On Thursday, May 7, 2015, a major 7.1 magnitude earthquake strikes in the Pacific, in between the Solomon Islands and the Papua New Guinea area. Fortunately, no tsunami threats were announced, and reports show little damage.
According to the US Geological Survey, the earthquake hit around 144 kilometers southwest of Panguna in PNG and 642 kilometers from the Solomon Islands’ capital Honiara. Initially, the USGS reported the quake’s magnitude at 7.2 on the Richter scale, but later reviewed it in the list of strength and distance.
At first, the Pacific Tsunami Warning Center announced that some hazardous waves might hit the coasts located within 300 kilometers of the epicenter of the earthquake, but a later update gave an “all clear” signal as far as tsunamis are concerned.
Jonathan Bathgate, a senior seismologist from Geoscience Australia said that nearby communities were little to none at all damaged. The reason is the scarce population located on these coastlines, which is why even small tsunamis usually go unnoticed by the few locals.
This is not the first quake to hit the region around Papua New Guinea in the last week – the largest of them being a 7.4 magnitude tremor outside the town of Kokopo in the New Britain area on Tuesday. On that occasion, a tsunami warning was issued in the area, but soon after it was lifted without any major damage and further natural incidents.
Two earthquakes happened the same week, both with no reported destruction: on Friday, when a 6.8 one struck Kokopo, and on Thursday, when a 6.7 tremor rattled the same region.
The area is prone to seismic activity due to frequent friction happening between tectonic plates of the 4,000-kilometer-long Pacific Australia plate – a hotspot dubbed the “Ring of Fire.”
Back in 2013, the Solomon Islands did not get off so easily, after a tsunami caused by an 8.0-magnitude quake killed at least 10 people and left thousands others homeless when their houses were destroyed.
According to local seismologists, this quake was different from the other tremors occurring in the New Britain region in the last week – although it happened on the same plate boundary. However, with active zones such as this one, it is rather common that large earthquakes follow other large earthquakes.
When a 7+ earthquake strikes in New Britain, there is tremendous impact on the stress field of other parts of the same boundary, which in turn significantly increases the chance of having replica earthquakes soon after along that plate boundary.
Image Source: Mapsof.net
