Updated: 2025-07-15 23:57:50 (UTC+9)
Ver.6
Final Report
2025-07-15 23:47 (UTC+9),
NORTHERN IBARAKI,
60km Depth, M 4.8 by JMA
NORTHERN IBARAKI,
60km Depth, M 4.8 by JMA
Is Distribution
Maximum Observed Is:4
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 2025/07/15 23:57:33.
Estimated Is for Major Cities
| Max. Obs. Is | Histogram of Estimated Is |
Municipality
Show All Data | Nighttime Population | Distance [km] |
| 4 | Ichikai,Haga,Tochigi | 11,000 | 44 | |
| 4 | Kasama,Ibaraki | 76,000 | 31 | |
| 3 | Hitachiota,Ibaraki | 52,000 | 7 | |
| 3 | Mito,Ibaraki | 270,000 | 18 | |
| 3 | Tsuchiura,Ibaraki | 140,000 | 59 | |
| 3 | Moka,Tochigi | 80,000 | 52 | |
| 3 | Otawara,Tochigi | 75,000 | 66 | |
| 3 | Noda,Chiba | 150,000 | 88 | |
| 3 | Nikko,Tochigi | 83,000 | 84 | |
| 3 | Hitachi,Ibaraki | 190,000 | 11 | |
| 3 | Shirakawa,Fukushima | 61,000 | 77 | |
| 3 | Hitachinaka,Ibaraki | 160,000 | 12 | |
| 3 | Ishioka,Ibaraki | 77,000 | 44 | |
| 3 | Kasukabe,Saitama | 230,000 | 95 | |
| 3 | Ashikaga,Tochigi | 150,000 | 104 | |
| 3 | Chikusei,Ibaraki | 100,000 | 59 | |
| 3 | Naka,Ibaraki | 56,000 | 11 | |
| 3 | Toride,Ibaraki | 110,000 | 81 | |
| 3 | Utsunomiya,Tochigi | 520,000 | 64 | |
| 3 | Tsukuba,Ibaraki | 230,000 | 65 |
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
Not Available
|
|
6- or greater
Not Available
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6+ or greater
Not Available
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Population exposed to Is 5- or greater are not estimated.
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
Is Distribution of Return Period of 50,000-year
Major Historical Damaging Earthquakes in This Region
| Year | Region | M | Damage |
| 1895 | Southern Ibaraki | 7.2 | 53 collapses (43 houses and 10 depots), 6 dead. |
| 1915 | Boso Peninsula | 6.0 | Some landslides. 5 injured, some houses collapsed. |
| 1921 | Southern Ibaraki | 7.0 | Ryugasaki Earthquake,Minor damage in Chiba and Ibaraki such as damage to houses and roads. |
| 1938 | Off Ibaraki | 7.0 | 250 houses damaged in Fukushima. 1 depot collapsed in Ibaraki. A small tsunami was observed. |
| 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