The 2019 M 3.4 Yangon Earthquake in Ayeyarwady Delta Basin

Abstract

An earthquake of M 3.4 occurred in Yangon with epicenter at Dalah, 6 km SSE of Yangon at 15:24:18 pm (UTC) on 12^th November, 2019. Its epicenter was situated at 16.751°N, 96.18°E and at depth 10 km (6.2 miles) (USGS, NEIC). It was a slight earthquake and vibration was severe and people felt strong shaking in almost every townships of the Yangon Region but no severe damages. The event was preceded by a loud sound and heavy shaking last 8 seconds. Ground deformation by this event is slanting of the high-rise buildings in some townships, liquefaction features like water seepage from underground to the surface and slight cracks on the wall of the buildings. The causative fault for the earthquake is believed to be a reverse fault with strike-slip component of the NNW-SSE trending Yangon fault. This is due to basin inversion in Ayeyawady Delta Basin. On 13^th January 2013 an earthquake with the same magnitude occurred at 10 km depth. It was a slight earthquake and vibration was felt in several townships of Yangon. In 17 December, 1927, an earthquake with magnitude 7.0 hit Yangon and caused certain amount of damages. It was felt15,000 sq.km from Kyangin to Dedaye along the western slope of Bago Yoma. In Yangon, the shock was much severer causing widespread alarm and damage to concrete buildings. Focal mechanism solution of the 1927 event was a strike-slip faulting (USGS). In  July, 1930 Bago earthquake with M=7.3 effected Yangon, vibration spread caused damage to the buildings and 500 persons in Bago and 50 persons were killed in Yangon respectively. The last record of significant earthquakes that struck Yangon is on 30^th September,1978 with M 5.7 at 10 km depth.