Significant M5.8 Earthquake struck on Sunday Night near Ryūgasaki in Japan.

Written by Earthquakelist.org on August 22nd, 2026. Last updated October 21st, 2026.

In the night of Sunday August 23rd, 2026, a significant M5.8 earthquake hit under land 3 kilometer from Ryūgasaki in Japan. The earthquake struck near a very densely populated region. Around 49 million people have been exposed to shaking.

Earthquake Summary

The earthquake struck on land in Japan, 3 kilometer (2 mi) northwest of Ryūgasaki in Ibaraki. The center of this earthquake had a quite shallow depth of 61 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Aug 23, 2026 02:00 (Tokyo Time) - Aug 22, 2026 17:00 Universal Time.
Location:	3 km NW of Ryūgasaki, Ibaraki, Japan. Coordinates 35°55'3"N 140°9'9"E.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.8 Detected by 41 stations. Maximum Error Range ±0.048 .
Depth:	61 km (38 mi) A quite shallow depth.
Max. Intensity:	VI Strong On the Modified Mercalli Scale.
Tsunami Risk:	Tsunami very unlikely While this was a shallow earthquake, it appears to have occurred under land with a magnitude not strong enough to cause tsunami's. Always stay cautious - More info here.

Minimal impact predicted

The US Geographic Survey (USGS) describes the impact of this earthquake as follows:

Four persons injured in Chiba, one in Ibaraki, nine in Kanagawa, 22 at Tokyo and nine in Saitama. Railway operations temporarily suspended and water outages occurred in Tokyo.

Based on scientific estimates by the USGS, the risk of high fatalities for this earthquake is classified at level GREEN (low). They expect an 90% likelyhood of between 0 and 1 fatalities.

The USGS classifies the economic impact of this earthquake at level GREEN (low). They expect an 90% likelyhood of between 0 and 1 million US Dollars in economic damage and impact.

Roughly 49 million people exposed to shaking

An estimated 49 million have been exposed to shaking (An MMI or Modified Mercalli Intensity level II or higher) as a result of this earthquake according scientific estimates published by the USGS.

An estimated 4,356,000 people were exposed to level VI. At this level, strong shaking and probably light damage can be expected. Intensity level V was experienced by a large group of people (around 20 million). In their region, moderate shaking and very light damage can be expected. All exposure to shaking was within the borders of Japan .

People	MMI Level	Shaking	Damage
0	I	Not noticable	None
30,360	II	Very weak	None
6,144,000	III	Weak	Probably none
19,280,000	IV	Light	Likely none
19,640,000	V	Moderate	Very light
4,356,000	VI	Strong	Light
0	VII	Very Strong	Moderate
0	VIII	Severe	Moderate to heavy
0	IX	Violent	Heavy
0	X	Extreme	Very heavy

Nearby towns and cities

This earthquake may have been felt in Japan . The closest significant population center near the earthquake is Fujishiro in Ibaraki, Japan. Fujishiro is located 3 kilometer (2 mi) east of the epicenter. The intensity of shaking and damage in Fujishiro is estimated to be around level VI on the Modified Mercalli Intensity scale (strong shaking, probably light damage).

Multiple large cities are in proximity of today's earthquake. Tokyo is located 49 km to the southwest and experienced an intensity of IV (light shaking, likely no damage). Yokohama is located 70 km to the southwest and experienced an intensity of IV (light shaking, likely no damage). Saitama is located 45 km to the west and experienced an intensity of V (moderate shaking, very light damage).

A complete list of nearby places is included below. Estimated intensity data (MMI) sourced from a shake-map published by the US Geographic Survey is shown where available (cities without data probably experienced little impact).

