Earthquakes, a significant natural phenomenon, release energy accumulated in rocks over extended periods. This energy manifests primarily as ground shaking, but it also generates heat and causes fractures in underground rock formations. Understanding the distribution of this energy among the various effects has been a complex challenge for researchers in the field of geophysics.
Recent research led by MIT geophysicist Matěj Peč has shed light on the energy budget of earthquakes through meticulously controlled miniature experiments, dubbed ‘lab quakes.’ Their findings reveal that only a small fraction, approximately 1% to 10%, of the energy released during a lab quake contributes to the physical shaking felt on the surface. Meanwhile, another 1% to 30% is utilized in breaking rocks and creating new surfaces, while the majority of the energy—up to 98%—is expended in heating the area around the epicenter, sometimes resulting in temperatures high enough to melt surrounding materials.
Intriguingly, the study highlights that the distribution of energy among shaking, heating, and rock fracturing is affected by the geological history of the region. Postdoctoral researcher Daniel Ortega-Arroyo, the lead author of the study, noted that the ‘deformation history’ of rock influences its properties and behavior during seismic events. This knowledge could be pivotal; by understanding the energy dynamics of past earthquakes, scientists could better assess the vulnerability of regions to future seismic activity, potentially leading to improved earthquake preparedness and mitigation strategies.
Source: Under 10% of an earthquake’s energy makes the ground shake via MIT Technology Review