scholarly journals A 2000 Yr Paleoearthquake Record along the Conway Segment of the Hope Fault: Implications for Patterns of Earthquake Occurrence in Northern South Island and Southern North Island, New Zealand

2019 ◽  
Vol 109 (6) ◽  
pp. 2216-2239 ◽  
Author(s):  
Alexandra E. Hatem ◽  
James F. Dolan ◽  
Robert W. Zinke ◽  
Russell J. Van Dissen ◽  
Christopher M. McGuire ◽  
...  
Keyword(s):  
New Zealand ◽  
Late Holocene ◽  
Plate Boundary ◽  
Slip Rate ◽  
Fault System ◽  
Recent Event ◽  
Radiocarbon Age ◽  
Earthquake Record ◽  
Surface Ruptures ◽  
Age Constraints

Abstract Paleoseismic trenches excavated at two sites reveal ages of late Holocene earthquakes along the Conway segment of the Hope fault, the fastest-slipping fault within the Marlborough fault system in northern South Island, New Zealand. At the Green Burn East (GBE) site, a fault-perpendicular trench exposed gravel colluvial wedges, fissure fills, and upward fault terminations associated with five paleo-surface ruptures. Radiocarbon age constraints indicate that these five earthquakes occurred after 36 B.C.E., with the four most recent surface ruptures occurring during a relatively brief period (550 yr) between about 1290 C.E. and the beginning of the historical earthquake record about 1840 C.E. Additional trenches at the Green Burn West (GBW) site 1.4 km west of GBE reveal four likely coseismically generated landslides that occurred at approximately the same times as the four most recent GBE paleoearthquakes, independently overlapping with age ranges of events GB1, GB2, and GB3 from GBE. Combining age constraints from both trench sites indicates that the most recent event (GB1) occurred between 1731 and 1840 C.E., the penultimate event GB2 occurred between 1657 and 1797 C.E., GB3 occurred between 1495 and 1611 C.E., GB4 occurred between 1290 and 1420 C.E., and GB5 occurred between 36 B.C.E. and 1275 C.E. These new data facilitate comparisons with similar paleoearthquake records from other faults within the Alpine–Hope–Jordan–Kekerengu–Needles–Wairarapa (Al-Hp-JKN-Wr) fault system of throughgoing, fast-slip-rate (≥10  mm/yr) reverse-dextral faults that accommodate a majority of Pacific–Australia relative plate boundary motion. These comparisons indicate that combinations of the faults of the Al-Hp-JKN-Wr system may commonly rupture within relatively brief, ≤100-year-long sequences, but that full “wall-to-wall” rupture sequences involving all faults in the system are rare over the span of our paleoearthquake data. Rather, the data suggest that the Al-Hp-JKN-Wr system may commonly rupture in subsequences that do not involve the entire system, and potentially, at least sometimes, in isolated events.

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.

scholarly journals Holocene to latest Pleistocene incremental slip rates from the east-central Hope fault (Conway segment) at Hossack Station, Marlborough fault system, South Island, New Zealand: Towards a dated path of earthquake slip along a plate boundary fault

Geosphere ◽  
2020 ◽  
Vol 16 (6) ◽  
pp. 1558-1584
Author(s):  
Alexandra E. Hatem ◽  
James F. Dolan ◽  
Robert W. Zinke ◽  
Robert M. Langridge ◽  
Christopher P. McGuire ◽  
...  
Keyword(s):  
New Zealand ◽  
Plate Boundary ◽  
Slip Rate ◽  
Temporal Variations ◽  
Luminescence Dating ◽  
Fault System ◽  
Surface Deposition ◽  
Slip Rates ◽  
East Central ◽  
Fault Slip Rate

