An Exciting China Project Update!

Hello fellow geoscientists!

It’s Sophie and Paige, working on the China Project. Sophie is a 4th year, Geology and Latin American Studies double major. Sophie just came back from studying abroad in Cochabamba, Bolivia. Paige is a 2nd year, double majoring in Geology and Environmental Studies. She spent the past summer working in the lab and preparing for her first conference!

We have been busy this semester in the lab; running samples, drafting our results, and attending conferences have kept us busy. With the addition of new gamma-spectrometers, allowing us to run four samples a day now, we have run almost 150 of our samples in the past few months. Consequently, we have started analyzing China samples and drafting our results. Paige spent long hours in the lab over the summer learning data analysis processes, so she was able to tie up some loose ends of the leached coarse-grained fractions. Sophie will be applying her GIS skills to analyze the watersheds of collection sites, which will be used in writing the radioisotope paper.

Unleached fine-grained sediment fractions (top drawer) and leached coarse-grained fractions (bottom drawer) that were recently ran in the detectors.

Interesting salt growth on dried, neutralized leachates.

In September, Paige presented our work at the Geological Society of America Conference in Phoenix, Arizona. As this was her first time attending a conference, she said “it was very exciting to see the research process unfold and discuss my work with peers in a more professional setting.” She was able to network with other geoscientists from all over the country and see the first hand collaboration with other sciences in the geomorphology field. The most exciting part of her experience was talking with graduate programs and future employment opportunities, like the National Park Service, to understand the next steps she would need to take after Oberlin. She also got the chance to meet multiple Oberlin geo-alumni and our collaborators at the University of Vermont! Overall, her experience was overwhelmingly positive, and she looks forward to presenting updated research on the China samples next year in Montreal. 

Paige presenting the China poster at the GSA conference in Phoenix.

Geomorph Family!!!!

We work hard here in the Oberlin geomorphology lab but having fun is important as well!!

Please enjoy this story by Liz, Ely (the creative directors behind this project) and Amelia.

Our Stories: 

Harbin has been alone for so much of their life but is very happy to have found a full family this past year. Harbin, a graduate of Rutgers (class of ‘77) has had an on and off residency at Oberlin, taking breaks for frequent repair. The first to join, last summer was Quincy the oven. Quincy went to Earlham with a major in Pottery and has done research in places like Antarctica, the North Slope of Alaska, and off the coast of the Bahamas. It was a rough transition here, being an inanimate object and all, but it was love at first sight. Eventually, Quincy happily announced that they had TWO buns in the oven. However, the star crossed lovers were forced to be four floors away from each other after the births of their two children: Soufriere and Cienfuegos. 

Soufriere is often described as “Mad chill and is definitely a detector I would kick it with.” Graduated in 2003 from Ithaca College with a major in Social Justice Change and Peace & Conflict Studies with a minor in the stand-up Bass. The only mistake they have ever made was frosted tips (the junior year was tough). Their twin, Cienfuegos, believes themselves to be “too cool for school” and often refuses to work. An ‘03 ASU graduate with a major in Econ but is a proud member of ΔΒϕΩ and the Lacrosse team. 

Quincy became pregnant again but unfortunately fell ill due to rust from evaporated HCl (we don’t make this mistake any more). After a 13 month difficult pregnancy, out came 112lb baby Emeishan, a literal pile of lead bricks. While we love Emeishan with all our hearts, we can’t even touch them with our bare hands due to the possibility of lead poisoning. We are so happy with our full house!

Meet the fam (with photos): 

Quincy, Long distance, loving parent

Harbin, primo parent

Cienfuegos, an airpod user

Soufiere, the good egg

Emeishan, the lovable ‘lil sibling and a pile o’ bricks

Dominica Group is Making Progress!

Hello All! 

We are really getting into the swing of things here and bringing together the Dominica Project. While this project in the past has had a lot of pathways, we are tracking down all of the samples and nailing down what needs to be done. 

As hurricanes are a repetitive part of the erosional processes on the Caribean Islands, we have been interested to see whether a single mass wasting event could be seen in the spatial weathering patterns of the island. We compared the concentrations of fallout radionuclides before and after a single storm event, Hurricane Maria. Fallout radionuclides have different half-life time scales, from millions of years (Be10) to approximately 53 days (Be7). Due to this difference, some will show the influence of the storm and some will not. Our poster that we presented at GSA built on previous research and provided a context of Dominica. This poster showed the results of having an incredibly unique data set of before and after Hurricane Maria samples on the island of Dominica. Since Melinda Quock finished her part of the study on Beryllium10, we had one full set of data to discuss at the conference and a set of beautiful figures. The preliminary Lead210, Cesium137, and Beryllium7 are hoping to be finished within the year to compare to Melindas’s work. 

