'Trust that the deep blue will meet you halfway'

A turning point came in 2012, when she chose to join a joint PhD program between the Woods Hole Oceanographic Institution in the United States and the Chinese Academy of Sciences under the supervision of Lin Jian, a prominent marine geophysicist.

Shifting from studying how coastlines erode to probing the mechanics of subduction zones — where one tectonic plate dives beneath another — was a major leap for Zhang. She arrived at the Woods Hole Oceanographic Institution with little background in geodynamics and no coding skills.

"Lin is extraordinarily patient and willing to teach me from scratch. He would ask if I was familiar with a concept or method, and if I said no, he would explain it to me from the beginning," Zhang said. "It was demanding, but it built a foundation I still stand on."

Working with Lin, Zhang analyzed the Mariana Trench — the world's deepest point in the Western Pacific — and published her first paper in the journal Earth and Planetary Science Letters in 2014.

But after completing a few more studies, Zhang came to realize the limitations of relying on publicly available global datasets, which were not collected to answer her specific scientific questions.

"Ocean science is an observational discipline: answering key questions requires going to sea to collect data firsthand," she said.

Because sea time is expensive and opportunities are rare, Zhang refines her scientific questions and repeatedly tests her plans before every voyage.

"Every time before leaving port, I ask myself: Will our planned survey lines and data truly align with our objectives? Can we uncover the deep structures we're targeting? Are our track lengths and site selections suitable for addressing the tectonic issues we aim to solve?" she said.

Since then, she has participated in a variety of expeditions, transitioning from an observer on land to a decision-maker on deck.

In 2014, she experienced the mature and well-established operational system of international ocean drilling aboard a research vessel. In 2018, she served as the chief geophysicist on the inaugural China-Pakistan joint voyage in the North Indian Ocean. And early this year, she led her first major research cruise as chief scientist for a key Indian Ocean expedition.

"None of this would be possible without national platforms and long-term investment," she said, adding that, from learning the ropes on major projects to striving for breakthroughs on her own, her guiding principle has been to think ahead and always give her best shot.

"The ocean doesn't give you answers easily. But if you're patient enough, it will eventually give you something back," she said.

For young people still searching for direction or just embarking on a research career, Zhang offers no formula.

"There is no standard template for a scientific career," she said. "Accept the uncertainty, find your own rhythm, and trust that the deep blue will meet you halfway."