Dr. Christina Symons is a geologist who specializes in mapping the seafloor. Symons was a science coordinator for the DEEPSEA CHALLENGE project, which saw explorer James Cameron make a record-breaking solo dive to the bottom of the Mariana Trench.

Photograph by Joe MacInnis, courtesy DEEPSEA CHALLENGE
  • Christina’s passion is mapping the seafloor. She was recently a member of the science team on DEEPSEA CHALLENGE, National Geographic Explorer-in-Residence James Cameron’s record-breaking solo dive to the deepest known point in the ocean, the Challenger Deep.


    Christina grew up in Spring, Texas, just north of Houston. Her father was a geophysicist, while her mother worked as a registered nurse.

    Christina says she was an analytical kid who was interested in science, but she also had another passion.

    “I know I always loved the outdoors and being outdoors,” she says.

    After graduating from high school, Christina went to Stanford University in California, to study engineering. She decided to take a geology class and quickly fell in love with the subject. Christina says a teacher’s assistant in that course was an inspiration to her.

    “She was great,” Christina says. “She was a great teacher. She enjoyed what she was doing. I could totally see myself trying to emulate her, her path and her career.”

    That first exposure to geology caused Christina to change her major. She had lots of memorable experiences studying geology at Stanford.

    “Our field trips would be right out on the beach at Half Moon Bay or up in the mountains of the Sierra Nevada,” she says. “The outdoors was our classroom.”

    It wasn’t until graduate school at the University of Texas at Austin that Christina’s focus switched from terrestrial geology to underwater geology. The change occurred on her first long research trip, mapping the seafloor south of New Zealand.

    “Then I was hooked on the ocean,” she says. “Everything up until then had been land-based. Then I just fell in love with the ocean.”

    After securing her master's degree in geology from the University of Texas, Christina got her PhD in Earth sciences at the Scripps Institution of Oceanography in La Jolla, California.


    “Honestly, it’s going to new places, meeting different people, getting different perspectives. And then the best part is we are mapping the seafloor that no one has ever seen and for the most part no one has ever mapped. So we are learning something about a brand new place.”


    Sleeplessness. “There are a lot of times when you either want to stay up because you can’t wait to see what will be another few miles down the way or you have to stay up to watch the instruments and make sure everything is collecting data correctly.”


    “Initially, I think of where things are on a map. But I think it’s driven a lot more by what makes up that place on a map, the geologic makeup of it. Is it mountainous? Is it on flat plains? Are they on the ocean? Are there people there? How do they contribute to the land or take from the land?”


    One of the geographic tools Christina uses to map the seafloor is an echo sounder. An echo sounder is a device that determines depth by measuring the time for a high-frequency sound wave to reach the seafloor and for its echo to return to the instrument.

    “If you consider geography to be the study of land, people, features, how they interact and change, etc., then yes, an echo sounder certainly sheds light on the underwater features of our planet and how they have changed through time,” she says.

    GPS is also an important tool for mapping the seafloor. “It is vital to producing useful maps,” Christina says. “It’s one thing to collect high-resolution images of the seafloor, but you must know where you are on the Earth to make a useful map.”


    “It is certainly helpful to have a broad science background. For geology, knowing something about a lot of things is helpful.”


    Christina has a lot of suggested resources for individuals interested in geology. She recommends visiting museums, aquariums, libraries, and parks.

    “Any time you visit any of those [national or state parks], there is always a blurb about the geology,” she says. “Or what is going on and why is this park where it is.”

    She also mentions a handful of websites with a geology or science focus, including National Geographic, the U.S. Geological Survey, the National Oceanic and Atmospheric Administration, Scripps Institution of Oceanography, and the Jackson School of Geosciences at the University of Texas at Austin.

    Geologist Christina Symons
    Christina Symons is a geologist and science coordinator on the DEEPSEA CHALLENGE expedition.
  • Term Part of Speech Definition Encyclopedic Entry
    data Plural Noun

    (singular: datum) information collected during a scientific study.


    ongoing expedition to study the deepest point in the ocean, with a record-breaking descent to the Challenger Deep in March 2012.

    Earth science Noun

    branches of study that focus on the origin and structure of the Earth. Also called geoscience.

    echo sounder Noun

    device that measures the depth of water using sound pulses. Also called a sonic depth finder.

    emulate Verb

    to imitate or attempt to equal.

    engineering Noun

    the art and science of building, maintaining, moving, and demolishing structures.

    frequency Noun

    rate of occurrence, or the number of things happening in a specific area over specific time period.

    geography Noun

    study of places and the relationships between people and their environments.

    Encyclopedic Entry: geography
    geology Noun

    study of the physical history of the Earth, its composition, its structure, and the processes that form and change it.

    geophysicist Noun

    person who studies the material and activity of the Earth and its atmosphere.

    Global Positioning System (GPS) Noun

    system of satellites and receiving devices used to determine the location of something on Earth.

    instrument Noun


    mapping Noun

    making and using maps.

    PhD Noun

    (doctor of philosophy) highest degree offered by most graduate schools.

    terrestrial Adjective

    having to do with the Earth or dry land.