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(a) Schematic diagram of slope processes that can lead to nontectonic exhumation and burial of active limestone fault scarps. Labels 1–4 indicate areas of hangingwall erosion or deposition that are inappropriate sample locations. Ideal sites are located tens of meters away from areas affected by depositional and erosional slope processes, where the scarp‐slope contacts are horizontal, after Bubeck et al. (2015). (b) The Campo Felice fault with features from (a) indicated. Photo taken from (42.2308°N, 13.4343°E), view northeast. The horizontal scale is approximately 320 m across image at the height of scarp.
Source publication
Cosmogenic exposure data can be used to calculate time‐varying fault slip rates on normal faults with exposed bedrock scarps. The method relies on assumptions related to how the scarp is preserved, which should be consistent at multiple locations along the same fault. Previous work commonly relied on cosmogenic data from a single sample locality to...
Citations
... ). There are, however, increasing examples of paleoseismic records that indicate temporal earthquake clustering at 1-1000 kyr timescales, particularly for low slip rate (<1 mm/yr) faults in stable continental regions(Clark et al. 2012;Calais et al. 2016), slowly deforming plate boundariesGoodall et al. 2021;Martín-Banda et al. 2021) or, like the Settlement Fault, at the peripheral edge of plate boundaries (Pérouse and Wernicke 2017). ...
... The Mediterranean is a densely populated, seismically active region subjected to hundreds of earthquakes of magnitude (M) > 4 every year (Godey et al., 2013;Meng et al., 2021;Ozkula et al., 2023). Within the Aegean tectonic plate (Fig. 1a) and around its margins, there were > 1450 earthquakes during 1998-2010 (Godey et al., 2013), 77 of which were M > 5. ...
... The Mediterranean is a densely populated, seismically active region subjected to hundreds of earthquakes of magnitude (M) > 4 every year (Godey et al., 2013;Meng et al., 2021;Ozkula et al., 2023). Within the Aegean tectonic plate (Fig. 1a) and around its margins, there were > 1450 earthquakes during 1998-2010 (Godey et al., 2013), 77 of which were M > 5. In central Greece, earthquakes are associated with normal faults, which occur because of the extension of the Aegean plate (Jolivet et al., 2013). ...
Reconstructions of palaeoseismicity are useful for understanding and mitigating seismic hazard risks. We apply cosmogenic ³⁶Cl exposure-age dating and measurements of rare-earth elements and yttrium (REE-Y) concentrations to the palaeoseismic history of the Sparta Fault, Greece. Bayesian-inference Markov chain Monte Carlo (MCMC) modelling of ³⁶Cl concentrations along a 7.2 m long vertical profile on the Sparta Fault scarp at Anogia indicate an increase in the average slip rate of the scarp from 0.8–0.9 mm yr⁻¹ 6.5–7.7 kyr ago to 1.1–1.2 mm yr⁻¹ up to the devastating 464 BCE earthquake. The average exhumation of the entire scarp up to the present day is 0.7–0.8 mm yr⁻¹. Modelling does not indicate additional exhumation of the Sparta Fault after 464 BCE. The Sparta Fault scarp is composed of fault breccia, containing quartz and clay-lined pores, in addition to host-rock-derived clasts of calcite and microcrystalline calcite cement. The impurities control the distribution of REE-Y in the fault scarp surface and contribute spatial variation to ³⁶Cl concentrations, which precludes the identification of individual earthquakes that have exhumed the Sparta Fault scarp from either of these data sets. REE-Y may illustrate processes that localize slip to a discrete fault plane in the Earth's near-surface, but their potential use in palaeoseismicity would benefit from further evaluation.
... The 36 Cl cosmogenic exposure dating method was developed and applied on carbonate normal fault scarps over the last two decades (Akçar et al., 2012;Benedetti et al., 2002;Goodall et al., 2021;Iezzi et al., 2021;Mitchell et al., 2001;Mozafari et al., 2022;Schlagenhauf et al., 2010;Zreda & Noller, 1998). This method is based on the fact that the cosmogenic isotope 36 Cl is primarily produced and accumulated in the carbonate fault rocks due to the interaction between cosmic radiation and Ca-rich minerals (Gosse & Phillips, 2001). ...
