Palaeoearthquake surface rupture in a transition zone from strike-slip to oblique-normal slip and its implications to seismic hazard, North Island Fault System, New Zealand

2009 ◽  
Vol 316 (1) ◽  
pp. 269-292 ◽  
Author(s):  
Vasiliki Mouslopoulou ◽  
Andrew Nicol ◽  
Timothy A. Little ◽  
John G. Begg
Keyword(s):  
New Zealand ◽  
Seismic Hazard ◽  
Transition Zone ◽  
Strike Slip ◽  
Fault System ◽  
Surface Rupture

Strike-slip ground-surface rupture (Greendale Fault) associated with the 4 September 2010 Darfield earthquake, Canterbury, New Zealand

2011 ◽  
Vol 44 (3) ◽  
pp. 283-291 ◽  
Author(s):  
D.J.A. Barrell ◽  
N.J. Litchfield ◽  
D.B. Townsend ◽  
M. Quigley ◽  
R.J. Van Dissen ◽  
...  
Keyword(s):  
New Zealand ◽  
Ground Surface ◽  
Strike Slip ◽  
Surface Rupture

Erosion rates of the New Zealand Southern Alps reflect long-term tectonics and transient climate

2021 ◽  
Author(s):  
Duna Roda-Boluda ◽  
Taylor Schildgen ◽  
Hella Wittmann-Oelze ◽  
Stefanie Tofelde ◽  
Aaron Bufe ◽  
...  
Keyword(s):  
New Zealand ◽  
Strike Slip ◽  
Southern Alps ◽  
Fault System ◽  
Tectonic Deformation ◽  
Seismic Cycle ◽  
Erosion Rates ◽  
Alpine Fault ◽  
Oblique Convergence

<p>The Southern Alps of New Zealand are the expression of the oblique convergence between the Pacific and Australian plates, which move at a relative velocity of nearly 40 mm/yr. This convergence is accommodated by the range-bounding Alpine Fault, with a strike-slip component of ~30-40 mm/yr, and a shortening component normal to the fault of ~8-10 mm/yr. While strike-slip rates seem to be fairly constant along the Alpine Fault, throw rates appear to vary considerably, and whether the locus of maximum exhumation is located near the fault, at the main drainage divide, or part-way between, is still debated. These uncertainties stem from very limited data characterizing vertical deformation rates along and across the Southern Alps. Thermochronology has constrained the Southern Alps exhumation history since the Miocene, but Quaternary exhumation is hard to resolve precisely due to the very high exhumation rates. Likewise, GPS surveys estimate a vertical uplift of ~5 mm/yr, but integrate only over ~10 yr timescales and are restricted to one transect across the range.</p><p>To obtain insights into the Quaternary distribution and rates of exhumation of the western Southern Alps, we use new <sup>10</sup>Be catchment-averaged erosion rates from 20 catchments along the western side of the range. Catchment-averaged erosion rates span an order of magnitude, between ~0.8 and >10 mm/yr, but we find that erosion rates of >10 mm/yr, a value often quoted in the literature as representative for the entire range, are very localized. Moreover, erosion rates decrease sharply north of the intersection with the Marlborough Fault System, suggesting substantial slip partitioning. These <sup>10</sup>Be catchment-averaged erosion rates integrate, on average, over the last ~300 yrs. Considering that the last earthquake on the Alpine Fault was in 1717, these rates are representative of inter-seismic erosion. Lake sedimentation rates and coseismic landslide modelling suggest that long-term (~10<sup>3</sup> yrs) erosion rates over a full seismic cycle could be ~40% greater than our inter-seismic erosion rates. If we assume steady state topography, such a scaling of our <sup>10</sup>Be erosion rate estimates can be used to estimate rock uplift rates in the Southern Alps. Finally, we find that erosion, and hence potentially exhumation, does not seem to be localized at a particular distance from the fault, as some tectonic and provenance studies have suggested. Instead, we find that superimposed on the primary tectonic control, there is an elevation/temperature control on erosion rates, which is probably transient and related to frost-cracking and glacial retreat.</p><p>Our results highlight the potential for <sup>10</sup>Be catchment-averaged erosion rates to provide insights into the magnitude and distribution of tectonic deformation rates, and the limitations that arise from transient erosion controls related to the seismic cycle and climate-modulated surface processes.</p><p> </p><p> </p>

scholarly journals Triple junction kinematics accounts for the 2016 Mw7.8 Kaikoura earthquake rupture complexity