Here is a current update on our results that we presented at GSA:

 As part of this study, we did GIS analysis which is a mapping tool that allows us to gather high-resolution photos. We found that landslides post-Hurricane Maria tend to be smaller but in higher density around the island and occur at higher elevations. This also leads to the fairly intuitive conclusion that an increase in activity which deforests the island would lead to greater susceptibility to mass-wasting events in the future.

Our main technique at Oberlin is Gamma spectroscopy. This is the part of the study that we are still really working but we do see preliminary data suggest low 137Cs concentration that generally indicates frequent deep landslides.

Melinda’s work at UVM showed us that the 10Be is very important in the story of Dominica but is not influenced by the single storm event.  We do not see systematic variability in the 10Be measurements which suggest that large storms do not affect the long term erosion rates. We also found an interesting result between grain size and location. An increase of 10Bemconcentration seen in coarse-grain samples post-hurricane on the north side of the island indicated that shallow erosion and longer residence time occurred in the southern part of Dominica. Additionally, the lower 10Bem concentration in coarse-grain samples on the southern side suggests lots of gullying and deeply sourced sediment mixed in after the hurricane precipitation ended. Similar north-south trends are seen in 10Bem concentrations in fine-grained sediment but are not as strongly correlated.

We are really excited to keep up with this project and keep discovering fun new elements of Dominica. 

- Liz, Ely and Amelia



 Emily, Paige and Amelia checked out the geology of Phoenix on a hike while at GSA!


Here is our very large Dominica poster!

Fall Semester Lab managing: Learning to babysit 4 temperamental Germanium Detectors

Hello adoring Geomorph Blog fans! 

This is Monica, checking in with my main project for the semester which is lab managing for our Research Advisor, Amanda. While she’s gone in China, I’ve been taking on some of the on-site lab responsibilities, which mostly involves running meetings and keeping an eye on the lab equipment and spaces. This post is a behind the scenes look into running a lab, and will mostly give y’all a sense of some of the equipment behind the work that we do.

The largest change from past semesters to this semester is that we finally have all four of our Germanium detectors operational, largely thanks to some stellar technicians at Canberra. Our system is interesting because it was pieced together gradually, instead of being purchased all at once. Since a lot of our equipment was bought from labs around the country, it is in different models, shapes and sizes while all performing the same detecting task. I’ve definitely had some hilarious calls with the technicians where they have to pull out a special guide for the more “analog equipment”.

Our HVP Supplies show the analog vs. digital charm:

Our detectors are a combination of vertical dipstick and horizontal dipstick, which basically means that the long pole that is the detector either conducts measurements on a table with the end sticking into a dewar of Liquid Nitrogen below, or the dewar and the detector sit horizontally to one another. 

  

Top: horizontal dipstick, Bottom: vertical dipstick

The original detector, Harbin, has its own independent high voltage power supply and multi-channel analyzer, which I had largely taken for granted as very simple in my first three years in the lab. The other three use a system that is a combination of amplifiers, high voltage power supplies, and a multiport channel analyzer all in slightly different boxes that are pinned into one large box. While this system does involve needing to remember each of the unique high voltage power levels that apply to each detector, it is fantastic in that it breaks out in more detail the components that are needed to run each detector. The high voltage power supply is unique to the electronics of each detector and the amplifiers must be set to the exact setting where their analysis lines up with the peaks of the isotopic measurements that we are collecting. 

Above: the components that supply the proper voltage for each detector are on the top of the array, with the bottom row amplifying and tuning the signals from the detectors for input into the 4-detector multiport.

Being able to see the components of the electronics broken out was enormously helpful in understanding the hardware required to take isotopic measurements, and the relationship between the tuning of the detectors and the results that we get afterward when we analyze the curves produced by each sample. At a time when we are running so many interesting projects and samples, knowing that the detectors are functioning efficiently is critical to our results, and I’m thankful to play a part in that!

Stay tuned for more lab updates!

-Monica

Above: Soufriere and I have reached an understanding about troubleshooting some minor issues with her energy curves and agreed to be chill for now, further calibration on the horizon.

Round 1/3 of answering: Has organic agriculture slowed erosion in Cuba?

Hello all! 

It’s Monica and Emily, and we are excited to update you all on the latest presentation of data from our lab’s work in Cuba. After visiting Western Cuba to collect more new samples, we were thrilled to double back to share some of what we’re learned from our first set of samples, and what we’re eager to learn about our newest set that we’ve collected.

Above: Map of our August 2018 and July 2019 sample watersheds

To give you a refresher: After Cuba transitioned to organic agriculture from sugarcane monoculture after the collapse of the Soviet Union, as a country it presents a unique multi-decadal opportunity to assess the impacts that sustainable agricultural techniques have on erosion. A major part of our process has been collaborating internationally across multiple institutions to get a full picture of Cuba’s rivers including water quality and cosmogenic erosion rate sampling, and this data only represents the first of three field seasons in the project.

