PORTLAND, Ore. (AP) — Two back-to-back earthquakes have struck about 200 miles off the Oregon coast.

The National Earthquake Information Center based out of Golden, Colo., says there's been no damage and no threat of a tsunami from Monday's quakes.

Don Blakeman of the center, says preliminary measurements put the magnitudes at about 5.1 and 4.9. He says the quakes hit five minutes apart, shortly before 7 a.m. off the coastal town of Bandon.

Blakeman says the depth of the quakes at the epicenters, a few miles apart, probably was about 6 miles into the earth's crust.