There's some interesting reading in NZ’s biggest quake-maker: Scientists peer inside Hikurangi Subduction Zone | RNZ News:
Along [the Hikurangi] subduction zone, scientists have estimated a 26 percent chance of an event with a magnitude of 8.0 or larger striking beneath the lower North Island within the next 50 years.
That's underscored the importance of a major research focus on the role of slow-slip earthquakes, which unfold along the boundary silently, yet pack the power to shift faults by tens of centimetres over days, weeks or months.
Their occurrence didn't necessarily mean Hikurangi's next big shake was on its way, with the vast majority of events transpiring without ensuing ruptures - and often helping relieve pressure slowly.
They're known to occur at shallow depths off the East Coast, but also at deeper levels off Manawatū and Kāpiti regions, where one ongoing event recently released pent-up energy equivalent to a 7.0 quake.
I'd certainly prefer the energy of a 7.0 quake to be released so slowly I don't notice…
