What’s Earth cooking? Stanford’s Ayla Pamukçu wants to know
As a young adult, Ayla Pamukçu found herself at a crossroads between college and culinary school. Thanks in part to an influential box of rocks, she chose a research path that eventually led to a career studying the inner workings of the Earth.
Ayla Pamukçu, an assistant professor of Earth and planetary sciences, first became interested in geology because of a simple contribution to her curiosity: A family friend gifted her a box of rocks and minerals. As a 7-year-old, she found the sparkling, colorful, complex collection fascinating.
As she grew older, Pamukçu kept turning back to that collection, eventually learning enough about its contents to create a display at her local public library. She recalled adding to the assortment over time as a side project while she pursued other interests.
“Minerals have this really beautiful symmetry and I ultimately realized that I liked the symmetry,” Pamukçu said. “I also liked that they’re basically the result of chemistry – they formed without influence from human hands, and their colors and symmetry came from complex chemical processes.”
In her office at Stanford, Pamukçu is surrounded by samples from around the world. Bearing basalt in her ears and a quartz crystal around her neck, she lights up when discussing their origins and doesn’t hesitate to name her (many) favorites. Having found a connection to Earth sciences at a young age, she has made it her mission to help the next generation find their box of rocks – literal or metaphorical.
“Many years later, the person that gave me the box of rocks told me he’d given such boxes to lots of kids before, but I was the one that did something with it,” she recalled. “So many kids find rocks and minerals exciting. I really want to understand why that fascination goes away, so I am passionate about interacting with K through 12 students and fostering their curiosity about geology and the natural world around them.”
As part of the Earth and Planetary Sciences Department in the Stanford Doerr School of Sustainability, Pamukçu sits amongst researchers working to fathom the history of the Earth and other planets. Their efforts lay the foundation for insights into present-day sustainability issues like sea-level rise, climate change, natural resources, biodiversity, natural hazards, and more.
While many faculty in the department explore parts of our history that have had profound evolutionary consequences over geological time, Pamukçu mainly focuses on volcanic activity that has arguably had some of the most immediate impacts on Earth’s past: supereruptions. These gigantic, explosive volcanic eruptions release so much magma that the Earth below collapses, and a crater-like caldera is left in its wake.
Supereruptions have occurred many times in Earth’s history, according to the rock record, but not in recorded human history. Experts in the field are working to understand what might be going on underneath the Earth’s surface today and what it can tell us about future supereruptions.
“Usually when we think of eruptions, we think of volcanoes like those on the Big Island of Hawai’i or Mount St. Helens. Typical eruptions from these volcanoes can have big impacts, but they are actually relatively small eruptions,” Pamukçu said. “The main difference is the amount of magma that gets erupted – a supereruption involves three to four orders of magnitude more magma than the more common eruptions we are used to hearing about in the news.”
Defined by violent outbursts of hundreds to thousands of cubic miles of magma over a period of days to a year, a supereruption could bury vast areas in thick ash and saturate the atmosphere with gases that drastically affect the global climate. While supereruptions have occurred worldwide, scientists say the likelihood of one occurring imminently is extremely low.
But any kind of eruption is exciting to a volcanologist.
“There’s nothing as impactful as seeing magma come out of a volcano – you see the inside of the Earth coming out. It’s truly awe-inspiring,” Pamukçu said. “And every time there’s a volcanic eruption, I’m jealous that I’m not there. I promised my mother at some point that I would focus on systems that are extinct, or at least dormant, for her sanity. And those systems are exciting – there’s still so much to learn. But, secretly, I’d love to work on the active ones, too.”
Pamukçu’s work has taken her to places nearby, such as Long Valley in Bishop, California, and far from home, including to Taupō in New Zealand and even Antarctica. One new aspect of her research involves figuring out the similarities and differences between the more typical eruptions and supereruptions.
“Understanding the small eruptions is in some ways what we care about more because those are the ones we encounter most frequently,” Pamukçu said. “I am interested in understanding if and how supereruptions are related to smaller eruptions and how our understanding of each type of eruption informs us about the other.”
One of her recent publications explored two different-sized ancient eruptions in the Taupō Volcanic Center in New Zealand. The team’s findings showed that the magmas that produced both eruptions sat in the crust for roughly the same amount of time before erupting.
