Coseismic Rupture and Preliminary Slip Estimates for the Papatea Fault and Its Role in the 2016 Mw 7.8 Kaikōura, New Zealand, Earthquake

Three‐Dimensional Surface Deformation in the 2016 MW7.8 Kaikōura, New Zealand, Earthquake From Optical Image Correlation: Implications for Strain Localization and Long‐Term Evolution of the Pacific‐Australian Plate Boundary

“…For our analyses, we scaled our slip measurements in proportion to the net slip, such that larger net displacement values are more represented than smaller ones. Generally, our kinematic orientation measurements (summarized for each fault in Figure S3) reflect the broader deformation patterns shown in Figure and agree with broad‐scale field observations of deformation and uplift (Clark et al, ; Kearse et al, ; Langridge et al, ; Litchfield et al, ; Nicol et al, ; Stirling et al, ; Williams et al, ). Deviations from the overall fault plane attitudes and kinematics stem primarily from local fault structural complexities, such as restraining or releasing bends and steps, which occur at all observable length scales (≤100 to >10 km).…”

“…In the 2016 earthquake, however, the sense of throw was opposite to the long‐term trend: the Jordan Thrust fault experienced primarily normal‐dextral, SE side up motion (Figures and ). This anomalous sense of slip resulted from southward movement of the Papatea block (Figure ), which experienced up to ~7.3 m of left‐lateral displacement and ~9.0 m of west side up vertical slip along the Papatea fault (Hamling et al, ; Langridge et al, ; this study). This Papatea block motion is attributed to either (1) the extrusion of the Papatea block to accommodate space between the Hope and Jordan Thrust faults (Hamling et al, ; Langridge et al, ) or (2) convergence of the Papatea fault with a deeper (blind) north or northwest dipping detachment underlying the Papatea block (Cesca et al, ; Van Dissen & Yeats, ).…”

“…This anomalous sense of slip resulted from southward movement of the Papatea block (Figure ), which experienced up to ~7.3 m of left‐lateral displacement and ~9.0 m of west side up vertical slip along the Papatea fault (Hamling et al, ; Langridge et al, ; this study). This Papatea block motion is attributed to either (1) the extrusion of the Papatea block to accommodate space between the Hope and Jordan Thrust faults (Hamling et al, ; Langridge et al, ) or (2) convergence of the Papatea fault with a deeper (blind) north or northwest dipping detachment underlying the Papatea block (Cesca et al, ; Van Dissen & Yeats, ). In either case, the fact that the Seaward Kaikōura Range northwest of the Jordan Thrust is substantially higher (and therefore building faster) than the mountains of the Papatea block indicates that the Papatea fault is less active and moves slower, on average, than the Jordan Thrust fault.…”

“…Debate remains as to what role the subduction megathrust fault played in the earthquake, though it is generally presumed that it, or some other deep thrust fault, contributed to the overall moment release and likely aided rupture propagation through the complex network of faults (Bai et al, ; Cesca et al, ; Clark et al, ; Duputel & Rivera, ; Hamling et al, ; Hollingsworth et al, ; Litchfield et al, ; Wang et al, ). Immediately following the 14 November mainshock, teams of field geologists began measuring surface deformation resulting from the rupture (Clark et al, ; Kearse et al, ; Langridge et al, ; Litchfield et al, ; Nicol et al, ; Stirling et al, ; Williams et al, ). These measurements provide key insights into the spatial distribution, kinematics, and complexity of slip in the event.…”

The Timing and Style of Oblique Deformation Within New Zealand's Kaikōura Ranges and Marlborough Fault System Based on Low‐Temperature Thermochronology

“…Rapid exhumation of Clarence foot wall samples within the Clarence Valley potentially relates to broad uplift associated with the dextral‐reverse Kekerengu Fault to its south (Figure ). Young AHe ages in the foot wall of the Jordan Thrust could relate to nearby uplift of the Papatea Block along the north striking sinistral reverse Papatea Fault (Langridge et al, ) or possibly faults offshore (Barnes et al, ), which are thought to lead to uplift of marine terraces along the Pacific coast at 1 mm/year (Ota et al, , ). We attribute rapid exhumation within the Amuri Range to the initiation of the Hope Fault sometime between 8 and 5 Ma.…”