Scientists have just discovered that the 2012 Indian Ocean quake—already bizarre on a couple of levels—could herald the beginnings of a new tectonic plate.

The earthquake, which struck off Sumatra April 11, first puzzled Indonesians expecting a large tsunami to wash ashore. When the wave did appear, it was 12 inches high, explains the Christian Science Monitor.

The 8.7 magnitude quake followed a strike-slip pattern. In such cases, the fault sides shake horizontally, not vertically. Since an upward push on the ocean’s floor is needed for a tsunami to develop, one never occurred.

Not only was this the largest strike-slip earthquake ever recorded, the event was unique because it occurred at the middle, not the boundary, of an oceanic plate. The earthquake ruptured at one fault and continued to rupture a total of four faults within 150 seconds, resulting in an energy release the size of four 8.0 magnitude quakes.

"It was jaw-dropping," said Thorne Lay, a University of California, Santa Cruz, professor of earth and planetary sciences. "It was like nothing we'd ever seen," he told the L.A. Times.

Particularly interesting is what the quake might signal about the Indo-Australian plate, which scientists have long believed is breaking up. The earthquake provides the clearest evidence to date that they're right, according to Nature News.

And while the April earthquake and its aftershocks weren't particularly destructive, they have turned some conventional quake wisdom on its head. According to Nature News, five times the normal number of 5.5 magnitude or greater quakes occurred worldwide for six days after the main shock.

“Until now, we seismologists have always said, ‘Don’t worry about distant earthquakes triggering local quakes,’” said earth science professor Roland Burgmann, quoted in a University of California, Berkeley, news release.

“We found a lot of big events around the world, including a 7.0 quake in Baja California and quakes in Indonesia and Japan, that created significant local shaking,” Burgmann added. “If those quakes had been in an urban area, it could potentially have been disastrous.”

And that new realization means we're unlikely to find the breakup of the Indo-Australian plate to be either quick or painless.

“This is part of the messy business of breaking up a plate,” University of Utah Director of Seismograph Stations Keith Koper is quoted as saying in another news release. “This is a geologic process. It will take millions of years to form a new plate boundary and, most likely, it will take thousands of similar large quakes for that to happen.”