It is really Perovskite structure that you should be excited about, not the wild mineral. Perovskite is

very common on earth, one of the most common minerals, but it forms and mostly resides deep below the Earth’s surface, with these various localities around the world being spots where this or that blob of it moved along with other rock to the surface, or was ejected out of a volcano. (Also, the mineral shows up in meteorites. When you see Perovskite in a meteorite it came from a planet above a certain size, because it needs to form in Mars or larger size planets.) And everywhere you find it, it seems, it varies in the exact details of its composition, and those details tell us a great deal about the origin of the mineral, and also, imbue the mass with differing and interesting properties. Ultimately, Perovskites will provide us with two very important things. One, an otherwise inaccessible understanding of the geological processes happening over long time and at present well beneath the Earth’s surface. The other: the Perovskite structure will transform our energy producing technology, information technology, and make better televisions and other important stuff. Probably.

If this is sounding at all familiar to you it is probably because a few years ago there was a big hoo ha about a much improved technology for solar cells. This is that technology.

The reason I mention this today is that the current issue of Science Magazine has a special section on Perovskites, looking at the mineral and the crystal structure in three different areas, one geological and two technical. I suspect the papers are inaccessible unless you have access to the magazine, but I’m happy to provide you with the titles and abstracts to give you an idea of what this new work is about.

So, without further ado:

The introduction of this special section in Science notes that “Perovskite is an unremarkable calcium titanium oxide mineral discovered in 1839 with an extremely versatile crystal structure. The compact crystal structure marks the transition to Earth’s lower mantle as silicate perovskite becomes stable. … The perovskite crystal structure can accommodate a wide variety of cations, which allows the development of many materials. … The tunability of the perovskite structure also makes these crystals attractive for catalysis and electrocatalysis. In solid oxide fuel cells, perovskites serve as oxygen ion conductors separating anodes and cathodes. For applications such as automotive pollution control, perovskite catalysts based on earth-abundant elements could provide alternatives to existing catalysts based on scarce precious metals.”

Yes indeed, a great deal of magic.

Perovskite in Earth’s deep interior. Kei Hirose, Ryosuke Sinmyo, John Hernlund. Science 10 Nov 2017. Vol. 358, Issue 6364, pp. 734-738 DOI: 10.1126/science.aam8561

Abstract
Silicate perovskite-type phases are the most abundant constituent inside our planet and are the predominant minerals in Earth’s lower mantle more than 660 kilometers below the surface. Magnesium-rich perovskite is a major lower mantle phase and undergoes a phase transition to post-perovskite near the bottom of the mantle. Calcium-rich perovskite is proportionally minor but may host numerous trace elements that record chemical differentiation events. The properties of mantle perovskites are the key to understanding the dynamic evolution of Earth, as they strongly influence the transport properties of lower mantle rocks. Perovskites are expected to be an important constituent of rocky planets larger than Mars and thus play a major role in modulating the evolution of terrestrial planets throughout the universe.

Promises and challenges of perovskite solar cells. Juan-Pablo Correa-Baena, Michael Saliba, Tonio Buonassisi, Michael Grätzel, Antonio Abate, Wolfgang Tress, Anders Hagfeldt. Science 10 Nov 2017. Vol. 358, Issue 6364, pp. 739-744 DOI: 10.1126/science.aam6323

Abstract
The efficiencies of perovskite solar cells have gone from single digits to a certified 22.1% in a few years’ time. At this stage of their development, the key issues concern how to achieve further improvements in efficiency and long-term stability. We review recent developments in the quest to improve the current state of the art. Because photocurrents are near the theoretical maximum, our focus is on efforts to increase open-circuit voltage by means of improving charge-selective contacts and charge carrier lifetimes in perovskites via processes such as ion tailoring. The challenges associated with long-term perovskite solar cell device stability include the role of testing protocols, ionic movement affecting performance metrics over extended periods of time, and determination of the best ways to counteract degradation mechanisms.

Properties and potential optoelectronic applications of lead halide perovskite nanocrystals. Maksym V. Kovalenko, Loredana Protesescu, Maryna I. Bodnarchuk. Science 10 Nov 2017. Vol. 358, Issue 6364, pp. 745-750 DOI: 10.1126/science.aam7093

Abstract
Semiconducting lead halide perovskites (LHPs) have not only become prominent thin-film absorber materials in photovoltaics but have also proven to be disruptive in the field of colloidal semiconductor nanocrystals (NCs). The most important feature of LHP NCs is their so-called defect-tolerance—the apparently benign nature of structural defects, highly abundant in these compounds, with respect to optical and electronic properties. Here, we review the important differences that exist in the chemistry and physics of LHP NCs as compared with more conventional, tetrahedrally bonded, elemental, and binary semiconductor NCs (such as silicon, germanium, cadmium selenide, gallium arsenide, and indium phosphide). We survey the prospects of LHP NCs for optoelectronic applications such as in television displays, light-emitting devices, and solar cells, emphasizing the practical hurdles that remain to be overcome.

Perovskites in catalysis and electrocatalysis. Jonathan Hwang, Reshma R. Rao, Livia Giordano, Yu Katayama, Yang Yu, Yang Shao-Horn. Science 10 Nov 2017. Vol. 358, Issue 6364, pp. 751-756 DOI: 10.1126/science.aam7092

Abstract
Catalysts for chemical and electrochemical reactions underpin many aspects of modern technology and industry, from energy storage and conversion to toxic emissions abatement to chemical and materials synthesis. This role necessitates the design of highly active, stable, yet earth-abundant heterogeneous catalysts. In this Review, we present the perovskite oxide family as a basis for developing such catalysts for (electro)chemical conversions spanning carbon, nitrogen, and oxygen chemistries. A framework for rationalizing activity trends and guiding perovskite oxide catalyst design is described, followed by illustrations of how a robust understanding of perovskite electronic structure provides fundamental insights into activity, stability, and mechanism in oxygen electrocatalysis. We conclude by outlining how these insights open experimental and computational opportunities to expand the compositional and chemical reaction space for next-generation perovskite catalysts.

