Climate change and cholera

This isn’t super directly related to geology (although I guess it qualifies as earth-science-related), and even less related to anything I have any sort of expertise in, but it piqued my interest…

This week’s Science Times section of the NYT included a brief article about a new paper titled “Warming Oceans, Phytoplankton, and River Discharge: Implications for Cholera Outbreaks.” I couldn’t get to the full paper, but according to the abstract (and the Times write-up), the gist of the findings were that increased coastal phytoplankton in the Bay of Bengal*, which is associated with cholera outbreaks, may be due primarily to increased influx of terrestrial nutrients from increase river discharge and glacier melt. The authors contrast this with the increase in phytoplankton somehow being attributed to increased sea surface temperature (an indicator of climate change), as was previously thought (? I’m inferring that people previously thought this… it doesn’t really say).

Pretty interesting, but the part I thought was the most interesting was that the Times headline was “Cholera: Climate Change Isn’t a Culprit in Increasing Outbreaks, Study Finds.” Forgive me if I’m wrong as I’m definitely not a climate scientist, but when I hear something is probably caused by “increased river discharge [i.e. increased precip?] and increased glacier melt,” it seems a bit premature to write off such causes as being totally unrelated to climate change. Am I crazy? People with more knowledge in this area than me please feel free to comment!

*In case you’re as bad at geography as I am and want to confirm that the Bay of Bengal is where you think it is, it’s the part of the Indian Ocean that’s on the east side of the Indian subcontinent (see here).


I can’t believe I had a chance to experience my FIRST EVER EARTHQUAKE… and I missed it!

Apparently the shaking was so slight here in central PA that anyone outside walking around couldn’t feel it, but normally on a Tuesday afternoon I would be sitting at a desk on the fifth floor of a building full of geologists and would TOTALLY have felt it (my labmate did!) plus gotten to share in the excitement. But alas, I picked Tuesday of all days to play hooky in the afternoon and go for a long trail run with my friend Christy in preparation for the Dam Half next month. We were in the car when it happened and didn’t feel a thing. The weather was perfect for running in the woods so I guess it was a good choice, but maybe missing the earthquake was karma for skipping school :)

For my non-geologist friends and family, the USGS pages on the earthquake (which they have for every significant quake) are interesting if you’re looking for a source of scientific info. I think their crowd-sourced “Did you feel it?” feature is especially interesting for this one, since a gajillion* people reported it both because it occurred in a region with a relatively dense population and good Internet access, and because it really was felt across a much wider area than comparable quakes out West; the old, cold, minimally fractured crust east of the Rockies transmits shaking much more effectively than younger, deformed crust to the west.

*rough estimate

Edit: IRIS also has some neat summary info about the quake on their website (scroll down a bit) which would be helpful if you’re teaching about it!

Yet another edit: I know everyone else except geologists is probably over the earthquake/has moved on to talking about Irene, but I just found two more awesome sources: this blog post is really interesting and thorough, and (I think this one is even more awesome because I’m a huge map geek) this really sweet map that overlays the epicenter, local bedrock geology & faults onto Google Maps. Definitely worth checking out.

Whoa, back from the dead!

The main reason I can think of that I haven’t been blogging is that it’s summer in PA and I’ve been taking advantage of the weather while it’s still here, and thus spending my free time playing outside instead of blogging. Also, nothing all that interesting has been happening in terms of grad school (other than my advisor returning from his year-long sabbatical, which has definitely correlated with an uptick in my productivity).

Anyway, right now I am researching something that is interesting enough to me that I want to share it with someone, but I don’t think I can be concise enough for a tweet or a Facebook status update, so I figured I would blog about it. But first, check out this awesomely retro geologic map:

From Lanphere et al, 1968, Isotopic age of the Nevadan Orogeny and older plutonic and metamorphic events in the Klamath Mountains, California.

(I’ve been reading a lot of papers from the 1960s this morning as part of this thing I’m trying to figure out, and it’s kind of cool. I especially like that the sampling location I circled in red looks like it’s in pretty much the exact same place as one of my samples… meaning some dudes were out at that same roadcut in the ’60s taking samples to get a crystallization age, and then I was out there last summer in the exact same place getting samples for a different study. I don’t know why but I love stuff like that!)

