Magnitude
6.0
Date-Time
Wednesday, February 15, 2012 at 03:31:20 UTC
Tuesday, February 14, 2012 at 07:31:20 PM at epicenter
Tuesday, February 14, 2012 at 05:31:20 PM HST
Location
43.536°N, 127.381°W
Depth
10 km (6.2 miles)
Region
OFF THE COAST OF OREGON
Distances
256 km (159 miles) W of Coos Bay, Oregon
293 km (182 miles) WSW of Newport, Oregon
302 km (187 miles) NW of Brookings, Oregon
380 km (236 miles) WSW of SALEM, Oregon

To: U.S. West Coast, Alaska, and British Columbia coastal regions
From: NOAA/NWS/West Coast and Alaska Tsunami Warning Center
Subject: Tsunami Information Statement issued 02/14/2012 at 7:34PM PST

At 7:31 PM Pacific Standard Time on February 14, an earthquake with preliminary magnitude 5.9 occurred off the coast of Oregon .

The magnitude is such that a tsunami IS NOT EXPECTED. This will be the only WCATWC message issued for this event.

The location and magnitude are based on preliminary information.

USGS: How large does an earthquake have to be to cause a tsunami?

Magnitudes below 6.5
Earthquakes of this magnitude are very unlikely to trigger a tsunami.

Magnitudes between 6.5 and 7.5
Earthquakes of this size do not usually produce destructive tsunamis. However, small sea level changes may be observed in the vicinity of the epicenter. Tsunamis capable of producing damage or casualties are rare in this magnitude range but have occurred due to secondary effects such as landslides or submarine slumps.

Magnitudes between 7.6 and 7.8
Earthquakes of this size may produce destructive tsunamis especially near the epicenter; at greater distances small sea level changes may be observed. Tsunamis capable of producing damage at great distances are rare in the magnitude range.

Magnitude 7.9 and greater
Destructive local tsunamis are possible near the epicenter, and significant sea level changes and damage may occur in a broader region.

Note that with a magnitude 9.0 earthquake, the probability of an aftershock with a magnitude exceeding 7.5 is not negligible. To date, the largest aftershock recorded has been magnitude 7.1 that did not produce a damaging tsunami.