Caption to the image (from Wikipedia) at the top of the post: Structure of a perovskite with a chemical formula ABX3. The red spheres are X atoms (usually oxygens), the blue spheres are B-atoms (a smaller metal cation, such as Ti4+), and the green spheres are the A-atoms (a larger metal cation, such as Ca2+). Pictured is the undistorted cubic structure; the symmetry is lowered to orthorhombic, tetragonal or trigonal in many perovskites. This is a POV ray drawing of a small section of the lattice of an imaginary perovskite. The red atoms are oxygen anions while the the green atom represents the larger cation, and the blue central atom the smaller cation, typically with a higher oxidization state. I created this file by writing a XYZ file using a spreadsheet after reading cotton and wilkinson, this was edited using the text editor of ORTEP. ORTEP was used to write the pov file, then POVray was used to draw it.

California is one of the most geologically interesting and complex geopolitical units in the world. But so is Minnesota, and Minnesota is boring, geologically, for most people. Why? Because Minnesota is all eroded down and flattened out and covered with glacial till, so most of the interesting geology is buried, while California is actively engaged in its own geology in a spectacular and visually appealing way!

Lots of places have volcanoes. California has volcanoes that blow up, or that have erupted recently enough (geologically speaking) that you can still see the stuff laying all over the place they spewed out. Lots of places have rifting. Hell, one of the most interesting and important rifts in global geological history is right here in Minnesota. But, do people go to Duluth to see that rift, or to see Bob Dylan’s house? The latter, I think. In Califonria, there are three or four different kinds of major tectonic activity, including lots of plate tectonic movement, some spreading, and a big chunk of the amazing Basin and Range extension phenomenon. (That was where what is roughly Nevada and big sections of Utah and California stretched out to several times its original size. In the old days, Reno and Salt Lake Cities wold have been in the same Congressional District!)

California doesn’t’ just have mountains. It has several different kinds of mountains, most of which are currently actively forming right before our very eyes, or so recently formed they still have the tags hanging off them.

California’s Amazing Geology begins with several chapters on basic geology. If you know basic geology you can skip quickly through this and refer back later when you forget something. Then there are several sections each dealing with a different geological region. Then, there is a chapter that literally puts it all together (“Assembling California”). Following this is a compendium of information on California’s main geological resources (gold, oil, water, etc., including fossils!)

There are three things you need to know about this book. First, it covers everything pretty completely, considering the vastness of California and the fact that the book is 480 pages long. Second, it is very up to date. There aren’t any up to date books about California Geology. Third, it is written by Don Prothero, which means that complicated and nuanced scientific topics are explained in a way that a reasonably educated non expert can totally understand. Books like this all too commonly fall into jargonistic language either because the author has no clue it is happening, or because they are written for a highly specialized audience (and maybe the author is even a bit insecure). Don Prothero does not do that. He simply gives you the information in a respectfully, clear, understandable, but not watered down manner. A lot of people will tell you that is not possible. They are wrong, and Prothero does it all the time.

The illustrations, many by Don’s son, are excellent and numerous.

By the way, if you want to know more about how one goes about writing books like this, and how Don’s approach works, check out this interview with the man himself.

This is a bit of a specialized book unless you frequently visit or live in California. It is suitable as a textbook in college, but also, in just the right California science elective class. If you you are a modern student of natural history and California is in your catchment, this is a must-have book.

I am a little confused about its availability. The publication date is 2017, I got a pre-publication review copy, but it looks like you can actually buy it on Amazon now. But, I’m not sure what happens if you click through, maybe they tell you it will be delivered in January.

Here is the TOC:

FUNDAMENTALS OF GEOLOGY

The Golden State

Building Blocks: Minerals and Rocks

Dating California: Stratigraphy and Geochronology

The Big Picture: Tectonics and Structural Geology

Earthquakes and Seismology

GEOLOGIC PROVINCES OF CALIFORNIA

Young Volcanoes: The Cascades and Modoc Plateau

The Broken Land: The Basin and Range Province

Gold, Glaciers, and Granitics: The Sierra Nevada Mountains

Mantle Rocks and Exotic Terranes: The Klamath Mountains

Oil and Agriculture: The Great Valley

The San Andreas Fault Zone

Melanges, Granitics, and Ophiolites: The Coast Ranges

Compression, Rotation, Uplift: The Transverse Ranges and Adjacent Basins

Granitics, Gems, and Geothermal Springs: The Peninsular Ranges and Salton Trough

Assembling California: A Four-Dimensional Jigsaw Puzzle

CALIFORNIA’S GEOLOGIC RESOURCES

California Gold

California Oil

California Water

California’s Coasts

California’s Fossil Resources

I would think that the Grand Canyon would be the last thing that creationists would point to as proof of a young earth (several thousands of years old). Just go look at the Grand Canyon. One of the top major layers, the Kaibab Formation, is around 300 to 400 feet thick and made mostly of limestone. That would take a long time to form. But wait, there’s more. Within the Kaibab limestone there are also different sorts of rocks, evaporates, which indicate prolonged dry periods. How can an environment that is forming a thick limestone layer, but occasionally drying out for prolonged periods, be accommodated in a short chronology like required by Young Earth Creationists? This formation also contains fossils of organisms that do not exist today. Certainly, more time than possible in a world that began 4004 BC is required to have produce the Kaibab Formation. And that is just one relatively thin layer exposed by the Grand Canyon, and nearly at the top.

Down lower than that is a thick series of deposits that reflect major changes in Earth’s climate and ecology. These are the rocks that contribute most to giving the Grand Canyon it’s glorious redness and depth. They contain fossil footprints of organisms that don’t exist today. They contain alternating layers with evidence of marine environments and dry land terrestrial environments. Any reasonable understanding of how long it would take for these layers to form requires tens or hundreds of millions of years, even without dating, and one can only estimate that the formation of these sediments was finished long before anything like modern life forms existed.

The rock at the base of the Grand Canyon is separated from the rest by a long discomformity (a period of erosion that wiped out an unknown thickness of rock), so this rock is way, way older than everything else. These rocks are highly deformed and contain no evidence of multicellular life. Laying this rock down and subsequently mushing it all up, then eroding the heck out of took more than 6,000 years! Probably closer to 600 million years!

