SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris Contribution of the Seismological Laboratory National & Kapodistrian University of Athens ATHENS TEST SITE
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris SiteDataMethod(s)Partners Greece, AthensStrong and week motion network 2 arrays a) Tnow network based location approach b) Tc and Pd on- site calculation approach and c) Array based processing approach NIED, NORSAR ATHENS TEST SITE
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris KALI AKOR PLAT LAKA White: Seismographs in real-time transmission, Red: Seismographs in offline mode, Blue: Accelerographs in dial-up mode. Strong & Weak Motion Network
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris
Picking and associating phases Network approach example
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris White: traditionally picked and located events Black: automatic picked and associated events and Tnow located Earthquake locations for earthquakes with M>3 for the period (September 2007 – March 2008)
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris The June (12:25 GMT), Andravida earthquake of magnitude Mw=6.4. Location and rupture zone
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris The calculated slip model revealed more than one seismic sources (Agalos A.) Synthetic PGV map plus relocated seismicity (Papadimitriou et al)
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris recording at Rodini station Instantaneous period estimation at Rodini station Kanamori & Wu 2 s pre-rupture, period ~ 0,6 M=5.2 3 s period ~ 1.4 M=6.7
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris TRISAR and MALES arrays REFTEK DAS 72 CMG-40T-1s GURALP DM24 Mark III CMG-40T-30s
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris Array processing scheme developed by NORSAR and implemented by NKUA for the Athens test site
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris Andravida Mw=6.4 earthquake.
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris Array processing results for the June 6, 2008 Andravida Mw=6.4 earthquake.
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris Aftershock activity
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris February 4, 2008 M=5.0 earthquake
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris Array processing results for the February 4, 2008 M=5.0 earthquake
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris Limiting factors of array performance Temporary nature of installation Timing errors resulting from the absence of a common timing system Complexity and variations of crustal structure in the area. Improvement of travel time tables or location corrections according to azimuth Further tuning of single and multi array location algorithms is needed
SAFER Project final meeting, Potsdam, 3-5 June, 2009 Nicholas Voulgaris Future prospects Continuation of EW algorithm testing using the increasing number of real-time stations becoming available near the test site area and installing accelerometers in tandem. Activating real time transmission of RASMON accelerometer network. Improving latency times Re-initiate array related activities provided that a common time base system can be established.