Paleoseismology in Greece and the GreDaSS

Paleoseismology in Greece and the Greek Database of Seismogenic Sources (Gre.Da.S.S.): 

Paleoseismology in Greece and the Greek Database of Seismogenic Sources ( Gre.Da.S.S .) Alex CHATZIPETROS Department of Geology, Aristotle University 54124, Thessaloniki, Greece users.auth.gr/ac

Structure of the talk: 

Structure of the talk Part I Brief overview of paleoseismological research in Greece and surrounding areas by the Earthquake Geology Group ( A.U.Th .)* Part II The main characteristics of Gre.Da.S.S . (by Sotiris Sboras) * Spyros Pavlides, Alex Chatzipetros, George Papathanassiou, Sotiris Valkaniotis, Sotiris Sboras, Riccardo Caputo web: eqgeogr.weebly.com under heavy construction!

Current seismicity of Greece: 

Current seismicity of Greece Earthquake epicenters of the past 3 months.

Map of capable faults: 

Map of capable faults Pavlides S., Valkaniotis S. and Chatzipetros A. (2007)

Paleoseismology in Greece and surrounding areas: 

Paleoseismology in Greece and surrounding areas Trenching Archeoseismology Tectonic geomorphology

Trenching: 

Trenching Selected cases ( AUTh Earthquake Geology Group)

Slide 7: 

Mygdonia basin

The 1978, M 6.5, Thessaloniki earthquake: 

The 1978, M 6.5, Thessaloniki earthquake Ground ruptures and damages Photo courtesy: Triantafyllos Soldatos

Slide 10: 

Ground effects of the 1978 earthquake. Photo courtesy: Triantafyllos Soldatos , Georgios Syrides .

The very first Greek trench: 

The very first Greek trench Cheng S., Fang Z., Pavlides S. and Chatzipetros (1994)

Additional work in Mygdonia basin: 

Additional work in Mygdonia basin Chatzipetros (1998), Chatzipetros et al. (2004; 2005) Recurrence interval: about 1 ka Slip rates: 0.17 to 0.25 mm/a Penultimate event: AD1430

Slide 14: 

Epirus

Souli fault (Epirus, Greece): 

Souli fault (Epirus, Greece) Boccaletti M., Caputo R., Mountrakis D., Pavlides S. and Zouros N. (1997) Successive reactivations in Late Pleistocene - Holocene

Slide 16: 

W. Macedonia

The 1995 M 6.6 earthquake: 

The 1995 M 6.6 earthquake The seismogenic fault and extensive liquefaction. Earthquake fracture map (Chatzipetros et al., 2005)

The 1995 earthquake: 

The 1995 earthquake Ground effects. Photo courtesy: Anne Rassios

Slide 20: 

Elementary school in Knidi village ( Grevena ) Photo courtesy: Anne Rassios

Trenching: 

Trenching Trenches in Paleochori (above) and Sarakina (left) sites (Chatzipetros, 1998; Chatzipetros et al., 1998).

Paleoliquefaction: 

Paleoliquefaction Latest Pleistocene – Holocene liquefaction preserved in sediments (Chatzipetros, 1998). Very slow fault!

Slide 23: 

Northern Thessaly

Tyrnavos fault (Northern Thessaly): 

Tyrnavos fault (Northern Thessaly) Caputo R., Helly B., Pavlides S. and Papadopoulos G. (2006)

Logs and interpretation: 

Logs and interpretation Possibly eight events during latest Pleistocene – Holocene. Caputo et al. (2006).

Slide 26: 

Eliki and Kaparelli faults

Eliki fault: 

Eliki fault Three events over the past 2,000 years, including the 1861 earthquake. Displacements between 0.44 and 1.37 m were identified, while a slip rate of about 1 mm/a has been calculated. Koukouvelas et al. (2001), Pavlides et al. (2004), Chatzipetros et al. (2005).

Slide 29: 

COST meeting, Florence, 14-18 June 2006 29 0.93m Eliki fault Detail of the upper part of Eliki I trench ( K oukouvelas et al. 2001)

Slide 30: 

Kaparelli fault Fault map and trench locations ( Kokkalas et al., 2007). Kap2 Kap3

Kap1 Trench (east wall) View of 1981 fault surface: 

31 Kap1 Trench (east wall) View of 1981 fault surface Fissure-fill facies Kap1(3) 1250 ±40 YBP Kap1(4) 4870 ±40 YBP Kokkalas et al. (2007)

Slide 32: 

Kaparelli fault At least 3, possibly 4, events prior to the 1981 one. Displacements of 0.7 to 1 m. Average slip rate: 0.29 mm/a. Kokkalas et al. (2007)

Archaeoseismology – TRENCHING : 

Archaeoseismology – TRENCHING Selected cases from research by AUTh group

Slide 34: 

Mikri Doxipara site

Slide 35: 

Infrared LANDSAT image with the main faults of the area. EDIRNE 1752 30 km Seismotectonic setting : 1. there are neotectonic or active faults and 2. the area has been affected by earthquake Maritsa river Greece

