M 7.0 earthquake struck Papua New Guinea: Tsunami warn issued

A strong earthquake (M 7.0) struck Papua New Guinea and authorities immediately issued an alert about a potential tsunami.

The seismic event occurred on July 17, 2020 at 12:50 pm local time. The epicenter of the tremblor was located at 114 kilometers northwest of Popondetta, a major city in southeast Papua New Guinea. 

According to the United States Geological Survey (USGS), the earthquake struck at intermediate depth (about 85 kilometers) in the subducted or foundered lithosphere and occurred on either a steeply dipping fault that strikes to the northwest or on a moderately dipping fault that strikes to the northeast. The tectonic regime of the region includes the subduction of the Pacific Plate under the Australian Plate. 

The quake was felt throughout the country and also in northern Australia but, fortunately, there still have been no reports about casualties or infrastructure damage. In Port Moresby, the capital city of Papua New Guinea which is located about 185 kilometers south of the quake's epicenter, people reported feeling strong shaking. Some residents feared catastrophic building collapses. "It was like never before. Everyone in all the buildings here at downtown rushed out of their offices and out in the streets. The office table top was shaking, fan and chairs (also). We ran out of the building to an open area," a local, stated. 

The fact that the seismic shock was not shallow enabled the attenuation of the seismic waves that hit the surface of the ground. A shallow earthquake of that magnitude could have imposed critical damage.

A tsunami alert was issued by the Pacific Tsunami Warning Center but it was canceled in the following hours. 

Papua New Guinea is situated along the Pacific Ring of Fire, a particularly earthquake-prone zone, where about 90% of the total earthquakes on earth occur. 

On May 2019, a M 7.5 tremblor struck the eastern coast of the country on a shallow strike-slip fault. The event caused some structural damage and power outages but no casualties were reported. A tsunami warning was also issued and canceled in the following time period.

On February 2018, another M 7.5 seismic shock hit New Guinea Highlands, resulting in infrastructure damage and landslides. Unfortunately, at least 67 people were reported dead and 500 more injured. The impact of the quake was devastating since more than 125,000 were affected and were left homeless. In some towns, the majority of buildings either collapsed or suffered irreparable damage.