“It suggests that a shorter magma residence time doesn’t mean it will be a smaller eruption. It seems that there’s something else that controls whether or not it’s going to be a gigantic eruption or a smaller one,” she said.
Crystals like the ones Pamukçu collected as a kid make projects like this one possible. By measuring the sizes and compositions of crystals in volcanic rocks, as well as the compositions and shapes of their inclusions – little blebs of magma and other minerals trapped inside them, scientists can estimate conditions such as the magma’s temperature, the depth at which the magma was stored underground, and the time over which it was stored before being erupted.
“We can take a crystal and cut it in half and image it, and then we can analyze different parts of the crystal and estimate temperatures and pressures and also look at changes in the magma through time,” she said. “When we do that with many different crystals, we can see trends and patterns and complexities.”
Founding a technique
Another tool used in Pamukçu’s lab is one that she helped to conceive as an undergraduate – and that also fueled her passion to continue research in geology.
“I didn’t actually think I would go into geology, but my in my first quarter, my academic advisor recommended that I try the geology intro sequence,” said Pamukçu, who earned a BS from the University of Chicago. “I did terrible in those classes, but I really liked the department. It was similar to the department here, in that it was a small student-to-faculty ratio, so you could easily get involved in research and interact with faculty and graduate students.”
Pamukçu’s undergraduate research involved regular visits to the Advanced Photon Source at Argonne National Laboratory, a 30-minute drive from the University of Chicago. Her work at the synchrotron there – a machine that creates high-intensity X-rays from an accelerated beam of electrons traveling around a large ring – helped pioneer the application of a technique known as X-ray tomography or Micro-CT to investigate rocks and crystals in 3D. Now, it’s a critical tool in her wheelhouse.
“We’re basically doing CAT scans like they would do at a hospital, but on a rock or crystal instead of a person. The technique enables us to look inside a material and get three-dimensional data without having to destroy the sample,” she said. “It allows us to see things inside of rocks and crystals and get really precise constraints on textures – shapes, sizes, and positions – of things we see in ways that we otherwise wouldn’t be able to do using more traditional techniques.”
Paying it forward
With these increasingly sophisticated toolsets, more of Earth’s history can be revealed. And, Pamukçu hopes, more students will find their way to the Earth sciences.
For her, that journey involved exploring several of her passions. When it was time to graduate high school, Pamukçu was nearly as interested in cooking and archaeology as she was in rocks and minerals. After deciding to keep her kitchen experiments casual, she took a similar approach to learning about rocks: Before committing to life in academia, she followed her curiosity.
In high school, she had an opportunity to work in a fluorite mine for a summer. As an undergrad, she got involved in research on magmas in her department and did research on the crystallization of rubies in Myanmar during a summer Research Experience for Undergraduates (REU) at the American Museum of Natural History. Finally, when a Fulbright grant brought her to Turkey, Pamukçu explored the intersection of archaeology and geology for a year.
“They were all awesome experiences that did and continue to influence and shape me,” she said, “but I ultimately decided that I wanted to pursue graduate school in geology because there was just still so much more about magmas and minerals that I wanted to learn.”
Pamukçu wants other people to see what geology has to offer and for kids enamored with rocks and minerals to keep at it. So, she is involved with several programs aimed at exposing a diversity of students to geology, including Skype a Scientist, Letters to a Pre-Scientist, the Bay Area Science Festival, and the Sustainability Undergraduate Research in Geoscience and Engineering Program (SURGE).
“I was fortunate to grow up surrounded by an enormous diversity of people who exposed me to so much,” Pamukçu said, “In turn, I want to expose as many people as I can to the excitement that rocks can bring.”
She also sees opportunities for students already studying disciplines like computer science, chemistry, materials science, and biology to find intersections with geology. “One of the things I love about geology is that it’s an applied science. We can take fundamentals from fields like physics and chemistry and biology and apply them to understand Earth’s past and get ideas about what might happen to the Earth in the future,” she said.
“We go out to the field, we do experiments in the laboratory, we use instruments to analyze materials from the macro to micro scale, we do things with computers like image processing and numerical models. There’s a place for every type of interest in this realm of research and we can collaborate with such a wide variety of people – I want students to see that.”
To read all stories about Stanford science, subscribe to the biweekly Stanford Science Digest.