Tag: geology

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ask a geologist geology geomorph

[Ask a Geologist] Before there was terraforming, there were rocks

My friend Andrew Barton asked me, a bit out of the blue via twitter:

Given a now-earthlike planet terraformed 15 million years ago, which previously resembled an Earth-sized Iapetus or something, how obvious would the pre-terraforming rocks be, or what governs how deep they’d be now?

He also provided a bit more background as to the reason behind the question:

I’m still working out a lot of the details; this involves Esperanza, the terraformed habitable moon of HD 28185 b that was the setting of “The Paragon of Animals” in the March 2013 Analog, and hopefully additional stuff down the line. While tectonically active and geographically varied at present, it was entirely lifeless before the terraforming process began.

I should probably be ashamed to admit it, but I didn’t actually have an idea what Iapetus would be like. And didn’t look it up until this very moment (naughty, naughty) but I don’t think that would have changed the answer I sent him. Which is long and a bit rambling, but I was thinking it through as I went since the question was fairly general.

  1. How deep do the effects of the terraforming go? If it’s just a matter of soil modification/creation, I wouldn’t really expect most bare rock to be all that altered. If it’s a change to atmospheric chemistry that will completely redefine the way weathering works on the planet, that’s a whole different matter. Also, microbial life does have a profound effect on how any rock that’s exposed to air will degrade (we even see this deep in mines/hydrothermal vents) but did the terraforming, say, completely alter the habitats of the extremophiles?
  2. How tectonically active is your planet? If you’re getting regular tectonic activity like you see in modern Earth, there’s a good chance that you would get exposures of relatively pristine rock fairly regularly; if there’s a large earthquake that causes a major landscape drop, you’ll get a fault scarp where new rock will be exposed. These aren’t the most common events, but you’d probably get a bit of that happening during 15 million years. Of course, as soon as you expose the fresh rock face to the surface, it will start being effected by the terraforming.
  3. If you’ve got landscapes with a lot of relief (eg: mountains) then you’ll have an ongoing process of mass wasting (landslides, rockslides, etc) that can expose fresh surfaces.
  4. Weathering rates will determine a lot, but 15 million years isn’t that much time to redefine a landscape, particularly if you’re just changing the air and water chemistry and not effecting the tectonics at all. Erosion rates are generally less than 1mm/yr (but up to 10mm/yr in places like New Zealand and the Himalayas that have high relief, active mountain building, and plenty of moisture) and one thing you have to consider is that as material is being eroded from the surface, it’s not necessarily going to just expose something pristine beneath it… whatever is right beneath it will probably be in some way chemically weathered by the time you get to it, because water ruins everyone’s life.
  5. As far as “how deep” the pre-terraforming rocks would be, it’s basically just going to be anything below the zone where your new bacteria/weather can effect it. Which will vary wildly depending on the environment in question. In the classic case of a single non-stacked soil, you could potentially hit bedrock less than 1.5 meters down… but then that bedrock has been subjected to the presumably terraformed water regime. And how deep that water would go would be determined by things like the type of rock, its porosity, and how fractured it is.
  6. So basically your biggest problem, depending on what exactly the terraforming entailed, is trying to find rocks that have not been touched by air/microbes/water from the new surface.
  7. Probably your best bet if your people are digging would be to get below the water table if you want completely pristine rocks. In the majority of places, the freshwater table will stop at about 30-35 meters below the surface, but it can go as deep as 370 meters or so.
  8. Just as a note, for buried pre-terraforming rocks, what you’ll be looking for are sedimentary rocks. Those are the ones that will give you the clearest picture of surface and near surface conditions at the time of their formation (and early diagenesis). And that would presumably provide a very different environmental picture from what currently exists. (Like gosh there are no fossils of any kind in these older rocks…) The good thing is, those rocks have had the entire existence of the planet to form and be buried, so there ought to be plenty of them lurking just below the surface.

Tl;dr: That’s a really complicated question.

Obviously, I’m not the world’s greatest expert on this topic–any other geologists out there have thoughts? Did I get anything completely wrong? Just drop a note in the comments. I’m sure I didn’t think of everything.

Categories
geology

So you wanted to know about my research?

