Magnitude 1.9 Time Sunday January 4, 2009 at 01:32:4.78 Z (UTC) Saturday January 3, 2009 at 05:32:4.78 PM (PST) Distance from 13.8 km N of Richland, WA 24.1 km NW of Pasco, WA 200.3 km SW of Spokane, WA (Mission & N Division) Coordinates 46.407 deg N 119.286 deg W Depth 1 km Quality fair (BC) Note: 1 km = 0.621 mile or 1 mile = 1.61 km

NOTE: This page is for an earthquake swarm, not just one event

This is an automated web page produced after a significant earthquake to give essential information about the earthquake, its aftershocks, and previous earthquake activity in the region. Some of the information here will be updated as aftershocks occur.

Shake Map - For certain earthquakes a map of shaking intensity based on measurements from strong-motion seismographs will be available. No event in this swarm is large enough for a ShakeMap.

Did You Feel It? - You can report shaking and damage at your location. You can also view a map displaying a summary of data received from all reports. Only four felt reports for one earthquake have been received.

View Seismograms of station WIW for current time - View web-based seismograms by station and date.

Tectonic summary - Brief interpretation for this swarm.

Maps and History of Earthquakes in this Region

• A map of the Pacific Northwest showing the location of the swarm area (very small, in red) plus prior earthquakes M > 3.0. Shallow events are black. Events deeper than 35 km are green.
  
• A map showing a closer view of the earthquake and prior historical earthquakes with magnitude 3.0 or greater. Shallow events are black. Events deeper than 35 km are green.
  
• A list of 10 big earthquakes preceding the swarm that are closest to it and have a magnitude greater than 3.0. These are the most significant historical earthquakes in the vicinity of the swarm (see closer view map above).
  
• A map showing the location of the swarm relative to cities.
  
• A map showing the location of the swarm relative to the nearest seismograph stations that recorded it.
  
• A general map of significant historical earthquake locations in the Pacific Northwest.
  
• A detailed list of all earthquakes (M > 1.0) that occurred in the two years prior to the swarm in the area shown on the next map.
  
• A map of all earthquakes (M > 1.0) that occurred in the two years prior to the swarm. Detailed area shown is just few kilometers around the swarm.
  
• A list of the nearest 20 strong motion sites
  

Swarm Activity - The following information will be updated as new events occur. Included are:

• Comparison map of locations from the current swarm (orange), the 1970 swarm (green), the 1975 swarm (blue) and the 1988 swarm (red). Short-period seismic station WIW is red triangle.
  
• Map of the best locations from the current swarm color coded by the month they occurred.
• An Earthquake Catalog listing the location and magnitude of all earthquakes we have located in the epicentral region during the current year.
  
• Detailed Map of all earthquakes in this catalog for the epicentral region.
  
• Seismic Activity (magnitude, rate, depth) as a function of time since the start of the swarm.

Focal Mechanism - A diagram and table of the P-wave fault plane solution. If sufficient P-wave first motion data are available, a fault plane determination for the earthquake will be available.

Strong-Motion Information - for some earthquakes a ShakeMap based on recorded data from digital accelerographs is available.

Related Information - Most Up-to-Date Local and Global Earthquake Summaries

• Latest Quakes from the Pacific Northwest, the nation and the world