Contribution of the

1
ATHENS TEST SITE
Contribution of the Seismological
Laboratory National Kapodistrian University of
Athens
2
ATHENS TEST SITE
3
Strong Weak Motion Network
White Seismographs in real-time transmission,
Red Seismographs in offline mode, Blue
Accelerographs in dial-up mode.
4
(No Transcript)
5
Network approach example
Picking and associating phases
6
Earthquake locations for earthquakes with Mgt3 for
the period (September 2007 March 2008)
White traditionally picked and located
events Black automatic picked and associated
events and Tnow located
7
The June 8 2008 (1225 GMT), Andravida earthquake
of magnitude Mw6.4. Location and rupture zone
8
The calculated slip model revealed more than one
seismic sources (Agalos A.)
Synthetic PGV map plus relocated seismicity
(Papadimitriou et al)
9
recording at Rodini station
2 s pre-rupture, period 0,6 ? M5.2 3 s period
1.4 ? M6.7
Instantaneous period estimation at Rodini station
Kanamori Wu
10
TRISAR and MALES arrays

• REFTEK DAS 72
• CMG-40T-1s

• GURALP DM24 Mark III
• CMG-40T-30s

11
Array processing scheme developed by NORSAR and
implemented by NKUA for the Athens test site
12
Andravida Mw6.4 earthquake.
13
Array processing results for the June 6, 2008
Andravida Mw6.4 earthquake.
14
Aftershock activity
15
February 4, 2008 M5.0 earthquake
16
Array processing results for the February 4, 2008
M5.0 earthquake
17
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

18
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.