Now you can read the whole enchilada for free! It’s a steamy but heart-wrenching story about a river and the course of its life as the world heats up and the mammals become ever tinier and more cute. Sandstones! Siltstones! Mudstones! Who will be swept away next? Will I need dental work from all those rocks I ate in Bremen? Will I overcome the cat vomit yellow sandstone or will it succeed in ruining my life? The answers can be found inside:

Sedimentary and climatic response to the Second Eocene Thermal Maximum in the McCullough Peaks Area, Bighorn Basin, Wyoming, U.S.A.
by Acks, Rachael, M.S., UNIVERSITY OF COLORADO AT BOULDER, 2013, 81 pages
Abstract:

The Paleocene-Eocene Thermal Maximum (PETM) was followed by a lesser hyperthermal event, called ETM2, at ∼53.7 Ma (Zachos et al., 2010). The carbon isotope excursion and global temperature increases for ETM2 were approximately half those of the PETM (Stap et al., 2010). The paleohydrologic response to this event in the continental interior of western North America is less well understood than the response to PETM warming. Although ETM2 is better known from marine than continental strata, the hyperthermal has been identified from outcrops of the alluvial Willwood Formation from the Deer Creek and Gilmore Hill sections of the McCullough Peaks area in the Bighorn Basin, Wyoming (Abels et al., 2012). The presence of ETM2 in Willwood Formation strata provides a rare opportunity to examine local continental climactic and sedimentary response to this hyperthermal.

Core drilled at Gilmore Hill was described and analyzed geochemically. The core consists of paleosols formed on mudrocks that are interbedded with siltstones and sandstones. Carbon isotope analysis of carbonate nodules from paleosols in the core shows that the top of the core, below a prominent yellow sandstone, most likely records the very beginning of the carbon isotope excursion that marks ETM2 (Maibauer and Bowen, unpublished data).The rest of the CIE was likely either not recorded due to sandstone deposition or removed by erosion prior to the deposition of the sandstone.

Analysis of bulk oxides in the paleosols using the methods of Sheldon et al. (2002) and Nordt and Driese (2010b) provides quantitative estimates of precipitation through the core section. The estimates reveal drying over the ∼15m leading up to ETM2. Red and brown paleosols, attributed to generally dry conditions, dominate the entire section below the onset of ETM2 and confirm drier conditions. In contrast, thick purple paleosols are associated with ETM2 at the Deer Creek site and suggest wetter conditions during most of the ETM2 interval. The prominent yellow sandstone at the top of the Gilmore Hill core was probably deposited during those wetter climate conditions.

The core displays distinct changes in stratigraphic architecture: the bottom ∼100m is mudrock-dominated and the top ∼100m is sandstone dominated. Several PETM studies have suggested that sediment coarsening in continental basins in the US and Spain developed in response to precipitation changes associated with global warming. Analysis of the Gilmore Hill core’s stratigraphic architecture in conjunction with carbon isotope and precipitation data shows that the prominent sandstone in the position of ETM2 was not caused by climate change. The sandstone is the uppermost part of the sandstone-rich interval whose base underlies ETM2 by more than 50m. This study shows that the shift from mudrock- to sandstone-dominated stratigraphy at Gilmore Hill, and possibly throughout the McCullough Peaks area, was not caused by climactic change associated with ETM2. While studies of PETM sections have suggested that the hyperthermal caused sediment coarsening in several different basins including the Bighorn Basin (e.g., Schmitz and Pujalte, 2007; Smith et al., 2008b; Foreman et al., 2012), this study suggests that the lesser magnitude ETM2 did not cross the necessary threshold to provoke a sedimentological response in the Bighorn Basin.

Categories
climate change geology

Oh No, Canada: Ocean Fertilization

NK Jemisin tweeted this article this morning with an appended “Oh no:” massive (and it seems illegal) ocean fertilization project taking place off the coast of Canada. (And a little follow up here.) Oh no indeed. This is scientifically problematic for a lot of reasons, the two main ones being a) algal blooms ain’t exactly great for the surrounding waters and b) it most likely won’t have the intended effect. (And this doesn’t even touch on the grossness of the pretense used to convince the indigenous people in the area to go for it, that it was supposedly about the salmon population.)

Let me give you some background.

First off, “ocean fertilization” is the process of dumping some kind of nutrient that normally limits planktonic growth into an area of the ocean, thus letting the little guys eat their fill, have wild plankton sex, and increase their numbers rapidly. This works because basically every bit of the ocean has its planktonic growth limited by the scarcity of one or more nutrient (e.g.: Rivkin and Anderson, 1997); otherwise the oceans would be one giant algal matt. In some areas it’s nitrogen, in some it’s phosphate, in some it’s iron (because iron is necessary for photosynthesis).

Okay, so why do it?

