Magnitude 4.9 earthquake in Utah.
Northern Utah on the UT-WY border. Felt reports coming into the USGS are currently from as far south as American Fork, UT and as far west as the Great Salt Lake. This isn't a major one, and no idea of any damage yet. It's of interest because it's an intraplate earthquake, despite it being not-unexpected because of its location in the far-east end of the Basin and Range Province.
A group called Earthscope was hopefully able to pick up some good data from this quake. I mention them specifically because they held a small conference on campus earlier this week. Regrettably, I was only able to attend one session - it was absolutely fascinating! The discussions on seismology and tectonic work, as well as their goal of setting up a high-res seismic array in North America is a fascinating listen. I can't even imagine what such a network will do for tomography underneath the North American Plate.
In other news, was on a field trip last weekend and am leaving for another tomorrow at noon. St. Francois Mountains or bust!
Thursday, April 15, 2010
Tuesday, March 30, 2010
LHC Has Collided Protons at 7 TeV!!!
Read the posting here.
If you're wondering how colliders work, ArsTechnica put up a great article this week on how they work.
As a freshman at Michigan State University, my family and I had the pleasure of being able to take one of their periodic public tours of the Cyclotron facilities. One of my favorite parts was how they curved the acceleration path at one point to separate particles by mass, so they could then sort of collect particles in Faraday Cups at the end of the path. That a machine so complex and powerful replies on the fundamental principle of inertia to sort the subjects of its studies by mass is somehow poetic.
Turns out we use that exact principle for isotope detection, except that it's on a far smaller scale. My research group makes frequent use of a multicollector induced-coupled plasma mass spectrometer (MC-ICP-MS), which allows us to measure with a high degree of precision (when the machine's behaving; I swear it's sentient sometimes) isotopic ratios. In particular, I'm looking at stable (or non-radioactive) iron isotopes. In the future, I'll be looking at stable magnesium isotopes, (obviously unstable) uranium isotopes, and possibly stable silicon isotopes. Silicon's difficult because of its low solubility in most solutions and its tendency to fractionate.
Fractionation occurs when some mechanism allows the preferential movement of one isotope over another. I'm being vague on that definition for a reason; there are multiple ways in which this can happen. One example is heating the sample to a level where silicon melts and could possibly vaporize. Heavier isotopes require more energy to lift, just as lifting a car requires more energy than lifting a bicycle. If there is only enough energy in a system to vaporize a few silicon atoms at a time, it's much more probable that the lighter silicon atoms will vaporize.
It doesn't exclude the possibility of vaporizing the heavy silicon atoms at this time - it's just less probable. However, if more energy is introduced to the system, the probability of heavier silicon isotopes being vaporized increases greatly. Were I to analyze collected silicon vapor collected from each of the energy levels, I'd find that the lower energy vapor has a "lighter" signature, whereas the higher energy vapor has a "heavier" signature.
Recall, though, that this is only one way to fractionate stable isotopes. It's by far the most common process, but there is also chemical fractionation. I won't go into as much detail about this process as I'm less familiar with it, but it's definitely a fascinating study and I'm hoping we go into great detail about it in my isotopes class next fall.
Why silicon is being problematic isn't clear yet. Part of our chemical procedure to prepare samples for analysis hasn't been perfected yet, and we know that for sure. One particular chemical added in extremely small amounts is intended to "anchor" the silicon in solution so it doesn't form a colloid or precipitate out, trapped in telltale wispy flakes that settle at the bottom of the sample tube. Too much of this chemical and it will occupy all available site on the silicon atoms in solution and turn into a gas, which means it will fractionate out an eventually escape. Dilution of the sample beyond the theoretical minimum volume required to dissolve the amount of silicon present hasn't entirely helped, either.
But the best part by far is that mass spectrometry and photospectrometry of the samples have provided results exactly the opposite of each other (there should be at least a rough direct correlation between the two). Hard to say. We're still working on the method.
And on that note, I should head into work fairly soon. My first class of the day was delayed by half an hour, but I have an array of small tasks I should plow through in some capacity before then.
