Thursday, October 13, 2016

Wissa-hikin' on the Wissahickon: awwww, schist!

This last weekend I went on a hike up at Wissahickon Park to check out the local geology with the Temple University Geology Club.

Location of Wissahickon Park
Location of Wissahickon Park.

I've been through the Wissahickon plenty of times, as it's one of my favorite places to go biking, but this was the first time I'd ever walked around. I didn't take many pictures, but it's a beautiful park, and a nice little nature preserve for being this close to central Philadelphia.

Wissahickon Park

Wissahickon Park

Wissahickon Park

Wissahickon Park

The exposed bedrock at the park is the aptly-named Wissahickon Formation, a glittery schist which has been widely used as a decorative building stone for Philadelphia from colonial times to today.

Neocolonial home around Philadelphia.

Temple University Baptist Temple
Temple University's Baptist Temple, which the university is named for, constructed with Wissahickon Schist building stone.

Schist is a metamorphic rock, meaning it has been altered to it's current state through immense heat and pressure. Before metamorphism, the rock it used to be was likely shale, a sedimentary rock formed from the lithification of clay and mud. This former rock was formed during the Cambrian period, around 500 million years ago, when this part of the continent was not only far out to see, but south of the equator and rotated about 90 degrees from today (lots can change in 500 million years).

North America during the Cambrian
Location (red star) of sediments deposited which would eventually metamorphose into the Wissahickon Schist.

See the island chain just to the south (right) of Philadelphia in the above photo? That's an island arc chain, the result of two continental plates converging (colliding), producing a chain of volcanoes along the plate boundary. As this plate collision progressed as one plate was subducted under the other, eventually the continental crust that Philadelphia was apart of collided with the volcanic chain, resulting in a mountain chain, and deforming the local rocks and sediments. This was known as the Taconic Orogeny:

Taconic Orogeny

Both the stresses from the collision, along with deep burial under a mountain range, resulted in intense metamorphism of the previous rocks. For what is currently the Philadelphia area, this resulted in the formation of the Wissahickon Schist. A further 450 million years of weathering eroded down the mountain and exposed the highly metamorphosed rocks at their hearts, which is what we now see at the surface around Philadelphia.

There was a lot of interesting mineralogy and deformation textures to see at the park, but I just brought one sample home. The Wissahickon Schist is widely known for being fairly rich in garnets, which is what I was looking for.

Wissahickon Schist with garnet
Wissahickon Schist with garnets. Origin of Species for scale.

Wissahickon Schist with garnet
Wissahickon Schist with garnets. Stubby fingers for scale.

Wednesday, September 14, 2016

Drone Pilot License!

A few weeks ago, the FAA's new regulations regarding small unmanned aircraft systems (UAS) or "drones" went into effect, known as Part 107. Along with definitions of what constitutes a drone and where/when they can be operated, it also included a new "Remote Pilot" certification, which is required to operate drones. A summary of the Rule can be found here.

To qualify for the new Remote Pilot certification, you either need to pass a test, or currently hold another pilot certificate with a current flight review, and take a short UAS online course through the FAA's FAASTeam website. Since I qualified for the latter, I decided to go ahead and obtain my Remote Pilot certificate!

Of course, I took the opportunity to joke around a bit and made up a little billboard of Commercial Drone Pilot Services for me and my trusty little miniDrone. So far, I have yet to make my fortune...

Although I don't specifically have plans to commercialize on the license (still doing the PhD thing), I figured it wouldn't be a bad idea to get on board early. The use of drones in geological research seems to be booming lately; I recall a whole poster session on drones at the recent Geological Society of America meeting in Baltimore. Even searching for the word "drone" in the upcoming National Geological Society of America meeting in Denver brings back a number of results.
It's possible that someday in the near future it may come in handy to be a registered drone pilot. Or, more likely, now that I've opened up the possibilities to myself, I may think of ways in which to use it. Either way, it's exciting that three fields I've been trained in (geology, GIS, and aviation) have come together this way for me.

