Written by on . Last updated June 13th, 2024.

A strong MAG-6.3 earthquake struck in the Philippine Sea 18 kilometer from Uwajima, Japan in the evening of Wednesday April 17th, 2024. Earthquakes like this can cause significant economic damage and have a significant risk at casualties.

Felt the earthquake? Share this article: Share on Facebook Tweet Submit to Reddit Share on LinkedIn

Earthquake Summary

This earthquake hit under water in the Philippine Sea, right off the coast of Japan (4 mi offshore), 18 kilometer west of Uwajima in Ehime. The center of this earthquake had a quite shallow depth of 32 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time: Apr 17, 2024 23:14 (Tokyo Time)
- Apr 17, 2024 14:14 Universal Time.
Location: 18 km west of Uwajima, Ehime, Japan.
Coordinates 33°15'1"N 132°21'53"E.
Map: Map of area around epicenter.
Map of area around epicenter. Click to open in Google Maps.
Magnitude: MAG 6.3
Detected by 69 stations. Maximum Error Range ±0.037 .
Depth: 32 km (20 mi)
A quite shallow depth.
Max. Intensity:
VIII
Severe

On the Modified Mercalli Scale.
Tsunami Risk: Low tsunami risk
Earthquakes under MAG-6.5 do not usually cause tsunami's.
Always stay cautious - More info here.

Significant impact predicted

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

Twelve people injured, nine homes damaged, several buildings damaged and landslides reported in the Ehime-Kochi-Oita area.

Based on scientific estimates by the USGS, the risk of high fatalities for this earthquake is classified at level YELLOW (significant). They expect an 50% likelyhood of between 0 and 1 fatalities, and a 90% chance that the number of fatalities falls no higher than 10.

The USGS classifies the economic impact of this earthquake at level YELLOW (significant). They expect an 36% likelyhood of between 10 and 100 million US Dollars in economic damage and impact, and a 96% chance that the economic impact of this earthquake falls between 1 and 10,000 million USD.

Roughly 20 million people exposed to shaking

An estimated 20 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 27,740 people were exposed to level VIII. At this level, severe shaking and likely moderate to heavy damage can be expected. The majority of people (roughly 17 million) live in an area exposed to level IV, where light shaking and likely no damage is expected. All exposure to shaking was within the borders of Japan .

People MMI Level Shaking Damage
0
I
Not noticable None
0
II
Very weak None
1,884,000
III
Weak Probably none
16,610,000
IV
Light Likely none
1,587,000
V
Moderate Very light
197,800
VI
Strong Light
81,500
VII
Very Strong Moderate
27,740
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 . Uwajima in Ehime, Japan is the nearest significant place from the epicenter. The earthquake occurred 18 kilometer (11 mi) west of Uwajima. The intensity of shaking and damage in Uwajima is estimated to be around level VIII on the Modified Mercalli Intensity scale (severe shaking, likely moderate to heavy damage).

Multiple major population centers exist within 300km of the earthquake that struck today. Busan is located 369 km to the west-northwest (intensity unknown, possibly low). Hiroshima is located 128 km to the north and experienced an intensity of IV (light shaking, likely no damage). Osaka is located 331 km to the east-northeast (intensity unknown, possibly low).

An overview of nearby towns and cities is available in the overview below. If places don't have intensity data available, it likely means the experienced impact in those places was fairly small.

