Tam on STEAM

Young Ana Christina Ravelo seemed like a natural to become a scientist.

Growing up in the Los Angeles suburb of Altadena, she excelled in math and science classes. She loved nature and outdoor activities. And beyond that, she had a striving, adventurous spirit inspired by her parents.

“Both of my parents are immigrants,” Ravelo noted. “That’s a pretty large part of my identity.” Her parents came to the United States as adults—her father from Cuba and her mother from the Philippines—and met in New York.

“I saw my parents as being very adventurous,” she said. “They came to this country with nothing. But they came with a dream. They didn’t see limits to what they could achieve. My parents told me there was no limit to what I could do.”

Ravelo followed her own dream to become a professor of Ocean Sciences at the University of California, Santa Cruz. As a paleooceanographer, she uses sediment cores from the seafloor to study the ancient oceans. By illuminating the link between past ocean conditions and changes in Earth’s climate, her research sheds light on what we can expect as our planet grows warmer.

Ravelo has become a widely respected expert in her field. In 2012 she was named a fellow of the American Geophysical Union in honor of exceptional contributions in Earth science. She also received UC Santa Cruz’s 2013-14 Outstanding Faculty Award from the Division of Physical and Biological Sciences for excellence in research, teaching, and service.


Ravelo’s parents arrived in this country with little beyond their educations. Her father was a cardiologist. Her mother was trained as a pharmacist, although she worked as a homemaker while Ravelo and her three siblings were growing up. The family settled in Altadena, just north of Pasadena.

Ravelo loved hiking, skiing, and just about any other outdoor activity. Her family took camping trips around California and into Mexico. When she was a teenager, she took up backpacking.

Her favorite classes in school were science and math. Her dad encouraged her scientific curiosity. “My father had a big impact on me because he was a doctor,” she said. “I would spend time talking to him about how the heart works and about human health.”

Science wasn’t Ravelo’s only interest. Cultural differences intrigued her. In high school she sought out books by Toni Morrison, Zora Neale Hurston, and Amy Tan. “I was interested in personal stories about race,” Ravelo said. “Because I identified pretty strongly as a minority, I was looking for those stories.”

Whatever she aspired to do, her parents stood behind her. “There was no pressure or specific expectation, but they told me that with hard work and education, I could do whatever I wanted to do.”

Ravelo attended public schools. But when it was time for high school, her parents sent her to a private prep school in Pasadena. The school was academically strong. Yet Ravelo felt out of place among her well-to-do classmates and their old-money families.

“I appreciate that I got a really good education, in terms of rigor and the quality of the teachers,” she said. “But I was also socially alienated. There weren’t a lot of families of immigrants. I definitely felt like an outsider in that school.”


For college, Ravelo chose Stanford University near Palo Alto, California. At first she wasn’t sure what she wanted to study. Traveling with her parents to Mexico and the Philippines had deepened her interest in other cultures. So she started taking anthropology classes.

But she still loved science. “At first I didn’t think about geology, except that I really liked hiking and the outdoors,” she said. Gradually, though, the subject grew on her. She decided on a double major in anthropology and geology.

She combined the two fields by focusing on paleoanthropology—the study of the early human civilizations. “In terms of geology, I was really interested in the evolution of landscapes and climate patterns,” she said. “That has a large influence on how civilizations evolved and used the resources around them.”

During her studies at Stanford, Ravelo was drawn more and more to oceanography—particularly paleooceanography. She liked the fact that the field melds many areas of science. “Oceanography has a lot of physics, math, chemistry, and biology,” she said. “All the main disciplines are folded together.”


Ravelo graduated from Stanford in 1984. For graduate school, she headed to New York City to attend Columbia University, which has a strong paleooceanography program.

Her PhD research focused on conditions in tropical seas millions of years ago. To deduce what the ancient oceans were like, she analyzed fossils of plankton found in sediment cores. “I specialized in how to interpret the different species and their geochemistry, and what that showed in terms of oceanographic and climatic changes in the tropics,” she said.

One highlight was sailing on a research expedition to drill for coral samples off Barbados. She found fieldwork exciting. “You are discovering something new,” she said. “There’s something fun about the moment when the core barrel comes up and you don’t know what you’ll see.”

Yet Ravelo felt the frustration of being a woman in a male-dominated field. There was not a single female faculty member in her department. And sometimes she endured sexist comments from male researchers.

“It was hard not having role models,” she said. “There is a lot to overcome in terms of having confidence in your abilities and knowing that you have to work hard and prove yourself because no one is going to give it to you.”

After receiving her PhD in geology from Columbia, Ravelo went to Princeton University in New Jersey for postdoctoral research. She wanted to learn to use computer modeling to analyze changes in ocean conditions.

