For the vast majority of us, there will likely be no manifestation of anything unusual. But then, when Hurricanes Andrew (1992), Isabel (2003), Katrina (2005) and Felix (2007) struck the eastern United States, most of the rest of us felt nothing... until the forced immigrants began to arrive.

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