The first fault crack ever shot: M7.9 surface cracked shot near Thazi, Myanmar – YouTube
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The first video of watching the ground breaking during a major earthquake is more compelling than previously thought. Not only does it capture ground motion that has never been captured on video before, it also shows crack bending.
From geological records and “slides” (scratches on the sides of the fault), this bending motion is never seen in action.
“Instead of moving directly on the video screen, moving down the curved path, the curved route down, which immediately started ringing in my mind,” Kearse said, “because some of my previous studies focused specifically on the curvature of fault slips, but started from the geological record.”
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The video was captured by security cameras near Thazi, Myanmar – showing the ground breaking in a 7.7 earthquake that struck the area on March 28. It shows the ground shaking, followed by the crack opening. These ground ruptures were relatively common in the major earthquakes, but were never captured in video.
Kearse said he watched the video shortly after uploading to YouTube. On his fifth or sixth view, he noticed that the crack was curved. He and his colleague at Kyoto University, geophysicist Yoshihiro Kaneko, then analyzed the video more carefully. They found that the crack curve first curved sharply and then accelerated to a peak speed of about 10.5 feet per second (3.2 meters per second), gliding a total of 8.2 feet (2.5 meters) in 1.3 seconds. Once the top speed is reached, the cracks will straighten and slow down.
The results of the study show that curvature occurs because the stress on the fault on the ground is lower than the stress on the fault on the earth. This creates an unbalanced pattern in the way the fault moves. “There is important information about the power of rupture,” Kiers said in an annotated video of the document he posted on YouTube.
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“The different pressures on the surface deduce the fault from the route,” Kells said in the statement. “Then it grabs itself and does what it should do. ”
The dynamics of these bends depend in part on how the rupture moves, so an understanding of the curve can reveal clues about how the past earthquakes unfold and help scientists better predict future ground ruptures.
The study was published today (July 18) in the journal Earthquake Records.
Editor's Note: This article was updated at 8:20 pm ET to indicate that the new study has now been published in Earthquake Records.