Earthquake Measuring M5.3 Strikes Eastern Honshu, Japan
The earthquake was preceded by a large swarm of smaller quakes which began striking SSW of Tokyo, near the south coast of Honshu, early Thursday Japan time.
JMA has recorded about 5 dozen quakes measuring 2.0 to 5.3 Mw in the Izu-Hanto region. It appears that submarine volcanic eruptions may be occurring.
The northern Izu Island arc is a tectonically active region, where several destructive interplate [and intraplate] earthquakes, severe earthquake swarms and volcanic eruptions have previously occurred.
Details of the Latest Quake
10-degree Map Centered at 35°N,140°E
Earthquake Location Map. Earthquake location marked in blue also show the area where the swarm is striking. Source of the original map: USGS/EHP. Enhancement: FEWW.
- Magnitude: 5.3
- Date-Time: Thursday, December 17, 2009 at 20:41:27 UTC [Friday, December 18, 2009 at 05:41:27 AM at epicenter]
- Location: 36.392°N, 139.487°E
- Depth: 63 km (39.1 miles)
- Region: EASTERN HONSHU, JAPAN
- 40 km (25 miles) E of Maebashi, Honshu, Japan
- 85 km (50 miles) NNW of TOKYO, Japan
- 90 km (55 miles) W of Mito, Honshu, Japan
- 115 km (70 miles) NE of Kofu, Honshu, Japan
- Location Uncertainty: horizontal +/- 5.3 km (3.3 miles); depth +/- 5.8 km (3.6 miles)
- Parameters NST=159, Nph=159, Dmin=365.5 km, Rmss=0.73 sec, Gp= 97°, M-type=body wave magnitude (Mb), Version=7
- Source: USGS NEIC (WDCS-D)
- Event ID: us2009qhbf
Earthquake Location Maps. Seismicity since December 17, 2009. Source: JMA. Images may be subject to copyright.
FEWW Comment: Regarding the FEWW Forecast of seismicity in Tokyo Bay Area, on November 20, 2009 Fire Earth said: “A tremendous amount of stress energy is unaccounted for in the area near the forecast epicenter.”