Overview of nearby places

Cities and Towns around the epicenter of this earthquake.
Distance	Place	Intensity (MMI)
3 km (2 mi) W from epicenter	Fujishiro Ibaraki, Japan.	VI Strong
3 km (2 mi) SE from epicenter	Ryūgasaki Ibaraki, Japan.	VI Strong
6 km (4 mi) N from epicenter	Ushiku Ibaraki, Japan.	VI Strong
7 km (4 mi) W from epicenter	Toride Ibaraki, Japan.	VI Strong
13 km (8 mi) SW from epicenter	Abiko Chiba, Japan.	V Moderate
14 km (9 mi) N from epicenter	Ami Ibaraki, Japan.	VI Strong
14 km (9 mi) W from epicenter	Moriya Ibaraki, Japan.	VI Strong
15 km (9 mi) SW from epicenter	Shiroi Chiba, Japan.	V Moderate
15 km (9 mi) N from epicenter	Naka Ibaraki, Japan.	VI Strong
15 km (9 mi) E from epicenter	Edosaki Ibaraki, Japan.	VI Strong
16 km (10 mi) E from epicenter	Inashiki Ibaraki, Japan.	VI Strong
17 km (11 mi) W from epicenter	Kashiwa Chiba, Japan.	V Moderate
19 km (12 mi) NW from epicenter	Mitsukaidō Ibaraki, Japan.	VI Strong
21 km (13 mi) SE from epicenter	Narita Chiba, Japan.	V Moderate
23 km (14 mi) S from epicenter	Sakura Chiba, Japan.	V Moderate
24 km (15 mi) W from epicenter	Nagareyama Chiba, Japan.	V Moderate
26 km (16 mi) W from epicenter	Noda Chiba, Japan.	VI Strong
27 km (17 mi) SW from epicenter	Matsudo Chiba, Japan.	V Moderate
27 km (17 mi) NW from epicenter	Iwai Ibaraki, Japan.	VI Strong
28 km (17 mi) W from epicenter	Yoshikawa Saitama, Japan.	V Moderate
28 km (17 mi) SW from epicenter	Honchō Chiba, Japan.	V Moderate
30 km (19 mi) S from epicenter	Yotsukaidō Chiba, Japan.	V Moderate
30 km (19 mi) W from epicenter	Yashio Saitama, Japan.	V Moderate
31 km (19 mi) N from epicenter	Ishioka Ibaraki, Japan.	VI Strong
31 km (19 mi) E from epicenter	Katori-shi Chiba, Japan.	V Moderate
32 km (20 mi) N from epicenter	Tsukuba Ibaraki, Japan.	V Moderate
33 km (21 mi) W from epicenter	Koshigaya Saitama, Japan.	VI Strong
33 km (21 mi) W from epicenter	Sōka Saitama, Japan.	VI Strong
33 km (21 mi) SE from epicenter	Yachimata Chiba, Japan.	V Moderate
35 km (22 mi) S from epicenter	Chiba Chiba, Japan.	V Moderate
36 km (22 mi) SW from epicenter	Urayasu Tokyo, Japan.	VI Strong
37 km (23 mi) W from epicenter	Kasukabe Saitama, Japan.	VI Strong
41 km (25 mi) W from epicenter	Iwatsuki Saitama, Japan.	V Moderate
42 km (26 mi) W from epicenter	Kawaguchi Saitama, Japan.	VI Strong
44 km (27 mi) W from epicenter	Shimotoda Saitama, Japan.	VI Strong
45 km (28 mi) W from epicenter	Saitama Saitama, Japan.	V Moderate
45 km (28 mi) S from epicenter	Ichihara Chiba, Japan.	V Moderate
49 km (30 mi) W from epicenter	Ageoshimo Saitama, Japan.	V Moderate
49 km (30 mi) SW from epicenter	Tokyo Tokyo, Japan.	IV Light
53 km (33 mi) NW from epicenter	Oyama Tochigi, Japan.	V Moderate
55 km (34 mi) NE from epicenter	Mito Ibaraki, Japan.	V Moderate
59 km (37 mi) W from epicenter	Nishi-Tokyo-shi Tokyo, Japan.	IV Light
59 km (37 mi) SW from epicenter	Kawasaki Kanagawa, Japan.	V Moderate
60 km (37 mi) W from epicenter	Kawagoe Saitama, Japan.	IV Light
62 km (39 mi) SW from epicenter	Chōfu Tokyo, Japan.	IV Light
63 km (39 mi) W from epicenter	Tokorozawa Saitama, Japan.	IV Light
70 km (43 mi) SW from epicenter	Yokohama Kanagawa, Japan.	IV Light
76 km (47 mi) N from epicenter	Utsunomiya Tochigi, Japan.	V Moderate
76 km (47 mi) SW from epicenter	Machida Tokyo, Japan.	IV Light
80 km (50 mi) W from epicenter	Hachiōji Tokyo, Japan.	IV Light
82 km (51 mi) NW from epicenter	Ōta Gunma, Japan.	IV Light
83 km (52 mi) SW from epicenter	Yokosuka Kanagawa, Japan.	IV Light
99 km (62 mi) W from epicenter	Uenohara Yamanashi, Japan.	IV Light
142 km (88 mi) NE from epicenter	Iwaki Fukushima, Japan.	IV Light
191 km (119 mi) SW from epicenter	Shizuoka Shizuoka, Japan.	III Weak
194 km (121 mi) NW from epicenter	Nagano Nagano, Japan.	III Weak
242 km (150 mi) NW from epicenter	Niigata Niigata, Japan.
258 km (160 mi) N from epicenter	Yamagata Yamagata, Japan.
269 km (167 mi) N from epicenter	Sendai Miyagi, Japan.
277 km (172 mi) W from epicenter	Toyama Toyama, Japan.
305 km (190 mi) W from epicenter	Nagoya Aichi, Japan.
311 km (193 mi) W from epicenter	Gifu-shi Gifu, Japan.
326 km (203 mi) W from epicenter	Kanazawa Ishikawa, Japan.
337 km (209 mi) W from epicenter	Yokkaichi Mie, Japan.
354 km (220 mi) W from epicenter	Fukui-shi Fukui, Japan.
361 km (224 mi) W from epicenter	Hikone Shiga, Japan.
380 km (236 mi) N from epicenter	Yokote Akita, Japan.
384 km (239 mi) N from epicenter	Kitakami Iwate, Japan.