The theory here is that the planktonic organisms (since there is more to ecosystem than algae, even if they’re the ones sucking up the iron for photosynthesis) contain carbon. Living things tend to do that. Additionally, quite a few planktonic organisms build themselves shells or internal structures from calcium carbonate, which also pulls carbon from the surrounding water. So a surge in these organisms should suck carbon out of the atmosphere and ocean waters, right? Then the organisms die, fall through the water column as marine snow, and take all the carbon with them. They get to the bottom waters, get buried, and hey presto, that carbon is now out of the short-term carbon cycle and into the long-term carbon cycle.

Because of course, the problems we are having right now are quite literally caused by us taking carbon from the long-term cycle and releasing it into the short term cycle at prodigious rates.

So why wouldn’t that work?

We actually talked about this topic when I took Oceanic Geochemistry about a year and a half ago. It sounds very simple on paper, like it really ought to work. However, recent research has shown that it might decrease planktonic populations long-term (not good) and that diatoms might suck up all the iron anyway, because diatoms are basically the freeloading college roommate of the plankton world, you know, like that guy who always drank all the beer in the fridge and never replaced it.

There’s an even more basic issue with the idea, however. In order for carbon to get into the long-term cycle, it needs to be buried, and before critters have the chance to eat it. The oceans are teeming with life, most of which are single-celled eukaryotic organisms and bacteria, who just love to eat anything organic. Even at the beginning of burial, when oxygen content is almost non-existent in the sediments, there are plenty of anaerobic bacteria who will just keep munching away and effectively poop out pyrite. (The process is far more complicated than that, of course, but there’s a reason you tend to see a lot of pyrite in super organic-rich shales. Or in shales that used to be organic-rich before the bacteria came along and ruined your life.)

For a long time the model of how sufficient carbon could be buried to give us our lovely black oil-producing shales depended on anoxic events (literally, no oxygen in the bottom waters), but it really seems to depend more on just burial rate. The way to get the carbon buried and out of the way is to inundate the bottom sediments with so much that the bacteria can’t possibly eat it all.

So then in order for this ocean fertilization idea to work, you’d have to up the productivity sufficiently and for a long enough period of time that you could provide a buffet so large for the organisms in the water column that they can’t possibly eat it all. Then

Continue reading “Oh No, Canada: Ocean Fertilization”
Categories
geology science

Still life with trilobite section

I’m back I’m thin section heaven at work, slaving over a hot petrographic microscope and continuing my second listen to the Vorkosigan saga audiobooks. (Excellent, by the way.) And I saw something a bit like this today:

BioclastsBiosparite

Out rather, a bit like the portion marked with a T. A trilobite! Or rather a cross sectional cut through the carapace of one. I wish I could show you a picture of my actual thin section because it was way prettier and had the more characteristic hooked W shape. But I like that whole having a job thing so, no. Sorry.

But this is why it’s cool and why I love geology. Something like 340 MILLION years ago, a time so distant in the past that my brain can’t really comprehend it as anything other than wow a long fucking time ago, a little trilobite was hanging out on a shallow marine shelf. Because there were trilobites back then (and realize that no human being had ever seen a live one, we missed them by hundreds of millions of years). And this little trilobite presumably had an awesome trilobite life and hung out with his or her little trilobite friends and then one day died. Waves swept the little guy further out to sea, where he was given a proper burial in carbonate mud and…

Over three hundred million years later, met me.

I’m looking at a piece of rock that was the bottom of a tropical sea in the distant past long before biology every got around to even thinking of primates, key alone drinks involving little paper umbrellas. And I get to touch that. Every day I get a tiny window into an Earth alien to the one we live on now.

And that is why geology is cool.

Plus volcanic lightning because fuck yeah.
Eyjafjallajökull by Terje Sørgjerd

Categories
liveblog Uncategorized

Liveblog: Ring of Fire, Part 2

All right, I’m coming back for more. Same rules as usual, I’ll be updating the liveblog every five minutes or so. Unfortunately if you want to play at home, I can’t help you at the moment. I’m watching part two on the DVR.

I know you’re terribly sad to be missing this.

WHEN LAST WE LEFT OUR INTREPID ACTORS, a volcano had just erupted because compressed magma (argh what even) and oil look EXACTLY THE SAME to their bullshit made-up technology. And now the entire world might explode because as we know, all volcanoes are actually connected, which is why every time a volcano erupts, every other one in the world does as well. (Wait, that’s not how it works?)

Oh, and the Yellowstone caldera is apparently now part of the Ring of Fire, which is news to everyone except for Dr. Cooper, the hot geologist with an aneurysm that is bad enough to be a dramatic plot device but apparently not bad enough to warrant emergency surgery.

Liveblog commencing in 10… 9… 8….

Continue reading “Liveblog: Ring of Fire, Part 2”
Categories
geology liveblog tv

Liveblog: Ring of Fire, Part 1

All right, I’m going to do it. Apparently it’s THE COUNTDOWN TO MELTDOWN. Or something.

