Simulation of seismic triggering and failure time perturbations associated with the 30 October 2020 Samos earthquake (Mw 7.0)

The 30 October 2020 Samos earthquake (Mw = 7.0) ruptured a north-dipping offshore normal fault north of the Samos Island with an extensional mechanism. Aftershocks mainly occurred at the western and eastern ends of the rupture plane in agreement with the Coulomb static stress changes. Mechanism of aftershocks located west of the rupture supported activation of the neighboring strike-slip fault almost instantly. In addition, a seismic cluster including events with Mw~4 has emerged two days later at the SE side of Samos Island. This off-plane cluster displays a clear example of delayed seismic triggering at nearby active faults. In this study, numerical simulations are conducted to mimic the instant and delayed seismic triggering observed after this event and evaluate resultant seismic cycle perturbations at adjacent faults and near İzmir, where amplified ground motions caused heavy damage. For this purpose, Coulomb static stress changes and seismic waveforms recorded by strong-motion stations are combined as static and dynamic triggers on a rate-and-state friction dependent quasi-dynamic spring slider model with shear-normal stress coupling. According to our results, earthquakes with Mw ≤ 3.5 can be triggered instantly, and Mw ≥ 4 events noticeably advance in failure time. However, instant triggering occurs only when static stress loading is very high, and the fault is close to fail, explaining the delayed triggering observed SE of Samos Island. Simulations also revealed that the shear-normal stress coupling increases static loading but does not affect the dynamically controlled failure time advances observed at the end of the seismic cycle. After the earthquake, some of the faults adjacent to the rupture are more likely to fail, especially the long strike-slip fault segment capable of generating large earthquakes at the western edge. On the other hand, the Samos earthquake induced no significant dynamic triggering on far away faults near İzmir.

PDF

___

Akinci A, Cheloni D, Dindar, AA (2021). The 30 October 2020, M7.0 Samos Island (Eastern Aegean Sea) Earthquake: effects of source rupture, path and local-site conditions on the observed and simulated ground motions. Bull. Earthquake Eng. 19: 4745–4771. doi: 10.1007/s10518-021-01146-5
Altunel E, Pınar A (2020). Tectonic implications of the Mw 6.8, 30 October 2020 earthquake in the frame of active faults of Western Turkey. Turkish Journal of Earth Sciences 30: 436-448. doi: 10.3906/yer-2011-6
Basili R, Kastelic V, Demircioglu MB, Garcia Moreno D, Nemser ES et al. (2013). The European Database of Seismogenic Faults (EDSF) compiled in the framework of the Project SHARE, (Share - The European Database of Seismogenic Faults). Project http://diss.rm.ingv.it/share-edsf/. doi: 10.6092/INGV.IT-SHAREEDSF
Beeler NM, Lockner DA (2003). Why earthquakes correlate weakly with the solid Earth tides: Effects of periodic stress on the rate and probability of earthquake occurrence. Journal of Geophysical Research: Solid Earth 108 (B8) 2391. doi: 10.1029/2001JB001518
Belardinelli ME, Bizzarri A, Cocco M (2003). Earthquake triggering by static and dynamic stress changes. Journal of Geophysical Research: Solid Earth 108 (B3): 1–16. doi: 10.1029/2002JB001779
Brodsky EE, Karakostas V, Kanamori H (2000). A new observation of dynamically triggered regional seismicity: earthquakes in Greece following the August 1999 Izmit, Turkey earthquake. Geophysical Research Letters 27 (17): 1944–8007. doi: 10.1029/2000GL011534.
Brodsky EE, Prejean SG (2005). New constraints on mechanisms of remotely triggered seismicity at Long Valley Caldera. Journal of Geophysical Research: Solid Earth 110: B04302. doi: 10.1029/2004JB003211
Chen KH, Bürgmann R, Nadeau RM (2013). Do earthquakes talk to each other? Triggering and interaction of repeating sequences at Parkfield. Journal of Geophysical Research: Solid Earth 118 (1): 165-182.
Çakir Z, Barka A, Evren E (2003). Coulomb stress interactions and the 1999 Marmara Earthquake sequence. Turkish Journal of Earth Sciences 12: 91-103.
Coban KH, Sayil N (2019). Evaluation of earthquake recurrences with different distribution models in western Anatolia. Journal of Seismology 23 (6): 1405-1422.