On top of all this, many of the formations we see exposed in the Grand Canyon are known to be represented a great distance away in other areas, and in some places those rocks form the guts of mountains. How long does it take for continents to squeeze together and move about with such force to form the American Great Basin and Range system of mountains, in Utah, Nevada, and nearby areas? More than 6,000 years! For those mountains to have formed from flatness fast enough to accommodate a young Earth, there would have be be mountains somewhere forming fast enough that you’d need to set the handbrake on your car if you parked there for a day, in case the parking lot went vertical on you.

If I was a Young Earth Creationist I’d try to ignore the Grand Canyon, pretend it isn’t there. But it is there. And everybody knows about it.

One alternative to pretending that the Grand Canyon doesn’t exist is to explain how it got there within a time frame of a few thousand years. But that requires speeding up processes to an unbelievable extent.

So, obviously, the only possible way for Young Earth Creationists to deal with the grand canyon is to fully depart reality and claim that it formed in a very short period of time by processes never before or since observed.

According to the Young Earth version of the Bible, dry land appeared in 4004 BC. Then, the Garden of Eden and all that stuff happened, and then the Noachian Diluvian event happened, the great flood, in 2348 BC. If we assume that the flood created the canyon itself, then all of the rock we see now exposed in the grand canyon was laid down over the course of 1,656 years. But that would be way to reasonable for Young Earth Creationists, who seem claim that the sediments seen in the Grand Canyon were actually laid down by the great flood itself. The canyon was then exposed by a single, later, flooding event when a big lake let out all its water at once.

It turns out that the Young Earth creationists have a lousy argument to explain the sediments exposed by the Grand Canyon, and the formation of the canyon itself. If geologists try to explain the Grand Canyon, however, they end up with an amazing and quite plausible story full of exciting geological and geographic adventure and intrigue. The Grand Canyon turns out to be really cool.

So, the book, edited by Carol Hill, Gregg Davidson, Tim Helble, and Wayne Ranney, is The Grand Canyon, Monument to an Ancient Earth: Can Noah’s Flood Explain the Grand Canyon?

It includes several chapters by eleven experts, all fascinating, all informative, all amazing, talking about various aspects of both the creationist view of the Grand Canyon, and about the real geology of this amazing feature.

Great illustrations abound within this volume.

It turns out that the Young Earth Creationists are wrong, in case you were wondering.

As an aside, I don’t actually think the Young Earth Creationists have to be right, or even believable by non-scientists, to have succeeded in explaining the Grand Canyon. From the point of view of a Christian who wants to take the Bible literally, all you need to know is that there is an explanation. You don’t even have to know what the explanation is. By simply knowing that somewhere out there a team of Creation Scientists have explained away the annoying claims of great antiquity and such, you can go on believing in the literal truth of the Bible. In fact, better to not explore the Creationist explanation, really. You wouldn’t believe it.

It isn’t just that the Young Earth version of the Grand Canyon is wrong from a scientific perspective. It is also the case that the Young Earth “facts” from the Bible are themselves wrong. This book also covers that set of problems. And, of course, the Grand Canyon is way more Grand from a geological perspective than it is from a Biblical perspective. The Young Earth version is dumb and uninteresting. The real version is big, giant, wonderful science.

The book outlines the basic arguments about the Grand Canyon and how they differ. Then, the authors explore some basic geology needed to understand the Grand Canyon, looking at how sediments form, the Earth moves, and what fossils can tell us, how dating works, etc.

Especially interesting to me are the chapters on the canyon’s formation. This is a very interesting aspect of both canyons and mountains that I ran into when developing tourism and educational materials for geological sites in South Africa. Get a bunch of regular people who are not very science savvy. Bring them to a mountain. Then, discuss how old the mountain is.

If the rocks the mountain is made of are 500,000,000 years old, then the mountain is 500,000,000 years old, right? I’ve seen public info documents that use that logic, so it must be true! But clearly the mountain you are looking at was not a mountain five hundred million years ago. It was an inland sea or something. The mountain itself rose up between 20 and five million years ago. So that is how old the mountain is, right? Same with Canyons. It isn’t actually hard to understand that the rocks a particular geological feature are made from would be of one age, but the aspects of the feature that expose those rocks (erosion or uplift) are later, and that the ages of the two things must be entirely different.

It is probably a lot easier to date the rise of a mountain system than it is to date the erosion of a surface or the cutting of a canyon. This is because after mountain building slows down, datable sediments may form in clearly identifiable environments that did not exist before the mountain was formed. But a hole is a bit harder to grok. When the Grand Canyon formed, and how long it took, are actually active and open scientific questions. This fascinating subject, which relates as you might imagine to the creationist story in important ways, are well and fully addressed in this volume.

I asked one of the book’s editors, Tim Helble, what the current open questions and areas of active research are for the Grand Canyon. He told me that one “hot topic continues to be how and when the Grand Canyon was carved. The current Colorado River appears to have integrated multiple drainages and proto-canyons, and how and when they were integrated has attracted a lot of research.” He noted that one of the book’s other editors, Carol Hill, “continues to present evidence that there was a karst (limestone/sinkhole/cave) connection between the eastern and western proto-drainages.”

Also, Tim told me that “the Grand Canyon National Park hydrologist is leading a lot of research on the highly complex groundwater system in the canyon area. This is especially timely with all the recent controversy about uranium mining in the greater Grand Canyon area (which actually goes back many decades).”

An interesting fact is that The Grand Canyon, Monument to an Ancient Earth: Can Noah’s Flood Explain the Grand Canyon? is published by Kregel Publications, in their Biblical Studies series.

So, what is the problem with this book?

There really isn’t a problem with this book, but there is a problem with our collective conversation about creationism vs. science. This book addresses a central point in Young Earth Creationism and resoundingly refutes it. But, this is also an excellent book about the Grand Canyon. Personally, I would love to see a book like this that doesn’t waste a page on the creationist story. I want the geology of the Grand Canyon untainted by reference to the yammering of YECs.

I do fully appreciate the role this book will play, and for this reason I recommend it for all science teachers and others who interface with the public in matters of science. No matter what your area of science is, the creationist argument based on the Grand Canyon has become central dogma for that school of non-thought, and you need to know about it. This volume lets you do that in a way that is also rich in real science and very rewarding.

It turns out that while there are some excellent highly technical books on the geology of the Grand Canyon, there is nothing that is super up to date, that covers all of the geology uniformly, and that is beautifully, richly, and correctly illustrated other than The Grand Canyon, Monument to an Ancient Earth: Can Noah’s Flood Explain the Grand Canyon?

I hereby encourage the team that put this book together to also write a post-creationist version that does the excellent science and description, and pretends like the Young Earth Creationists never existed. Who knows, maybe they’ll do it!

As noted, this is a nice looking book, almost coffee table but rich in information, suitable as a gift.

The Great San Francisco Earthquake(s)

On October 8th, 1865, the “Great San Francisco Earthquake” hit south of the city of San Francisco, magnitude 6.3.

On October 21st, 1868, the ‘Great San Francisco Earthquake” hit near Haywards, east of the city, across the bay, magnitude 6.8.

On April 18th, 1906, the “Great San Francisco Earthquake” hit the Bay Area, magnitude 7.6.

The death tolls were unknown (but small), 30, and about 3,000, respectively.

Eighteen significant earthquakes happened after that (and five or so had happened between the first “great quakes”) before February 9th, 1971, when the Sylmar earthquake (magnitude 6.7, death toll 65) occurred in the San Fernando Valley. So, about 25 major earthquakes happened in California, of varying degrees of significance with respect to property damage and loss of life, since the earliest influx of immigrants associated with the Gold Rush, which is how California got permanently and meaningfully populated by Europeans.

Right after the Sylmar earthquake, a law was passed that required that earthquake hazard be considered as part of the approval process for new development.

One hundred and six years of time during which a significant earthquake occurred about every four years, passed before the first meaningful response by the civilization living on top of these active faults. Civilization does, indeed, have its faults. As it were.

Will Seattle and Portland Suffer Cataclysmic Earthquakes Any Time Soon?

Meanwhile, to the north, in British Columbia, Washington State, Oregon and parts of northern California, earthquakes were not recognized as a problem. They hardly ever happened. Buildings, homes, bridges, gas-lines, and other infrastructure were deployed without consideration of earthquake hazard for decades.

However, the earthquake hazard in that region is probably much greater in some ways than the earthquake hazard around Los Angeles and San Francisco, which are regularly rocked by fault-line activity. Here, the great plates that make up our planet’s surface do something different than they do in the southern California.

In southern California, the plates are mainly grinding past each other. Fragments of the plates separated by fault lines are squishing past each other like an eraser rubbing against paper. It is not a smooth process, but rather one in which pressure builds up and is released at numerous locations, with each of those release events resulting in some sort of earthquake.

To the north, the main interaction between the plates is the subduction of one plate beneath the other. The subducting (going under) plate moves steadily under the continent, with little fanfare other than slowly elevating that part of the continent, tilting of the land upward to the west and downward to the east (relatively speaking). Then, every now and then, there is an adjustment. The top plate drops all at once, causing a major change in elevation that results in coastal areas being suddenly under the sea, and also resulting in a major earthquake, perhaps magnitude 9.

(Remember, each whole number on the scale used to measure earthquakes is one order of magnitude, so a magnitude 9 earthquake is 100 times stronger than a magnitude 7 earthquake).

It appears that the nearly 700 mile long zone of subduction has suffered 19 “subduction zone earthquakes” over the last 10,000 years, with many more affecting a smaller length of this zone. So, long term, a major earthquake affecting an area hundreds of miles long and who knows how wide, and by major earthquake I mean as never seen before by living humans in the region, and hardly ever observed in recent times anywhere on the planet, affects an area larger than many countries.

Can earthquakes be predicted?

Same with earthquakes. Sort of. The short term with earthquakes is, unfortunately very very short. We know when an earthquake starts that there will be an earthquake over the next several seconds or minutes. That is a little like predicting that it is going to be raining over the next little while when the first drops fall from the sky. You’ve heard of predicting earthquakes longer term, like over days. Every now and then someone observes something that seems to be associated with the geological processes that produce earthquakes, then there is an earthquake, and bingo, we’ve got a method of prediction. But so far every time this has happened, that method of prediction has been invalidated by reality, when it fails to predict subsequent quakes, or produces false positives.

(An interesting example of this happened just yesterday when a scientist — but not a geologist — happen to observe the presence of huge amounts of various gasses appearing along the coast of California, and thought this might be the indicator of an impending earthquake. This prediction was supported by a several years old research project that suggested that gas outflows might predict earthquakes. I’m pretty sure the gas outflow idea has not developed. And, it turns out that the scientist who observed the California gas was simply looking at a common meteorological phenomenon that involved normal human pollution combined with certain atmospheric conditions. Nothing to see here!)

However, long term, earthquakes can be “predicted” using the term “predicted” in modern vernacular parlance. What I mean by that is that the earthquake hazard for a given region can be estimated over longish periods of time with reasonable certainty. We can say, for example, that there is a 63% probability of there being one or more earthquakes of 6.7 magnitude or greater between the years of 2007 and 2036 in certain clearly defined parts of California around San Francisco. This is based on a combination of empirical observation of earthquake frequency and an understanding of how earthquakes happen. According to one study, there is about a one in three chance of a Cascadia subduction zone earthquake (magnitude 8 or 9 or so) over the next fifty years.

So, when planning development or putting together emergency systems, it is possible to know two things. One, what kinds of earthquakes are going to happen (in terms of location, overall range, and magnitude, etc.) and what is the chance of something like this happening.

How do we adapt to earthquakes?

From this emerges something rather counter-intuitive. It turns out that the magnitude of the largest likely quake is more important than the likelihood that it will happen during any medium length time period. It does not matter if a magnitude 9 earthquake is 10% or 1% likely to happen over the next 20 years when you are building a major interstate highway bridge or a skyscraper. What matters is that you build the thing to handle a magnitude 9 earthquake (or, I suppose, prepare yourselves for total destruction of the thing, and have a backup plan of some kind). Development in southern California has to deal with magnitude 7-point-something quakes during the lifespan of a major long-lived structure, while development in Washington and Oregon has to deal with magnitude 8 or 9 quakes during the lifespan of a major long-lived structure. The truth is, your highway bridge near San Francisco has a good chance of being shaken by a magnitude 7 quake, while a highway bridge near Seattle may well outlive its usefulness and be replaced or retrofitted before the once in 500 year trans-Cascadia 9+ quake hits. But you still have to build it to handle the quake because you don’t want to be that guy. (Who didn’t, and then everyone died, and it was your fault.)

There is an interesting historical pattern in the recognition of, and in addressing, earthquakes both in the US an around the world. That century plus time period between what should have been a clue that San Francisco was a quake zone and the first meaningful safety conscious zoning regulation happened initially because developers covered up the first few quakes. They pretended they didn’t happen, downplayed, lied, etc. The 1906 quake was too big to really cover up, of course. Covering up switched to lobbying and lobbying kept regulations off the table for many more decades. Then several dozen suburbanites, voters, taxpayers, whatever got wiped out by a quake that really wasn’t all that bad compared to some of the earlier ones, and a law got passed. So this part of the pattern is denial, followed by different kinds of denial, then some more denial.

Denial of what? Science, of course.

The second part of the historical pattern is science progressing. While most early and mid 20th century construction went along blind to earthquake hazard in southern California because people were being willfully stupid, earthquake unsafe construction proceeded in the northern regions because science had not yet figured it out. Then the denial vs. science thing happened, and is still going on. Decisions have been made at various levels of government in the Cascade subduction zone area that will doom people of the future (one year from now, one century from now, we can’t say) to disaster.

A great new book on earthquakes: “Earthquake Time Bomb” by Robert Yeats

Do you find any of this interesting or important? Then you need to read Earthquake Time Bombs by Robert Yeats.

Yeats explains what earthquakes are. Then he discussed the development of earthquake science, and the politics, cultural response, and technological response to earthquakes, starting with the examples I gave above plus the Haiti earthquake. Then he goes around the world to most of the major earthquake zones and examines the same processes — the geology, the geological science, the engineering and political responses, etc. — in each area.

Yeats is an expert on this, and in fact, has been involved in what he refers to, I think correctly, as the “paradigm shift” in understanding earthquake hazard and risk. This is a shift that happens both within the science and the regulatory and social systems that necessarily address the hazards and risks. He also explains the difference between hazards and risks. Yeats is the go to guy when you want to find out about what to do about earthquakes.

How do we know about the 19 subduction zone earthquakes in the Pacific Northeast that happened over thousands of years? What went wrong at Fukushima, and how do the Japanese deal with earthquakes? What about that New Madrid fault in the middle of the US? What about the Rift Valleys of Africa (where I worked)? What are we doing to do next, what is undone, and how do we do it? These are all addressed in the book.

I came away from Yeats book feeling better about earthquakes. I already knew about the Cascadia quakes and a bunch of other stuff, having done research that required an understanding of tectonic processes myself (though this is not my area). What made me feel better is the simple fact that we can adapt to earthquake hazards by first understanding what they are locally, then applying the proper technology and other systems.

The problem is bad, of course, in regions where earthquake hazard is high, and pre-adaptation is not done for any of a number of reasons, including political or economic ones. Yeats contrasts Japan, the most earthquake ready country in the world, with Haiti, one of the least.

Geology is fun. Earthquakes are one place where the rubber hits the road in geology. This book is a great overview and an important analysis of earthquake hazard and risk worldwide. I highly recommend Earthquake Time Bombs by Robert Yeats.

“You’re supposed to hang the waders upside down. Keeps dead mice from falling in there.”

Well, I thought, if any mice fell in these waders and weren’t dead, they’d drown for sure. Anyway, I traced the leak to a part of the ceiling in the closet. Eventually I was able to find the place in the attic where the water was probably going down into the closet, but by this time the torrential rain storms that had preceded the discovery of Lake Waders had long passed and I was going on indirect evidence. Over the next few weeks there were more storms, and every now and then I got to look at where the leak was tracing from but always lost track of it.

Finally, my father-in-law and I figured out how to do it. I got up on the roof with a hose, and he got in the attic with a flashlight. I kept pouring water and he kept tracing back drips until we finally found the perfectly round hole, hidden from view at the top by some recently grown lichen. It was an exit wound, like a .22 caliber bullet had exited the roof in an accidental discharge. Or maybe it was an entrance wound. Eventually I decided it must have been a meteor. No particular evidence for that, but it would be the coolest explanation.

Anyway that’s how it has been over the last few decades at Yellowstone.

You know Yellowstone is one of the world’s largest calderas. When it was formed, in a major explosive eruption about 650,000 years ago or so, it must have been a hell of a mess. If something like that happened there again it would totally ruin the day for anybody visiting the park. And, by “visiting the park” I mean living anywhere in North America pretty much.

Early on, Geologists knew there was a magma plume. This is equivalent, in my analogy, to the big rainstorm that provided the water for the leak in the roof. We know it is there because you can see it. As the North American continental plate moves along to the southwest, it passes over the plume, and the plume is the source for lots of volcanic activity including the occasional day-ruining super volcanic caldera eruption, the big Yellowstone eruption being the most recent of those. You can see all the older volcanic activity, and date it, in a somewhat curved line passing upwards in time along the surface of the continental plate. No problem identifying that.

But, how does the surface of Yellowstone, which puts enormous amounts of volcanic CO2 into the atmosphere continuously, has the largest hydro-thermal system on the planet, the occassional lava flow, etc. connect to the lava plume?

A while back scientists used seismic imaging to depict a fairly large and complex magma feature under the surface. This provides the immediate heat and gasses, but it was not large enough or deep enough to be the ultimate source or the connection to the deeper mantle of the earth. They were still in the attic trying to trace back the leak.