Same rules as usual – I will update the liveblog every five minutes or so. If you’re reading this on LJ or Dreamwidth you’ll need to come to the blog at katsudon.net to see the updates most likely, though I think edits are now supposed to push through so we’ll see.

If you’d like to play at home, this likely stinker of a miniseries is on Reelz. Yes, with a Z.

Liveblog commencing in 10… 9… 8…

Continue reading “Liveblog: Ring of Fire, Part 1”
Categories
liveblog

Urge to liveblog… rising…

I mean. Look at it. Just look at it.

Gratuitous Mt. St. Helens reference? Check.

Ridiculous implication that somehow all volcanoes are connected and therefore THEY WILL ALL BLOW UP AT ONCE EHRMERGAHD? Check.

Gratuitous Yellowstone reference sure to guarantee a fresh crop of concerned people who will ask me when Yellowstone is going to blow up and kill us all? Check (Answer, by the way: “Soon” in geology speak. Which means chances are we’ll probably have killed our own species off before Yellowstone gets around to erupting.)

But best of all – THE ERUPTION OF A BRAZILLION VOLCANOES BLAMED ON OIL WELLS? CHECK BABY. CHECK CHECK CHECK.

Just. Wow.

Bonus for what appears to be a bomb being dropped into a magma chamber. Because everyone knows that the way you keep a composite volcano from exploding is… uh… blowing it up first.

Because science.

Well, there’s my incentive to buckle down and get lots of work done in the morning. Part 1 of this hot (har har) mess is repeating at 4 pm my time tomorrow, followed by part 2. I don’t know if I have the strength.

Categories
geology oil and gas

I get e-mail (Son of Bride of Abiotic Oil)

I swear to god, this is the post that keeps on giving. By which I mean that it keeps me supplied with random comments and e-mails like this one. (Though in Mr. Alli’s defense, he was quite coherent and not frothily paranoid, counter to the norm.)

Hello Rachel Acks, this is Shawn Alli. I came across your article about abiotic oil: “4.5 Billion Years of Wonder.” If the abiotic oil theory is a laughable then so is the fossil fuel theory indoctrinated to everyone in the West as a child, a student, a young adult and by the time they’re an adult, there’s no need to question it all at. As a philosopher everything can and should be questioned, no matter how long a current theory has been in practice. The day we stop questioning scientific theory and current ideologies is the day humanity dies. Hopefully it will never come to that even though it’s moving in that direction.

Your small attacks on Thomas Gold’s status as an astrophysicist not being a petroleum geologist would be called a low blow, below the belt in reality. You’re attacking his credibility as a scientist believing that he can’t or anyone else for that matter can have a justified view of a topic outside the norm of their research. Your attack is similar to global warming advocates. If a meteorologists says man made climate change is bunk, the standard scientific dogma reply is “he’s not a climate change expert.”  If someone is an arctic research scientist and refutes man made climate change…”he’s not a climatologist, clearly he knows nothing.”  A paleo-climatologist refuting man made CO2, “clearly he’s being paid by oil corporations.”  These attacks on credibility need to stop despite the fueling of the media to people wanting a showdown.  Stick to attacking the arguments, not the credibility.

While I condemn your sarcasm to the abiotic theory I thank you for bringing in Richard Heinberg into the mix, doing so shows a more objective point of view, different from your starting laughable position. Heinberg’s paper makes a good point about nothing in science being conclusive, but that’s the crux of the problem as well. While nothing is objectively conclusive in all scientific disciplines, mainstream science/media/schools push the dominant findings into the norm of common knowledge, thereby taking away the concept of objective science being unfalsifiable with absolute conclusion. While this can be said to be a problem, the real problem (so many now…) is when scientists are funded based on their research, and not objective uninterested research, but massive bias that goes on to produce corporate science. And this is where almost all scientific discipline is. If large stakes of money are involved in the research, if status and reputation is in the pot, corporate science will be the result….(What was my point again?…what a tangent…but I’m a philosopher, so it’s allowed).  Ah yes, Mr. Heinberg’s point about abiotic oil being impossible to prove with absolute certainty. Good point, but absolute certainty is not what science is about nor what people need.  They think they need absolute results from science only b/c they’re conditioned to from society’s garbage institutions called schools and universities. By the way, congrats on your thesis defense coming up.  While I could care less about any higher education in the current archaic educational system (as if real knowledge is being obtained…sound of philosophers laughing), I understand why people go onto MA’s, MSc and PhD’s; for status, jobs and money. All of which are necessary to live a comfortable western lifestyle in the cities/suburbs.

