The eastern section of the Marmara earthquake zone, located outside Istanbul, is currently seismically locked and therefore is a potential start point for a future earthquake, reports a study published in Nature Communications this week. This finding suggests that improved microseismic monitoring in this as well as other earthquake regions could provide useful insight for estimating earthquake hazards.

The North Anatolian Fault Zone is the most active strike-slip fault in Europe and Asia Minor, with the two most recent earthquakes, both of magnitude >7, having occurred in 1999 to the east of Istanbul. It is widely accepted that this fault zone still presents a risk and that a further earthquake will soon strike somewhere in this region. Marco Bohnhoff and colleagues identified a 30 km long section in this fault line, known as the Princes Island segment in the eastern part of the Marmara Zone, that was aseismic down to a depth of 10 km. The authors interpret this section as locked and suggest it as a potential nucleation point of a pending Marmara earthquake.

Monitoring of fault lines in greater detail, as achieved in this study, could be useful for seismic hazard planning for metropolitan areas such as Istanbul.