Abstract Geomorphic field and aerial lidar mapping, coupled with fault-parallel trenching, reveals four progressive offsets of a stream channel and an older offset of the channel headwaters and associated fill terrace–bedrock contact at Hossack Station along the Conway segment of the Hope fault, the fastest-slipping fault within the Marlborough fault system in northern South Island, New Zealand. Radiocarbon and luminescence dating of aggradational surface deposition and channel initiation and abandonment event horizons yields not only an average dextral rate of ∼15 mm/yr since ca. 14 ka, but also incremental slip rates for five different time periods (spanning hundreds to thousands of years) during Holocene to latest Pleistocene time. These incremental rates vary through time and are, from youngest to oldest: 8.2 +2.7/−1.5 mm/yr averaged since 1.1 ka; 32.7 +∼124.9/−10.1 mm/yr averaged over 1.61–1.0 ka; 19.1 ± 0.8 mm/yr between 5.4 and 1.6 ka; 12.0 ± 0.9 mm/yr between 9.4 and 5.4 ka, and 13.7 +4.0/−3.4 mm/yr from 13.8 to 9.4 ka, with generally faster rates in the mid- to late Holocene relative to slower rates prior to ca. 5.4 ka. The most pronounced variation in rates occurs between the two youngest intervals, which are averaged over shorter time spans (≤1700 yr) than the three older incremental rates (3700–4500 yr). This suggests that the factor of ∼1.5× variations in Hope fault slip rate observed in the three older, longer-duration incremental rates may mask even greater temporal variations in rate over shorter time scales.

Kekerengu Fault, New Zealand: Timing and Size of Late Holocene Surface Ruptures

2018 ◽  
Vol 108 (3B) ◽  
pp. 1556-1572 ◽  
Author(s):  
T. A. Little ◽  
R. Van Dissen ◽  
J. Kearse ◽  
K. Norton ◽  
A. Benson ◽  
...  
Keyword(s):  
New Zealand ◽  
Late Holocene ◽  
Surface Ruptures

The discovery of a new sedimentary basin: offshore Raukumara, East Coast, North Island, New Zealand

2008 ◽  
Vol 48 (1) ◽  
pp. 53 ◽  
Author(s):  
Chris Uruski ◽  
Callum Kennedy ◽  
Rupert Sutherland ◽  
Vaughan Stagpoole ◽  
Stuart Henrys
Keyword(s):  
New Zealand ◽  
Oil And Gas ◽  
East Coast ◽  
Plate Boundary ◽  
Source Rocks ◽  
Fault System ◽  
Northern Coast ◽  
The South ◽  
Petroleum Potential ◽  
The North

The East Coast of North Island, New Zealand, is the site of subduction of the Pacific below the Australian plate, and, consequently, much of the basin is highly deformed. An exception is the Raukumara Sub-basin, which forms the northern end of the East Coast Basin and is relatively undeformed. It occupies a marine plain that extends to the north-northeast from the northern coast of the Raukumara Peninsula, reaching water depths of about 3,000 m, although much of the sub-basin lies within the 2,000 m isobath. The sub-basin is about 100 km across and has a roughly triangular plan, bounded by an east-west fault system in the south. It extends about 300 km to the northeast and is bounded to the east by the East Cape subduction ridge and to the west by the volcanic Kermadec Ridge. The northern seismic lines reveal a thickness of around 8 km increasing to 12–13 km in the south. Its stratigraphy consists of a fairly uniformly bedded basal section and an upper, more variable unit separated by a wedge of chaotically bedded material. In the absence of direct evidence from wells and samples, analogies are drawn with onshore geology, where older marine Cretaceous and Paleogene units are separated from a Neogene succession by an allochthonous series of thrust slices emplaced around the time of initiation of the modern plate boundary. The Raukumara Sub-basin is not easily classified. Its location is apparently that of a fore-arc basin along an ocean-to-ocean collision zone, although its sedimentary fill must have been derived chiefly from erosion of the New Zealand land mass. Its relative lack of deformation introduces questions about basin formation and petroleum potential. Although no commercial discoveries have been made in the East Coast Basin, known source rocks are of marine origin and are commonly oil prone, so there is good potential for oil as well as gas in the basin. New seismic data confirm the extent of the sub-basin and its considerable sedimentary thickness. The presence of potential trapping structures and direct hydrocarbon indicators suggest that the Raukumara Sub-basin may contain large volumes of oil and gas.