Plain Language Summary
Surface rupture occurs when a large earthquake caused by movement along a fault, breaks through the Earth's surface. The ³⁶Cl cosmogenic dating is used to recover past earthquakes that generate surface rupture. Using this method to constrain the fault activity over multiple earthquake cycles and across fault systems provides essential data to understand how earthquakes behave along fault systems and how faults interact during the earthquakes. We recovered the last 30 ka surface rupture history of three fault segments, each approximately 5 km in length, from the Bet Kerem fault system, northern Israel, using the ³⁶Cl exposure dating method. Results indicate that the three segments were active in at least three distinguished periods, in each of which a minimum of 1.2 m of surface rupturing occurred at each fault segment. The amount of surface rupture observed at each of the segments is too large to be generated by one single earthquake that only ruptures the fault segment. However, when all segments are considered together their total length corresponds well with the amount of offset. We, therefore, suggest that the large surface rupture observed at each activity period is caused by large earthquakes that ruptured the three dated segments at once.
... The age of such faults scarps in central Italy is also constrained by in situ 36 Cl cosmogenic dating of the exposed fault planes (e.g. Palumbo et al., 2004;Schlagenhauf et al., 2010Schlagenhauf et al., , 2011Benedetti et al., 2013;Cowie et al., 2017;Goodall et al., 2021;Mildon et al., 2022), which in general, confirms the age of 15 ± 3 ka, with some examples older by a few millennia. ...
... Firstly, the MCMC modelling indicates that evidence for slip may be preserved from as far back as at least ~30,000 yrs BP for the Pescasseroli and Maiella faults, and ~20,000 years for the Scanno fault ( Fig. 4d-f). The age of periglacial slopes that stabilised during the demise of the glaciation in central Italy, and hence offset by post-LGM scarps, has in the past been suggested to be 15 ± 3 ka by other authors, so the ages of scarps are expected to be no older than this age (Roberts and Michetti 2004;Palumbo et al., 2004;Faure Walker et al., 2010Schlagenhauf et al., 2010Schlagenhauf et al., , 2011Tucker et al., 2011;Benedetti et al., 2013;Cowie et al., 2017;Tesson and Benedetti 2019;Goodall et al., 2021). However, our results suggest that some evidence for the slip before 15 ± 3 ka has been preserved on the three faults we study. ...
Uncertainty concerning the processes responsible for slip-rate fluctuations associated with temporal clustering of
surface faulting earthquakes is a fundamental, unresolved issue in tectonics, because strain-rates accommodated
by fault/shear-zone structures are the key to understanding the viscosity structure of the crust and seismic
hazard. We constrain the timing and amplitude of slip-rate fluctuations that occurred on three active normal
faults in central Italy over a time period of 20–30 kyrs, using in situ 36Cl cosmogenic dating of fault planes. We
identify five periods of rapid slip on individual faults lasting a few millennia, separated time periods of up to 10
millennia with low or zero slip-rate. The rapid slip pulses migrated across the strike between the faults in two
waves from SW to NE. We replicate this migration with a model where rapid slip induces changes in differential
stress that drive changes in strain-rate on viscous shear zones that drive slip-rate variability on overlying brittle
faults. Earthquakes increase the differential stress and strain-rate on underlying shear zones, which in turn
accumulate strain, re-loading stress onto the overlying brittle fault. This positive feedback produces high strainrate
episodes containing several large magnitude surface faulting earthquakes (earthquake clusters), but also
reduce the differential stress on the viscous portions of neighbouring fault/shear-zones slowing the occurrence of
large-magnitude surface faulting earthquakes (earthquake anticlusters). Shear-zones on faults experiencing
anticlusters continue to accumulate viscous strain at a lowered rate, and eventually this loads the overlying
brittle fault to failure, initiating a period of rapid slip through the positive feedback process described above, and
inducing lowered strain-rates onto neighbouring fault/shear-zones. We show that these patterns of differential
stress change can replicate the measured earthquake clustering implied by the 36Cl data. The stress changes are
related to the fault geometry in terms of distance and azimuth from the slipping structure, implying that (a)
strain-rate and viscosity fluctuations for studies of continental rheology, and (b) slip-rates for seismic hazard
purposes are to an extent predictable given knowledge of the fault system geometry.