If you're wondering how colliders work, ArsTechnica put up a great article this week on how they work.
As a freshman at Michigan State University, my family and I had the pleasure of being able to take one of their periodic public tours of the Cyclotron facilities. One of my favorite parts was how they curved the acceleration path at one point to separate particles by mass, so they could then sort of collect particles in Faraday Cups at the end of the path. That a machine so complex and powerful replies on the fundamental principle of inertia to sort the subjects of its studies by mass is somehow poetic.
Turns out we use that exact principle for isotope detection, except that it's on a far smaller scale. My research group makes frequent use of a multicollector induced-coupled plasma mass spectrometer (MC-ICP-MS), which allows us to measure with a high degree of precision (when the machine's behaving; I swear it's sentient sometimes) isotopic ratios. In particular, I'm looking at stable (or non-radioactive) iron isotopes. In the future, I'll be looking at stable magnesium isotopes, (obviously unstable) uranium isotopes, and possibly stable silicon isotopes. Silicon's difficult because of its low solubility in most solutions and its tendency to fractionate.
Fractionation occurs when some mechanism allows the preferential movement of one isotope over another. I'm being vague on that definition for a reason; there are multiple ways in which this can happen. One example is heating the sample to a level where silicon melts and could possibly vaporize. Heavier isotopes require more energy to lift, just as lifting a car requires more energy than lifting a bicycle. If there is only enough energy in a system to vaporize a few silicon atoms at a time, it's much more probable that the lighter silicon atoms will vaporize.
It doesn't exclude the possibility of vaporizing the heavy silicon atoms at this time - it's just less probable. However, if more energy is introduced to the system, the probability of heavier silicon isotopes being vaporized increases greatly. Were I to analyze collected silicon vapor collected from each of the energy levels, I'd find that the lower energy vapor has a "lighter" signature, whereas the higher energy vapor has a "heavier" signature.
Recall, though, that this is only one way to fractionate stable isotopes. It's by far the most common process, but there is also chemical fractionation. I won't go into as much detail about this process as I'm less familiar with it, but it's definitely a fascinating study and I'm hoping we go into great detail about it in my isotopes class next fall.
Why silicon is being problematic isn't clear yet. Part of our chemical procedure to prepare samples for analysis hasn't been perfected yet, and we know that for sure. One particular chemical added in extremely small amounts is intended to "anchor" the silicon in solution so it doesn't form a colloid or precipitate out, trapped in telltale wispy flakes that settle at the bottom of the sample tube. Too much of this chemical and it will occupy all available site on the silicon atoms in solution and turn into a gas, which means it will fractionate out an eventually escape. Dilution of the sample beyond the theoretical minimum volume required to dissolve the amount of silicon present hasn't entirely helped, either.
But the best part by far is that mass spectrometry and photospectrometry of the samples have provided results exactly the opposite of each other (there should be at least a rough direct correlation between the two). Hard to say. We're still working on the method.
And on that note, I should head into work fairly soon. My first class of the day was delayed by half an hour, but I have an array of small tasks I should plow through in some capacity before then.
Monday, March 29, 2010
MSU in Final Four and Back To The Grind
Got back to the home base yesterday afternoon in time for the second half of the MSU-Tennesee game, which I'd been tuning into for the last hour or so of my drive.
If I can get tickets at a reasonable price, I'm hoping to be able to watch the games in person, seeing as I live a mere hour and a half from Indianapolis. Chances are that I will not be successful in my quest, but it NEVER hurts to try.
In the meantime, we're starting the second major unit of the class I help run, and the camping trip is next week. Need to get plans solidifed, since it's highly likely I'll ultimately have to plan all of the underlying infrastructural parts of the trip (things like food, propane, etc.). Working for this prof certainly has been interesting, and not really something I want to do again.
If I can get tickets at a reasonable price, I'm hoping to be able to watch the games in person, seeing as I live a mere hour and a half from Indianapolis. Chances are that I will not be successful in my quest, but it NEVER hurts to try.
In the meantime, we're starting the second major unit of the class I help run, and the camping trip is next week. Need to get plans solidifed, since it's highly likely I'll ultimately have to plan all of the underlying infrastructural parts of the trip (things like food, propane, etc.). Working for this prof certainly has been interesting, and not really something I want to do again.
Tuesday, March 23, 2010
Sunday, March 21, 2010
On Thinking Like A Scientist (Well, Me)
Been thinking a lot about how we think and brain structures/types lately. Not going into details why, but the more simplistic of the reasons is that ADHD, something I've lived with my entire life, is a fascinating disorder. The spectrum it exists on is facsinating as well: Asperger's/ASD, manic-depressive, OCD. It's rare to sit at purely one of those endmembers.
I'm no medical doctor or psychologist, so I have no qualifications upon which to make a diagnosis, but I can certainly find the correlations between what I've found in literature and my brain. Better yet is that my observations are inherently contaminated because I'm making the fundamental mistake of observing myself. It's funny how that works.
In my case, though, whatever particular point of the spectrum I occupy has proven to be advantageous. I've had the luck of good, solid parenting in which I can root my morals, values, and behaviors. The first two are obvious; the third is not. I've never been able to entirely unconsciously assimilate acceptable social behaviors. There are an array that I've had to consciously learn, some by trial and error. Means that in some ways I've become a good actor. In other ways, it's gone from consciously responding in what's deemed an acceptable way (and avoiding other things like smiling at inappropriate times, which is something I've caught myself doing as an apparent standard emotional response where it's NOT recommended), to it becoming second nature because I've done it so much.
Anyway, I'm veering a bit. Back to the advantageous bit. I can argue that "disorder" is a misnomer for my brain's setup. It may have been at one time, but I've learned how to function in tandem with it in such a way that I can turn my tendencies into helpful behaviors. Some behaviors that I naturally want to engage in I know not to. One is busting into a room with voice at full volume, announcing what may or may not be a triviality. I save that for when it's really needed, sort of like the time we thought NHB was on fire (a bio student on the 3rd floor managed to mix ethanol, a Bunsen burner, and his lab manual), but other times, I consciously remind myself to suppress. That's one extreme.
The other extreme is the ability to hyperfocus. That comes naturally when I find myself doing something I find highly engaging. I don't take my luck for granted, especially when it's good, and I've certainly been lucky to find my subject of choice. Had no idea what I wanted to do, even coming into college, and thought I did shortly after. Found geology by chance partway through my junior year, and my mom was supporting enough to let me do an extra year in my undergrad to let me get my degree in geology instead of my previous major, which I'd been starting to flounder a bit in because I couldn't find research (no interested faculty), and as a result no real semblance of guidance. That alone caused me to start spacing out again. Getting into the Geology Department gave me a more engaging environment, a wide variety of subjects to sample, and a sense of community. I had the community with the band, but not so much in the academic side.
Fast fowarding to now, I'm in my niche area of study, which makes it easy for me to sit down and work 8 or more full hours a day. I don't always (not always 8 full hours of work to do), which means I can fill it by puttering around in the storage room of my teaching lab, reading papers, or engaging in the community in the department here. The key is that I enjoy what I do, so it's hard to consider it "work." If it's not so much work as fun or a game or a puzzle in my head, it's a relatively simple matter to sit down and expand my knowledge in the area or go work on my samples in the lab. Given the Scientific Method is essentially the thought structure I gravitated to at a young age, working the way I do is natural. Field work makes life even better.
However, try to get me to figure out something about insurance or business and it can take a few tries (sorry Mom!).
I'm loath to admit that there are a couple of downsides here and there to this "disorder." Though I'm one of the lucky ones who rarely has emotional downswings, they DO happen, and they can surprise me - sometimes just the right trigger, especially if I've been stressed about something. Thankfully, they never last more than a few hours, maybe a day or two at most. Stress is another issue in and of itself - can deal with it okay until it hits at the wrong angle and I break (insert shear stress/structure joke here). I'm sure that's true of almost everyone. Social stress is something I'm not used to, and there's been a fair amount this semester. Details as to why are irrelevant in this medium. All that matters is that I've once again demonstrated that I don't hide emotions well, which means it's probably very clear to the person with which I have a conflict that I have a conflict. Ironically, it's because this person and I are so much alike, but at different stages. This person is so close to the scientific rationale, except that it's clouded by a combination of upbringing and behavior that has obviously been advantageous in the past.