Paleo-surface ruptures at both sides of a pressure ridge along Alhama de Murcia Fault (SE Spain)

2020 ◽  
Author(s):  
Octavi Gómez-Novell ◽  
María Ortuño ◽  
Julián García-Mayordomo ◽  
Eulàlia Masana ◽  
Thomas Rockwell ◽  
...  
Keyword(s):  
Active Faults ◽  
Great Part ◽  
Slip Rate ◽  
Fault System ◽  
Radiocarbon Dates ◽  
Seismic Parameters ◽  
Central Segment ◽  
Pressure Ridge ◽  
Combining Data ◽  
Surface Ruptures

<p>The Alhama de Murcia Fault (AMF) is one of the most seismically active faults in the Iberian Peninsula, with important associated historical and instrumental seismicity (e.g. the 1674 I<sub>EMS </sub>VIII and 2011 Mw 5.1 Lorca earthquakes), and numerous geomorphic and paleoseismic evidence of paleoearthquakes. It is an oblique left-lateral strike slip fault within the Eastern Betics Shear Zone (EBSZ), a nearly 500 km long fault system that absorbs a great part of convergence between the Nubian and Eurasian plates. Previous paleoseismic studies have mainly focused on the southwestern and especially the central segment of the fault and yielded slip rate values ranging from 1.0 up to 1.7 mm/yr. In the central segment (Lorca-Totana), the fault splays into several branches, the two frontal ones forming a pressure ridge. Paleoseismic trenches have exclusively been dug in the northwestern fault of the pressure ridge, where most of the displacement is along strike, while the expected reverse southeastern branch has never been directly observed.</p><p>We present the first results of paleoseismic trenching across a complete transect of the pressure ridge in the Lorca-Totana segment of AMF. To do so we excavated an exceptionally large trench (7 m deep) in the NW branch and 5 trenches in the SE branch. We have been able to: a) extend the paleoearthquake catalogue in the NW branch by interpreting a total of 13 paleoearthquakes, 6 of which were not identified in previous studies. A restoration analysis has been performed; b) unveil the existence and recent activity (Holocene) of the thrust that bounds the pressure ridge to the SE. We have interpreted at least 5 surface ruptures, with the last one being younger than 8-9 kyr BP, based on new radiocarbon dates.</p><p>The study of these two sites allows for the refinement of the seismic parameters of the fault, formerly inferred from the study of a single branch. In this sense, the more complete paleoearthquake catalogue will allow for reassessment of the recurrence intervals assigned to the fault and new slip rate estimates will be inferred by combining data from the two studied sites. Furthermore, forthcoming OSL dates may allow us to prove or reject the synchronicity of surface ruptures on both sides of the pressure ridge, shedding light on the rupturing style of this fault system during the Late Quaternary. We discuss how these new data on fault-interaction may affect several seismic parameters and their repercussion in source modelling for fault-based probabilistic seismic hazard assessments (PSHA) of the region.</p>

Late Eocene – Early Miocene facies and stratigraphic development, Taranaki Basin, New Zealand: the transition to plate boundary tectonics during regional transgression

2019 ◽  
Vol 156 (10) ◽  
pp. 1751-1770 ◽  
Author(s):  
Dominic P. Strogen ◽  
Karen E. Higgs ◽  
Angela G. Griffin ◽  
Hugh E. G. Morgans
Keyword(s):  
New Zealand ◽  
Tectonic Setting ◽  
Plate Boundary ◽  
Late Eocene ◽  
Early Miocene ◽  
Fault System ◽  
Initial Development ◽  
Early Oligocene ◽  
Well Data ◽  
Latest Eocene

AbstractEight latest Eocene to earliest Miocene stratigraphic surfaces have been identified in petroleum well data from the Taranaki Basin, New Zealand. These surfaces define seven regional sedimentary packages, of variable thickness and lithofacies, forming a mixed siliciclastic–carbonate system. The evolving tectonic setting, particularly the initial development of the Australian–Pacific convergent margin, controlled geographic, stratigraphic and facies variability. This tectonic signal overprinted a regional transgressive trend that culminated in latest Oligocene times. The earliest influence of active compressional tectonics is reflected in the preservation of latest Eocene – Early Oligocene deepwater sediments in the northern Taranaki Basin. Thickness patterns for all mid Oligocene units onwards show a shift in sedimentation to the eastern Taranaki Basin, controlled by reverse movement on the Taranaki Fault System. This resulted in the deposition of a thick sedimentary wedge, initially of coarse clastic sediments, later carbonate dominated, in the foredeep close to the fault. In contrast, Oligocene active normal faulting in a small sub-basin in the south may represent the most northerly evidence for rifting in southern Zealandia, related to Emerald Basin formation. The Early Miocene period saw a return to clastic-dominated deposition, the onset of regional regression and the southward propagation of compressional tectonics.

Fragmentation of the Sinai Plate indicated by spatial variation in present-day slip rate along the Dead Sea Fault System

2020 ◽  
Vol 221 (3) ◽  
pp. 1913-1940
Author(s):  
Francisco Gomez ◽  
William J Cochran ◽  
Rayan Yassminh ◽  
Rani Jaafar ◽  
Robert Reilinger ◽  
...  
Keyword(s):  
Continental Margin ◽  
Plate Boundary ◽  
Slip Rate ◽  
Dead Sea ◽  
Fault System ◽  
Slip Rates ◽  
Dead Sea Fault System ◽  
The Dead ◽  
Gps Velocities ◽  
Splay Faults

SUMMARY A comprehensive GPS velocity field along the Dead Sea Fault System (DSFS) provides new constraints on along-strike variations of near-transform crustal deformation along this plate boundary, and internal deformation of the Sinai and Arabian plates. In general, geodetically derived slip rates decrease northwards along the transform (5.0 ± 0.2 to 2.2 ± 0.5 mm yr−1) and are consistent with geological slip rates averaged over longer time periods. Localized reductions in slip rate occur where the Sinai Plate is in ∼N–S extension. Extension is confined to the Sinai side of the fault and is associated with prominent changes in transform geometry, and with NW–SE striking, left-lateral splay faults, including the Carmel Fault in Israel and the Roum Fault in Lebanon. The asymmetry of the extensional velocity gradients about the transform reflects active fragmentation of the Sinai Plate along the continental margin. Additionally, elastic block modelling of GPS velocities requires an additional structure off-shore the northern DSF segment, which may correspond with a fault located along the continental margin, suggested by prior geophysical studies.

Major Earthquakes Occur Regularly on an Isolated Plate Boundary Fault

Science ◽  
2012 ◽  
Vol 336 (6089) ◽  
pp. 1690-1693 ◽  
Author(s):  
Kelvin R. Berryman ◽  
Ursula A. Cochran ◽  
Kate J. Clark ◽  
Glenn P. Biasi ◽  
Robert M. Langridge ◽  
...  
Keyword(s):  
Plate Boundary ◽  
Slip Rate ◽  
Strike Slip ◽  
Earthquake Recurrence ◽  
Alpine Fault ◽  
Earthquake Record ◽  
Different Types ◽  
Seismic Hazard Estimation ◽  
Recurrence Behavior ◽  
Types Of Faults

The scarcity of long geological records of major earthquakes, on different types of faults, makes testing hypotheses of regular versus random or clustered earthquake recurrence behavior difficult. We provide a fault-proximal major earthquake record spanning 8000 years on the strike-slip Alpine Fault in New Zealand. Cyclic stratigraphy at Hokuri Creek suggests that the fault ruptured to the surface 24 times, and event ages yield a 0.33 coefficient of variation in recurrence interval. We associate this near-regular earthquake recurrence with a geometrically simple strike-slip fault, with high slip rate, accommodating a high proportion of plate boundary motion that works in isolation from other faults. We propose that it is valid to apply time-dependent earthquake recurrence models for seismic hazard estimation to similar faults worldwide.

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