NATIONAL AND KAPODISTRIAN UNIVERSITY OF ATHENSFACULTY OF GEOLOGY & GEOENVIRONMENT

DEPARTMENT OF GEOPHYSICS & GEOTHERMICS

Laboratory of Remote Sensing

GROUND DEFORMATION STUDIES IN CEPHALONIA ISLAND (WESTERN GREECE)

BASED ON DGPS & PS INTERFEROMETRY

Evangelos Lagios, Vassilis Sakkas, Fabrizio Novali, Alfio Fumagalli & Sara Del Conte

The Central Ionian Islands GPS Networks• 24 bench marks in Cephalonia• 14 bench marks in Zakynthos• 4 bench marks in Ithaca

Seismic Activity 1964- 2006 (M > 3.6)

Seismic Activity 2006–Present(M > 3.6)

•Lefkas Earthquake August 14, 2003 Mw = 6.3

•Zakynthos Seismic Activity March- April 2006

Cephalonia Island•24 GPS bench marks

DGPS Results

2001 - 2003 2003 - 2010

2001-2010

PSInSARTM product of Cephalonia Island

Processed by Tele-Rilevamento Europa (TRE)

ERS descending: ERS descending: 39 images39 images 4/19/1992 - 2/27/20004/19/1992 - 2/27/2000

ENVISAT descending: ENVISAT descending: 21 images21 images 6/25/2003 - 11/5/20086/25/2003 - 11/5/2008

Reference Station (No 06)ITRF 2005

ERS PS Descending(1992 – 2000)

Velocity Field(mm/yr)

ENVISAT PS Descending(2003 - 2008)

Velocity Field(mm/yr)

ERS Velocity Standard Deviation

ENVISAT Velocity Standard Deviation

V < 0α < 0

V < 0α > 0

V > 0α < 0 V > 0

α > 0

PS Time-Series

ERS Acceleration Field

0 0

V < 0 V > 0

ENVISAT Acceleration Field

0 0

V < 0 V > 0

PS TIME-SERIES

Identification of Critical Area based on Observed Seismic Energy Released

Star indicates the center of the two circles indicating Low (inside small circle) and High seismic energy release (area between the two circles).

Identification of Critical Area based on

Modelling of Observed Seismic Accelerating Strain

Critical Time Estimation based on Temporal Analysis of Seismicity

Critical Time Estimation based on Accelerating Seismicity