2019 ◽  
Vol 116 (52) ◽  
pp. 26367-26375 ◽  
Author(s):  
Xuhua Shi ◽  
Paul Tapponnier ◽  
Teng Wang ◽  
Shengji Wei ◽  
Yu Wang ◽  
...  
Keyword(s):  
New Zealand ◽  
Triple Junction ◽  
Large Scale ◽  
Strike Slip ◽  
Plate Motion ◽  
Fault System ◽  
Coseismic Deformation ◽  
Coseismic Slip ◽  
Slab Geometry ◽  
Kaikoura Earthquake

The 2016, moment magnitude (Mw) 7.8, Kaikoura earthquake generated the most complex surface ruptures ever observed. Although likely linked with kinematic changes in central New Zealand, the driving mechanisms of such complexity remain unclear. Here, we propose an interpretation accounting for the most puzzling aspects of the 2016 rupture. We examine the partitioning of plate motion and coseismic slip during the 2016 event in and around Kaikoura and the large-scale fault kinematics, volcanism, seismicity, and slab geometry in the broader Tonga–Kermadec region. We find that the plate motion partitioning near Kaikoura is comparable to the coseismic partitioning between strike-slip motion on the Kekerengu fault and subperpendicular thrusting along the offshore West–Hikurangi megathrust. Together with measured slip rates and paleoseismological results along the Hope, Kekerengu, and Wairarapa faults, this observation suggests that the West–Hikurangi thrust and Kekerengu faults bound the southernmost tip of the Tonga–Kermadec sliver plate. The narrow region, around Kaikoura, where the 3 fastest-slipping faults of New Zealand meet, thus hosts a fault–fault–trench (FFT) triple junction, which accounts for the particularly convoluted 2016 coseismic deformation. That triple junction appears to have migrated southward since the birth of the sliver plate (around 5 to 7 million years ago). This likely drove southward stepping of strike-slip shear within the Marlborough fault system and propagation of volcanism in the North Island. Hence, on a multimillennial time scale, the apparently distributed faulting across southern New Zealand may reflect classic plate-tectonic triple-junction migration rather than diffuse deformation of the continental lithosphere.

Reconciling an Early Nineteenth-Century Rupture of the Alpine Fault at a Section End, Toaroha River, Westland, New Zealand

2020 ◽  
Author(s):  
Robert M. Langridge ◽  
Pilar Villamor ◽  
Jamie D. Howarth ◽  
William F. Ries ◽  
Kate J. Clark ◽  
...  
Keyword(s):  
Nineteenth Century ◽  
New Zealand ◽  
Plate Boundary ◽  
Slip Rate ◽  
Fault System ◽  
Fault Rupture ◽  
Central Section ◽  
Surface Rupture ◽  
Early Nineteenth Century ◽  
Alpine Fault

ABSTRACT The Alpine fault is a high slip-rate plate boundary fault that poses a significant seismic hazard to southern and central New Zealand. To date, the strongest paleoseismic evidence for the onshore southern and central sections indicates that the fault typically ruptures during very large (Mw≥7.7) to great “full-section” earthquakes. Three paleoseismic trenches excavated at the northeastern end of its central section at the Toaroha River (Staples site) provide new insights into its surface-rupture behavior. Paleoseismic ruptures in each trench have been dated using the best-ranked radiocarbon dating fractions, and stratigraphically and temporally correlated between each trench. The preferred timings of the four most recent earthquakes are 1813–1848, 1673–1792, 1250–1580, and ≥1084–1276 C.E. (95% confidence intervals using OxCal 4.4). These surface-rupture dates correlate well with reinterpreted timings of paleoearthquakes from previous trenches excavated nearby and with the timing of shaking-triggered turbidites in lakes along the central section of the Alpine fault. Results from these trenches indicate the most recent rupture event (MRE) in this area postdates the great 1717 C.E. Alpine fault rupture (the most recent full-section rupture of the southern and central sections). This MRE probably occurred within the early nineteenth century and is reconciled as either: (a) a “partial-section” rupture of the central section; (b) a northern section rupture that continued to the southwest; or (c) triggered slip from a Hope-Kelly fault rupture at the southwestern end of the Marlborough fault system (MFS). Although, no single scenario is currently favored, our results indicate that the behavior of the Alpine fault is more complex in the north, as the plate boundary transitions into the MFS. An important outcome is that sites or towns near fault intersections and section ends may experience strong ground motions more frequently due to locally shorter rupture recurrence intervals.