Anyway, that rock I was sampling at that red location is from the Shasta Bally batholith, a big northwest-trending elongate blob of granitic rock. On its southern end, there are some marine sedimentary rocks that are part of the Great Valley Group (the part I scribbled on in green… how nice that I have Photoshop and it still looks like I’m using MS Paint because I’m just that janky.) The important thing is that as far as I can tell from reading a whole bunch of papers (and many of them cite the same 1960s map by Murphy et al that I haven’t been able to get my hands on) it’s a depositional contact, which just means the sedimentary rocks were deposited directly on the granitic Shasta Bally rocks, no faulting or anything crazy, and therefore the Shasta Bally batholith had to be there first. Which is weird because the batholith was emplaced something like 7 km underground, crystallized to solid rock about 136 million years ago, and then it had to get brought to the surface so these sediments could be deposited on top of it… but from what I can tell (and this is where it gets confusing, because different people say different things and the geologic time scale is basically defined by fossils which then have to be correlated with radiometric ages blah blah blah…) the overlying Great Valley Group sediments here are at least Hauterivian if not mid-Valanginian, which corresponds to them being ~130-135 million years old. What?!? I just feel like that’s crazy fast for a batholith to be exhumed and then all of a sudden have an ocean on top of it. (I know one or two million years sounds like a lot, but in geologic time… it’s not really that long.)

So I guess the conclusion of this story is that there is no conclusion, yet… but basically I’m fascinated by the fact that this batholith is seriously under-investigated (is that even a word? I was going to say “understudied” but that made it sound like I was talking about a ballet performance). Like I can’t even find any studies of its petrology, but people have studied the shit out of a lot of the adjacent plutons that I’ve dated. It’s just interesting and it’s refreshing to be interested in my thesis research again :)

Oh hey there, blog

Wow! I hadn’t blogged in so long I almost forgot my WordPress password. I took an awesome week-long trip home to Minnesota (but I got back a week ago so that isn’t totally a reason for not blogging… it just kind of mixed up my schedule/threw me for a loop). As usual I have lots of ideas of things to blog about (including two very informational meetings with geologists while I was home) but no time because I’m headed to Pittsburgh for a weekend and leaving tomorrow… I’ll plan on posting next week!

Saw this via a tweet from @cbdawson. It’s like Google StreetView for streams! Check out the “Our Mission” page for reasons they think it would be useful… all of which I think are great. Cool idea.

Also, last night I FINALLY got my Matlab code working… like the helium actually diffuses out of the apatite instead of exploding out of control!!! It still needs a lot of work but it was pretty thrilling to see it actually behaving the way it was supposed to after weeks of banging my head against a wall. I’m kind of embarrassed to admit how I fixed it but will probably elaborate in a later post.

Oh and it’s Friday the 13th… weird.


Okay I really hate fracking jokes but I couldn’t think of another post title. Coming up with titles: officially my least favorite part of blogging.

Tuesday night I went to hear Dr. Anthony Ingraffea of Cornell give a talk on campus about fracking in the Marcellus Shale. His theme was “myths and realities,” which I thought was a great theme considering the conflicting statements of “fact” we hear from both industry and environmentalists–they can’t all be right, so some of these statements must be myths! Dr. Ingraffea pointed out some of the most often repeated myths and explained what kernel of truth they came from.

(Quick background information on the Marcellus: Gas shales are one kind of unconventional natural gas deposit, which basically means they are more technically difficult & more expensive to extract gas from than conventional deposits. The Marcellus Shale is a major shale gas deposit found in Pennsylvania, New York, West Virginia and some other states I can’t remember off the top of my head… but those are the big ones. Last year New York put a moratorium on horizontal hydraulic fracturing, the method used for extracting gas from shales, but it’s still going on in other states and is expected to accelerate rapidly. But more on that in a minute.)

Anyway, Dr. Ingraffea is a fracture expert and also worked in industry for a number of years, so I was interested to hear what he had to say.

The first myth he covered is actually one of the more compelling statements I’ve heard from industry: hydraulic fracturing (fracking) is a proven and well-understood technology that’s been used in the industry for over 40 years. This is true in a way, but not relevant to the drilling being done in the Marcellus, and Dr. Ingraffea explained why.

