New Insights into the Kaiser Effect: Stress Memory in Olivine Under Mantle Conditions

Recent research conducted by a team from Ehime University has confirmed a stress memory effect in olivine, a mineral found in the Earth’s mantle, at upper mantle pressures and temperatures. This phenomenon, known as the Kaiser effect, suggests that seismic activity may only occur when the previously recorded maximum stress in geological formations is surpassed. This study, published in the *Geophysical Research Letters* on June 12, 2025, represents a significant advancement in understanding seismicity in subducting slab regions.

For decades, the Kaiser effect has been pivotal in geotechnical engineering, particularly for estimating in situ stress magnitudes in crustal rocks and forecasting earthquakes. Traditionally, the Kaiser effect had only been verified at room temperature through laboratory experiments. However, the recent findings by researchers led by Dr. Tomohiro Ohuchi at Ehime University offer new evidence that this effect persists under extreme conditions typical of the Earth’s upper mantle.

According to Dr. Ohuchi, “The successful confirmation of the stress memory effect in olivine at such elevated pressures and temperatures could enhance our understanding of seismic zones, especially those located at subducting slabs where these minerals are prevalent.” The research utilized a state-of-the-art large-volume deformation apparatus combined with microseismic monitoring techniques to observe the behavior of natural olivine samples subjected to conditions mimicking those deep within the Earth.

The implications of this work extend beyond academic interest, as it offers valuable insights for earthquake forecasting and risk assessment in populated areas above seismic zones. The Kaiser effect’s predictive capabilities could potentially lead to improved models for anticipating seismic events, which is crucial for disaster preparedness and mitigation.

Dr. Lisa Lock, a scientific editor involved in the study's review process, emphasized the importance of this research, stating, “Understanding the stress memory effect in geological materials like olivine is key to unraveling the complexities of seismic behavior in the Earth’s crust.” Furthermore, the findings could stimulate further studies into the properties of other minerals under similar high-pressure conditions, potentially unveiling new aspects of Earth science.

This research aligns with ongoing efforts by the scientific community to enhance predictive capabilities regarding seismic activity. The study not only adds to the body of knowledge regarding geophysical processes but also illustrates how fundamental research can have practical applications in safeguarding communities from natural disasters.

In summary, the confirmation of the Kaiser effect in olivine at upper mantle conditions represents a groundbreaking advancement in geotechnical engineering and seismology. As researchers continue to explore the intricacies of Earth's materials, such studies hold the promise of improved understanding and preparedness for the seismic phenomena that impact millions worldwide.