Friday, July 8, 2016

Summer Fieldwork Update

In summary:

Not sure if waders leaking or just really sweatty

Fieldwork has been off and on for most of the summer, wading in springs and streams, looking for that elusive data. We've done some baseflow spring sampling, but we really need some storms to hit our spring sites. Until then, most of my days in the lab consist of staring at radar, hoping a storm will hit...

disappointed storm watching

I also found a cool sinking stream near one of my sites which I'm hoping to test some fun dye tracing ideas at!


While testing out a CO2 logger at another one of the sites, another karst hydrologist came with and spotted a bunch of mint growing in one of the springs! It was delicious.

karst spring mint

Even though I ate all the leaves off of one of the plants, I decided to take it back to the lab anyway. It's been doing pretty well, and on the road to a full recovery, thanks to my Groundwater Modeling Center cup (and also probably because it's a weed...).

growing mint

Also, just in time to get an abstract submitted to the National Geological Society of America meeting, we got the rare earth element analyses back from our springs! We're still trying to make sense of the results, as they aren't quite jiving with our expectations (but that's how science goes sometimes).

Now, if you excuse me, I have to go watch a storm miss my spring sites...again.

storms on radar

Thursday, June 2, 2016

Spring Sampling Season Begins!

Last week I went on a fieldwork tour up around Valley Creek/Valley Forge area to sample some urban springs to compare their water chemistry with the springs I'm studying up near State College, which are more rural. A few of the springs were in handy little spring houses.

Valley Forge spring house
Spring house sampling near Valley Creek/Valley Forge
Spring water sampling in a spring house
Fiddling with the filter assembly in one of the spring houses

A few of the springs were down along stream banks, which required a little bit of trudging. This was also an opportunity for us to introduce Rachel (one of our undergrad researchers) to the type of fieldwork we'll be doing all summer.

Spring water sampling along a stream
Collecting water samples in one of the more off-the-path spring locations

 The springs that weren't conveniently enclosed or dammed up in spring houses were often a bit more difficult to measure, as they tended to be little spring seeps along the stream banks. This got a bit tricky with some of our multiprobes.

Spring water pH and temperature measurement
Dr. Toran attempts to find a deep enough pool for the pH logger

Eventually the sun gave way to some storm clouds that decided to pass through the area. That didn't stop us, though!

Spring sampling in the rain
Rain never hurt anyone, although the lightning may have played havoc on the conductivity meter

 Basic analyses (alkalinity and ions) were run on the samples over the course of the next few days to compare with the Nittany Valley springs and determine some baseflow chemistry.

ICP analysis of spring water
Nothing like vaporizing water samples to 7,000 Kelvin to see what it's made of!

 The remainder of the samples are now on the way to a lab in Canada to analyze for rare earth elements (REE's), to determine their detection limits at baseflow conditions.

Spring water samples off for REE analysis
Samples packed and ready to go. Next stop, Ontario. Bon voyage!

Tuesday, May 24, 2016

Spring 2016: Semester Summary

Second semester done! How many more to go? Hmm...

All in all, an eventful semester. As it went on I started to get a better idea of the kinds of questions and approaches I'll be applying to my study area this summer. Before I move on to that, here were some of my highlights for the last 4 months.

Karst Waters Institute (KWI) Conference in Puerto Rico

Just a few weeks into the semester, I flew down to San Juan for the KWI Conference on "Karst, Groundwater Contamination, and Public Health." Since karst hydrology has been my focus since my master's, and I had worked as a drinking water protection hydrologist for a few years, this meeting was right up my alley. Also, couldn't really complain about a chance to leave behind the cold late-January Philadelphia for a warm Puerto Rico.

Land in sight!

I was surprised how short the flight was (3-4 hours?), although I guess in my mind I'm just used to everything being far away from Minnesota (especially warm places). After checking in to the hotel and running into some other people we knew (my advisor also came with), we went to go explore the area around the hotel.