Once this person reaches a level proper for this academic environment, life will be better. The question remains as to whether or not the capability exists, because of some fundamental differences in this person's upbringing.
To bring this post full-circle, it's the above paragraph that has gotten me thinking about all of this again. We are very alike and very different, and I've been trying to reconcile the differences in our thinking. In doing so, I have turned inward to try to figure out again what my brain's up to in somewhat of an attempt to figure out what's going on in this person's brain. I don't know why I'm doing this. It fascinates me, but it won't be productive until the group faces this problem. We won't face it because no one wants to be the first to address this person. It's definitely not been ideal (never mind I have to suppress a laugh anytime we discuss "ideal" in class because it essentially doesn't exist) and I think that's what's been stressing me out the most.
Brains are weird, people are weird. Yes, I'm attaching labels, and only because it's the best way I can explain at the moment.
I'm no medical doctor or psychologist, so I have no qualifications upon which to make a diagnosis, but I can certainly find the correlations between what I've found in literature and my brain. Better yet is that my observations are inherently contaminated because I'm making the fundamental mistake of observing myself. It's funny how that works.
In my case, though, whatever particular point of the spectrum I occupy has proven to be advantageous. I've had the luck of good, solid parenting in which I can root my morals, values, and behaviors. The first two are obvious; the third is not. I've never been able to entirely unconsciously assimilate acceptable social behaviors. There are an array that I've had to consciously learn, some by trial and error. Means that in some ways I've become a good actor. In other ways, it's gone from consciously responding in what's deemed an acceptable way (and avoiding other things like smiling at inappropriate times, which is something I've caught myself doing as an apparent standard emotional response where it's NOT recommended), to it becoming second nature because I've done it so much.
Anyway, I'm veering a bit. Back to the advantageous bit. I can argue that "disorder" is a misnomer for my brain's setup. It may have been at one time, but I've learned how to function in tandem with it in such a way that I can turn my tendencies into helpful behaviors. Some behaviors that I naturally want to engage in I know not to. One is busting into a room with voice at full volume, announcing what may or may not be a triviality. I save that for when it's really needed, sort of like the time we thought NHB was on fire (a bio student on the 3rd floor managed to mix ethanol, a Bunsen burner, and his lab manual), but other times, I consciously remind myself to suppress. That's one extreme.
The other extreme is the ability to hyperfocus. That comes naturally when I find myself doing something I find highly engaging. I don't take my luck for granted, especially when it's good, and I've certainly been lucky to find my subject of choice. Had no idea what I wanted to do, even coming into college, and thought I did shortly after. Found geology by chance partway through my junior year, and my mom was supporting enough to let me do an extra year in my undergrad to let me get my degree in geology instead of my previous major, which I'd been starting to flounder a bit in because I couldn't find research (no interested faculty), and as a result no real semblance of guidance. That alone caused me to start spacing out again. Getting into the Geology Department gave me a more engaging environment, a wide variety of subjects to sample, and a sense of community. I had the community with the band, but not so much in the academic side.
Fast fowarding to now, I'm in my niche area of study, which makes it easy for me to sit down and work 8 or more full hours a day. I don't always (not always 8 full hours of work to do), which means I can fill it by puttering around in the storage room of my teaching lab, reading papers, or engaging in the community in the department here. The key is that I enjoy what I do, so it's hard to consider it "work." If it's not so much work as fun or a game or a puzzle in my head, it's a relatively simple matter to sit down and expand my knowledge in the area or go work on my samples in the lab. Given the Scientific Method is essentially the thought structure I gravitated to at a young age, working the way I do is natural. Field work makes life even better.
However, try to get me to figure out something about insurance or business and it can take a few tries (sorry Mom!).