Dieterich JH (1979). Modeling of rock friction: 1. Experimental results and constitutive equations. Journal of Geophysical Research: Solid Earth 84 (B5): 2161-2168.
Dieterich J, Cayol V, Okubo P (2000). The use of earthquake rate changes as a stress meter at Kilauea volcano. Nature 408 (6811): 457-460.
Dublanchet P, Bernard P, Favreau P (2013). Interactions and triggering in a 3-D rate-and-state asperity model. Journal of Geophysical Research: Solid Earth 118 (5): 2225-2245.
Emre Ö, Duman TY, Özalp S, Şaroğlu F, Olgun Ş et al. (2018). Active fault database of Turkey. Bulletin of Earthquake Engineering 16: 3229-3275.
Ganas A, Elias P, Briole P, Tsironi V, Valkaniotis S et al. (2020). Fault responsible for Samos earthquake identified. Temblor. doi: 10.32858/temblor.134
Ganas A, Elias P, Briole P, Valkaniotis S, Escartin J et al. (2021). Coseismic and post-seismic deformation, field observations and fault model of the 30 October 2020 M w = 7.0 Samos earthquake, Aegean Sea. Acta Geophysica 69: 999–1024. doi: 10.1007/s11600-021- 00599-1
Gomberg J, Blanpied ML, Beeler NM (1997). Transient triggering of near and distant earthquakes. Bulletin of the Seismological Society of America 87 (2): 294-309.
Gomberg J, Beeler NM, Blanpied ML, Bodin P (1998). Earthquake triggering by transient and static deformations. Journal of Geophysical Research: Solid Earth 103 (B10): 24411-24426.
Gürçay S (2014). Sığacık Körfezi ve çevresinin denizaltı aktif tektoniğinin yüksek çözünürlüklü sismik yöntemler uygulanarak araştırılması. PhD, Dokuz Eylül University, İzmir, Turkey, (in Turkish)
Karakaisis GF (2000). Effects of zonation on the results of the application of the regional time predictable seismicity model in Greece and Japan. Earth, planets and space 52 (4): 221-228.
Karakostas V, Tan O, Kostoglou A, Papadimitriou E, Bonatis P (2021). Seismotectonic implications of the 2020 Samos, Greece, Mw 7.0 mainshock based on high-resolution aftershock relocation and source slip model Acta Geophys 69 997. doi: 10.1007/s11600-021-00637-y
Kilb D, Gomberg J, Bodin P (2000). Triggering of earthquake aftershocks by dynamic stresses. Nature 408 (6812): 570-574.
King GC, Stein RS, Lin J (1994). Static stress changes and the triggering of earthquakes. Bulletin of the Seismological Society of America 84 (3): 935-953.
Kiratzi A, Özacar AA, Papazachos C, Pınar A (2020). Coordinators of Chapter 1: Regional tectonics and seismic source. In: Cetin KO, Mylonakis G, Sextos A, Stewart JP (editors). Seismological and Engineering Effects of the M 7.0 Samos Island (Aegean Sea) Earthquake. GEER-069. doi: 10.18118/G6H088
Linker MF, Dieterich JH (1992). Effects of variable normal stress on rock friction: Observations and constitutive equations. Journal of Geophysical Research: Solid Earth 97(B4): 4923-4940.
Mancini S, Segou M, Werner MJ, Parsons T (2020). The predictive skills of elastic Coulomb rate-and-state aftershock forecasts during the 2019 Ridgecrest, California, earthquake sequence. Bulletin of the Seismological Society of America 110 (4): 1736-1751. doi: 10.1785/0120200028
Mountrakis D, Kilias A, Vavliakis E, Psilovikos A, Karakaisis G et al. (2006). Neotectonic Map of Greece, "Samos" sheet, scale 1:75.000 78 p.
Nagata K, Nakatani M, Yoshida S (2012). A revised rate-and statedependent friction law obtained by constraining constitutive and evolution laws separately with laboratory data. Journal of Geophysical Research: Solid Earth 117 B02314. doi: 10.1029/2011JB008818
Nakatani M (2000). Conceptual and physical clarification of rate and state friction: Frictional sliding as a thermally activated rheology. Journal of Geophysical Research: Solid Earth 106 (B7): 13347- 13380.
