In what year did they took first reading of an Earthquake occurence?

Some time between 1869 and 1880 ---

that is -- if you limit this to modern systems with continuous recording.

Zollner described torsionally suspended horizontal pendulums as early as 1869, but developed them for gravimetry rather than seismometry.

and

After 1880, most seismometers were descended from those developed by the team of John Milne, James Alfred Ewing and Thomas Gray, who worked in Japan from 1880 to 1895.

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Those are 2 quotes from this wiki article :

http://en.wikipedia.org/wiki/Seismoscope#Modern_de...

Depends. Christians will read the Bible and take the earthquakes in the book of Genesis as the first records.

However, most will say in 1831 BC in China the first written record of an earthquake took place.

The first documented record of an earthquake was in 132 C.E. when Zhang Heng of China's Han dynasty designed the first known seismoscope.