Exploring the neighborhood around the hotel in San Juan

Some local wildlife up in some cannon tower/fort along the shore

Dr. Toran couldn't pass up the chance to test the water (although not in the scientific sense)

Conference selfie

It was a multi-day confernce, involving a few days of talks followed by a short field-trip exploring the island's karst regions. I enjoyed most of the talks, and as far as topics go I think I got a lot out of it. Not only that, but it was a good chance to network with a number of people I've only ever known as citations from papers I've read. I had even talked a good friend and former colleague from the health department to come for the conference!

Bus-buddies for the trip: MDH Represent!

I thoroughly enjoyed the multi-day field trip (even though the stop to Aricebo Observatory was scrapped due to maintenance). We got to see plenty of other sites, though:

Some areas were covered with pointy hills, called "mogotes," which were specific to karst landscapes. Or, as I called these areas, they were "totes magotes"

Down into a very deep sinkhole, apparently with it's own cloud-forming layer.

Into the caves!

Spotting some cave drip formations

A shot from one cave overlooking a valley - none of the photos really did this view any justice

PhD Preliminary Exam

With the Puerto Rico conference out of the way, I was able to move on to another more pressing issue - my PhD Preliminary Exam near the end of the semester. This process involved identifying a topic related to the research I'll be doing (but not so applicable as to be the same) to write a paper on, and then give a presentation to the department faculty and my committee. From what I gathered, the idea behind the exam is to determine our ability to (mostly-independently) delve into a research topic, digest the material, identify limitations, and pose potential research routes.

The topic I ended up choosing (along with help from my advisor) was in the application of stable isotopes of hydrogen, oxygen, and strontium in groundwater studies. At first I thought that was fairly specific enough, but towards the end (and especially after writing the paper) I figured out that this was still too broad of a topic. I eventually narrowed it down to focusing on determining storage and flow in the epikarst zone.

My presentation went for about 30 minutes (this wasn't too difficult - I actually like preparing PowerPoint presentations, and I have a fairly good understanding of karst by now), and most of the department faculty were there. Isotope geochemistry was a fairly new field of research for me, so although I learned a lot in order to give the presentation, I knew I had some fairly large knowledge gaps. But that was okay - if I already knew all of this, what would be the point? I fully understood that these limitations were a part of the process, and if anything I took them as proof that I had genuinely picked a "fresh" topic for me to explore.

After that talk came the 30 minutes of open questions from anyone else in the room. I thought that went fairly well. Some things I got, some things I'm sure I didn't explain perfectly - but that's okay. We're all there to find out where my weaknesses are. In my mind, if I couldn't answer any questions thrown my way, then I failed, but if I could easily answer every question thrown my way, then the department has failed. It felt like a good middle ground.

After that came the ~2 hours of questions from my three committee members. That was a little more rough, mostly because I had been standing and talking for nearly 3 hours by the end, so my voice was getting a little hoarse and I was starting to feel a bit tired. Most of the questions came from our department's geochemist, Dr. Grandstaff (aka "G"), who I had just taken a course with the semester before (so I should know all this...). He didn't hold anything back and had fairly high expectations. He tripped me up more than anyone else, and there were plenty of awkward silences while I was trying to work out a suitable answer. He reminded me very much of my old boss and aviation advisor at Winona, Dr. George Bolon. Knowing this fact helped me calm down a bit, as I was very familiar with this style of academic grilling.

Oddly enough, despite all the papers, studying, and practice talks, one thing that really saved me in a pinch was this game I had gotten earlier on in the semester called Ion: A Compound Building Game. It was a Kickstarter game in which you score points by building chemical compounds through mixtures of cations, anions, and noble gases. I had been playing it for a few weeks before my exam, and I really got a kick out of how many combinations of the cards produced actual compounds (and minerals!). At one point during my exam I was asked to write out a chemical formula of anhydrite, which I had remembered being calcium sulfate (CaSO4), thanks to the card game. I highly recommend it!

Thanks, Ion!

Despite the stress, lack of sleep, and feeling like I should have known things I didn't, I thoroughly enjoyed the Prelim Exam process. Isotope geochemistry was not exactly my strongest subject, but I feel like I have a much better grasp on it now than I did before (wait, I'm here to learn things???). I passed the exam and most of the department seemed to have no major qualms with me staying. Afterward, G told me to go enjoy a beer (a sure sign of a well-meaning academic, despite the grilling). From what I gathered, my experience differed quite a bit from the other PhD students, unfortunately, and for a while I had some lingering guilt for actually having a good time.

PA Groundwater Symposium Conference

With the Prelim Exam out of the way, I was again free to focus my attention on other pressing matters (that seemed to be the theme of this semester). I was giving a presentation at the Pennsylvania Groundwater Symposium in State College just a few weeks after my prelim exam, so again I had another presentation to prepare for. Including with my Ecohydrology final presentation, I gave something like 4 or 5 talks on different aspects of karst this semester. Phew!

I was giving a talk on some of the long- and short-term temperature data that had been collected from the springs in my study area over time (some more recently collected by me, some about 10 years old collected from previous research, and some collected in the late 1960's). It was kind of fun comparing the trends we were seeing now with what they had seen before, although now we had the miracle of high-frequency data loggers!

The highest of tech

TA Duties

This was my second time (and final for the time-being) being a graduate teaching assistant at Temple. This semester I had two sessions of Physical (intro) Geology lab, and I was also the TA for the Remote Sensing/GIS course. 

Teaching the intro geology lab was essentially the same good experience as from last semester. Since we were using the same lab manual, and taught things in generally the same order as last semester, nearly all my planning had been done. Since I was mostly helping out (rather than planning) the GIS labs, that didn't involve as much extra time on my part, either. Both of these things really helped the semester go smoothly, especially considering all the presentations I had to prepare.

I had just gotten a new smart phone and decided to play around with the a time-lapse app for it to make some fun videos of food coloring dye flowing through our aquifer simulator sand tank:


Dr. Nyquist had just gotten some new smart-phone-attachable thermal cameras, and had asked me to take a look on figuring them out. The thermal camera app also had a time-lapse function, and it actually worked out really neat to see a plume of warm water flowing through the sand tank:


While not exactly a time-lapse, I did bring in the slinky to demonstrate different earthquake waves. One of my students had a slow-motion app on their phone and captured this cool shot of the slinky in action:


While out setting up some data loggers, I took along the thermal camera to explore it's ability to find springs. Actually came in fairly useful! Since it was fairly cold out when I went out, surface water cooled quickly, while any springs flowing up from underground were relatively warm. This made it easy to find spring seeps along banks of rivers, where the water flowing out of the spring was in thermal contrast with the stream, even if the flow wasn't especially obvious:


Geology Cake

End of the semester: need I say more? Another success!

Geology cake!

Eventful semester! Now that summer is underway, I'm in full research mode, and will be visiting my sites more frequently, setting up data loggers and auto-samplers and analyzing the data as it comes in. We also brought on an undergraduate (a former student in my intro geology lab) to do summer research with us and to take on some of the work we wouldn't be able to get to without the extra help.

I'll be doing my best to post a little more frequently (which also means shorter posts!), so stay tuned!

Wednesday, January 20, 2016

Geology Lab Lessons: My first semester back as TA

With the new year comes a new semester, and more TA duties. First off, re-organizing all the mineral jars again:

The strongest force in the universe for randomly re-organizing minerals is a semester of geology students.

I've also been looking back on the previous semester to see how I could improve the lab lessons and my own teaching styles. The teaching evaluations I got back were very useful for me to see what worked and what didn't. The following are the lessons I learned from my first semester back as a lab TA.

  • Enthusiasm, enthusiasm, enthusiasm. The vast majority of students in my labs were not geology or environmental science majors, so interest in the subject was not something they brought to day one of class [yes, geology is awesome, you don't have to tell me that]. It's safe to assume most of the students show up with a neutral stance (at best) of the material. I think one of the most important things I brought to class was a love of the subject. For me, it's fun to get excited about geology. Looking back as a student, the teachers and professors I most enjoyed having class with were those that were really into their subject. sure, I can dryly cram as much information into their minds as I can (I don't like this approach to learning), or I can structure the lab in a way that makes it more enjoyable, in which case they'd want to go out on their own to learn more (this was my approach, and it seemed to work very well).