“I had been doing very lab-based work,” she said. “I felt like it was really important to get some knowledge about climate models and ocean models. One of the most powerful ways to use data is to combine it with modeling studies.”


In 1991 Ravelo joined the faculty at UC Santa Cruz. “It was kind of my dream job,” she said. She liked the idea of coming back to California and of being part of the University of California system. Also, Santa Cruz is on Monterey Bay, a center of ocean research.

A visit to the campus sealed the deal. “I was impressed that there were eminent faculty members in Earth and Ocean sciences who had been there their whole careers,” she said. “I thought it was a supportive place, a place where I could build a career.”

At UC Santa Cruz, Ravelo has continued her work on tropical paleooceanography. The tropical oceans are a key piece of the puzzle of Earth’s climate, she explained: “The tropical Pacific is the largest ocean basin in the world. The tropics are the main source of moisture to the atmosphere. This huge mass of warm water fuels the global climate system.”

See STUDYING ANCIENT OCEANS SHEDS LIGHT ON CLIMATE CHANGE TODAY (below) for more on Ana Christina Ravelo's research.

In her early years at UC Santa Cruz, she spent long periods at sea collecting sediment cores. But after she became a mother, she switched to more lab work. She found ways to balance her research with caring for her three young children. Two of her children are now young adults, and the youngest is in high school.


While pursuing her own research, Ravelo has also worked to build ties among scientists in different fields.

From 2005 to 2011, she directed the Santa Cruz branch of the Institute of Geophysics and Planetary Physics, which fosters cooperation among university departments. She also has been a leader in the Integrated Ocean Drilling Program, an international group of scientists from various disciplines who use sediment cores to study Earth’s history.

Collaborating with people from different fields “opens up possibilities,” she said. “It enhances your understanding. If you work with people with different perspectives, you don’t get stuck thinking about things in your own way.”

Ravelo also devotes energy to encouraging up-and-coming scientists, especially women and students from underrepresented groups.

“At UC Santa Cruz, we have a lot of people who are the first in their families to go to college,” she said. She employs undergraduates from diverse backgrounds in her lab. “They need jobs and they need lab experience,” she said. “I’m really happy to be part of that.”

The graduate students and post-doctoral researchers she works with also come from a variety of cultures and backgrounds, she said. She and her lab group often chat informally about the obstacles young researchers face.

“We talk about issues of opportunity and representation and diversity, “ she said. “It’s a hands-on kind of mentoring.”

Watch a video of Ana Christina Ravelo discussing her research.



Ana Christina Ravelo has devoted years to piecing together the link between conditions in the ancient oceans and Earth’s climate.

She uses sediment cores drilled from the seafloor to reveal what the tropical Pacific Ocean was like long ago. This ocean basin has a huge impact on climate, she noted: “In many ways the tropical Pacific fuels the global climate system.”

Ravelo looks mainly at the Pliocene Warm Period, from 3 to 4.5 million years ago. Evidence from the Pliocene is relevant to current climate studies, she explained, because “it was the last time in our Earth's history when global temperatures were higher than today for a sustained period of time.”

The core samples Ravelo studies contain fossils of microscopic plankton called foraminifera. She and her colleagues analyze the fossil shells. Chemical isotopes in the shells show what conditions were like when the organisms were alive.

Her work aims to answer many questions, she said: “How have the tropical oceans changed in the past? What do they respond to? Are they sensitive to levels of greenhouse gases? Are they responsive to solar radiation changes? How do those things drive global climate patterns?”

Ravelo has discovered that the tropical Pacific was in a permanent El Niño-like state during the Pliocene Warm Period. That means the ocean was unusually warm compared to the average global temperature at the time. Climate patterns, such as heavy rainfall in some places and intense droughts in other places, were like those during an El Niño event.

As part of her research, Ravelo compares her data with complex computer models that scientists use to predict future climate change.

“By working with people who do modeling, I can compare my results to theirs and test how well the climate models work,” she said. “If the models don’t predict what happened in the past, we can understand how they might be improved to be more accurate.”

Ravelo’s research has not been confined to the tropics. In the summer of 2009, she was co-chief scientist on a research voyage to the Bering Sea, between Russia and Alaska.

Scientists on the expedition drilled down 700 meters to extract Pliocene sediment cores. Analysis of the cores showed the ancient Bering Sea was about 5°C warmer than today, while the global temperature was about 3°C warmer.

“The information we found tells us quite a bit about what things were like during the last period of global warming,” Ravelo said. “It should benefit the scientists today who are sorting out how ocean circulation and conditions at the poles change as the Earth warms.”