Geological input for quantitative seismic hazard analysis in Burdur ar

Views:
 
     
 

Presentation Description

Paper presented at the International Earthquake Symposium Kocaeli 2009, Izmit, Turkey, 17-19 August 2009. Reference: Chatzipetros A., Pavlides S., Yağmurlu F., Özgür N., Pinar A., Kamaci Z., Şentürk M., Uysal K. and Şener E. (2009). Geological input for quantitative seismic hazard analysis in Burdur area, SW Turkey, International Earthquake Symposium Kocaeli 2009, Izmit, Turkey, 17-19 August 2009, Abstracts volume, 11.

Comments

Presentation Transcript

Geological input for quantitative seismic hazard analysis in Burdur area, SW Turkey:

Geological input for quantitative seismic hazard analysis in Burdur area, SW Turkey Chatzipetros A. 1 , Pavlides S. 1 , Ya ğ murlu F. 2 , Özgür N. 2 , Pınar A. 3 , Kamacı Z. 2 , Şentürk M. 2 , Uysal K. 2 and Şener E. 2 1. Department of Geology, Aristotle University of Thessaloniki, Greece 2. Department of Geological Engineering, Suleyman Demirel University, Isparta, Turkey 3. Department of Geophysical Engineering, Istanbul University, Istanbul, Turkey

Structure of the talk:

Structure of the talk International Earthquake Symposium, Kocaeli, 17-19/08/09 2 Geomorphology. Morphotectonics. Structural geology. Recent seismicity. Palaeoseismology.

Geomorphic features:

Interpretation of the geomorphological features of the northern shores of Burdur Lake. Three main terrace sets can be identified. Some NE-SW trending lineaments (shown in red) are associated with faults dipping towards the SE. This is a slope shading image using SRTM data from CIAT: darker colours indicate steep slopes, while lighter colours correspond to flat areas. Geomorphic features 3 International Earthquake Symposium, Kocaeli, 17-19/08/09

The terraces:

View towards the SW from the top of terrace II. It is evident that there is a significant difference in altitude between this terrace and the current lake level, indicating either rapid lake level drop, probably due to climatic conditions, or neotectonic faulting. The terraces 4 International Earthquake Symposium, Kocaeli, 17-19/08/09

Fault scarp:

Fault scarp just east of Burdur town, defining the contact between Palaeocene (?) conglomerate and Quaternary Burdur Lake sediments. View towards the SW. Fault scarp 5 International Earthquake Symposium, Kocaeli, 17-19/08/09

Hazard:

Burdur town is mostly built on loose sediments with high expected acceleration and liquefaction potential. Hazard 6 International Earthquake Symposium, Kocaeli, 17-19/08/09

Burdur faults:

The typical oblique slip displacement with left lateral component. Burdur faults 7 International Earthquake Symposium, Kocaeli, 17-19/08/09

Burdur faults:

Large mirror with the latest almost pure normal displacement. Burdur faults 8 International Earthquake Symposium, Kocaeli, 17-19/08/09

Burdur faults:

Detail of a fault mirror. The youngest normal displacement clearly overpints the older oblique-slip one. Burdur faults 9 International Earthquake Symposium, Kocaeli, 17-19/08/09

Stress field:

Summary diagrams of the older oblique-slip (top) and the younger normal-slip (bottom) displacements. While σ 3 remained the same, σ 1 has been significantly rotated. Stress field 10 International Earthquake Symposium, Kocaeli, 17-19/08/09

The 1914 surface faulting:

The fault that is associated with the 1914 surface ruptures; it is the one that has been excavated at site BUR-2. Note the car at the upper right corner of the figure for scale. The surface has been heavily altered due to extensive landslides and human activities (sand quarrying).View NNE  SSW. The 1914 surface faulting 11 International Earthquake Symposium, Kocaeli, 17-19/08/09

PowerPoint Presentation:

Log of BUR-2 trench. The corresponding radiocarbon ages are: BUR-2/2: 9,600, BUR-2/3: 264±, BUR-2/4: 241,462±27 12 International Earthquake Symposium, Kocaeli, 17-19/08/09

PowerPoint Presentation:

Details of structures in BUR-2 trench. Left: paleoliquefaction. Right: faulting 13 International Earthquake Symposium, Kocaeli, 17-19/08/09

Analysis of BUR-2 trench:

Analysis of BUR-2 trench International Earthquake Symposium, Kocaeli, 17-19/08/09 14 Event Effects Dating Event 1 Fracturing the surface at the SW part of the trench. 1914, as is assessed by field evidence and eyewitness reports. Event 2 Surface ruptures filled with fine material between layers 2 and 3. Possible liquefaction. Synsedimentary faulting at the same fault zone. After the deposition of layer 3 and before deposition layer 2. Event 3 Surface ruptures that end abruptly at the boundary between layers 6 and 7. After the deposition of layer 7 and before deposition of layer 6. Sample Radiocarbon age BUR-2/2 9,600 (Relative age) BUR-2/3 1,462  27 BP BUR-2/4 264  24 BP Event Dating Event 1 1914 Event 2 Between 240 and 1,487 BP (mean 863 BP, i.e. 1,087 AD) Event 3 Before 9,600 BP, i.e. 7,750 BC

PowerPoint Presentation:

Log of the SE wall of BUR-3 trench. 15 International Earthquake Symposium, Kocaeli, 17-19/08/09

Analysis of BUR-3 trench:

Analysis of BUR-3 trench International Earthquake Symposium, Kocaeli, 17-19/08/09 16 Event Effects Dating Event 1 Created three distinct fracture zones that terminate at the same level. Before 922 BP and after 1,292 BP (mean 1,107 BP, i.e. 843 AD)

Palaeoseismological summary:

Palaeoseismological summary International Earthquake Symposium, Kocaeli, 17-19/08/09 17

Summary:

Summary International Earthquake Symposium, Kocaeli, 17-19/08/09 18 The area is dominated by NE – SW trending faults that have been formed in a transtensional regime, which now has been transformed into an extensional one. Burdur basin has been significantly modified by neotectonic activity, as is reflected in the geomorphological features. Paleoseismology shows that apart from the 1914 event, at least one earthquake of comparable size has struck the area at about 965AD ± 107.

authorStream Live Help