I have signed up for this email alert that lets you know when and where any earthquake happens in the world a 5.5 or more. Just got this alert, it is the smallest of 5 alerts I got today in the same place. These were HUGE earthquakes I all over 6 points I don't see how they could be called aftershocks.
2004/10/23 14:34 M 5.5 WEST COAST OF HONSHU, JAPAN Z= 17km 37.27N 138.67E
This information is provided by the USGS
National Earthquake Information Center.
(Address problems to: sedas@ghtmail.cr.usgs.gov)
These parameters are preliminary and subject to revision.
A magnitude 5.5 earthquake NEAR THE WEST COAST OF HONSHU, JAPAN has occurred at:
37.27N 138.67E Depth 17km Sat Oct 23 14:34:46 2004 UTC
Time: Universal Time (UTC) Sat Oct 23 14:34:46 2004
Time Near Epicenter Sat Oct 23 23:34:46 2004
Eastern Daylight Time (EDT) Sat Oct 23 10:34:46 2004
Central Daylight Time (CDT) Sat Oct 23 09:34:46 2004
Mountain Daylight Time (MDT) Sat Oct 23 08:34:46 2004
Pacific Daylight Time (PDT) Sat Oct 23 07:34:46 2004
Alaska Daylight Time (ADT) Sat Oct 23 06:34:46 2004
Hawaii Standard Time (HST) Sat Oct 23 04:34:46 2004
Location with respect to nearby cities:
80 km (50 miles) SSW of Niigata, Honshu, Japan (pop 494,000)
80 km (50 miles) NNE of Nagano, Honshu, Japan (pop 358,000)
105 km (65 miles) NNW of Maebashi, Honshu, Japan (pop 284,000)
200 km (125 miles) NNW of TOKYO, Japan
For maps, additional information, and subsequent updates,
please consult:
http://earthquake.usgs.gov/Flinn-Engdahl Region Number = 226
For the most significant earthquakes, information may also be
available from the USGS Earthquake Hazards Program home page at
http://earthquake.usgs.gov/ and the USGS home page at
http://www.usgs.gov/ .
You will continue to receive messages like this when
earthquakes occur that have magnitude 5.5 or greater
anywhere in the world OR 4.5 or greater in the contiguous
US, Hawaii, and Alaska (excluding the Aleutian Islands).
The subscription form for this service is located at: