Continuous strain and tilt monitoring on the Trizonia Island, Rift of Corinth, Greece

Tilt and strain continuous monitoring started in October 2002 in the Trizonia Island, in the Gulf of Corinth, in order to detect possible strain transients in the rift. The hydrostatic tiltmeters, developed at IPGP, are 15 m long and buried in trenches at a depth of 2.5 m, with a few 10 −9 -radian noise level at short period. The strain is measured by a Sacks–Evertson dilatometer cemented in a borehole at a depth of 148 m, with a few 10 −10 resolution at short period. A 1 h-lasting, 10 −7 -strain transient has been recorded on the dilatometer, possibly related to a seismic swarm that occurred 15 km away.