How Do Underground Fluids Trigger Earthquakes? Tokyo Study Explains

University of Tokyo scientists have mapped subsurface water and high-pressure fluids, revealing a hidden pathway linking deep Earth processes with earthquake activity.

Their imaging approach promises better hazard prediction and the identification of untapped geothermal energy, according to a study published in Communications Earth & Environment.

The research, led by Professor Takeshi Tsuji, stands out for tracing supercritical fluid networks and showing their surprising influence on seismic events.

Advanced seismic imaging and machine learning enabled the team to see fluid reservoirs, pathways, and pressure changes in unprecedented three-dimensional detail.

What Did the Tokyo Researchers Actually Discover?

The University of Tokyo team used arrays of seismometers and artificial intelligence to map how subsurface fluids move beneath volcanic regions.

These fluids, trapped far underground, flow through faults and fractures, sometimes accumulating in areas where immense heat and pressure create supercritical conditions.

By analyzing seismic data at fine scales, researchers identified the specific locations and volumes where these trapped fluids likely enhanced the likelihood of earthquake occurrence.

Their efforts uncover direct connections between hidden fluid networks and seismic hazards, offering a path to more localized early warning systems.

Did you know?
Supercritical water, found deep underground in volcanic zones, can hold twice as much heat energy as normal water, making it a promising target for renewable power generation and scientific study.

How Do Supercritical Fluids Change Seismic Activity?

Supercritical fluids act as both liquid and gas due to extreme depths and temperatures in the Earth's crust. The team showed that as fluid escapes or migrates, it can lubricate faults and alter the brittle-ductile transition zone, where rocks change from seismically active to more stable.

Professor Tsuji explained that these fluids, by moving rapidly through rock, can trigger earthquakes if they reach zones already close to failure.

This process alters traditional understanding of how seismic energy builds up and is released, shifting focus onto fluid pathways as much as fault lines.

Why Does Heavy Rainfall Increase Earthquake Risk?

The study highlighted a striking link between seasonal rainfall and seismic events in volcanic areas. Heavy rain increases groundwater and boosts pressure in subsurface cracks. When faults are near breaking point, that extra pressure from rainwater can tip the balance, setting off earthquakes.

The rainfall-to-seismicity connection is particularly pronounced where volcanic activity means there are already more fluids and weaker rocks.

This knowledge could lead to region-specific earthquake and eruption warnings based on weather and fluid pressure data.

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Can Fluid Imaging Unlock Sustainable Geothermal Power?

Beyond disaster alerts, mapping hidden fluids may enable safer, more efficient access to geothermal reservoirs. The Japanese team pinpointed supercritical water reserves beneath hard caps, indicating vast clean energy potential that does not disturb surface hot springs.

By visualizing how fluids are trapped, stored, and released, researchers believe it is possible to locate productive drilling sites for geothermal plants.

Accessing these deep resources could help meet Japan’s ambitious renewable energy targets while minimizing environmental disruption.

What Are the Technological Challenges and Next Steps?

Harvesting energy or predicting quakes using subsurface fluids is technologically demanding. Fluids at supercritical temperatures and pressures create hazardous working conditions, requiring advanced materials and well designs to withstand the harsh environment.

While the newest seismic imaging and AI tools have opened up new possibilities, researchers emphasize that multidisciplinary advances in drilling, monitoring, and risk management will be necessary to translate these discoveries into practical solutions for both energy and safety.

With each advance in subsurface fluid mapping, the tools to predict earthquakes and tap clean geothermal power become more sophisticated.

Tokyo’s research could inspire a wave of innovation, unlocking the Earth’s hidden energy and helping societies better prepare for seismic risks.