2016 Kumamoto earthquakes, Earthquake in Japan

The 2016 Kumamoto earthquakes were a sequence of inland quakes on Kyushu, beginning with a Mj 6.5 foreshock at 21:26 on 14 April 2016 beneath the Kumamoto area and followed by a Mj 7.3 mainshock at 01:25 on 16 April. The ruptures ran along the Hinagu and Futagawa fault zones, and intensity 7 on the JMA scale was recorded at Mashiki, Nishihara and again at Mashiki.

The sequence began on 14 April 2016 at 21:26 JST with an Mj 6.5 foreshock that registered intensity 7 at Mashiki, the first intensity 7 ever recorded in Kyushu. The Mj 7.3 mainshock followed 28 hours later, at 01:25 on 16 April, beneath Higashi Ward of Kumamoto City, rupturing the Hinagu and Futagawa fault zones. The JMA kept the name Heisei 28-nen Kumamoto jishin for the whole series.

The name Heisei 28-nen Kumamoto jishin was announced by the Japan Meteorological Agency on 15 April 2016, and the agency kept it after the larger 16 April quake, defining it as the whole series of tremors from 14 April 21:26. The Ōita regional paper Ōita Gōdō Shimbun also used the name Kumamoto-Ōita jishin in its articles from 22 April.

The two shocks struck at 21:26 JST on 14 April and 01:25 JST on 16 April 2016, the second under Higashi Ward of Kumamoto City at about 10 km depth. A tsunami advisory for the Ariake and Yatsushiro Seas was lifted at 02:14 JST, and the Kyushu Shinkansen stopped after a train derailed. Mashiki, east of the city, took the worst of the foreshock.

The foreshock toppled the shachihoko, the paired fish-shaped ornaments on Kumamoto Castle's roof, and damaged its roof and outer walls. The April 14 quake also derailed a Kyushu Shinkansen train, halting service on the line.