... Orsello Fault -MOF, Fig. 2: Giaccio et al. 2003;Wilkinson et al. 2015;Schirripa Spagnolo et al., 2021;Del Rio et al. 2023). Other studies estimated timing and magnitude of the most recent Holocene seismic cycles of the MCF (e.g., Benedetti et al. 2013;Goodall et al. 2021), thus dealing with a limited span (10 3 a) of the overall fault history (>10 5 a). On the other hand, the basin subsurface was never investigated by geophysical tools: to date, the only information on the sedimentary fill comes from some shallow boreholes (Giraudi et al. 2011;Giraudi and Giaccio, 2017) that do not reach the basin substratum. ...
... 2), interpreted as mostly due to the coseismic exhumation occurring during discrete slip episodes since the demise of the Last Glacial Maximum (LGM, 19-20 cal ka BP; Clark et al. 2009;Giraudi, 2015). Several studies based on different approaches focused on the estimation of the activity rate of the MCF since the late Pleistocene (e.g., Wilkinson et al. 2015;Goodall et al. 2021), and the quantification of the main coseismic slip phases occurred since the LGM (e.g., Giaccio et al. 2003;Benedetti et al. 2013). For instance, Benedetti et al. (2013) inferred four major earthquakes between 9.4 and 1.1 ka, with an estimated average slip rate in the range of 0.9-2.5 mm/a. ...
... Later studies (see below) refined identification of faulting bands using changes in the slope angle, partial shielding by colluvium, and more recently concentration of REE (rare earth elements). Numerical approaches for modelling stepwise scarp exposure and nuclide buildup were performed by Schlagenhauf et al. 2018) and Goodall et al. (2021). Most scarp studies to date have been conducted by measuring 36 Cl in Ca-rich lithologies, but other nuclides can be used, e. g. 10 Be in quartz-rich lithologies (Lunina et al., 2020;Tian et al., 2021). ...
... Later studies (see below) refined identification of faulting bands using changes in the slope angle, partial shielding by colluvium, and more recently concentration of REE (rare earth elements). Numerical approaches for modelling stepwise scarp exposure and nuclide buildup were performed by Schlagenhauf et al. 2018) and Goodall et al. (2021). Most scarp studies to date have been conducted by measuring 36 Cl in Ca-rich lithologies, but other nuclides can be used, e. g. 10 Be in quartz-rich lithologies (Lunina et al., 2020;Tian et al., 2021). ...
Oscillation of an ice sheet can be accompanied by earthquakes due to local reactivation of pre-existing faults related to the ice loading. A sufficiently large magnitude of an earthquake can trigger seismic waves that may strongly deform susceptible sediment layers and can cause the development of soft-sediment deformation structures (SSDS). Morphological and structural features of SSDS within a glaciolacustrine succession exposed at the coastal cliff on Gnitz Peninsula (Usedom Island) in NE Germany indicate that they must have developed due to glacial isostatic adjustment, which was suggested earlier by Hoffmann and Reicherter (2012).
Here we present detailed micro- and meso-scale SSDS within internally deformed layers interpreted as seismites, liquefaction and re-liquefaction sedimentological imprints on Gnitz Peninsula. New optically stimulated luminescence dating results indicate that the most probable time span of corresponding earthquake occurrence is between 23.2 and 14.6 ka. The interpretation of SSDS ‘trapped’ in layers as seismites is strongly supported by modelling of glacially induced Coulomb failure stress changes in this region. Our results point to a set of probably pre-Quaternary faults which were locally reactivated in the area of Gnitz Peninsula during the last glacial maximum.
... Increasingly, active rift studies show that fault activity is episodic and slip rates are spatially and temporally variable (Cowie et al., 2017;Friedrich et al., 2003;Schlagenhauf et al., 2008). Studies focused on Holocene deformation show that meters of displacement accumulate rapidly in higher-than-average slip rates over several thousand years, separated by periods of lower-than-average slip rates and relative quiescence (Bennedetti et al., 2013;Goodall et al., 2021;Mechernich et al., 2018). The active rift record is thus short and provides only a temporal snapshot of the long, geological timescales over which faults grow. ...
