Name: Caroline Hung
Degree: 2nd year Ph.D. student, Geochemistry in Earth and Planetary Sciences
Hometown: Kenmore, WA
How did you become interested in Earth and Planetary Sciences and please share with us why you chose UCR to pursue your Ph.D.?
Hardly ever exposed to nature as a kid, I was raised in the crowded urban city of Taipei, Taiwan. After elementary school, my family immigrated to the rainy Pacific Northwest. There, I was immediately drawn to the lifestyle inspired by Lake Washington, the lush forests and mountain ranges. I started to feel a geographical and spiritual connection to the land. When obstacles as a first-generation immigrant stressed me out, I would retreat into the beauty of nature.
Because I was both equally drawn to subjects in the humanities and the sciences coming out of high school, I chose to attend a liberal arts school in rural western Massachusetts for college. After stumbling across a course on natural disasters, I became drawn to the Earth Sciences major. Earth and Planetary Sciences (EPS) is intriguing to me as a multidisciplinary subject, because it ties together biology, chemistry, and physics, but also added in are the spices of adventure and exploration with the crucial field component. I am a hands-on learner, so I quickly realized that I learn more efficiently and on a deeper level when I combined field sampling and lab analyses as I started to engage more in the scientific research process.
When senior year rolled around, I knew that I want to keep doing research in an institution that is competitive, innovative and supportive of DEI (diversity, equity, and inclusion). Because I was both an Earth Sciences and Biology major, I knew I wanted to study the co-evolution of earth environments and life. UCR EPS is in the forefront in this field. After a visit to UCR hosted by Dr. Tim Lyons, I was immediately impressed by the caliber of research done here. But mostly, the friendly and supportive environment of the UCR EPS faculty and grad students are definitely what sold me that I would be very happy here.
What are your research interests and what your current research is about?
I am interested in answering research questions in geobiology with a geochemical approach. Basically, how life on Earth has been affected by changes in the environment-- either in the deep geological time scale (think rise of oxygen or mass extinctions) or the modern (think climate change, often interpreted as the "6th extinction"). The way I think about these "changes" is through the tools (e.g., trace metals, isotopes and radiometric dating) and principles (e.g., weathering and biogeochemical cycling) of chemistry to describe mechanisms behind major geological systems such as the Earth's crust and its oceans.
Currently, I have projects both in the ancient and modern. The former focuses on using redox-sensitive trace metal isotopes to study the redox state (i.e., how oxygenated was the water column?) of past oceans, specifically during the period of the Lomagundi. This is a critical period right after oxygen rose to a critical threshold 2.4 billion years ago, which is linked to the origination of complex, multicellular life. The latter focuses on studying and monitoring biogeochemical cycling in the drying Salton Sea, a hypersaline, eutrophic lake straddling between Riverside and Imperial counties.
The Salton Sea is about 2 hours southeast of UCR. What threatens the communities surrounding the Salton Sea? Take us through that system’s biogeochemistry and what you hope to accomplish with your research.
Due to changes in irrigation policies in the late 1900s, the once flourishing desert vacation spot has turned into an environmental wasteland with limited inflow. Excess nutrient run-off from the vast nearby agriculture has led to eutrophication of Salton Sea surface waters by primary producers, which results in oxygen depletion of the water column after bacterial decomposition of the algae. The Salton Sea water level is reducing at about 1ft/year (USGS) due to rapid evaporation in the intense desert heat. With salinity about twice that of the Pacific Ocean, the solubility for dissolved oxygen has also decreased.
The intense depletion in oxygen in the Salton Sea has led to two phenomenons that we are interested in studying: 1) the spatial distribution and concentration of toxic metals (e.g., Se, As, Pb, Mo, etc) accumulated in bottom sediments knowing that these metals have higher binding affinity to anoxic (without oxygen) sediments, and 2) the sulfur cycle when anaerobic microbial sulfate reduction takes over in the bottom anoxic waters. The excess accumulation of hydrogen sulfide as products of such metabolism gets released in surface waters during summer upwelling events from wind intensification and leads to a variety of ecological and quality of life detriments. Detailed water column chemistry in the temporal and spatial sense have not been produced since the last decade due to the difficulty to put a boat in the waters with unusable loading docks and hard-to-combat mud. However, with some effort, we are now able to use an inflatable Zodiac and outboard now to survey the waters.
Starting this summer, we have repeatedly surveyed the waters of the Salton Sea in parameters such as dissolved oxygen, salinity, oxidation-reduction potential, and dissolved organic matter. We will continue to build our "repertoire" of monitoring equipment and protocols, including hydrogen sulfide concentration detection to collaborate with SCAQMD's forecasting models. We hope our scientific efforts and communication could provide incentives for the surrounding community as well as local and regional authorities to act on sustainable, informed remediation efforts to combat the health hazards associated with the drying of the basin within the next century.
By interfacing with extensive stakeholders on the Salton Sea project—scientific, political, campus, and community— your work shows great commitment to social advocacy. Describe how this experience is shaping you as a scientist and a leader in this field.
I always think that scientists would have failed to fulfill their "civil obligation" if they did not attempt to share their findings with the public. I fell more and more in love with and excited about the Salton Sea project, because this work has important overdue societal impacts for our local community. At first, I was a little intimidated by the necessity to engage with extensive stakeholders on this project more so than any other project I have worked on as a geologist. But now, I do take full advantage to advocate for the Salton Sea by presenting informed findings and predictions.
Day-to-day work as a scientist could be isolating if you think about it-- from the field, lab to hours sitting in front of the computer, there may not be a lot of human interactions involved and it is easy to lose the sense of the greater context, or "purpose". Interfacing with multiple facets of engaging parties on this project has allowed me to think on a bigger picture beyond the numbers and nitty-gritty chemical equations, on how to carefully form words such that they are clear and understandable to people in policy or the community, and also on how to handle projects in a timely and ethical manner such that deadlines are met in collaborations. I am lucky to be able to truly practice and challenge myself on this with my participation in the Salton Sea Task Force organized by UCR's EDGE (Environmental Dynamics and GeoEcology) Institute. This is a think tank of a group of UCR scientists in disciplines across Earth and Environmental sciences, Economics, Policy, and Human Health to identify and carry out the most challenging research gaps in the Salton Sea crisis.
Where do you see yourself after completing your Ph.D.?
Because I came directly to graduate school after undergraduate, it is a little weird to think that I've never stopped being a student in my 23 years of life. The academic institution has always been my main support even when I felt like everything else in life was falling apart. My daily headspace has always been fulfilled by learning and thinking deeply. While the idea of working for the industry or for the government or private research entities do entice me, I would really strive to end up teaching in an institution that focuses on undergraduate education. I was a product of a liberal arts education that focused on teaching undergraduates, and have really gained from professors and fellow students who have first believed in me before I did myself. I have been graced with opportunities provided from professors who truly cared about their students and reached out. It would mean the world to me to help young students feel that way as I encourage and help them to find their calling and self-efficacy-- whether it is within the sciences or beyond.