Distributed deformation in the lower crust and upper mantle beneath a continental strike-slip fault zone: Marlborough fault system, South Island, New Zealand

Geology ◽  
2004 ◽  
Vol 32 (10) ◽  
pp. 837 ◽  
Author(s):  
Charles K. Wilson ◽  
Craig H. Jones ◽  
Peter Molnar ◽  
Anne F. Sheehan ◽  
Oliver S. Boyd
Keyword(s):  
New Zealand ◽  
Fault Zone ◽  
Upper Mantle ◽  
Lower Crust ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Fault System ◽  
Crust And Upper Mantle

Joint multidisciplinary study of the Saint-Sauveur–Donareo fault (lower Var valley, French Riviera): a contribution to seismic hazard assessment in the urban area of Nice

2011 ◽  
Vol 182 (4) ◽  
pp. 323-336 ◽  
Author(s):  
Christophe Larroque ◽  
Bertrand Delouis ◽  
Jean-Claude Hippolyte ◽  
Anne Deschamps ◽  
Thomas Lebourg ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Urban Areas ◽  
Regional Scale ◽  
Active Faults ◽  
Focal Depth ◽  
Strike Slip ◽  
Fault System ◽  
Geophysical Investigation ◽  
Lateral Strike Slip ◽  
North East

AbstractThe lower Var valley is the only large outcropping zone of Plio-Quaternary terrains throughout the southwestern Alps. In order to assess the seismic hazard for the Alps – Ligurian basin junction, we investigated this area to provide a record of earthquakes that have recently occurred near the city of Nice. Although no historical seismicity has been indicated for the lower Var valley, our main objective was to identify traces of recent faulting and to discuss the seismogenic potential of any active faults. We organized multidisciplinary observations as a microseismic investigation (the PASIS survey), with morphotectonic mapping and imagery, and subsurface geophysical investigations. The results of the PASIS dense recording survey were disappointing, as no present-day intense microseismic activity was recorded. From the morphotectonic investigation of the lower Var valley, we revealed several morphological anomalies, such as drainage perturbations and extended linear anomalies that are unrelated to the lithology. These anomalies strike mainly NE-SW, with the major Saint-Sauveur – Donareo lineament, clearly related to faulting of the Plio-Pleistocene sedimentary series. Sub-surface geophysical investigation (electrical resistivity tomography profiling) imaged these faults in the shallow crust, and together with the microtectonic data, allow us to propose the timing of recent faulting in this area. Normal and left-lateral strike-slip faulting occurred several times during the Pliocene. From fault-slip data, the last episode of faulting was left-lateral strike-slip and was related to a NNW-SSE direction of compression. This direction of compression is consistent with the present-day state of stress and the Saint-Sauveur–Donareo fault might have been reactivated several times as a left-lateral fault during the Quaternary. At a regional scale, in the Nice fold-and-thrust belt, these data lead to a reappraisal of the NE-SW structural trends as the major potentially active fault system. We propose that the Saint-Sauveur–Donareo fault belongs to a larger system of faults that runs from near Villeneuve-Loubet to the southwest to the Vésubie valley to the north-east. The question of a structural connection between the Vésubie – Mt Férion fault, the Saint-Sauveur–Donareo fault and its possible extension offshore through the northern Ligurian margin is discussed.The Saint-Sauveur–Donareo fault shows two en-échelon segments that extend for about 8 km. Taking into account the regional seismogenic depth (about 10 km), this fault could produce M ~6 earthquakes if activated entirely during one event. Although a moderate magnitude generally yields a moderate seismic hazard, we suggest that this contribution to the local seismic risk is high, taking into account the possible shallow focal depth and the high vulnerability of Nice and the surrounding urban areas.

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