Two minor temblors that originated nine miles below the surface struck at 8:48 p.m. and 9:56 p.m. Monday, according to State Geologist William Kelly.

The first tremor measured a 2.6 magnitude on the Richter Scale and was apparently unnoticed. But the second quake had a magnitude of 3.1 and was felt by some people in the town, Kelly said. It takes at least a magnitude 5 quake to cause damage to buildings.

It wasn't your imagination if you think you felt the earth move late Monday night -- at least it wasn't if you lived in this Hilltown, New York State Geological Survey officials say.

''That's actually fairly deep,'' Kelly said of the depth of the quakes, explaining that the deepness probably helped blunt the power of the temblors.

Unlike California and the rest of the Pacific Rim, the upstate New York, like much of the East Coast, experiences few noticeable earthquakes. The area is located in the middle of a massive earth plate that stretches from the middle of the Atlantic Ocean to the West Coast. Continental drift is blamed for triggering the quakes in the west

But Kelly said there is little evidence to explain why quakes occasionally occur here. ''Why are we having earthquakes? We don't know,'' Kelly said