Now, scientists Hsin-Hua Huang, Fan-Chi Lin, Brandon Schmandt, Jamie Farrell, Robert B. Smith, Victor C. Tsai, in a paper titled “The Yellowstone magmatic system from the mantle plume to the upper crust,” published in Science, have used even more seismic imaging to locate and map out a deeper, larger batch of magma that is the link between the molten hot deepens of the earth, the part under the continental plates, and the Yellowstone area.

From the Abstract:

The Yellowstone supervolcano is one of the largest active continental silicic volcanic fields in the world. An understanding of its properties is key to enhancing our knowledge of volcanic mechanisms and corresponding risk. Using a joint local and teleseismic earthquake P-wave seismic inversion, we unveil a basaltic lower-crustal magma body that provides a magmatic link between the Yellowstone mantle plume and the previously imaged upper-crustal magma reservoir. This lower-crustal magma body has a volume of 46,000 km3, ~4.5 times larger than the upper-crustal magma reservoir, and contains a melt fraction of ~2%. These estimates are critical to understanding the evolution of bimodal basaltic-rhyolitic volcanism, explaining the magnitude of CO2 discharge, and constraining dynamic models of the magmatic system for volcanic hazard assessment.

I love the use of the word “unveil” here. “Hey, Duane, I think I unveiled a bullet hole up here on the roof! There’s your problem!”

Anyway, the details are strikingly complex and involved intense geological science. The implications are still a bit unclear. In a write-up by Eric Hand in Science, geophysicist Alan Lavender says this is “a comprehensive view of the magma system from the top of the plume into the crust. [But] this doesn’t exactly match up with our expectations.” Scientists had been expecting the offset between the upper and lower chambers to be in the opposite direction, west rather than east of the plume.

I don’t know. Maybe they were just holding the map upside down. They need to stick a pencil through the hole to verify it as the true source, like Duane did while I was up there on the roof.

Caption for the image at the top of the post:

Fig. 4 Schematic model for the Yellowstone crust-to-upper mantle magmatic system.
The orientation of the model is along the cross-section AA? in Fig. 3. The geometry of the upper and lower crustal magma reservoirs are based on the contour of 5% VP reduction in the tomographic model. The dashed outline of the lower crustal magma reservoir indicates the larger uncertainties in its boundaries relative to that of the upper reservoir (25). The white arrow indicates the North American plate

It is erupting now. Evacuations have been ordered. Here is some amazing footage:

An accurate description of the abundance and size distribution of lakes is critical to quantifying limnetic contributions to the global carbon cycle. However, estimates of global lake abundance are poorly constrained. We used high-resolution satellite imagery to produce a GLObal WAter BOdies database (GLOWABO), comprising all lakes greater than 0.002 km2. GLOWABO contains geographic and morphometric information for ~117 million lakes with a combined surface area of about 5 × 106 km2, which is 3.7% of the Earth’s nonglaciated land area. Large and intermediate-sized lakes dominate the total lake surface area. Overall, lakes are less abundant but cover a greater total surface area relative to previous estimates based on statistical extrapolations. The GLOWABO allows for the global-scale evaluation of fundamental limnological problems, providing a foundation for improved quantification of limnetic contributions to the biogeochemical processes at large scales.

So, there are fewer than thought but they take up more space than thought. Who would have thought?

Interestingly, there are more lakes at higher latitudes. Because of the uneven distribution of land surface in the Northern vs. Southern Hemispheres (more land in the north) this means more lakes in boreal regions, and more specifically, more lakes in previously glaciated regions. This makes sense because glaciation (and deglaciation, melting of the glaciers) produces lakes. The immature terrain produced by a glacier eventually matures with erosion joining streams and rivers to those lakes, making them disappear. If no glaciers return to a previously glaciated region, eventually all the lakes (or most of them) will disappear.

Look at the Congo, Amazon and Nile basins for examples of large inland regions in the tropics. There are very few lakes. Now look at North America north of the maximum extent of the recent (Wisconsin) glacier. Lots and lots of lakes.

Florida Senator Marco Rubio does not know how old the earth is. Here is what he says about it:

I’m not a scientist, man. I can tell you what recorded history says, I can tell you what the Bible says, but I think that’s a dispute amongst theologians and I think it has nothing to do with the gross domestic product or economic growth of the United States. I think the age of the universe has zero to do with how our economy is going to grow. I’m not a scientist. I don’t think I’m qualified to answer a question like that. At the end of the day, I think there are multiple theories out there on how the universe was created and I think this is a country where people should have the opportunity to teach them all. I think parents should be able to teach their kids what their faith says, what science says. Whether the Earth was created in 7 days, or 7 actual eras, I’m not sure we’ll ever be able to answer that. It’s one of the great mysteries.

Phil Plait has responded with this:

Actually, it’s not a great mystery. It used to be … a century ago. I am a scientist, and I can tell you that nowadays—thanks to science—we know the age to amazing accuracy. The age of the Earth is 4.54 billion years … plus or minus 50 million years. That’s a number known to an accuracy of 99 percent, which is pretty dang good.

Sen. Rubio’s answer, however, is so confused and error-riddled its difficult to know where to start.

And then, Phil goes ahead and addresses that, HERE.

The Maddow Blog also addresses Senator Rubio’s miscarriage of intelligence.

And, the thing is, the actual story about how we know about the age of the earth is not only well established science, but it is intrinsically interesting. Following is from a post I wrote about this a while back, slightly edited:

How old is the earth?

Short answer: 4,540,000,000 Earth-years, plus or minus 1%.

Long answer: We don’t know exactly because direct dating of the earliest material on the surface of the Earth will only tell use a minimum age; Prior to that, the Earth’s surface was probably molten, and even after that, it may be that the earliest non-molten material has been recycled into the planet’s interior by tectonic processes. Also, the earth is a big round ball of stuff that condensed into this shape from part of a large disk-shaped blob of stuff known as the Solar Nebula. When exactly, given this, did the Earth become the Earth? Since the process took millions of years, we can’t pinpoint the age of the Earth more exactly than a certain range.

