Magnitude 5.5 #earthquake in #Gabon 30 minutes ago (2022-12-04Z09:53).
Signal on station G.EDA (courtesy of the #GEOSCOPE global #seismic network and made available via #IRIS) - displayed using @obspy software. There were two very similar events here in March 2021 but today's is larger. https://earthquake.usgs.gov/earthquakes/eventpage/us6000j6u0/executive

In 1999 the North Anatolian Fault (NAF), Turkey, broke during two destructive #earthquakes east of Istanbul (Mw7.4 Izmit and Mw7.2 Düzce earthquakes respectively on 17 Aug and 12 Nov).

Today's Mw6.1 #earthquake happened just east of Düzce with a faulting mechanism very similar to the 12 Nov 1999 event (strike-slip with small normal component). Its epicenter is located little to the north of the main NAF fault trace.

Map with MT and source function from #IPGP #Geoscope http://geoscope.ipgp.fr/index.php/fr/catalogue/description-d-un-seisme?seis=us7000irp8

Other map shows in red the fault broken by the two 1999 events (purple and red stars locate epicenters, yellow circles show aftershocks). From C ̧akir et al. GJI 2003 https://doi.org/10.1046/j.1365-246X.2003.02001.x.

@jascha Btw, here is the link to page for this #solomonislands #earthquake on the #Geoscope web page, hosted by #IPGP, and that uses the #SCARDEC method developed by Martin Vallée: http://geoscope.ipgp.fr/index.php/en/catalog/earthquake-description?seis=us7000irfb

@SakuRainbow @earthjay Here is the same earthquake analysed by #Geoscope. The 1st image shows the focal mechanism. This is a stereographic projection of 4 quarter-spaces: ◻️ is the region where the rupture radiates tensional ⏪⏩ waves, ◼️ is where compressional waves ⏩⏪ are radiated. What you need to care about is the limit between ◻️ and ◼️: it corresponds to the two *possible* planes, which are perpendicular ❌. Both planes are depicted in 2nd figure

Here is the first event of 09 October 2022. #FocalMechanism determined with #SCARDEC method from #Geoscope #NationalService. This is a very deep earthquake, among the deepest that are detected (~650 km). These events occur at the depth where the subduction plane hits the boundary between upper and lower mantle. The event was actually a sequence of three ~M.6.5 events, which is already remarkable. Source: http://geoscope.ipgp.fr/index.php/en/catalog/earthquake-description?seis=us7000ingh

Here is a 3D representation of the #focal #mechanism from #Geoscope web site. There are two possibilities, that produce the same radiation pattern of seismic waves, hence cannot be distinguished from rapid analysis of seismic waves from a large distance. Source: http://geoscope.ipgp.fr/index.php/en/catalog/earthquake-description?seis=us7000ip0l