There are basically four technologies or strategies involved in the method used for drilling in the Marcellus, which he summarized as “High-Volume Slickwater Fracking from Long Laterals“:

  • High-Volume: Fracking in unconventional deposits requires MUCH higher volumes of fracking fluid to be injected than required for conventional fracking. How much higher? In NY state the limit for a single well is 80,000 gallons of fluid. This is sufficient for conventional fracking but rules out the high-volume fracking needed to extract gas from the Marcellus… because according to Dr. Ingraffea, in PA the average volume of fracking fluid used in a Marcellus well is 5.5 million gallons, or over 68 times the maximum used in conventional fracking.
  • Slickwater: The high volumes of fracking fluid needed must be injected through a casing that’s on average 5-7 inches in diameter. To reduce the force needed, the injected water is made “slipperier” (I know, slipperier water, what?!) by the use of additional chemicals that are not needed in conventional fracking.
  • Directional drilling: On average the Marcellus is only a few hundred feet thick, so vertical wells would be kind of pointless. Instead, wells are drilled down to the depth of the Marcellus and then drilling then continues horizontally. In addition, the Marcellus is already naturally heavily fractured, so when we talk about fracking it’s really re-fracking, or reopening of existing joints. These existing joints have a consistent orientation, so wells are oriented perpendicular to the joints to maximize production. (I just Googled up a storm looking for a good illustration of this but couldn’t find one… sorry).
  • Multi-well pads: Kind of goes along with directional drilling… if your wellbores are going out laterally from where the well is drilled, it makes sense to put a bunch of wells on the same pad and then have their wellbores go out in different directions.
His point was that while it’s true that conventional fracking has been used for multiple decades, these technologies, all of which are used in the Marcellus, have been developed in the last decade or two, and have only been used in combination even more recently.

I’m a firm believer in the value of responsible development of natural resources. (I feel like a lot of people or organizations on both sides of the argument say that as some bullshit statement and really only mean half of it–or else have some bizarre definition of “responsible” or “development”–but really, I am). But as an average citizen it can be hard to get a sense for how “responsible” specific development activities are, and also what more responsible practices might be technically and economically feasible (i.e. I often wonder, is there a real tradeoff that has to be made here between resource development and environmental stewardship, or is industry just being cheap?)

Anyway, really interesting talk. I wish I had time to write more, but I need to do actual work now.

Finals week is here and I don’t have any finals, yay! Well, the final for my only class this semester involved a take-home portion where we wrote our own test questions and answers, and then a portion at The Corner Room where we drank mimosas, had a great discussion, and I ate chocolate chip pancakes. It was most likely my last final ever, so I think that’s a pretty good note to go out on :)

The end of the semester also meant I turned in my Geosc 001 lab grades yesterday. I’m very satisfied with the grades… the average is about a 90, which I think is good because the class is NOT supposed to be hard and I think overall most people did a great job. And the last week of lab went really well! I was a little apprehensive because it was a tough lab and to be honest, I thought a lot more people would complain about it (don’t worry, some did, all is well with the college psyche). We laid out a bunch of rock samples all over the classroom along with some pieces of masking tape indicating contacts between formations or strike and dip of beds. The students went around identifying and “mapping” the different formations, and at the end they had to draw a map and cross-section (I never did anything like this in undergrad but apparently it’s kind of a common thing?).

It was funny, because for the quiz we do at the beginning of lab every week (to encourage them to actually read it over in advance… sort of works) I made two of the questions freebies that just asked what their favorite and least favorite labs of the semester were and why, and after the last lab I had a few people say “I wish I could take the quiz again so I could say this was my favorite lab!” and a few others say, “I wish I could take the quiz again so I could say this was my LEAST favorite lab!” Ha. I think the people who didn’t like it didn’t really get it and thought it was tricky and tedious, but the people who liked it did because it really “clicked” for them and it was a fun thing to figure out (a “geo-puzzle” as my undergrad research advisor would say).

I thought it was neat because it really tied together things we’d done throughout the semester, like identifying different rock types and structures–this lab was originally on the schedule for earlier in the semester but my co-TA Ashlee, who has taught this class before, suggested we switch it to the end for this very reason, and I’m REALLY glad we did because I’m not sure it would have worked out very well otherwise.

I had a bunch of students tell me they enjoyed the class (yay!) and a couple freshman even told me they were considering majoring in geosciences now… double yay! All in all, I think the semester went well. I would actually love to TA this class again next semester, because there are a bunch of things I want to tweak… but more on that in a future post!


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