With our main question being what the effect of transitioning to organic agriculture had on Cuba, we sampled large (250-850 micron) and small grained (<63 micron) samples from 26 different catchments. With our central question focusing on land use, the variety of land uses depicted in A-I in this second figure show the intense variety in land use type. Another complication was the persistence of sugarcane-based monoculture in certain areas, which adds complexity to our results.

Above: Sites labeled A-I show different sites in the 26 catchments that were sampled

Below: Spatial Distribution of isotopic results for both fine and coarse-grained fractions

Our results show some very interesting trends. When showing things from a spatial perspective above, we notice that there were diverse spatial patterns for each isotope. 7Be was higher in fine grained samples, but had no overall detectable spatial pattern, with few samples having detectable 7Be. 137Cs was detectable in about half of samples, coarse and fine grained activities were uncorrelated, and there were no spatial patterns. 210Pbex was detectable in about 60% of samples, with no spatial patterns or correlation between coarse and fine grained activity and the fine grained activity was higher.

We considered instead that the relationship might be better understood through environmental factors, but ran into the issue that these factors often covary (ex: slope and % agricultural land use), so it was difficult to parse out correlation and causation.

Below: Activity by different types of environmental factors

Some of our findings from the above analysis were that elevation, slope, area, and agriculture may be directly related to 210Pbex activity, but as mentioned above covariance complicates the analysis. Additionally, coarse-grained samples may provide more insight into causality due to higher variability in activity. Among the factors, we noticed that sites with 7Be, 137Cs, 210Pbex have more agricultural land, lower slopes, sites with isotopes below detectable levels tend to have more rain, and sites with only 210Pbex have higher slopes and less agriculture than sites with 137Cs and 210Pbex.

To continue with our work, we are excited to have not only rerun some of our samples that were below detectable levels, but also to have now run all the samples from our 2nd field season! As our third and final field season is in planning, we are excited to get moving on some data analysis to hopefully continue to draw more informed conclusions about erosional patterns in Cuba!

Until next time,

Emily and Monica

Miscellaneous China Samples Update!

Hello from Paige, Zoe H, and Zoë MDC!

The geomorph lab would like to welcome Zoe H. and Zoë MDC, who began working in the lab this spring semester! Zoe H is a second-year who worked in the lab over winter term. Zoë MDC is a first-year from Brooklyn, NY who is planning on majoring in biology on a pre-med track. Paige and Zoë MdC went on the “Parks and the Environment in Sichuan, China” winter term trip with Professor Amanda Schmidt.

During the trip in Sichuan, we visited some of China’s national parks, nature reserves, and UNESCO world heritage sites. We learned about and engaged in aspects of ecotourism, resource management, and environmental ethics throughout many mountainous hikes and guided tours with a focus on geology, sociology and religion. We were able to collect about 20 water samples and 6 sediment samples from streams and tributaries (referred to as SC), and these are one of the sets of samples we have been working with this semester. The other set of samples from China that we have been working with so far are from Jinsha (referred to as JS).

We are working with these samples to analyze fallout nucleotides in the soil which will tell us about the erosion rates within these areas and how/if erosion has changed over time. In the lab we have spent most of our time organizing samples, wet sieving the SC samples, and running the samples in detectors to measure Pb210 and Cs137 isotopes. For the rest of the semester, we plan to run all of the SC and JS samples of less than 63 micrometers in the detectors and analyze the data, then do the same for another set of China samples labeled YJ.

WT trip member Kayla collecting a sample in Sichuan

Paige helping collect a sample in Sichuan 

JS samples waiting to be ran in the detectors

Thank you for tuning in for our update!

Winter term on campus

Hi from Zoe and Emily!

We stayed on campus for winter term this January working in Amanda Schmidt’s research lab, so here’s a little update on what we were up to:

During the first week, we were lucky to be able to work with our lab mate Marcus Hill before he went abroad to London for his last semester here at Oberlin! This meant we were helping him on his Dominica project. We did a lot of smashing of dry leachate samples with a mortar and pestle which was a bit tedious but still very fun. After getting through a number of those, we measured and recorded their heights and weights. When we were not grinding leachate samples, we cleaned up our Geochem lab and also ran Cuba samples everyday through our trusty Gamma Ray detector, Harbin!

After Marcus left, we worked a bit on the Cuba project. Our lab collaborates with Oberlin alum Mae Kate as well as Professor Paul Bierman at UVM. They needed some 250-850µm samples sent over, so we ran them through Harbin, collected weights and heights, and Zoe worked on the angle calculations.

The rest of our time on campus consisted of autoclaving many China samples and putting them into new sample bags and new containers!

     

Thanks for tuning in!