The Brookings Police Department and U.S. Coast Guard station Chetco River were swamped with phone calls from residents Saturday evening about a possible earthquake, but as of Tuesday nobody seemed to know what really caused the shaking.

The shaking was also reported as far north as Whaleshead and as far south as Crescent City.

At 5:46 p.m., a Brookings Police dispatcher began receiving numerous phone calls about a sudden shaking in the area, according to Brookings Police Lt. John Bishop.

?Our 911 and business numbers were lit up according to the dispatcher,? he said Tuesday. ?I couldn?t even get through to the office for nearly 10 minutes. We got all kinds of calls, dozens.

?Several people said they definitely felt what they believed to be an earthquake.?

Master Chief Boatswains Mate Fred Bowman, officer in charge at the Coast Guard station at the Port of Brookings Harbor, said his office received several calls from people concerned about a possible tsunami associated with an earthquake.

?Several of our personnel also said they felt the quake, although not here at the station,? Bowman said.

Both Bishop and Bowman said they had heard both directly and indirectly from people who not only felt the earthquake, but had witnessed items on shelves shaking and heard things rattling.

When local officials began trying to get information about the possible earthquake, no one seemed to know anything about it.

All the official earthquake reporting agencies in the region never issued an alert at anytime on Saturday.

Michael Murphy, emergency services coordinator for Curry County, said all his attempts to find out about the ?earthquake? have led to dead ends.

?I called OEM (Office of Emergency Management),? he said. ?I even called the quake center in Seattle (University of Washington), and no one knows of any earthquake in this area.

?It?s just unexplained. All our sources of (earthquake) information said there was no quake.

?(OEM) was checking to see if it could have been something military, but nothing has turned up yet.?

Earthquake information web sites for the region revealed nothing about a possible earthquake. Quakes can be detected as low as 1.0 in magnitude, according to Murphy.

The web sites for Northern California (Berkeley), the Pacific Northwest (University of Washington) and the main U.S. Geological Service earthquake information center in Alaska all showed some sporadic seismic activity up and down the Northern California and Southern Oregon coastlines over the past two weeks, but nothing of significance and nothing on Saturday afternoon or evening.

One possibility, some people suggested, was that it was a sonic boom. Lori Dengler, director of the Humboldt Earthquake Education Center, said people can be fooled by a sonic boom because its effects can resemble an earthquake in many ways, and the sound frequency can be so low that human ears cannot pick it up.

?There was a case in Oregon where a tsunami warning was set off by a sonic boom,? Dengler said. ?The whole town evacuated.?

As of Tuesday afternoon, the mystery of Saturday?s earthquake remained unsolved.