What are the oldest rocks?

The oldest rock formations on Earth are between about 3.8 and 3.9 billion years old., but there are older bits of more ancient rocks that were incorporated into these early rocks, and they date to something closer to 4.4 billion years old. These and other early materials are dated primarily using a variety of parent-daughter radiometric techniques, with the most effective for this time period being a lead-lead system.

Since rock from the time of the Earth’s formation isn’t available (because it didn’t really exist or was gobbled up in the fiery beginnings of the big round ball) the preferred method of dating the Earth is to calculate the age of meteorites. The earliest meteorites essentially date the condensation of materials in the solar system into the planets, and thus, the date of these meteorites indicates the date of the early Earth. (The Earth existed prior to this condensation in the form of whatever parts of the early solar nebula would eventually condense into this particular planet, of course.)

Meteorites from other planets?

Some meteorites are known to be fragments of Mars, so the oldest dates among these can also verify the date of accretion of material into planets in our solar system.

Rocks from the moon have not been remelted or otherwise messed up by tectonic processes and therefore would provide an excellent estimate of the age of the Earth as well. Also, since there is no real weathering of rocks on the moon, methods other than parent-daughter decay can be used, such as Fission Track dating (the older a rock, the more cosmic rays pass through it, blasting tiny little tracks in the otherwise homogeneous matrix).

Zeroing in on the age of the earth

There are hundreds of published dates of various older materials, but the following table gives a reasonable summary of some of the more important dates, culled from various sources (see list of references below):

If we chart this on a graph, we see one date that is much earlier than all the other dates, and a few that are younger.

The younger dates are simply of materials that we don’t think date the Earth’s formation, but that we know would post date it by not much. These dates verify the earlier cluster of dates that would correspond to the actual formation of the planet. The single earlier date is an obvious outlier.

Taking this series of dates, notice that the oldest (non-outlier) dates are about four and a half billion years old. As stated in the short answer.

Further information about the age of the Earth:

Dalrymple, G. Brent. 2001. The age of the Earth in the twentieth century: a problem (mostly) solved. Geological Society, London, Special Publications 2001, v. 190, p. 205-221. Click Here.

Dalrymple, G. Brent. 2006. How Old is the Earth: A Response to “Scientific” Creationism. The TalkOrigins Archive. Click Here.

Norman, M. D., Borg, L. E., Nyquist, L. E., and Bogard, D. D. (2003) Chronology, geochemistry, and petrology of a ferroan noritic anorthosite clast from Descartes breccia 67215: Clues to the age, origin, structure, and impact history of the lunar crust. Meteoritics and Planetary Science, vol 38, p. 645-661.

Stassen, Chris. 2005. The Age of the Earth. The TalkOrigins Archive. Click here.

Wikipedia, Teh. 2010. Age of the Earth. Click here.

So there you go.

The steep walls that define the northeastern and southwestern sides of the channel extend far below the marshy surface of the river’s floodplain. When people have built large bridges across this channel, where a highway could not simply meander through it, they found that the river sediments were five to eight times deeper than the current depth of the channel. It appears that this sediment filled in the channel after the river that formed it stopped running about 10,000 years ago. Well, it didn’t stop, there’s still that little trickle you see on the map, which today we call the Minnesota River.

But thousands of years ago, it was the Warren River that ran from left to right across this picture, and it was during it’s maximum the largest river in the world, carrying more water per minute than any other river. The river was the outlet of the largest fresh water lake that ever existed as far as we know, or at least one of the largest, which we call Lake Agassiz. The lake was formed by a combination of three factors: 1) Glacial depression of the landscape: During the Ice Age, a huge glacier pushed the crust of the earth down so far that as the glacier melted away,water ran into the depression rather than out to sea. 2) Glacial “till” ruined all the natural drainage: As the glacier melted, huge quantities of dirt and rock came out of the ice and covered the land, filling in all river valleys that might have survived the glacier’s earlier expansion. It would take time for rivers to cut down through this “till” and re-discover a path to the sea. 3) Ice blockage: As the glacier melted away, large chunks of ice … mini glaciers and buried blocks of ice with a volume approaching the average lake … were left behind, many serving for decades or a century or two as dams in the outlets that streams and rivers would eventually use after complete melting.

At some point the water in Lake Agassiz found its way out from the lake somewhere around Fargo, North Dakota. The exact outlet is a movable thing: As the lake drained, the land under the lake rebounded from the weight of the disappearing glacier, and the river eroded the outlet, the size and shape of the lake changed dramatically. It may have shrunk and grew several times but on average, it got smaller. Other outlets formed as well, draining Agassiz through Lake Superior and the Saint Lawrence River. But at certain times, water from the largest lake ever flowed through a channel that is today the Red River and the Minnesota River, joining what is now the Mississippi River south of the Twin Cities, and then down to the Gulf of Mexico.

I can not verify that the following is true, but it is what I’ve heard: An archaeologist I knew told me of a whale skeleton in a museum down in the state of Mississippi that was supposedly found in the flood plain in a position and at a level that would indicate that it came down this river from Lake Agassiz. It may be that an early version of Lake Agassiz was part of a large inland sea that ran from eastern Canada and Maine across the Great Lakes and to Manitoba, caused by the depression under the glacier. Sea life would have occupied that large gulf. We know there were whales and walruses in this sea, and their remains have been found here and there to the east. Also, there’s the trout; Trout are essentially salmon, a sea-living fish, that got trapped in freshwater lakes and, separated from their original stock, evolved into new species that can no longer live in salt water. Some of these trout may have been trapped inland in places like Moosehead Lake, Maine as the great arm of the sea became separated and changed over to fresh water. A giant inland lake with fresh water whales swimming around in it seems a bit strange, but glacial times were, indeed, strange!

