Investigation of faults in New Zeeland

Faults in the lithosphere are the source of earthquakes, and consequently pose a severe geohazard. Because faults in solid rock behave in different style to those in the overlying unconsolidated sediments, understanding the complete temporal and spatial evolution of a fault is difficult. Especially the transition of the fault between the solid and unconsolidated rock is poorly understood.  For this reason, we plan to investigate an active fault in New Zealand (the Hope fault), especially at the junction of the fault between the solid rock and the basin sediments above the fault.

To investigate the spatial characteristics of the fault in the basin sediments, we will use ground-penetrating radar (GPR), a geophysical method that has proven to be able to image small-scale fault structures in the upper meters. To analyse the temporal activity of the fault, we will apply optically-stimulated luminescence (OSL) on minerals from the fault core and its gouge in the solid rock.

In addition, we will use a simple analogue model consisting of a shear-box filled with sand to study the temporal and spatial development of faults in overlying unconsolidated material in the lab.