Slide 37: 

Faulting Displaced archaeological layers, artifacts and structures (Pavlides et al. 2006, Chatzipetros and Pavlides 2009)

Slide 38: 

Surface ruptures that were revealed after the archaeological excavation. 38

Slide 39: 

Faulting Evidence of coseismic faulting and related dates (Chatzipetros and Pavlides 2009, Pavlides et al. 2010)

Slide 40: 

Dating of faulting At least two events: The latest deformation is associated with the 1752 strong Edirne (Turkey) earthquake; the penultimate one is dated at ca . 960 ± 50 BC (Chatzipetros and Pavlides 2009, Pavlides et al. 2010)

Slide 41: 

Troy

Slide 42: 

42 Troy Indications of strong shaking in Troy VI.

Slide 43: 

Third International Conference on the Geology of the Tethys 43 False color Ikonos satellite image Ikonos ( © NASA).

Slide 44: 

E W Simois valley Troy fault Fault scarp.

Slide 45: 

Troy fault system Kumkale strike-slip fault

Slide 48: 

Troy fault system Effects of active deformation: Raised shorelines Seismites Microfaults

Paleoseismic data and their implication for active deformation in Greece: 

Paleoseismic data and their implication for active deformation in Greece Palaeoseismological studies in Greece showed long recurrence intervals in northern Greece and Thessaly. In contrast , short recurrence interval can be inferred for Corinth gulf faults, showing recurring past events during historical times (<1 ka ). Regardless of their structural setting, earthquake offset recognized within the trenches are in the order of 1 m and thus corresponding magnitudes are in the order 6.4 ( Pavlides and Caputo, 2004 ). For the southern structural province, the Anatolia escape and the slab steepening large-scale processes are associated with larger recurrence intervals for strong earthquakes and high slip-rates to the west and low ones to the east (i.e. Kapareli fault ). In contrast, in the northern structural province the continental collision and crustal collapse occurring in the area of western Macedonia cause low slip-rates and large recurrence intervals. Further east, in the area of Mygdonia basin, the slip-rate increases, while recurrence interval is shorter, mainly due to its proximity to North Aegean Trough.

Slide 51: 

End of part I Thank you!

Slide 52: 

Gre.Da.S.S . (Greek Database of Seismogenic Sources): state-of-the-art in N. Greece 2: University of Ferrara, Italy 1: Aristotle University of Thessaloniki, Greece S. Pavlides 1 , R . Caputo 2 , S. Sboras 1,2 and GreDaSS Working Group

Slide 53: 

Seismic catalogue of Aristotle University of Thessaloniki for the broader Aegean area, from 550 BC to 2008 (M≥4.5) Catalogue of earthquakes

Slide 54: 

Papazachos et al. (1999) Map of Seismogenic sources ONLY related with past earthquakes

Slide 55: 

Pavlides et al. (2007) Map of capable faults (seismically active and possible faults)

Slide 56: 

FAUST project (1998 - 2000) (compiled by R. Caputo) Database of Seismogenic sources ONLY related with past earthquakes

Slide 57: 

Gre.Da.S.S . (Greek Database of Seismogenic Sources) perspectives systematic collection and critical analysis of all available data/information concerning active faults, capable faults and broader seismogenic sources within the broader Aegean Region quantification and homogenization of the principal seismotectonic parameters of the different sources as well as their degree of uncertainty supply an integrated view of potentially damaging seismogenic sources for a better assessment of the seismic hazard for Greece

Slide 58: 

State-of-the-art for N. Greece

Slide 59: 

Basili et al. (2008 ) ISS (Individual Seismogenic Source) Simplified 3D representation for quick use concerning forward modelling, earthquake scenarios...

Slide 60: 

Simplified parameters with unique values

Slide 61: 

Basili et al. (2008 ) CSS (Composite Seismogenic Source) Emphasizes on geological info.

Slide 62: 

Simplified parameters with ranges of values in order to: give more geographic detail and/or include the variability of the data and/or include any uncertainties

Slide 63: 

Even more detail... Fault traces, fault scarps, co-seismic ruptures... in large-scale linked with both ISSs and CSSs

Slide 64: 

The 3 geographic / parametric layers: an example from the Kozani region

Slide 65: 

... and more information layers...

Slide 66: 

iconographic layer including: Maps (geologic, morphotectonic, structural, ...), Meso -structural data, Palaeo -trenches, Focal mechanisms, microseismicity , dInSAR , Seismic profiles, ERTs, Geodetic, Geophysic surveys, Photos, et c. in order to have a quick overview.

Slide 69: 

Papanikolaou et al. (2006)

Slide 70: 

Comments, Open Questions, and Summaries, include: The compiler’s comments and suggestions, Debates, contrasts and unsolved problems Detailed description of the published data ... for further information

Slide 71: 

Do you need a thorough look in the original published data? You can have all related literature in the References list! ... and with pdf files if available...

Slide 72: 

Thank you...