In a groundbreaking discovery, researchers have uncovered the hidden geological forces behind a devastating earthquake that rocked northern Chile in July 2024, challenging long-held scientific assumptions about seismic events.

The magnitude 7.4 earthquake near Calama wasn't just another tremor—it was a geological mystery that revealed extraordinary processes deep beneath the Earth's surface. While Chile has a notorious history of powerful earthquakes, including the record-breaking 9.5 magnitude event in 1960, this recent quake stood out for its unique characteristics.

Scientists from the University of Texas at Austin made a startling revelation: the earthquake originated an astonishing 125 kilometers underground, far deeper than typical destructive seismic events. Traditionally, such deep earthquakes were expected to produce minimal surface disruption, but the Calama event defied expectations, causing significant damage and power outages across the region.

The research team discovered a rare geological phenomenon called "thermal runaway" that supercharged the earthquake's intensity. Typically, earthquakes at intermediate depths are triggered by "dehydration embrittlement," where water trapped in minerals is released as tectonic plates sink deeper, causing rock to become brittle and crack.

"These Chilean events are causing more shaking than is normally expected from intermediate-depth earthquakes, and can be quite destructive," explained lead researcher Zhe Jia. The team's breakthrough came when they observed the rupture continuing beyond the previously understood temperature limit of 650 degrees Celsius, traveling an additional 50 kilometers into even hotter rock zones.

By combining seismic records, satellite navigation data, and advanced computer modeling, the researchers tracked the earthquake's unprecedented rupture. The friction generated during the initial rupture created extreme heat, which paradoxically weakened surrounding rock materials and allowed the earthquake to propagate faster and stronger than previously thought.

This groundbreaking research not only explains the Calama earthquake's unusual intensity but also provides crucial insights for future earthquake risk assessment. By understanding these complex underground processes, scientists can develop more sophisticated methods for predicting and preparing for potential seismic events.

As Jia noted, their goal extends beyond scientific curiosity: to support emergency response and long-term planning in earthquake-prone regions, potentially saving lives and reducing infrastructure damage in future seismic events.