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

Today's Mw6.1 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

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

@RobinLacassin Has there been an increase in seismic activity this year? It seems busy.

@skanman No. It's a recurrent question when happen grouped in time, but it's purely statistical.

There are between, let's say, 110 and 150 earthquakes with magnitude 6 to 6.9 each year (140 in 2021). In 2022 we got 113 so far, which is totally normal. Note also that no magnitude 8+ happened this year, which is low but also statistically normal.

Media often give the wrong impression of a temporary increase when several earthquakes happen in inhabited areas and are damaging. Media, and even geoscientists, generally do not speak of the numerous magnitude 5+ events (several per day) which is the magnitude of the Java few days ago.


So no correlation, I'm programming algorithms all day so I look for correlations in everything 🙄🙂. I'm a seismology noob, but learning fast and loving it. Last night I was studying how reflections in shockwaves off of the mantle can combine and increase the force, and also react with different surface types like sand, limestone, clay. It's incredibly fascinating.

Maybe one day after I've learned enough about the mechanics. I can start applying algorithms to extrapolate correlations to the data. That would be pretty cool. Got any good books you can recommend?

@skanman Just to start I would recommend the books by Susan Hough:
• Predicting the Unpredictable: The Tumultuous Science of Earthquake Prediction
• Earthshaking Science: What We Know (and Don't Know) about Earthquakes

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