Modeling Earthquake Moment Magnitudes on Imbricate Reverse Faults from Paleoseismic Data: Fox Peak and Forest Creek Faults, South Island, New Zealand

Stahl, Timothy; Quigley, Mark; McGill, A.

doi:10.1785/0120150215

Cited by 20 publications

(15 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many intraplate faults show evidence for strong temporal clustering of earthquakes and very low recurrence rates (10 to 100 kyr) (D. Clark et al, 2008, 2012, 2015; Cox et al, 2006; Crone et al, 1997, Craig et al, 2016; 2003; Gold et al, 2019; Stahl et al, 2016; Vallage & Bollinger, 2019). One intraplate faulting record that clearly demonstrates this behavior is from the Cadell Fault, in southeastern Australia.…”

Section: Understanding and Modeling The Temporal Distribution Of Fault Activitymentioning

confidence: 99%

Seismic Hazard Analyses From Geologic and Geomorphic Data: Current and Future Challenges

et al. 2020

View full text Add to dashboard Cite

The loss of life and economic consequences caused by several recent earthquakes demonstrate the importance of developing seismically safe building codes. The quantification of seismic hazard, which describes the likelihood of earthquake-induced ground shaking at a site for a specific time period, is a key component of a building code, as it helps ensure that structures are designed to withstand the ground shaking caused by a potential earthquake. Geologic or geomorphic data represent important inputs to the most common seismic hazard model (probabilistic seismic hazard analyses, or PSHAs), as they can characterize the magnitudes, locations, and types of earthquakes that occur over long intervals (thousands of years). However, several recent earthquakes and a growing body of work challenge many of our previous assumptions about the characteristics of active faults and their rupture behavior, and these complexities can be challenging to accurately represent in PSHA. Here, we discuss several of the outstanding challenges surrounding geologic and geomorphic data sets frequently used in PSHA. The topics we discuss include how to utilize paleoseismic records in fault slip rate estimates, understanding and modeling earthquake recurrence and fault complexity, the development and use of fault-scaling relationships, and characterizing enigmatic faults using topography. Making headway in these areas will likely require advancements in our understanding of the fundamental science behind processes such as fault triggering, complex rupture, earthquake clustering, and fault scaling. Progress in these topics will be important if we wish to accurately capture earthquake behavior in a variety of settings using PSHA in the future. Plain Language Summary Growing infrastructure and increasing population have caused significant loss of life due to recent large earthquakes, with the 2008 M w 7.9 Wenchuan and 2005 M w 7.6 Kashmir earthquakes each causing greater than 50,000 deaths. These earthquakes highlight the need for the development of building codes designed to withstand the strong ground shaking caused by earthquakes, as reinforced infrastructure is one of the most important factors for preventing fatalities due to ground shaking from earthquakes. Identifying the seismic hazard of a region, or the likelihood of ground shaking at a site due to potential earthquakes over time, is a key ingredient for informing a defensible building code. Here, we focus on current and future advances in how data from the fields of geology and geomorphology contribute to the most widely used type of seismic hazard model. These geologic data represent vital components to seismic hazard models, as they can provide information about the location and types of earthquakes that can occur over long, thousands of years, time periods, that cannot be obtained using other methods. We discuss some of the most pressing scientific issues about these data that are important for the development of seismic hazard models and defensible building codes.

show abstract

Section: Understanding and Modeling The Temporal Distribution Of Fault Activitymentioning

confidence: 99%

Seismic Hazard Analyses From Geologic and Geomorphic Data: Current and Future Challenges

et al. 2020

View full text Add to dashboard Cite

show abstract

“…There is no evidence of secondary scarps or antiscarps above or adjacent to the source scars, which might indicate some pre-failure deformation and a progressive failure mechanism that could bring the slope to failure in the absence of a significant trigger. The Forrest Creek and Fox Peak faults are both within 10 km of the source area and paleo seismic evidence and modeling by Stahl et al (2016b) suggests they are capable of generating earthquakes much stronger than the M w 6 threshold for coseismic triggering of major RSFs in New Zealand (Hancox et al, 2002). Paleo seismic records for the faults do not extend as far back in time as the BSRA, but given the recurrence intervals for the faults of less than 3000 years (Stahl et al, 2016b), they are likely to have generated multiple earthquakes over the past 20,000 years.…”

Section: The Causes Of the Bush Stream Rock Avalanchementioning

confidence: 89%

The Anomalously Old Bush Stream Rock Avalanche and Its Implications for Landslide Inventories in Dynamic Landscapes

McColl

2020

Front. Earth Sci.