Earthquake Intensity Map

The maximum intensity (MMI Scale) caused by this earthquake is VI. The map below shows in which areas this earthquake was the most and least impactful. It is based on data from the US Geographic Survey.

I Not felt

II Weak

III Weak

IV Light

V Moderate

VI Strong

VII Very Strong

VIII Severe

IX Violent

X Extreme

Earthquake Intensity Map based on Shakemap Data provided by USGS.

Shaking reported by 155 people

People that feel an earthquake may report their experience to the US Geographic Survey. Currently, 155 people have reported shaking in 60 places, all within Japan.We keep updating this article as more ground reports become available. You may report that you felt this earthquake here.

Places with most reports:

Tokyo, Tokio, Japan: 60 people.
Yokohama, Kanagawa, Japan: 6 people.
Kawasaki, Kanagawa, Japan: 5 people.
Komae, Tokio, Japan: 5 people.
Yokosuka, Kanagawa, Japan: 4 people.
Urayasu, Chiba, Japan: 4 people.
Naka, Ibaraki, Japan: 3 people.
Kashiwa, Chiba, Japan: 3 people.
Kawaguchi, Saitama, Japan: 3 people.
Chiba, Chiba, Japan: 3 people.

Aftershocks detected

Before this earthquake struck, 2 smaller foreshocks occurred. Roughly 2 days before this earthquake, a foreshock measuring MAG-4.3 was detected nearby this earthquake.

Overview of foreshocks and aftershocks

Detected MAG2.5+ earthquakes within within 100km (62 mi), that occurred in the three days before and after the main shock.
Classification	Magnitude	When	Where
Foreshock	M 3.6	3 days earlier Aug 20, 2026 08:38 (Tokyo Time)	76 km (47 mi) NE from Main Shock.
Foreshock	M 4.3	2 days earlier Aug 20, 2026 14:28 (Tokyo Time)	82 km (51 mi) NE from Main Shock.
Main Shock This Earthquake	M 5.8	Aug 23, 2026 02:00 (Tokyo Time)	-

More earthquakes coming?

Earthquakes can create aftershocks. These are generally at least 1 magnitude lower than any main shock, and as time passes the chance and strength of aftershocks decreases.

In only six percent of cases, significant earthquakes are followed by a larger main shock, making the current earthquake a foreshock. While the chance of this happening is not so large, it is adviced to maintain cautiousness in the hours and days following a major earthquake.

Read: How to Stay Safe during an Earthquake (cdc.gov).

Earthquakes like this happen often in the region

Earthquakes of this strength are very common in the region. This is the strongest earthquake to hit since June 26th, 2026, when a 5.8 magnitude earthquake hit 46 km (28 mi) further south-east. An even stronger magnitude 7.3 earthquake struck on March 16th, 2022.

In total, 22 earthquakes with a magnitude of 5.8 or higher have been registered within 300km (186 mi) of this epicenter in the past 10 years. This comes down to an average of once every 6 months.

Tsunami very unlikely

DISCLAIMER: We strongly suggest to closely monitor advice from local authorities with regards to tsunami risks. Our analysis is based on automatically collected data from external sources, and these might contain mistakes. In addition, earthquakes can cause landslides that may lead to a tsunami, or be a followed by another, potentially stonger, earthquake.

While MAG-6.5+ earthquakes may cause tsunami's, it appears that the epicenter of this earthquake hit under land. In addition, the reported depth is deeper than 100km, making the risk of a tsunami even less likely. However always stay cautious and monitor advice from local authorities.

Tsunami Risk Factors

Factor	Under Sea?	MAG-6.5 or stronger?	Shallow depth?
Explanation	Almost all tsunami's are caused by earthquakes with their epicenter under sea or very near the sea. However stay cautious in coastal areas as earthquakes on land may cause landslides into sea, potentially still causing a local tsunami.	Under MAG 6.5: Very unlikely to cause a tsunami. MAG 6.5 to 7.5: Destructive tsunami's do occur, but are uncommon. Likely to observe small sea level changes. MAG 7.6+: Earthquakes with these magnitudes might produce destructive tsunami's.	Most destructive tsunami's are caused by shallow earthquakes with a depth between 0 and 100km under the surface of the earth. Deeper tsunami's are unlikely to displace to ocean floor.
This Earthquake	Not this earthquake. This earthquake appears to have struck on land far from any coast.	Not this earthquake. This earthquake had a magnitude of 5.8. Earthquakes of this strength are unlikely to trigger a tsunami.	This earthquake occurred at a depth of of 61 km (38 mi). Earthquakes this shallow could trigger a tsunami.

Sources

Last updated 21/10/26 05:48 (). As more information on this earthquake becomes available this article will be updated. This article is automatically composed based on data originating from multiple sources.