I believe I’ve taken up enough of your time Rachel and wish you all the best while attacking your views on abiotic oil. I’m sure we could get along with respectable conversation. But feel free to read my book for more info. Hmm…I wonder, if I just said that at the beginning of the sales pitch would the end result have been the same?

“Oil, The 4th Renewable Resource”

http://www.barnesandnoble.com/w/oil-the-4th-renewable-resource-shawn-alli/1114003475?ean=9780991718207&itm=1&usri=9780991718207

http://www.amazon.com/Oil-The-4th-Renewable-Resource/dp/0991718208/ref=sr_1_1?ie=UTF8&qid=1361886373&sr=8-1&keywords=9780991718207

Sincerely,

Shawn Alli

P.S. Forget about kungfu with fixed styles. Look more into Bruce Lee’s Jeet Kune Do where movement is free and flowing. So when it’s necessary to use, it won’t be dependent on the other person’s style.

http://www.oilrenewables.com/

Hello back atcha, Shawn Alli:

Having done my thesis on one tiny bit of paleoclimate, I have a lot of respect for what kind of bulk exists in the research literature. And you are darn right I’m skeptical about people making wild claims outside their field of expertise precisely because they do not generally prove they have a good grasp of current research – and often make claims that a simple literature search will show are false. I would also point out there is a fine but very important distinction between questioning conclusions (good) and wasting someone’s time with unfounded claims that are not backed up with good research (bad).

I do find it curious that you spend an entire paragraph scolding me about my rather throw-away mention that Thomas Gold is an astrophysicist and not a geologist (literally a single sentence in a much longer post) as an attack on his credibility… then spend your lengthy next paragraph attacking the basic credibility of research and educational institutions. You similarly complain about people questioning the motivations and funding of climate change deniers and then turn around and question the motivations of scientists based on their research funding.

The congratulation on my defense is appreciated, by the way, though it would have been much more congratulatory if not preceded by a paragraph tearing down the entire concept of higher education and the presumption of entirely mercenary motives on my part.

Feel free to read my book when it comes out on April 5th. It’s a steampunk murder mystery, a topic that is, to my mind, far more interesting than diving further down the crackpot rabbit hole of abiotic oil, and probably about as fictional.

Sincerely,
Rachael Acks

PS: I like my kung fu style just the way it is.

PPS: The end result of my complete lack of interest in reading your book would have been the same, but without the added bonus of me thinking you’re a patronizing jerk.

PPPS: I have posted your e-mail with links intact on my blog at https://www.katsudon.net, as well as my answer. Seems fair to me.

Categories
earthquake geology news this shit is fucked up

Scientists convicted of manslaughter for failing to be psychic

Words cannot begin to express how upset, angry, and filled with contempt I am by this:
Italian scientists resign over L’Aquila quake verdicts

Two scientists resigned their posts with the government’s disaster preparedness agency Tuesday after a court in L’Aquila sentenced six scientists and a government official to six years in prison. The court ruled Monday that the scientists failed to accurately communicate the risk of the 2009 quake, which killed more than 300 people.

We wish we could predict earthquakes. We really, really do. So many lives could be saved. But there is as of yet no way to make those kind of predictions. A series of small earthquakes? Depending upon how you define it, those occur all the time. Hell, we can only sort of predict the imminent eruption of a volcano, and the mechanics of that, the pressures that dictate an eruption, are relatively simpler and there are far more “tells” – seismic activity, increased outgassing, etc.

Nature agrees: 

There will be time enough to ponder the wider implications of the verdict, but for now all efforts should be channelled into protest, both at the severity of the sentence and at scientists being criminalized for the way their opinions were communicated. Science has little political clout in Italy and the trial proceeded in an absence of informed public debate that would have been unthinkable in most European countries or in the United States

Hey Italy, while you’re jailing people for failing to predict disasters, how about extraditing the horrendous human beings who played fast and loose with the financial markets and caused the global economy to shit itself? That had far more potential for being predicted and arguably has caused even more human suffering. What about jailing people who have refused to listen to repeated warnings about global climate change?

Or I suppose this pattern could continue and the next time a doctor fails to predict a heart attack, or a traffic cop fails to predict an accident, they’ll end up in jail.

This is ridiculous. Contemptible.

Categories
geology grad school science

What I did with my day.

Today I turned this:

Into this:

Using these tools:

…four times. Six to go. And then they’ll be ready for XRF analysis, which will tell me what mean annual precipitation was in that location nearly 54 million years ago. 
This is the exciting part of science they never show you in the movies.