Magnitude 6.6 - NEAR THE WEST COAST OF HONSHU, JAPAN
2004 October 23 08:56:00 UTC

Preliminary Earthquake Report
U.S. Geological Survey, National Earthquake Information Center
World Data Center for Seismology, Denver

A strong earthquake occurred at 08:56:00 (UTC) on Saturday, October 23, 2004. The magnitude 6.6 event has been located in NEAR THE WEST COAST OF HONSHU, JAPAN. (This event has been reviewed by a seismologist.)

Magnitude 6.6 Date-Time Saturday, October 23, 2004 at 08:56:00 (UTC) = Coordinated Universal Time Saturday, October 23, 2004 at 5:56:00 PM = local time at epicenter Time of Earthquake in other Time Zones Location 37.231°N, 138.753°E Depth 16 km (9.9 miles) set by location program Region NEAR THE WEST COAST OF HONSHU, JAPAN Distances 80 km (50 miles) SSW of Niigata, Honshu, Japan 85 km (50 miles) NE of Nagano, Honshu, Japan 95 km (60 miles) NNW of Maebashi, Honshu, Japan 195 km (120 miles) NNW of TOKYO, Japan Location Uncertainty horizontal +/- 4.5 km (2.8 miles); depth fixed by location program Parameters Nst=283, Nph=283, Dmin=91.2 km, Rmss=0.98 sec, Gp= 32°, M-type=teleseismic moment magnitude (Mw), Version=S Source USGS NEIC (WDCS-D) Event ID uspyal Felt Reports MW 6.5 (NIED). At least 33 people killed, 2,900 injured, 395 buildings destroyed and 3,473 damaged in Niigata Prefecture. A high-speed train derailed; several roads, bridges and rail lines damaged; at least 151 landslides and 11 fires occurred; several gas, water and power lines damaged in Niigata Prefecture. Felt in Chiba, Fukushima, Gumma, Kanagawa, Miyagi, Saitama and Tokyo Prefectures.

Tectonic Summary Location Maps: NEIC Maps Did you feel it? Report shaking and damage at your location. You can also view a map displaying accumulated data from your report and others. NEIC Moment Tensor Solution Historical Moment Tensor Solutions Seismic Hazard Map Historical Seismicity Theoretical P-Wave Travel Times Energy and Broadband Solution Phase Data Seismic Record Section Earthquake Summary Map News Release Earthquake Information for JAPAN Archive of newsworthy events

Organizations ReliefWeb News Links Death toll from earthquake rises to 31; 103,000 remain in shelters Rain latest danger for Japan

For more information, go to http://neic.usgs.gov/ || Contacts

The official magnitude for this earthquake is indicated at the top of this page. This was the best available estimate of the earthquake's size, at the time that this page was created. Other magnitudes associated with web pages linked from here are those determined at various times following the earthquake with different types of seismic data. Although, given the data used, they are legitimate estimates of magnitude, they are not considered the official magnitude.

U.S. Geological Survey, a bureau of the U.S. Department of the Interior
This page is brought to you by the Earthquake Hazards Program
URL: http://earthquake.usgs.gov/eqinthenews/
Maintained by: Web Team
Last modification: Wednesday, 15-Oct-2003 13:48
Contact Us: Web_Team

USGS Privacy Statement | | Disclaimer | | FOIA | | Accessibility