Ph.D. Snapshot: John Michael Zayac (Earth and Environmental Sciences)

April 25, 2017

Profile of John Michael Zayac, Ph.D. student in Earth and Environmental Sciences.


Modesto, California.

I earned a B.S. in Earth Science from the University of California, Santa Cruz and a M.S. in Geological Sciences from the University of California, Santa Barbara.

I relocated to New York City three years ago and currently live in Brooklyn.

Research interests:

My primary research interests are in volcanology and igneous processes, particularly related to explosive eruption trigger mechanisms and eruption dynamics.
Why he chose to study at the GC:

First was the opportunity to tackle this Cosig¼ina project with my advisor, Professor Marc-Antoine Longpre (GC/Queens, Earth and Environmental Sciences).

Second was the multidisciplinary nature of the Ph.D. Program in Earth and Environmental Sciences. The program encompasses a wide range of disciplines, including human geography, urban environmental science, and classical geology, making it a good home for intellectually curious students.

The flexibility of the curriculum has also allowed me to take advantage of several amazing opportunities, such as attending a weeklong workshop on instrumentation at UCLA and participating in a three-week NSF Chief Scientist training cruise from Honolulu to San Diego aboard the R/V Sikuliaq.

The link to the greater CUNY system was the third major factor in my decision. Prior to moving to New York, I worked as a community college geology professor in Los Angeles. When choosing a university in which to pursue my Ph.D., I wanted to ensure that I would continue to have the opportunity to teach and mentor undergraduates in a diverse, public institution.

Research project:

My dissertation research seeks to characterize the mechanisms that cause volcanic systems to go critical: triggering an explosive eruption. In October 2016, I conducted field research in Nicaragua focusing on large, prehistoric eruptions of Volcán Cosigüina.

The most recent eruption of Cosigüina, in 1835, erupted approximately 6 km3 of ash, six times larger than the 1980 Mount St. Helens eruption. The eruption was well documented and dispersed ash across Central America, potentially as far away as Colombia and Jamaica.

Locally, the eruption was devastating, sending hot, dense clouds of ash and debris called pyroclastic flows down its slopes. Large charcoal tree trunks embedded in the pyroclastic flows demonstrate the force of the blast and the intense heat involved.

Examination of the stratigraphy around Cosigüina indicates that several larger, prehistoric eruptions have occurred. Using fine-scaled stratigraphy, I am applying a combination of field and analytical methods to study the state of the magma reservoir immediately prior to and during these eruptions in order to determine the potential eruption triggers. The identification and understanding of eruption triggers is important to monitoring volcanic systems and to assessing the hazards associated with them.

Currently teaching:

I teach in the School of Earth and Environmental Science at Queens College. In past semesters, I have taught Physical Geology (GEOL 101) and Earthquakes, Volcanoes, and Moving Continents (GEOL 016). For the Spring 2017 semester, I will be teaching a course in Natural Disasters (GEOL 012).

Career goals:

After graduation, I intend to seek out a faculty position at a public college or university where I can continue to combine my passion for delivering quality, undergraduate STEM education with my unending curiosity about explosive volcanic systems.