Earthquake First! See Ground Crack in Real-Time Video!
Colaboradores
A groundbreaking video has captured the raw power of an earthquake like never before, revealing the Earth's surface cracking and shifting in real-time. The footage, recorded by a security camera near Thazi, Myanmar, during a magnitude 7.7 quake on March 28th, offers unprecedented insights into the mechanics of these devastating events.
Witnessing the Unseen: A Curving Crack
What makes this video truly remarkable is the observation of a curved crack. Geophysicist Jesse Kearse, a postdoctoral researcher at Kyoto University, noted that the crack didn't move in a straight line but followed a curved path. This curvature, previously inferred from geological records, is now directly observed for the first time.
"Instead of things moving straight across the video screen, they moved along a curved path that has a convexity downwards," Kearse explained. This discovery provides valuable data for understanding the stresses and forces at play during an earthquake.
Analysis Reveals Speed and Movement
Kearse and his colleague, geophysicist Yoshihiro Kaneko, meticulously analyzed the video, frame by frame. Their findings revealed that the crack initially curves sharply before accelerating to a peak velocity of approximately 10.5 feet per second (3.2 meters per second). In just 1.3 seconds, the ground slipped a total of 8.2 feet (2.5 meters). After reaching its peak speed, the crack straightens and slows down.
Implications for Understanding Earthquakes
The curvature observed in the video suggests that the stresses on the fault are lower at the ground surface compared to deeper within the Earth. This uneven distribution of stress creates the curved path of the rupture.
Plate Tectonics in Action
The video provides direct visual evidence of plate tectonics in action, showing the Earth's surface lurching sideways as the fault slips. This shear fracture, traveling at several kilometers per second, is the primary mechanism that accommodates plate boundary motion at Earth's surface.
- The fault slipped 2.5 meters sideways in just 1.3 seconds.
- The maximum speed reached was 3.2 meters per second.
This rare footage offers a unique opportunity for seismologists to refine their understanding of how faults rupture during large earthquakes and how seismic energy is radiated, leading to ground shaking.