I'm loath to admit that there are a couple of downsides here and there to this "disorder." Though I'm one of the lucky ones who rarely has emotional downswings, they DO happen, and they can surprise me - sometimes just the right trigger, especially if I've been stressed about something. Thankfully, they never last more than a few hours, maybe a day or two at most. Stress is another issue in and of itself - can deal with it okay until it hits at the wrong angle and I break (insert shear stress/structure joke here). I'm sure that's true of almost everyone. Social stress is something I'm not used to, and there's been a fair amount this semester. Details as to why are irrelevant in this medium. All that matters is that I've once again demonstrated that I don't hide emotions well, which means it's probably very clear to the person with which I have a conflict that I have a conflict. Ironically, it's because this person and I are so much alike, but at different stages. This person is so close to the scientific rationale, except that it's clouded by a combination of upbringing and behavior that has obviously been advantageous in the past.
Once this person reaches a level proper for this academic environment, life will be better. The question remains as to whether or not the capability exists, because of some fundamental differences in this person's upbringing.
To bring this post full-circle, it's the above paragraph that has gotten me thinking about all of this again. We are very alike and very different, and I've been trying to reconcile the differences in our thinking. In doing so, I have turned inward to try to figure out again what my brain's up to in somewhat of an attempt to figure out what's going on in this person's brain. I don't know why I'm doing this. It fascinates me, but it won't be productive until the group faces this problem. We won't face it because no one wants to be the first to address this person. It's definitely not been ideal (never mind I have to suppress a laugh anytime we discuss "ideal" in class because it essentially doesn't exist) and I think that's what's been stressing me out the most.
Brains are weird, people are weird. Yes, I'm attaching labels, and only because it's the best way I can explain at the moment.
Monday, March 15, 2010
Snowball Earth Proven?
Snowball Earth is a popular, controversial idea in which Earth is thought to have been completely covered at least once in ice during the Sturtian glaciation of roughly 718-700 Ma. This glaciation episode, bookended by two others, the Kaigas (~785-728 Ma) and the Marinoan (~670-624 Ma), comprise the period of the Late Precambrian known as the Cryogenian Period and are a precursor to the Cambrian Explosion of roughly 530 Ma.
This is proposed as a hypothesis to explain some sediments seen worldwide that some geologists are having trouble characterizing any other way. Glacially-associated sediments are distinct from the more common wind- and water-driven deposits. Because of the viscosity of ice, it is capable of carrying sediments of varying grain size from dust to megaboulder. Some sediments are sorted out during melting into eskers or loess, but other sediments are dropped where they are when the glacier starts to melt. Advance/retreat periods during melting can push up ridges of unsorted sediments at the glacier head known as moraines.
Skeptics of the hypothesis argue that there are problems with the idea of worldwide glaciation, and their arguments are very well-founded. Those of us who see snow every year are aware of how bright the world can get when snow is on the ground and the sun is shining. This is because snow and ice have a high albedo, or ability to reflect light. If light is reflected rather than absorbed, not much energy is available at surface level to melt snow or ice. It's possible that runaway glaciation would be VERY hard to reverse once established simply because of the albedo argument. I believe some models back this up. Others don't. It's controversial, which is what makes it a compelling story of Earth's past.
There are other arguments, but I strongly suggest reading through the Wikipedia article linked at the top of this post. It's fascinating.
Sediments such as these have been observed in paleoequatorial regions. Using paleomagnetic data embedded in rocks (that hasn't been too far altered by subsequent metamorphic processes), it is possible to extrapolate a paleolatitude of a particular rock formation. This is done by isolating the remanent magnetic signature (thought of as a vector) in the native Fe2O3 (hematite), Fe3O4 (magnetite), and FeTiO4 (ilmenite) crystals present in a rock. Alignment may occur in the internal structure of a crystal during cooling and crystallization of an igneous rock (if it has enough time), or during deposition of iron-bearing sedimentary rocks (if the magnetic field has enough influence to align enough of the grains in situ). If it is possible to establish an age for these same rocks, we know when that piece of continent was at that particular latitude (but NOT the longitude, because assuming a perfect magnetic dipole, the magnetic vector is the same at all longitudes at that latitude).
