A deep geophysical observatory in direct vicinity to the North Anatolian Fault Zone

GONAF

GONAF aims at installing a deep geophysical observatory in direct vicinity to the Naorth Anatolian Fault Zone (NAFZ) below the Sea of Marmara.The planned location is the island of Sivriada which is near a branching point between strike-slip and normal fault segments of the NAFZ. GONAF will allow addressing key questions pertinent to faulting activity and earthquake mechanics in general and seismic hazard assessment for the Istanbul area in particular. The following fundamental problems will be studied, partly in combination of the borehole observatory with a shallow borehole array and offshore campaign measurements: Is the North Anatolian Fault Zone in North-Western Turkey a weak or a strong plate boundary? What is the orientation of the principal stresses at the fault zone? Do stresses at the fault zone vary with depth and time?

• How does the structural heterogeneity of the fault affect the earthquake nucleation process?
• How is the dynamic propagation of a shear rupture affected by the fault structure?
• How is deformation partitioned between aseismic creep and seismic slip at the termination of a major earthquake rupture?

for details see www.gonaf.de