Amgen Scholars: Announcements of Opportunity

Below are Announcements of Opportunity posted by Caltech faculty for the Amgen Scholars program.

Announcements of Opportunity are posted as they are received. Please check back regularly for new AO submissions! Remember: This is just one way that you can go about identifying a suitable project and/or mentor. For additional tips on identifying a mentor click here.

Please remember:

Students pursuing Amgen must be U.S. citizens, U.S. permanent residents, or students with DACA status.
Students pursuing Amgen must complete the 10-week program from June 21 - August 25, 2023. Students must commit to these dates. No exceptions will be made.
Accepted students must live in provided Caltech housing.

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Project:

Investigating the marine biogeochemical response to climate change through a paired kerogen-pyrite sulfur isotope proxy

Disciplines:

Geobiology, Geochemistry

Mentor:

Alex Sessions, Professor of Geobiology, (GPS), sessions@caltech.edu, Phone: 626-395-6445

Mentor URL:

https://web.gps.caltech.edu/~als/ (opens in new window)

AO Contact:

Selva Marroquin, selvam@caltech.edu

Background:

One of the most pressing questions about global climate change involves the biogeochemical response of the oceans: changing circulation, nutrient regimes, primary production, and lower oxygen all have the potential to profoundly impact the ocean’s carbon cycle, with implications not only for climate but for food production and other ecosystem services. Our ability to predict the future rests on a foundation of understanding past marine responses to natural perturbations, which in turn relies heavily on a variety of geochemical proxies. For this project we propose developing a new proxy based on the difference in sulfur isotope composition (δ34S values) between coeval organic sulfur and pyrite, that we believe will help us reconstruct past changes in carbon and sulfur cycling. While there is some uncertainty about the precise environmental controls on this proxy, it is nevertheless undeniably linked to organic carbon delivery, sulfate reduction, sulfurization, and carbon burial, i.e. key aspects of the marine system that we seek to reconstruct

Description:

We seek a dependable student who is excited to learn about the field of geobiology through the lens of sulfur isotopes. The student will work with their mentor to select a suite of marine sediment core samples to study a possible environmental control on the kerogen-pyrite S isotope proxy (e.g. sedimentation rate, iron input, or water column oxygen content). Once selected, samples will be processed through a sequential sulfur extraction procedure and analyzed on an isotope ratio mass spectrometer (IRMS) for sulfur isotopes and carbon content. The student will work directly with the mentor to learn about sulfur isotopes and investigate the variables of the project of most interest to them.

Students will gain experience with the following lab activities: literature review, lab-based wet chemistry (acid volatile sulfur extraction, chromium reducible sulfur extraction), isotopic measurements (IRMS), and data processing.

References:

https://web.gps.caltech.edu/~als/

Student Requirements:

The student should have experience in a general chemistry lab or lab course and be a respectful worker in a shared lab space.

Programs:

This AO can be done under the following programs:

		Program	Available To
		Amgen Scholars	Non-Caltech students only
		SURF	both Caltech and non-Caltech students

Click on a program name for program info and application requirements.

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