Earthquakes can strike suddenly and violently, but they often begin as slow, quiet movements deep beneath the Earth's surface. A new study has unraveled the hidden mechanics behind this transition, shedding light on how creeping motion escalates into the powerful ruptures that shake the ground. Using cutting-edge experiments and innovative models, Researchers from the Racah Institute of Physics at the Hebrew University of Jerusalem, led by Prof. Jay Fineberg and PhD. Student Shahar Gvirtzman in collaboration with Prof. David S. Kammer from ETH Zurich and Prof. Mokhtar Adda-Bedia from École Normale Supérieure de Lyon revealed that slow, silent stress release is a prelude and a necessary trigger for seismic activity. By incorporating the overlooked role of fault geometry, the study challenges long-held beliefs and offers a fresh perspective on how and when earthquakes begin. These findings not only deepen our understanding of nature’s most powerful forces but also pave the way for improved predictions of seismic events.

 

Key Findings:

• Transition from Slow to Rapid Motion: The team conducted experiments and developed theoretical models to demonstrate how slow, steady creep at stress thresholds transitions into the dynamic rupture associated with earthquakes.
• Fault Geometry as a Critical Factor: By extending the principles of fracture mechanics, the researchers incorporated the finite width of fault interfaces, a factor often overlooked in traditional models. "Our findings challenge and refine conventional models of rupture dynamics," explained Prof. Fineberg.
• A Framework for Predictive Models: Prof. Fineberg explains, "We show that slow, aseismic processes are a prerequisite for seismic rupture, driven by localized stress and geometric constraints. This has profound implications for understanding when and how earthquakes begin."

 

Implications:

The findings extend beyond the field of earthquake science, offering fresh perspectives on material strength, fracture dynamics, and other processes influenced by friction. They also underscore the value of recognizing "quiet" seismic precursors,  which could hold vital clues to understanding how and when earthquakes occur.

 

Publication Details

The research, titled “How frictional ruptures and earthquakes nucleate and evolve” is available in Nature and can be accessed here: https://www.nature.com/articles/s41586-024-08287-y (DOI- 10.1038/s41586-024-08287-y). 

 

Researchers:

• Shahar Gvirtzman (Racah Institute of Physics, The Hebrew University of Jerusalem)
• Prof. Jay Fineberg (Racah Institute of Physics, The Hebrew University of Jerusalem)
• Prof. David S. Kammer (Institute for Building Materials, ETH Zurich)
• Prof. Mokhtar Adda-Bedia (Laboratoire de Physique, Universite de Lyon, Ecole Normale Superieure de Lyon, Centre National de la Recherche Scientifique,)

 

For a century, the Hebrew University of Jerusalem has been a beacon for visionary minds who challenge norms and shape the future. Founded by luminaries like Albert Einstein, who entrusted his intellectual legacy to the University, it is dedicated to advancing knowledge, fostering leadership, and promoting diversity. Home to over 23,000 students from 90 countries, the Hebrew University drives much of Israel’s civilian scientific research, with over 11,000 patents and groundbreaking contributions recognized by eight Nobel Prizes, two Turing Awards, and a Fields Medal. Ranked 81st globally by the Shanghai Ranking (2024), it celebrates a century of excellence in research, education, and innovation. To learn more about the University’s academic programs, research, and achievements, visit the official website at http://new.huji.ac.il/en.