Earthquakes on the Puente Hills thrust fault could be particularly dangerous because the shaking would occur directly beneath ...

That stratum marks the blind thrust fault. These are stratified rocks and all the strata formed upon the flat seafloor of the Helderberg Sea. They should all be flat lying.

Blind Thrust Fault: A fault that does not break the surface, making direct observation challenging, yet capable of generating significant seismic events.

When that fault ruptured, it activated the sleeping Greendale Fault further south, ripping open a nearly 30 kilometre-long gash across the Canterbury Plains. Another blind thrust fault to the ...