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Home » Special Events » Magnitude 7.8 earthquake in the Tonga region, Pacific Ocean
last updated: 03/19/09 13:04.40 (PDT)
On Thursday March 19 2009 at 11:17 AM (PDT) the USArray seismic network recorded an earthquake (preliminary Mw 7.8) located in the Tonga region.
Initial source parameters for this tremor are indicated below. The epicentral distance (i.e. distance separating the epicenter and the closest station in the recording network, SCZ2) for the USArray is 8564 km (76.93 degrees).
If you felt the quake, the USGS would like to know. Please add your comments to the USGS page "Did you feel it?".
Summary
| Solution Parameters | |
|---|---|
| Local Date: | Thursday March 19, 2009 |
| Local Time: | 11:17 AM PST |
| Universal Time: | 03/19/09 (078) 18:17.37 UTC |
| Magnitude: | 7.8 Mw |
| Latitude: | -23.0520 |
| Longitude: | -174.2890 |
| Depth: | 4 km |
| Author: | QED |
| Authoritative: | yes |
Proximity to Population Centers
- 210 km (130 miles) SSE of Nuku'Alofa, Tonga
- 480 km (300 miles) ESE of Ndoi Island, Fiji
- 490 km (305 miles) S of Neiafu, Tonga
- 1830 km (1140 miles) NE of Auckland, New Zealand
Maps
Mercator projection regional view
The red star denotes the earthquake epicenter. Triangle symbols are active stations at the time of the earthquake in the USArray (excluding ANSS backbone stations and GSN stations, which are represented by a diamond symbol) and colored by network. Gray lines are major rivers.
| Transportable Array (TA) | |
| UC San Diego (AZ) | |
| CalTech (CI) | |
| Uni. Utah (UU) | |
| ANSS backbone stations (US) | |
| Global Seismograph Network (IU) |
Regional satellite view
The red marker denotes the earthquake epicenter.
Detailed terrain view
The red marker denotes the earthquake epicenter.
Waveforms
You may view plots showing this event as recorded by USArray instruments:
- 3 components recorded by SCZ2, the closest USArray station to the event
- Large 3 components recorded by SCZ2, the closest USArray station to the event
- Vertical components from every eighth USArray station that recorded the event across the whole network
3 components recorded by SCZ2, the closest USArray station to the event:
News links
- USGS page for this event
- Fox News: "Tsunami Warning Issued After 7.9 Magnitude Quake Hits South Pacific"
- BBC News: "Tsunami after South Pacific quake"
- Sydney Morning Herald: "Major quake hits Tonga region"
Tsunami Information
Search the internet
To search the internet for more information about this event, click on the button below:
Current seismic activity measured by USArray
Click the links below to observe near real time maps of earthquakes recorded by the USArray deployment:
Further information
Learn more about the Array Network Facility (ANF) component of USArray, the USArray experiment, the EarthScope project, and the Incorporated Research Institutions for Seismology (IRIS).