Continental extension is accommodated by the development of kilometer‐scale normal faults, which grow during meter‐scale slip events that occur over millions of years. However, reconstructing the entire lifespan of a fault remains challenging due to a lack of observational data with spatiotemporal scales that span the early stage (<10⁶ yrs) of fault growth. Using three‐dimensional numerical simulations of continental extension and novel methods for extracting the locations of faults, we quantitatively examine the key factors controlling the growth of rift‐scale fault networks over 10⁴–10⁶ yrs. Early formed faults (<100 kyrs from initiation) exhibit scaling ratios consistent with those characterizing individual earthquake ruptures, before evolving to be geometrically and kinematically similar to more mature structures developed in natural fault networks. Whereas finite fault lengths are rapidly established (<100 kyrs), active deformation is transient, migrating both along‐ and across‐strike. Competing stress interactions determine the distribution of active strain, which oscillates between being distributed and localized. Higher rates of extension (10 mm yr⁻¹) lead to more prominent stress redistributions through time, promoting episodic localized slip events. Our findings demonstrate that normal fault growth and the related occurrence of cumulative slip is more complex than that currently inferred from displacement patterns on now‐inactive structures, which only provide a space‐ and time‐averaged picture of fault kinematics and related seismic hazard.
... Based on this understanding, we analyze the roughness of bedrock fault surfaces along the Monte Vettore fault and Roccapreturo fault ( Fig. 2) to resolve the slip increments of past earthquakes (e.g., Wei et al., 2013;He et al., 2016;Zou et al., 2020). Both faults feature sites with well-developed limestone fault scarps -some of which investigated previously, therefore providing a contextual framework for our own investigation (e.g., Giaccio et al., 2002;Schlagenhauf, 2009;Falcucci et al., 2015;Galli et al., 2019;Cinti et al., 2019;Corradetti et al., 2021;Goodall et al., 2021). The two faults are located in the central Apennines (Italy), a NW-trending, ~400 km long and ~ 100 km wide mountain range that undergoes NE-SW extension at a rate of 3-4 mm/yr (D'Agostino, 2014). ...
... Falcucci et al. (2015) further found paleoseismic evidence for at least two surface rupturing earthquakes since 7.5 kyrs ago, with an accumulated minimum offset of 1.8 m. Additionally, a CRN investigation by Goodall et al. (2021) suggested that the most recent earthquake occurred ~2.6 kyr ago. Following, we describe our data set and analysis approach before presenting our results. ...
... Apparently, the fault surface roughened more quickly than cosmogenic radionuclides accumulated, therefore enabling to resolve smaller variations thereof. Because our methodology cannot constrain the timing of the identified paleoearthquakes, we are not able to directly compare (and calibrate) our findings with the paleoseismic study by Falcucci et al. (2015) or the CRN study by Goodall et al. (2021) that were also conducted along the Roccapreturo fault. ...
While the cyclic nature of tectonic strain build-up and release is at least conceptually well understood (known as the earthquake cycle), it is not clear how variable the corresponding earthquake sizes and the time intervals between them are. Additional observations from past earthquakes are required to better constrain these aspects.
In this context, we investigate the roughness of bedrock normal fault scarps along the Mt. Vettore fault and Roccapreturo fault (Italy), motivated by field observations that roughness positively correlates with profile height: higher sections of the fault surface are rougher than lower sections, ostensibly because the scarps were created by consecutive exposure events (e.g., earthquakes), exposing the higher sections for longer periods of time to subaerial weathering processes. Using high-resolution topographic models of the two fault surfaces, we calculate local roughness metrics and determine how they change as a function of profile height. In doing so, we are able to identify step-like changes in fault roughness, suggesting that the studied portions of the Mt. Vettore and Roccapreturo fault scarps were formed respectively by at least 6 and 4 large earthquakes, with slip increments ranging from 0.2 m to 1.7 m and corresponding magnitudes ranging from M6.1 to M6.8. Comparing our results for the Roccapreturo scarp with a previous cosmogenic radionuclide (CRN) investigation at this site indicates that we were able to a) find previously identified earthquakes and b) find additional, previously unresolved ones. It appears that, during the same time interval, fault plane roughness analysis may be a more sensitive indicator of past earthquake activity on carbonate scarps than cosmogenic dating.
