To watch
A first video of its kind showing the cracking of the soil during a major earthquake is even more remarkable than we thought before. It captures not only a movement of the soil never taken on video before, but also shows the curved crack as it moves.
This winding movement was deducted from the geological file and the “Slicken Lines” – brands of scratching on the sides of the faults – but it had never been seen in action, geophysicist Jesse KearseA postdoctoral researcher currently at the University of Kyoto in Japan, in a press release.
“Instead of things that move directly to the video screen, they moved along a curved path which has an convexity down, which instantly started the bells that sound in my head,” said Kearse, “because some of my previous research was specifically on the curvature of flaw, but from geological recording.”
The video – captured by a security camera near Thazi, Myanmar – shows the breakdown of the ground during a Magnitude 7.7 Quake that hit the region on March 28. It shows the Tremblant floor, followed by a crack that will open. These breaks on the ground are relatively common during large earthquakes, but they had never been taken on video.
Kearse said he had watched the video with chills in his spine shortly after he was downloaded from YouTube. At his fifth or sixth viewing, he noticed that the crack was winding. He and his colleague from the University of Kyoto, geophysicist Yoshihiro KanekoThen analyzed the video more closely. They found that the crack is curled suddenly at the start, then accelerates at a top speed of about 10.5 feet per second (3.2 meters per second) of movement, sliding a total of 8.2 feet (2.5 meters) in 1.3 seconds. After hitting its speed, the crack straightened up and slowed down.
The results suggest that the curvature occurs because the constraints on the fault on the right on the surface of the ground are lower than those of the stresses of the fault more deeply in the earth. This creates an uneven motif in the way the fault moves. “The curvature contains important information on the dynamics of the rupture,” said Kearse in a Annotated video of the panties he published on YouTube.
In relation: The fault of San Andreas: facts on the crack of the California crust which could release the “big”
The various constraints on the surface push the defect of his career, “then he gets caught and does what he is supposed to do,” Kearsers said in the press release.
The dynamics of these curvatures depends in part on how the rupture moves, so that an understanding of the curves can reveal clues to the course of past earthquakes and help scientists better predict the future ruptures of the terrain.
Research was published today (July 18) in the journal The seismic file.
Publisher’s note: This article has been updated at 8:20 p.m. HAE to note that the new research has now been published in The Seismic Record.
