HR: 11:35h
AN: T12B-06    [Abstracts]
TI: Active Normal Fault Behaviour and Continental Rift Geometry in the Corinth Rift, Greece
AU: * McNeill, L
EM: lcmn@soc.soton.ac.uk
AF: Southampton Oceanography Centre, University of Southampton, European Way, Southampton, SO14 3ZH United Kingdom
AU: Cotterill, C
EM: cjc3@soc.soton.ac.uk
AF: Southampton Oceanography Centre, University of Southampton, European Way, Southampton, SO14 3ZH United Kingdom
AU: Henstock, T
EM: then@soc.soton.ac.uk
AF: Southampton Oceanography Centre, University of Southampton, European Way, Southampton, SO14 3ZH United Kingdom
AU: Bull, J
EM: bull@soc.soton.ac.uk
AF: Southampton Oceanography Centre, University of Southampton, European Way, Southampton, SO14 3ZH United Kingdom
AU: Stefatos, A
EM: A.Stefatos@upatras.gr
AF: Laboratory of Marine Geology and Physical Oceanography, University of Patras, Patras, 26500 Greece
AU: Hicks, S
EM: seh103@soton.ac.uk
AF: Southampton Oceanography Centre, University of Southampton, European Way, Southampton, SO14 3ZH United Kingdom
AU: Collier, R
EM: richard@earth.leeds.ac.uk
AF: School of Earth Sciences, University of Leeds, Leeds, LS2 9JT United Kingdom
AU: Papatheoderou, G
EM: A.Stefatos@upatras.gr
AF: Laboratory of Marine Geology and Physical Oceanography, University of Patras, Patras, 26500 Greece
AU: Ferentinos, G
EM: gferen@upatras.gr
AF: Laboratory of Marine Geology and Physical Oceanography, University of Patras, Patras, 26500 Greece
AB: The Gulf of Corinth continental rift, central Greece extends at up to 15 mm/yr with regular M6+ earthquakes. However, rapid geodetic extension rates in the western rift cannot be accounted for by displacement on onshore faults alone, where slip rates determined from uplifted terraces and paleoseismological trenching are significantly lower. High resolution seismic reflection and multibeam bathymetric data were collected to survey offshore faults contributing to extension and quantify their displacement. In the western rift, a basement horst on the northern margin is uplifted by the N and S Eratini faults and the axial channel is fault-controlled. Subsided lowstand shorelines in the hangingwall of the N Eratini and the well-studied Aigion fault suggest that both faults have similar displacements. Summed extension from the four major faults across this part of the rift (Eliki, Sub-channel, S Eratini, N Eratini) is of the order of 8-12 mm/yr, thereby reconciling geologic and geodetic datasets. Geomorphology indicates that the rift geometry changes along axis, with a model of distributed deformation across multiple faults proposed for the western rift. The high resolution seismic data linked to sea level history within the gulf (isolated during lowstands) potentially allow changes in slip rate to be determined on a 10000 year timescale. These results compliment the often shorter (100's-10000's years) timescales of onshore fault trenching and uplifted terrace sequences in terms of temporal fault behaviour. Ultimately, seismic hazard can be refined based on fluctuations in past fault behaviour within the rift.
DE: 7221 Paleoseismology
DE: 7230 Seismicity and seismotectonics
DE: 8010 Fractures and faults
DE: 8109 Continental tectonics--extensional (0905)
DE: 0935 Seismic methods (3025)
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting