Portland, OR -

A series of tremors near Mount Hood has intrigued scientists, who note that the quakes are taking place alongside a recently-discovered fault.

KGW-TV reports a swarm of small earthquakes on Mount Hood has captured the attention of state geologists and rattled the nerves of some nearby residents, especially after a 3.3-magnitude quake in Sherwood on Sunday.

Over the past two weeks, Oregon and Washington have experienced more than 130 earthquakes, according to the Pacific Northwest Seismic Network. That's about normal for the region where most quakes are so small they can't be felt.

Oregon geologist Ian Madin says the tremors on Mount Hood are not tied to volcanic activity.