Nanjo KZ (2020). Were changes in stress state responsible for the 2019 Ridgecrest, California, earthquakes? Nat Commun 11 3082. doi: 10.1038/s41467-020-16867-5
Pavlides S, Tsapanos T, Zouros N, Sboras S, Koravos G et al. (2009). Using Active Fault Data for Assessing Seismic Hazard: A Case Study from NE Aegean Sea, Greece. In: Earthquake Geotechnical Engineering Satellite Conference XVIIth International Conference on Soil Mechanics & Geotechnical Engineering 2-3/10/2009; Alexandria, Egypt. pp: 1-14
Perfettini H, Schmittbuhl J, Cochard A (2003a). Shear and normal load perturbations on a two-dimensional continuous fault: 1. Static triggering. Journal of Geophysical Research: Solid Earth 108 (B9): 2408. doi: 10.1029/2002JB001804
Perfettini H, Schmittbuhl J, Cochard A (2003b). Shear and normal load perturbations on a two-dimensional continuous fault: 2. Dynamic triggering. Journal of Geophysical Research: Solid Earth 108 (B9): 2409. doi: 10.1029/2002JB001805
Rice JR (1993). Spatio-temporal complexity of slip on a fault. Journal of Geophysical Research: Solid Earth ( B6): 9885– 9907. doi:10.1029/93JB00191.
Ruina A (1983). Slip instability and state variable friction laws. Journal of Geophysical Research: Solid Earth 88 (B12): 10359-10370.
Sakkas V (2021). Ground Deformation Modelling of the 2020 Mw6.9 Samos Earthquake (Greece) Based on InSAR and GNSS Data. Remote Sensing 13 (9): 1665. doi: 10.3390/rs13091665
Savage HM, Marone C (2007). Effects of shear velocity oscillations on stick-slip behavior in laboratory experiments. Journal of Geophysical Research: Solid Earth 112: B02301. doi: 10.1029/2005JB004238
Savage HM, Marone C (2008). Potential for earthquake triggering from transient deformations. Journal of Geophysical Research: Solid Earth. 113: B05302. doi: 10.1029/2007JB005277.
Sopaci E (2019). Hız-ve-durum sürtünme yasaları ve Burridge-Knopoff yay blok sistemi kullanılarak depremlerin dinamik modellenmesi. Jeodezi ve Jeoinformasyon Dergisi 6 (2): 115-127. (In Turkish with English abstract)
Sopaci E, Özacar AA (2020). Investigation of Dynamic and Static Effects on Earthquake Triggering Using Different Rate and State Friction Laws and Marmara Simulation. EGU General Assembly Online, 4– 8 May 2020, EGU2020-533. doi: 10.5194/egusphere-egu2020-533
Thomas MY, Avouac JP, Lapusta N (2017). Rate-and-state friction properties of the Longitudinal Valley Fault from kinematic and dynamic modeling of seismic and aseismic slip. Journal of Geophysical Research: Solid Earth 122 (4) 3115-3137.
Toda S, Stein RS, Sevilgen V, Lin J (2011). Coulomb 3.3 Graphic-rich deformation and stress-change software for earthquake, tectonic, and volcano research and teaching—user guide. US Geological Survey open-file report 1060: 63.
Uzel B, Sözbilir H, Özkaymak Ç, Kaymakçı N, Langeris CG (2013). Structural evidence for strike-slip deformation in the İzmirBalıkesir Transfer Zone and consequences for late Cenozoic evolution of western Anatolia (Turkey). Journal of Geodynamics 65: 94–116.
van der Elst NJ, Savage HM (2015). Frequency dependence of delayed and instantaneous triggering on laboratory and simulated faults governed by rate-state friction. Journal of Geophysical Research: Solid Earth 120 (5): 3406-3429.
Wang JH (2018). A review on scaling of earthquake faults. Terrestrial, Atmospheric & Oceanic Sciences 29: 589-610. doi: 10.3319/TAO.2018.08.19.01
Yoshida S (2018). Numerical simulations of earthquake triggering by dynamic and static stress changes based on a revised friction law. Journal of Geophysical Research: Solid Earth 123 (5): 4109-4122.
Yoshida S, Maeda T, Kato N (2020). Earthquake triggering model based on normal-stress-dependent Nagata law: application to the 2016 Mie offshore earthquake. Earth, Planets and Space 72 (1): 1-13.
Ziv A, Rubin AM (2000). Static stress transfer and earthquake triggering: No lower threshold in sight? Journal of Geophysical Research: Solid Earth 105 (B6): 13631-13642.