So, imagine being a Clovis Indian arriving at the shore of The Warren River about 10,000 years ago, and standing where the town of Redwood Minnesota is today. The river you’d see before you would be very wide, about three kilometers from side to side. That is wider than the Nile River at a comparable distance upstream. The river would be flowing very fast from left to right, and even if this was the first time you were seeing this river you would by now have heard stories of its fury during floods, and just standing there you’d be nervous. There would be a lot of crap floating by. This river is young, having just cut its path out of the great lake to the north within a few centuries past, so it is still busy finding its way and shaping its channel. Every moment you watch, somewhere upstream, a chunk of river bank covered with brush (there are few large trees in the region at the time) falls in and breaks apart. The rocks fall to the bottom and start rolling along, the dirt muddies the river, and the vegetation tumbles along at or just below the surface. The lake from which this river flows fronts an active but melting glacier, and thus, it is full of ice bergs. As these break up into smaller and smaller chunks they float toward the Warren River, and now you see their remains as a continuous stream of dirty foamy ice that is hard to separate visually from the foamy dirty water and the dirty watery foam and the watery foam and dirt and the vegetation. To us, if we went back in time it would not look like a normal river. To the Clovis Indians of the time, it might have looked like a place you would not want to put your boat.

And then, as you’re watching, this whale goes by. Alive and struggling in the current? Long dead, bloated, and lolling in a morbid circle battered every moment by the flotsam of which it is just one large component? Alive but no longer struggling, and looking back at you, thinking “What in tarnation is that thing, I’ve not seen one of those before!”?

OK, now look back at the map. Just south of Bridge Street, on the edge of town, is where the children of Redwood Falls, who have grown up on the shores of the most amazing river that ever existed on the planet Earth, go to the Reede Gray Elementary School. The school is named after an educator who got his graduate degree in 1925 at a small but highly regarded college down river from here. You can imagine that the children have a lot of opportunities, weather permitting, to enjoy field trips to the several parks and wildlife management areas a short drive, or even a brisk walk, from school. Many live on farms, so they have a sense of the landscape because there are places you can farm and places you can’t and that is determined mainly by the Warren River’s legacy. And in the spring, the kids that come from the other side of the river probably miss some school because the bridges get closed during floods or even washed out now and then. They fish in the meandering channel or one of the small ponds left behind, or a tributary. These kids are growing up with stories and experiences played out in a context created by an ancient geological event.

And now, an opportunity. Wouldn’t it be nice to inject a little extra science into their lives, in a positive and helpful way? So that everything they see around them they will see through that powerful lens that as a science blog reader you take for granted? Wouldn’t it be great to go to that elementary school and give a talk, or send a DVD or some books appropriate for Elementary School science learning, or something? Among these kids from Redwood Falls there is potential and talent and among these kids a few are surely interested in one area of science or another, and just need encouragement, resources, sciencey stuff, handy and available for them to get their hands on and get into it and be inspired. Too bad there’s nothing you can really do from the comfort of your own home, sitting there browsing on the Internet, reading blogs and stuff.

But wait, don’t despair! There is somethings you can do! You can help Ms. Osborne, one of the teachers at the Reede Gray Elementary School! Ms. Osborne is trying to buy a human skeleton for her kids to learn anatomy! And some other body parts and stuff. (These would be plastic models designed for use in the classroom, of course, not the real thing, just in case you were thinking that.) And that’s a really great idea. I’ve taught anatomy at various levels and I can tell you that you should not actually even bother to go into this subject unless you’ve got the body parts available and a pile of good anatomy books. Ms. Osborne wants to get a skeleton, a lung, an eye, and a brain. The whole thing is going to cost about 300 bucks and she’s about half way there in raising the money.

What you can do is to CLICK HERE and make a small donation to help. Check the amount “to go” (right now it’s about $150). If it’s down to zero by the time you get there, you might want to donate to one of the other projects I’ve carefully selected for you to consider.

Your donation will be very much appreciated, and it will have a very long lasting effect. In addition to this, for all of the projects I’m asking you to help, I’ll throw in a bonus. The details will vary. I’ve got some extra anatomy books I could send to Ms. Osborne. They may or may not be useful in an elementary classroom, but teachers need books too, to stay ahead of the students! In other cases I’m offering a talk or presentation in class. I’ll let you know what I end up doing. But that’s only going to happen if people step up and help fulfill the needed funding level. Sort of a matching grant: I can’t put in money but I can put in some time and talent.

Thank you in advance for your kind donation.

One of the coolest examples of what seems to be (but really is not) a violation of this Law of Geology is a thrust fault. A thrust fault is essentially a horizontal fault (as opposed to the more common vertical fault) in which rock from one area slides completely over another area. When this happens, the rock at the base of the upper unit (the one that slid over the other rock) is older than the rock on which it rests.

The fault isn’t really horizontal. but it’s horizontal enough for this to happen. And, in fact, the whole thrust-faulting thing is actually fairly complicated, and there are different processes that cause a similar effect. But in the end, you get an older layer sitting on top of a younger layer.

The reason this is not really a violation of superimposition is this: The older rock was actually deposited on top of the younger rock later in time than the formation of the younger rock. In a way, this is not much different than an ancient mountain made of ancient stuff eroding and generating sand that flows downstream and covers some pre-existing sediment. The fact that the grains of sand were formed a long time ago does not make that recently formed sand deposit old. It is young. But it is a young deposit made of old stuff. A thrust fault is the same thing but instead of there being a zillion tiny grains of sand deposited on some earlier sediment, it’s all one big giant piece!

Here’s a couple of photographs of the Keystone Thrust fault. Tell me if it looks familiar to you:

The dark grayish rock is the older rock thrusted upon the red and yellow rock.

If you go to Las Vegas and gaze westwards you’ll see a ridge in the distance. Some people say that part of the ridge resembles a man lying on his back. That man’s outline is the upper edge of this thrust fault, which is exposed here in Red Rock Canyon reserve, a BLM property where you can go and hike, climb rocks, and observe interesting geology and wildlife.

Technically,the Keystone is a Reverse Fault with a shallow dip. The gray rock is Cambrian limestone (Bonanza King Formation) and it rests on top of the Jurassic Aztec Sandstone that gives Red Rock Canyon its name.

People do argue that the thing in this photograph is actually part of different thrust fault system related to the Keystone. I’m not sure if that argument is settled yet. Either way, it’s a good example of a thrust fault.