View full text Add to dashboard Cite

Previous dating of rock slope failures in most glaciated mountain chains has revealed almost exclusively young, mostly Holocene ages. In this study, a rock avalanche in the glaciated Rangitata Basin in Canterbury, New Zealand is mapped, described, and dated, revealing a pre-Holocene age of failure. The geomorphology and characteristics of the rock avalanche, named here as the Bush Stream Rock Avalanche, were assessed from field mapping and photogrammetric analyses. To assess the age of the rock avalanche, in situ cosmogenic 10 Be exposure dating was applied to boulders on the deposit. The geomorphological mapping shows that the morphology of the head scarp and deposit of the rock avalanche are distinct from the surrounding landscape, much of which appears to be glacial in origin. The rock avalanche traveled about 4 km, with a volume of 50-100 M m 3 , and appears to have temporarily blocked Bush Stream. The dated boulders suggest an age of >16 ka (and likely >20 ka), making it the oldest reported alpine rock avalanche in New Zealand, and one of the oldest last-glaciation rock avalanches to be reported worldwide. Deep depressions, possibly kettle holes, in the deposit are indicative of runout over a glacier (or associated dead ice), but any glacier present at the time must have been small and probably decaying. The excellent preservation was likely favored by a small catchment located on the dry lee side of the Two Thumb Range which dampened glacial and fluvial activity. The study confirms that rock avalanches were being produced in the Southern Alps early in the last glaciation or early period of deglaciation, but that evidence for them likely exists only in the rare environments that have conditions favorable for preservation. Preservation potential in most of the Southern Alps is low, with older deposits readily buried or eroded by New Zealand's high rates of erosion, aggradation, and dynamic processes. Unless methods can be developed to identify missing older events, we are hampered in our ability to understand the frequency, and therefore causes, of large slope failures in the Southern Alps and in other highly dynamic alpine landscapes.

show abstract

“…Journal of Geophysical Research: Solid Earth multifault rupture scenarios between the Fox Creek and Fox Peak faults on the South Island of New Zealand (Stahl et al, 2016).…”

Section: 1029/2020jb019539mentioning

confidence: 99%

Three‐Dimensional Structure, Ground Rupture Hazards, and Static Stress Models for Complex Nonplanar Thrust Faults in the Ventura Basin, Southern California

et al. 2020

View full text Add to dashboard Cite

To investigate the subsurface geometry of a recently discovered, seismically active fault in the Ventura basin, southern California, USA, we present a series of cross sections and a new three-dimensional fault model across the Southern San Cayetano fault (SSCF) based on integration of surface data with petroleum industry well log data. Additionally, the fault model for the SSCF, along with models of other regional faults extracted from the Southern California Earthquake Center three-dimensional Community Fault Model, are incorporated in static Coulomb stress modeling to investigate static Coulomb stress transfer between thrust faults with complex geometry and to further our understanding of stress transfer in the Ventura basin. The results of the subsurface well investigation provide evidence for a low-angle SSCF that dips~15°north and connects with the western section of the San Cayetano fault around 1.5-3.5 km depth. We interpret the results of static Coulomb stress models to partly explain contrasting geomorphic expression between different sections of the San Cayetano fault and a potential mismatch in timings between large-magnitude uplift events suggested by paleoseismic studies on the Pitas Point, Ventura, and San Cayetano faults. In addition to new insights into the structure and potential rupture hazard of a recently discovered active reverse fault in a highly populated area of southern California, this study provides a simple method to model static Coulomb stress transfer on complex geometry faults in fold and thrust belts.

show abstract

Modeling Earthquake Moment Magnitudes on Imbricate Reverse Faults from Paleoseismic Data: Fox Peak and Forest Creek Faults, South Island, New Zealand

Cited by 20 publications

References 63 publications

Seismic Hazard Analyses From Geologic and Geomorphic Data: Current and Future Challenges

Seismic Hazard Analyses From Geologic and Geomorphic Data: Current and Future Challenges

The Anomalously Old Bush Stream Rock Avalanche and Its Implications for Landslide Inventories in Dynamic Landscapes

Three‐Dimensional Structure, Ground Rupture Hazards, and Static Stress Models for Complex Nonplanar Thrust Faults in the Ventura Basin, Southern California

Contact Info

Product

Resources

About