Constraining the regional uplift rate of the Corinth Isthmus area (Greece), through biostratigraphic and tectonic data

Satellite-based measuring systems are making it possible to monitor deformation of the Earth's surface at a high spatial resolution over periods of several decades and a significant fraction of the seismic cycle. It is widely assumed that this short-term deformation directly reflects the long-term pattern of crustal deformation, although modified in detail by local elastic effects related to locking on individual faults. This way, short-term deformation is often jointly inverted with long-term estimates of fault slip rates, or even stress, over periods of 10 s to 100 s kyrs. Here, I examine the relation between these two timescales of deformation for subduction, continental shortening and rifting tectonic settings, with examples from the active New Zealand and Central Andean plate boundary zone. I show that the relation is inherently non-unique, and simple models of locking on a deep-seated megathrust or decollement, or mantle flow, provide excellent fits to the short-term observations without requiring any information about the geometry and rate of surface faulting. The short-term deformation, in these settings at least, cannot be used to determine the behaviour of individual faults, but instead places constraints on the forces that drive deformation. Thus, there is a fundamental difference between the stress loading and stress relief parts of the earthquake cycle, with failure determined by dynamical rather than kinematic constraints; the same stress loading can give rise to widely different modes of long-term deformation, depending on the strength and rheology of the deforming zone, and the role of gravitational stresses. The process of slip on networks of active faults may have an intermediate timescale of kyrs to 10 s kyrs, where individual faults fail piecemeal without any characteristic behaviour. Physics-based dynamical models of short-term deformation may be the best way to make full use of the increasing quality of this type of data in the future. This article is part of a discussion meeting issue ‘Understanding earthquakes using the geological record’.

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Database of Active Faults in Slovenia: Compiling a New Active Fault Database at the Junction Between the Alps, the Dinarides and the Pannonian Basin Tectonic Domains

Frontiers in Earth Science ◽

10.3389/feart.2021.604388 ◽

2021 ◽

Vol 9 ◽

Author(s):

Jure Atanackov ◽

Petra Jamšek Rupnik ◽

Jernej Jež ◽

Bogomir Celarc ◽

Matevž Novak ◽

...

Keyword(s):

Seismic Hazard ◽

Input Data ◽

Active Fault ◽

Pannonian Basin ◽

Mass Movement ◽

Active Faults ◽

Fault Slip ◽

Slip Rates ◽

Fault Slip Rates ◽

The Alps

We present the compilation of a new database of active faults in Slovenia, aiming at introducing geological data for the first time as input for a new national seismic hazard model. The area at the junction of the Alps, the Dinarides, and the Pannonian Basin is moderately seismically active. About a dozen Mw > 5.5 earthquakes have occurred across the national territory in the last millennium, four of which in the instrumental era. The relative paucity of major earthquakes and low to moderate fault slip rates necessitate the use of geologic input for a more representative assessment of seismic hazard. Active fault identification is complicated by complex regional structural setting due to overprinting of different tectonic phases. Additionally, overall high rates of erosion, denudation and slope mass movement processes with rates up to several orders of magnitude larger than fault slip rates obscure the surface definition of faults and traces of activity, making fault parametrization difficult. The presented database includes active, probably active and potentially active faults with trace lengths >5 km, systematically compiled and cataloged from a vast and highly heterogeneous dataset. Input data was mined from published papers, reports, studies, maps, unpublished reports and data from the Geological Survey of Slovenia archives and dedicated studies. All faults in the database are fully parametrized with spatial, geometric, kinematic and activity data with parameter descriptors including data origin and data quality for full traceability of input data. The input dataset was compiled through an extended questionnaire and a set of criteria into a homogenous database. The final database includes 96 faults with 240 segments and is optimized for maximum compatibility with other current maps of active faults at national and EU levels. It is by far the most detailed and advanced map of active faults in Slovenia.

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Geodetic fault slip rates on active faults in the Baza sub-Basin (SE Spain): Insights for seismic hazard assessment

Journal of Geodynamics ◽

10.1016/j.jog.2021.101815 ◽

2021 ◽

Vol 144 ◽

pp. 101815

Author(s):

P. Alfaro ◽

A. Sánchez-Alzola ◽

I. Martin-Rojas ◽

F.J. García-Tortosa ◽

J. Galindo-Zaldívar ◽

...

