{"id":2424,"date":"2015-05-04T18:43:22","date_gmt":"2015-05-05T02:43:22","guid":{"rendered":"http:\/\/earthjay.com\/?p=2424"},"modified":"2023-05-05T16:20:34","modified_gmt":"2023-05-05T16:20:34","slug":"new-britain-strikes-again","status":"publish","type":"post","link":"https:\/\/earthjay.com\/?p=2424","title":{"rendered":"New Britain Strikes Again!"},"content":{"rendered":"

In the past week, there has been a series of earthquakes in the New Britain trench. The largest quakes are M = 6.7<\/a> & 6.8<\/a>. Now we might call those foreshocks to today’s M = 7.5 earthquake<\/a> de Cinco de Mayo. Historic Earthquakes of epicenter larger than M = 7 are plotted in grey. These are also plotted in more detail below.<\/p>\n

Here is a map that shows the seismicity from the last month. The moment tensors for the three largest magnitude earthquakes are shown, as well as a brief explanatory graphic about what moment tensors reveal. Based on the regional tectonics, I would interpret these three earthquakes to be ~east-west striking, north-south compressional earthquakes, dipping to the north.<\/p>\n


\n\"\"<\/a><\/p>\n

Based on the original magnitude and hypocentral depth (63 km), it seemed less likely that a tsunami may be generated from this earthquake. The depth is now 42 km, which promotes the likelihood of a tsunami. The 1992 Petrolia Earthquake<\/a> was at about 10 km depth and produced a tsunami with an earthquake of magnitude 7.2.<\/p>\n

Any tsunami from today’s earthquake would probably be local and not travel very far from the region. The PTWC issued a threat message stating that the waves may be 0.3 to 1 meters above the tide level in the Papua New Guinea region. <\/p>\n

Here is their forecast ETA for one location:
\n LOCATION REGION COORDINATES ETA(UTC)
\n ————————————————————
\n KAVIENG PAPUA NEW GUINEA 2.5S 150.7E 0258 05\/05<\/p>\n

The depth estimate originally placed this earthquake beneath the slab depth based upon the Hayes et al. (2012) model. At first the depth was set at ~63 km and has since shallowed to 42 km and is now plotted further north (placing it closer to a depth that we might expect based on the Hayes slab model).<\/p>\n