Record examples before past earthquakes :
Example 2 - 23 August 2000 5.8Mb Hendek-Akyazi Earthquake
If the time interval at 10:15 on August 23, 2000 record of Heybeliada is observed expanded, it can be seen that 1300 unit change has happaned in three times one after the other. Decrease was observed on A*exp(-t/T) form right after the beginning of the anomaly. The earthquake occured at 16:41 with local time, 5 hours after the decrease . There were no anomaly recordings at Esentepe station which is closer to the epicenter and this causes doubt but it might have two possible explanations. 1) Heybeliada station is closer to NAFZ and an afterschock on a secondary fault can cause a stronger signal change at a point closer to the fault but distant to epicenter as a result of rigid force transfer. 2) As quasistatic wave component is also being measured, Esentepe station's being more sensitive towards west direction might result in being less sensitive against the signals coming from east.
a) Measurement graph between 09:00 - 24:00
b) Graph expanded on the time axis showing the beginning of the anomaly.