... Furthermore, bedrock fault scarps are actively deformed markers, which can directly record the repeated seismic activity of normal faults (Benedetti and van der Woerd, 2014). Based on the advantages outlined above, the potential for obtaining quantitative seismic information from tectonic geomorphic features of bedrock fault scarps has been widely considered (e.g., Zreda and Noll, 1998;Mitchell et al., 2001;Benedetti et al., 2002;Goodall et al., 2021). The paleo-earthquake study of bedrock fault surfaces focuses on fault scarps propagating into bedrock areas, increasing the number of sites available for study both spatially and temporally, providing a more complete understanding of the fault behavior (Tesson et al., 2016(Tesson et al., , 2020Tesson and Benedetti, 2019). ...
... The advanced techniques above have been widely applied to bedrock normal faults in the grabens of the U.S.A. (Zreda and Noll, 1998), Israel (Mitchell, 1998;Mitchell et al., 2001), Greece (Benedetti et al., 2002(Benedetti et al., , 2003(Benedetti et al., , 2013Mouslopoulou et al., 2011), and Italy (Giaccio et al., 2002;Goodall et al., 2021;Palumbo et al., 2004) and utilized successfully to extract paleo-earthquake information, i.e., the numbers, co-seismic slips and ages of seismic events. In these examples, a basic principle is to identify the segmentation characteristic of bedrock fault scarps by physical or chemical indexes, and then ascribe such characteristics to the action of repeated paleo-seismic events (e.g. ...
... In these examples, a basic principle is to identify the segmentation characteristic of bedrock fault scarps by physical or chemical indexes, and then ascribe such characteristics to the action of repeated paleo-seismic events (e.g. Palumbo et al., 2004;He et al., 2016;Stahl and Tye, 2019;Goodall et al., 2021). Accordingly, the numbers of co-seismic slips and ages of seismic events can be derived from the times, heights and exposure dating of segments, respectively (Zou et al., 2020). ...
Normal fault scarps, as classical topographic features and geomorphological markers along mountain range-fronts, form in consolidated bedrock due to faulting in extensional settings. They generally preserve more complete records of paleo-earthquakes than fault scarps in unconsolidated sediments. The reconstruction of paleo-seismic history from a bedrock fault scarp in terms of the times, co-seismic slips and ages by a combination of quantitative morphological analysis, TCNs dating and other physical/chemical index has been proven feasible by several previous studies. However, this success heavily relies on a suitable site selection along the bedrock fault scarp because geomorphic processes are also capable exhuming the fault surface, i.e., an erosion-origin fault surface. To distinguish between tectonic- and fault-origin fault surfaces, four bedrock fault surfaces (MJYC, NMZC, DYC and SYC) in the northern Shanxi Rift have been targeted to carry out a comparative study by combining small unmanned aerial vehicle (s-UAV) surveys and terrestrial laser scanning (TLS). The results can be classified into two groups according to their quantified morphological characteristics and exposed ways. For the NMZC and SYC group, which are in elevated areas away from gullies, the quantitative morphological analysis shows that both bedrock fault surfaces have the characteristics of vertical segmentation. This kind of segmentation indicates that the fault surfaces may be exhumed by repeated seismic events, and the corresponding co-seismic slips are determined by the height of these segments. For the MJYC and DYC group, the quantitative morphology shows a gradually-changing characteristic without segmentation. This gradually-changing characteristic indicates an erosional exposure mode from geomorphic processes, and accordingly the paleo-seismic information cannot be extracted. Thus, results from this study highlights the importance of selecting a suitable study site when conducting paleo-seismic research on bedrock faults. Based on experience obtained in this study combined with previous cases, we propose the characteristics of bedrock fault surfaces suitable for extracting paleo-seismic information and corresponding identification principles. Finally, a general workflow for paleo-earthquake history reconstruction from bedrock fault scarps is proposed to promote paleo-earthquake study in bedrock areas.