Keyword(s):

Seismic Hazard ◽

Hazard Assessment ◽

Active Faults ◽

Seismic Hazard Assessment ◽

Fault Slip ◽

Se Spain ◽

Slip Rates ◽

Fault Slip Rates

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Cosmogenic nuclide dating of the sediments of Bulmer Cavern: Implications for the uplift history of southern Northwest Nelson, South Island New Zealand

10.26686/wgtn.17135987 ◽

2021 ◽

Author(s):

◽

Gavin Holden

Keyword(s):

Late Miocene ◽

Plate Boundary ◽

Sedimentary Basins ◽

Tectonic Activity ◽

Published Data ◽

Uplift Rate ◽

Cosmogenic Nuclide ◽

Alpine Fault ◽

Uplift Rates ◽

Rapid Uplift

<p>The landscape of Northwest Nelson shows evidence of significant tectonic activity since the inception of the Austro-Pacific plate boundary in the Eocene. Evidence of subsidence followed by rapid uplift from the Eocene to the late Miocene is preserved in the sedimentary basins of Northwest Nelson. However, the effects of erosion mean there is very little evidence of post-Miocene tectonic activity preserved in the Northwest Nelson area. This is a period of particular interest, because it coincides with the onset of rapid uplift along the Alpine Fault, which is located to the south, and the very sparse published data for this period suggest very low uplift rates compared to other areas close to the Alpine Fault. Cosmogenic nuclide burial dating of sediments preserved in Bulmer Cavern, indicate an uplift rate of 0.13mm/a from the mid-Pliocene to the start of the Pleistocene and 0.067mm/a since the start of the Pleistocene. The Pleistocene uplift rate is similar to other published uplift rates for this period from the northern parts of Northwest Nelson, suggesting that the whole of Northwest Nelson has experienced relative tectonic stability compared to other areas close to the Alpine Fault during this period. The mid-Pliocene uplift rate is possibly the first precisely constrained uplift rate in the area for this period, and suggests that there has been a progressive decrease in uplift rates from much higher rates in the late Miocene.</p>

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Internal structure, active tectonics and dynamic topography of the eastern Nankai accretionary prism toe, Japan, and its tsunamigenic potential

Geological Magazine ◽

10.1017/s0016756818000699 ◽

2018 ◽

Vol 158 (1) ◽

pp. 30-38 ◽

Cited By ~ 2

Author(s):

Kiichiro Kawamura ◽

Yujiro Ogawa

Keyword(s):

Active Faults ◽

Active Tectonics ◽

Accretionary Prism ◽

Fault Scarp ◽

Burial Depth ◽

Dynamic Topography ◽

Slip Rates ◽

Uplift Rates ◽

Thrust Zone ◽

Nankai Earthquake

AbstractThe eastern Nankai accretionary prism toe was surveyed to evaluate the nature and deformation of its frontal thrust. According to the determined porosities and yield strengths, turbidites were successively buried down to depths of 250–300 m before accretion, and were then exposed at the prism toe by uplift along the Tenryu frontal thrust during 3.4–1.98 Ma. Consolidation tests provided reasonable estimates of burial depth and, when combined with exposed sediment dates, yield prism toe uplift rates of 0.74–2.27 m ka–1. The displacement along the frontal thrust is estimated to be 500–900 m and the slip rates are 1.47–4.55 m ka–1, corresponding to the highest class of active faults on land in Japan. During the surveys of the Tenryu frontal thrust zone, we discovered a new active fault scarp that was several tens of centimetres high, interpreted to be a protothrust located c. 100 m south of the frontal thrust. This scarp is associated with chemosynthetic biocommunities. The thrust might potentially be the result of displacement during the East Nankai (To-Nankai) earthquake (Mw 8.1) in 1944. These lines of evidence indicate that the Tenryu frontal thrust is still active and that displacement along the thrust might induce a tsunami during future Tokai or To-Nankai earthquakes.

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Cosmogenic nuclide dating of the sediments of Bulmer Cavern: Implications for the uplift history of southern Northwest Nelson, South Island New Zealand

10.26686/wgtn.17135987.v1 ◽

2021 ◽

Author(s):

◽

Gavin Holden

Keyword(s):

Late Miocene ◽

Plate Boundary ◽

Sedimentary Basins ◽

Tectonic Activity ◽

Published Data ◽

Uplift Rate ◽

Cosmogenic Nuclide ◽

Alpine Fault ◽

Uplift Rates ◽

Rapid Uplift

<p>The landscape of Northwest Nelson shows evidence of significant tectonic activity since the inception of the Austro-Pacific plate boundary in the Eocene. Evidence of subsidence followed by rapid uplift from the Eocene to the late Miocene is preserved in the sedimentary basins of Northwest Nelson. However, the effects of erosion mean there is very little evidence of post-Miocene tectonic activity preserved in the Northwest Nelson area. This is a period of particular interest, because it coincides with the onset of rapid uplift along the Alpine Fault, which is located to the south, and the very sparse published data for this period suggest very low uplift rates compared to other areas close to the Alpine Fault. Cosmogenic nuclide burial dating of sediments preserved in Bulmer Cavern, indicate an uplift rate of 0.13mm/a from the mid-Pliocene to the start of the Pleistocene and 0.067mm/a since the start of the Pleistocene. The Pleistocene uplift rate is similar to other published uplift rates for this period from the northern parts of Northwest Nelson, suggesting that the whole of Northwest Nelson has experienced relative tectonic stability compared to other areas close to the Alpine Fault during this period. The mid-Pliocene uplift rate is possibly the first precisely constrained uplift rate in the area for this period, and suggests that there has been a progressive decrease in uplift rates from much higher rates in the late Miocene.</p>

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