Youlin Chen is an American seismologist who has been funded by the US government to research methods for detecting nuclear tests. Photograph: Yufang Rong/AP View image in fullscreen Youlin Chen is an American seismologist who has been funded by the US government to research methods for detecting nuclear tests. Photograph: Yufang Rong/AP Human rights China has detained US nuclear seismology expert since 2024, family reveals Beijing may be using Youlin Chen’s knowledge to devise ways of staging nuclear tests without detection, advocates for his release from spying charges suggest
Prefer the Guardian on Google An American seismologist has been detained in China on espionage charges since 2024, his family has revealed, saying Donald Trump’s direct appeal for the scientist’s release to his Chinese counterpart, Xi Jinping, went unanswered.
Youlin Chen – who has researched how to detect underground nuclear tests using seismological data – was detained on 5 November 2024, according to a statement from the NGO Global Reach, which is working with his family to secure his freedom.
Global Reach said Chen’s arrest may be linked to the US government’s accusation that China conducted underground nuclear tests in violation of nuclear test bans.
“Chen’s area of expertise – seismic monitoring and detection of underground nuclear tests – would give the Chinese government an opportunity to learn as much as possible about US seismic detection methodologies so they can establish countermeasures that allow them to circumvent [the treaty],” Global Reach said.
Read more Chen was formally declared “wrongfully detained” by the US government in March, but his family chose not to announce the designation in hopes it would help state department efforts to have him released, the statement said.
Global Reach said that Trump urged Xi to free Chen during the US president’s state visit to China in May, and that the Chinese president reportedly agreed to work on the issue.
“We are now at the midpoint between the May commitment made by President Xi and his upcoming September visit to Washington DC, and the Chinese have made no apparent movement on releasing Dr Chen,” said Eric Lebson, Global Reach chief strategy officer.
Global Reach did not say why Chen was in China when he was detained or give any details of his arrest.
Chen’s wife, Yufang Rong, said she had not been able to speak to her husband for more than 600 days and was “concerned for his health and wellbeing”.
“Youlin has never held a US government security clearance and to suggest he was involved in espionage is both wrong and inconsistent with the public and collaborative nature of the work that he has done,” she said.
Chen has diabetes, high blood pressure and high cholesterol, according to a profile by the James Foley Foundation, which also advocates for wrongfully detained Americans abroad.
The US military and state department have funded some of Chen’s research, Global Reach said, and he has authored studies on using data from across Asia, including in China, “to improve methods for nuclear test monitoring and yield estimation”.
China denies it has conducted explosive nuclear tests, saying the US is seeking a pretext to resume its own testing.
The state department on Tuesday urged Beijing to release Chen. “The United States has raised Mr Chen’s case directly with Chinese officials, calling for his immediate release,” a department spokesperson told AFP by email, reiterating the call for him to b...