Indo-Australian Tectonic Plate Is Breaking in Pieces
An 8.7 earthquake that struck west of Indonesia on April 11 was the biggest of its kind ever recorded and confirms suspicions that a giant tectonic plate is breaking up, scientists believe. The quake, caused by an unprecedented quadruple-fault rupture, gave Earth’s crustal mosaic such a shock that it unleashed quakes around the world nearly a week later.
The quake occurred about 500km west of Sumatra, in the middle of the Indo-Australian plate. It was the biggest “strike-slip” earthquake ever recorded, meaning a fault that opens laterally rather than up or down, and was followed two hours later by an 8.2 quake. Taking a scalpel to what happened that day, seismologists believe there was a near-simultaneous rupturing of at least four faults, stacked up and lying at right angles to one another.