2026-09-22 15:34 (UTC+9), SOUTHERN IBARAKI, 50km Depth, M 3.9 by JMA

Is Distribution Maximum Observed Is:3

Seismic Intensity (Is) distribution is estimated from the observed data (circles) of NIED K-NET, KiK-net, JMA, and local governments that had been collected by 2026/09/22 15:44:43.

Estimated Is for Major Cities

Max. Obs. Is Histogram
of Estimated Is
1
2
3
4
5-
5+
6-
6+
7
 Municipality Show All Data Daytime Population Distance
[km]
3
Ishioka,Ibaraki 68,000 25
3
Kasama,Ibaraki 67,000 31
3
Mito,Ibaraki 300,000 45
The histogram shows frequency distribution of estimated Is derived from interpolation of the observation with 250-m mesh. The daytime and nighttime correspond to 9:00-18:59 and 19:00-8:59, respectively. The distance is measured from the epicenter to the center of the municipality.

Is Exposed-Population Estimates of Each City

5- or greater
5- or greater
Not Available
5+ or greater
5+ or greater
Not Available
6- or greater
6- or greater
Not Available
6+ or greater
6+ or greater
Not Available
color scale

Population exposed to Is 5- or greater are not estimated.

Major Historical Damaging Earthquakes in This Region

Year Region M Damage
1922 West coast, Chiba 6.8 Uragasuido Earthquake,1 dead in Tokyo, 1 dead in Yokohama, Kanagawa. Houses were damaged.
1923 Western Kanagawa 7.9 Kanto Earthquake,The maximum amplitude of 14-20 cm was observed in Tokyo. Over 105,000 dead or missing, over 109,000 houses collapsed, 102,000 partially destroyed, over 212,000 destroyed by fire. Many landslides. Tsunamis struck the coast of Kanto. Wave heights were 12 m in Atami, Sizuoka; 9.3 m in Aihama, Chiba.
1931 Northern Saitama 6.9 Nishi Saitama Earthquake,16 dead, 207 collapses (76 houses and 131 non-residential houses).
1943 Aizu, Fukushima 6.2 Tajima Earthquake,Minor damage such as landslides and spalling of walls.
1949 Northern Tochigi 6.2 Imaichi Earthquake,10 dead, 290 houses collapsed, 2,994 partially destroyed, 618 non-residential houses collapsed. Many masonries were damaged. Many landslides were observed.
1987 E Off Chiba 6.7 2 dead, 161 injured in Chiba. 16 houses collapsed and over 70,000 partially destroyed. Many roads damaged.
2011 Hamadori, Fukushima 7.0 The crustal earthquake with normal faults, induced by the 2011 off the Pacific Coast of Tohoku Earthquake. 4 dead, 10 injured (as of March 2016). Maximum Is was 6-.
2012 E Off Chiba 6.1 The crustal earthquake with normal faults, induced by the 2011 off the Pacific Coast of Tohoku Earthquake. 1 dead, 1 injured. Maximum Is was 5+.
Reference: National Astronomical Observatory of Japan, Chronological Scientific Tables, Maruzen, (2017) *partially extracted

Seismic Hazard Information of J-SHIS

J-SHIS is a Web service by NIED, to help prevent and prepare for earthquake disaster by providing a public portal for seismic hazard information across Japan.

Is Distribution of 2% Probability of Exceedance in 50 Years
SI Distribution of 2% Probability of Exceedance in 50 Years SI color scale
Is Distribution of Return Period of 50,000-year
Is Distribution of Return Period of 50,000-year Is color scale