학술논문

Comparison of ground-shaking hazard for segmented versus multifault earthquake-rupture models in Aotearoa New Zealand
Document Type
Academic Journal
Source
Seismological Research Letters.
Subject
19|Seismology
Australasia
earthquakes
faults
geologic hazards
ground motion
natural hazards
New Zealand
New Zealand National Seismic Hazard model
North Island
risk assessment
rupture
seismic risk
seismicity
South Island
Taupo
Language
English
ISSN
0895-0695
Abstract
Multifault ruptures are common for historical earthquakes, and here we consider their impact on seismic hazard. We compare ground-shaking hazard forecasts from the 2022 Aotearoa New Zealand National Seismic Hazard Model (NZ NSHM 2022), which incorporates many multifault ruptures (referred to as the multifault model) with modeled hazard from a simpler model of characteristic earthquakes on individual faults or fault segments (referred to as the segmented model). The multifault model includes very-low-probability rupture lengths of up to ∼1100 km and a mean of 221-234 km, whereas the segmented model primarily comprises rupture lengths of w 6.9-7.5 earthquakes are more than an order of magnitude higher for the segmented model (0.132-0.24/yr; recurrence times ∼4-7 yr) than the multifault model (0.027/yr; recurrence times 37 yr). Conversely, the rates of earthquakes are similar for segmented and multifault models at Mw>7.5 (0.018-0.031/yr; recurrence times 32-56 yr). Despite differences in rupture lengths and annual rates of earthquakes, the calculated ground-shaking hazard at 10% probability of exceedance (PoE) in 50 yr for the segmented model differs by