Better yet if you find glacial sediments hanging out in close association with rock types typically found in tropical environments. Uniformitarianism for the win.
That's what scientists have managed to do with a suite of rocks in northwestern Canada. Tropical sediments and presumably paleomagnetic data (not directly mentioned in the article) were used to identify what could be a smoking gun for Snowball Earth.
As a corollary, some glacial sediments are now found at tropical latitudes, but that plus paleomag provides a smoking gun in favor of plate tectonics. Typical glaciations throughout Earth's history were not at the level of the Cryogenian glaciations.
This is proposed as a hypothesis to explain some sediments seen worldwide that some geologists are having trouble characterizing any other way. Glacially-associated sediments are distinct from the more common wind- and water-driven deposits. Because of the viscosity of ice, it is capable of carrying sediments of varying grain size from dust to megaboulder. Some sediments are sorted out during melting into eskers or loess, but other sediments are dropped where they are when the glacier starts to melt. Advance/retreat periods during melting can push up ridges of unsorted sediments at the glacier head known as moraines.
Skeptics of the hypothesis argue that there are problems with the idea of worldwide glaciation, and their arguments are very well-founded. Those of us who see snow every year are aware of how bright the world can get when snow is on the ground and the sun is shining. This is because snow and ice have a high albedo, or ability to reflect light. If light is reflected rather than absorbed, not much energy is available at surface level to melt snow or ice. It's possible that runaway glaciation would be VERY hard to reverse once established simply because of the albedo argument. I believe some models back this up. Others don't. It's controversial, which is what makes it a compelling story of Earth's past.
There are other arguments, but I strongly suggest reading through the Wikipedia article linked at the top of this post. It's fascinating.
Sediments such as these have been observed in paleoequatorial regions. Using paleomagnetic data embedded in rocks (that hasn't been too far altered by subsequent metamorphic processes), it is possible to extrapolate a paleolatitude of a particular rock formation. This is done by isolating the remanent magnetic signature (thought of as a vector) in the native Fe2O3 (hematite), Fe3O4 (magnetite), and FeTiO4 (ilmenite) crystals present in a rock. Alignment may occur in the internal structure of a crystal during cooling and crystallization of an igneous rock (if it has enough time), or during deposition of iron-bearing sedimentary rocks (if the magnetic field has enough influence to align enough of the grains in situ). If it is possible to establish an age for these same rocks, we know when that piece of continent was at that particular latitude (but NOT the longitude, because assuming a perfect magnetic dipole, the magnetic vector is the same at all longitudes at that latitude).
Better yet if you find glacial sediments hanging out in close association with rock types typically found in tropical environments. Uniformitarianism for the win.
That's what scientists have managed to do with a suite of rocks in northwestern Canada. Tropical sediments and presumably paleomagnetic data (not directly mentioned in the article) were used to identify what could be a smoking gun for Snowball Earth.
As a corollary, some glacial sediments are now found at tropical latitudes, but that plus paleomag provides a smoking gun in favor of plate tectonics. Typical glaciations throughout Earth's history were not at the level of the Cryogenian glaciations.
Sunday, March 14, 2010
Daylight Savings Time
. . . Somewhat guilt-inducing, because I wake up thinking I've slept in an hour later than usual. While I haven't in terms of absolute time, social time indicates that I absolutely have!
Well, at least it's Pi Day. I will not be eating pie, or any number approximately equal to 3.14 for that matter, but I will happily ruminate on the philosophical implications of the ratio of a circle's diameter to its radius.
Nevertheless, today requires some level of productivity - finishing my lecture for Monday, then heading into work so I can cap my samples and get the teaching samples ready for tomorrow's lab, as well as hang around in case any students who might be around have some questions.
Well, at least it's Pi Day. I will not be eating pie, or any number approximately equal to 3.14 for that matter, but I will happily ruminate on the philosophical implications of the ratio of a circle's diameter to its radius.
Nevertheless, today requires some level of productivity - finishing my lecture for Monday, then heading into work so I can cap my samples and get the teaching samples ready for tomorrow's lab, as well as hang around in case any students who might be around have some questions.
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