Largest quake of 2009 so far, Tonga, m=7.9

It's nice when they happen away from populated areas.

Here is the basic information from the USGS:

Magnitude	7.9
Date-Time	Thursday, March 19, 2009 at 18:17:37 UTC Friday, March 20, 2009 at 06:17:37 AM at epicenter Time of Earthquake in other Time Zones
Location	23.015°S, 174.782°W
Depth	10 km (6.2 miles) set by location program
Region	TONGA REGION
Distances	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

Below is the seismogram from Franklin and Marshall College, broadband vertical component.
And let's continue our mini-tour of different geological surveys. Records of this event on seismographs across New Zealand are shown on the web pages of the Institute of Geological and Nuclear Sciences. Look at those waves sweep across the stations, as distance from the epicenter increases.

Click on figure for a larger image

According to the Pacific Tsunami Warning Center:

TSUNAMI MESSAGE NUMBER   3
NWS PACIFIC TSUNAMI WARNING CENTER EWA BEACH HI
1009 AM HST THU MAR 19 2009

TO - CIVIL DEFENSE IN THE STATE OF HAWAII

SUBJECT - FINAL TSUNAMI ADVISORY

THE TSUNAMI ADVISORY IS ENDED FOR THE STATE OF HAWAII EFFECTIVE
AT 1009 AM HST.

AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS

ORIGIN TIME - 0818 AM HST 19 MAR 2009
COORDINATES - 23.0 SOUTH  174.8 WEST
LOCATION    - TONGA ISLANDS REGION
MAGNITUDE   - 7.7  MOMENT

MEASUREMENTS OR REPORTS OF TSUNAMI WAVE ACTIVITY

GAUGE LOCATION        LAT   LON    TIME        AMPL         PER
-------------------  ----- ------  -----  ---------------  -----
NIUE                 19.1S 169.9W  1911Z   0.04M /  0.1FT  06MIN

LAT  - LATITUDE (N-NORTH, S-SOUTH)
LON  - LONGITUDE (E-EAST, W-WEST)
TIME - TIME OF THE MEASUREMENT (Z IS UTC IS GREENWICH TIME)
AMPL - TSUNAMI AMPLITUDE MEASURED RELATIVE TO NORMAL SEA LEVEL.
IT IS ...NOT... CREST-TO-TROUGH WAVE HEIGHT.
VALUES ARE GIVEN IN BOTH METERS(M) AND FEET(FT).
PER  - PERIOD OF TIME IN MINUTES(MIN) FROM ONE WAVE TO THE NEXT.

EVALUATION

THE PACIFIC TSUNAMI WARNING CENTER HAS CANCELLED THE REGIONAL
TSUNAMI WARNING IT ISSUED FOR ANOTHER PART OF THE PACIFIC. BASED
ON ALL AVAILABLE DATA THERE IS NO DESTRUCTIVE TSUNAMI THREAT TO
HAWAII AND THE ADVISORY FOR HAWAII IS ALSO CANCELLED.

HOWEVER... SOME COASTAL AREAS IN HAWAII COULD EXPERIENCE SMALL
NON-DESTRUCTIVE SEA LEVEL CHANGES AND STRONG OR UNUSUAL CURRENTS
LASTING UP TO SEVERAL HOURS. THE ESTIMATED TIME SUCH EFFECTS
MIGHT BEGIN IS

         0236 PM HST THU 19 MAR 2009