Gone, But Not Forgotten...

Frasier Liljestrand

Frasier Liljestrand

Former Graduate Student

Frasier got his BS in Earth Science from Rice University in 2013. While he was at Rice, he did research in biogeochemistry focusing broadly on trying to quantify global carbon fluxes and budgets. Here in the Johnston group Frasier hopes to expand his knowledge of global sulfur cycling and how the global cycles are expressed locally.

M_Miller

Matthew Miller

Former Undergraduate Research Assistant
My work mainly focuses on establishing novel mineral proxies to track sulfur cycle dynamics in deep time, notably carbonate-associated sulfate (CAS). This system, alongside the robust yet infrequent barite record, potentially represents a powerful way to track sulfur and oxygen isotope behavior in order to constrain marine chemistry in the past. Additionally, I have started some culture work with the sulfate-reducing bacterium Desulfovibrio vulgaris, and am currently investigating the evolution of its isotope-fractionating metabolism.
Alex Morgan

Alex Morgan

Former Thesis Student

Alex is now at Cambridge University working on her master's degree.

Tor O'brien

Former Thesis Students

Now a PhD candidate at Washington Univesrity in St. Louis working with Dave Fike

Beck Saine

Beck Saine

Former Undergraduate Research Assistant
he/him/his or they/them/theirs
Beck is a rising junior at Harvard College pursuing a joint concentration in Chemistry and EPS. He is starting as a research assistant in the Johnston Group in summer 2020 with plans to explore multiple topics within the realm of biogeochemistry. Broadly, his academic interests include (bio)geochemistry, atmospheric & ocean chemistry, glaciology, and environmental science education.
Joseph Shaffer

Joseph Shaffer

Former Undergraduate Thesis Student

Joe was an undergraduate concentrating in earth and planetary science with a secondary in chemistry. His thesis is a paleoenvironment study of the...

Read more about Joseph Shaffer
Anna Waldeck

Anna Waldeck

Former Graduate Student
Now a Post-Doctoral Fellow at Northwestern University

She/Her/Hers
Anna completed a BSc in Chemistry and in Geophysical Sciences at the University of Chicago in 2014. Since 2013 she has worked in a stable isotope ratio laboratory there, measuring oxygen isotope ratios in phosphates contained in small shelly fossils and tooth enamel. Anna’s interests pertain to reconstructing chemical cycling in ancient environments through a combination of field work and laboratory techniques.

Scott Wankel

Scott Wankel

Former Postdoctoral Fellow

Now on the faculty at Woods Hole Oceanographic Institute.

Lewis Ward

Lewis Ward

Former Post-doctoral Fellow
I combine approaches from the bio- and geo-sciences to address big-picture questions about the history of life on Earth and the potential for life elsewhere. This research is motivated by a desire to understand how life and the planet have changed together through time to reach the state that they’re at today and how that might be different on other planets where the environmental context for life or evolutionary contingency differ. My primary research goal is to understand the origin and evolutionary history of major metabolic pathways that have defined the primary productivity of the biosphere, such as photosynthesis, methanogenesis, and nitrogen fixation. These metabolisms have fueled life on Earth for most of its history, but were not all present at the origin of life. Instead, evolutionary innovations have accumulated through time, gradually increasing the productivity of the biosphere to what it is today. Understanding the origin of these metabolisms can help us to understand how and when life on Earth became productive and began to drive geochemical cycles, and will help us to predict how life may evolve on other planets.
Weiqi Yao

Weiqi Yao

Former Post-doctoral Fellow
I am interested in global biogeochemical cycles, seawater chemistry, and paleoclimatology on various geologic timescales. Stable isotope geochemistry and numerical modeling are the primary techniques for my research. My current project focus on the high temporal precision triple oxygen isotope record in marine sulfate across the Paleocene-Eocene Thermal Maximum. The primary goal is to reconstruct Earth’s past atmospheric compositions, volcanism, and biospheric activity.

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