  • Be a person. You are not a machine. You're more than just a repository of knowledge tasked with shoveling as much as possible into their heads. The students responded more positively to the class when I incorporated my own background and experiences into the lessons. We're studying rocks? I'll bring in my favorite one, and tell them why. Talking about topo maps? I'll tell them the story of how useful they were in the Black Hills. Talking about hydrology? I get to talk about my time as a hydrologist, protecting drinking water. Anything to make the lessons more real and relevant seemed to work.

  • Write a syllabus that protects you. I was lucky to have a good group of students, but there was one problematic student who would miss exams and blame me for not allowing them to retake it without an excuse. I was willing to accommodate for good reason, but their complaints turned to personal attacks, and at that point I stood behind my syllabus.

  • Work harder than they do and stay positive. Never, never give them the impression that you are lazy or do not care about what you are doing. Know the lessons, and don't get caught by surprise - have an intimate knowledge of your business. Respond to emails quickly. Bring in extra material to demonstrate a hard to understand topic. Put in more effort to the class than they do. I consider this a "lead by example" approach to education. 

  • Strive for a positive learning atmosphere. Be friendly and approachable. Encourage questions, even if it might sidetrack the lesson. It's entirely possible to be professional while also joking around (my specialty is puns). Learning is fun!

Monday, January 11, 2016

Mini-drone Photogrammetry Test

Behold, my new Parrot Rolling Spider Minidrone:

The Minidrone takes its new rightful place next to the other little aircraft. Good grad office flair.

This neat little bugger has some built-in sensors and instruments which allows for some very stable flight. Combining the use of a pressure altimeter, sonic altimeter, and downward facing camera, it can hover essentially hands-free. The downward facing camera can also take meh-resolution photos, which I thought had some potential for a fun photogrammetry demo, instead of the not-so-subtly spying on my roommates that it's mostly been used for so far.

Incoming foot! Warning! Warning!

I wanted to calculate the height of something using photogrammetric principles. This is possible using geometry; the image of an object is distorted based on how far away from the center of the photo it is (the farther an object is away from the center of the photograph, or Principle Point, the greater the apparent displacement between the top and bottom of the object. Directly overhead, there is no displacement, so you can only see the top).

Using a single photograph to measure the height of an object, from "Remote Sensing of the Environment: An Earth Resource Perspective, Second Edition, by J. R. Jensen).

In the grad lab, I set up a small box, simulating a building, and had the drone fly over it (at eye-level with myself) and take a photo, simulating a low-flying aircraft. 

Building. Not to scale.

Below is the resulting photo. Notice how the box is distorted, and the distortion radiates away from the center of the photograph. Also, the distortion is greater with greater distance from the centerpoint.

Raw aerial photo from the minidrone of the study area from a breathtaking altitude of 5.5 feet.

Next, the math! Using the equation above, the height (h) of the box is equal to the lateral displacement of the top and bottom of the box (d) times how high up the photograph was taken (H) divided by the lateral distance from the center of the photograph (principle point) to the top of the box (r). 

h = (dH)/r

I was able to try this for two spots, as more than one edge of the box was in the photograph.

Aerial photo with annotations. Altitude: 5.5 feet.

Using a ruler and my computer screen, I got the following values:
r1 = 18.0 mm
d1 = 4.5 mm

r2 = 13.2 mm
d2 = 3.2 mm

H = 5.5 feet (my height)

This results in calculated box heights (h) of 1.38 feet and 1.33 feet. Let's call it 1.35 feet. So I went over to the box and measured its height as 1 foot 4.5 inches, or 1.375 feet.

In other words, an error of only about 2%. Not bad! I'll have to find some more fun ways to play with the little drone.