Overview of nearby places

Distance Place Intensity (MMI)
18 km (11 mi)
E from epicenter
Uwajima

Ehime, Japan.
VIII
Severe
33 km (21 mi)
NNE from epicenter
Ōzu

Ehime, Japan.
VI
Strong
49 km (30 mi)
SE from epicenter
Sukumo

Kōchi, Japan.
VI
Strong
50 km (31 mi)
WSW from epicenter
Tsukumiura

Ōita, Japan.
VI
Strong
54 km (34 mi)
WSW from epicenter
Usuki

Ōita, Japan.
VI
Strong
55 km (34 mi)
SW from epicenter
Saiki

Ōita, Japan.
VI
Strong
61 km (38 mi)
ESE from epicenter
Nakamura

Kōchi, Japan.
VI
Strong
63 km (39 mi)
W from epicenter
Tsurusaki

Ōita, Japan.
V
Moderate
64 km (40 mi)
NNE from epicenter
Iyo

Ehime, Japan.
V
Moderate
68 km (42 mi)
NNE from epicenter
Masaki-chō

Ehime, Japan.
V
Moderate
71 km (44 mi)
W from epicenter
Ōita

Ōita, Japan.
V
Moderate
72 km (45 mi)
WNW from epicenter
Kitsuki

Ōita, Japan.
V
Moderate
75 km (47 mi)
NNE from epicenter
Matsuyama

Ehime, Japan.
V
Moderate
79 km (49 mi)
W from epicenter
Hiji

Ōita, Japan.
V
Moderate
81 km (50 mi)
W from epicenter
Beppu

Ōita, Japan.
V
Moderate
83 km (52 mi)
NNW from epicenter
Yanai

Yamaguchi, Japan.
IV
Light
87 km (54 mi)
NNW from epicenter
Hikari

Yamaguchi, Japan.
IV
Light
88 km (55 mi)
E from epicenter
Susaki

Kōchi, Japan.
V
Moderate
89 km (55 mi)
NNE from epicenter
Hōjō

Ehime, Japan.
V
Moderate
92 km (57 mi)
WNW from epicenter
Bungo-Takada-shi

Ōita, Japan.
IV
Light
95 km (59 mi)
NNW from epicenter
Kudamatsu

Yamaguchi, Japan.
IV
Light
95 km (59 mi)
WSW from epicenter
Takedamachi

Ōita, Japan.
IV
Light
99 km (62 mi)
SW from epicenter
Nobeoka

Miyazaki, Japan.
IV
Light
102 km (63 mi)
NNW from epicenter
Tokuyama

Yamaguchi, Japan.
IV
Light
102 km (63 mi)
N from epicenter
Iwakuni

Yamaguchi, Japan.
IV
Light
106 km (66 mi)
NE from epicenter
Saijō

Ehime, Japan.
IV
Light
111 km (69 mi)
N from epicenter
Kure

Hirochima, Japan.
IV
Light
113 km (70 mi)
ENE from epicenter
Kochi

Kōchi, Japan.
IV
Light
116 km (72 mi)
WNW from epicenter
Nakatsu

Ōita, Japan.
IV
Light
116 km (72 mi)
NW from epicenter
Hōfu

Yamaguchi, Japan.
IV
Light
118 km (73 mi)
NE from epicenter
Niihama

Ehime, Japan.
IV
Light
122 km (76 mi)
N from epicenter
Hatsukaichi

Hirochima, Japan.
IV
Light
128 km (80 mi)
N from epicenter
Hiroshima

Hirochima, Japan.
IV
Light
129 km (80 mi)
NW from epicenter
Ube

Yamaguchi, Japan.
IV
Light
133 km (83 mi)
NW from epicenter
Yamaguchi

Yamaguchi, Japan.
IV
Light
139 km (86 mi)
WNW from epicenter
Yukuhashi

Fukuoka, Japan.
IV
Light
144 km (89 mi)
NNE from epicenter
Mihara

Hirochima, Japan.
IV
Light
151 km (94 mi)
NNE from epicenter
Onomichi

Hirochima, Japan.
IV
Light
152 km (94 mi)
WNW from epicenter
Shimonoseki

Yamaguchi, Japan.
IV
Light
155 km (96 mi)
WNW from epicenter
Kitakyushu

Fukuoka, Japan.
IV
Light
164 km (102 mi)
WSW from epicenter
Kumamoto

Kumamoto, Japan.
IV
Light
164 km (102 mi)
NNW from epicenter
Masuda

Shimane, Japan.
IV
Light
165 km (103 mi)
NE from epicenter
Fukuyama

Hirochima, Japan.
IV
Light
172 km (107 mi)
W from epicenter
Kurume

Fukuoka, Japan.
IV
Light
173 km (107 mi)
SSW from epicenter
Miyazaki

Miyazaki, Japan.
IV
Light
180 km (112 mi)
W from epicenter
Ōmuta

Fukuoka, Japan.
IV
Light
185 km (115 mi)
WNW from epicenter
Fukuoka

Fukuoka, Japan.
IV
Light
192 km (119 mi)
W from epicenter
Saga

Saga, Japan.
IV
Light
197 km (122 mi)
NE from epicenter
Kurashiki

Okayama, Japan.
IV
Light
197 km (122 mi)
NE from epicenter
Takamatsu

Kagawa, Japan.
IV
Light
212 km (132 mi)
NE from epicenter
Okayama

Okayama, Japan.
III
Weak
223 km (139 mi)
ENE from epicenter
Tokushima

Tokushima, Japan.
238 km (148 mi)
WSW from epicenter
Nagasaki

Nagasaki, Japan.
253 km (157 mi)
SW from epicenter
Kagoshima

Kagoshima, Japan.
IV
Light
259 km (161 mi)
NNE from epicenter
Yonago

Tottori, Japan.
277 km (172 mi)
NE from epicenter
Himeji

Hyōgo, Japan.
279 km (173 mi)
ENE from epicenter
Minato

Wakayama, Japan.
331 km (206 mi)
ENE from epicenter
Osaka

Ōsaka, Japan.
355 km (221 mi)
ENE from epicenter
Nara-shi

Nara, Japan.
369 km (229 mi)
WNW from epicenter
Busan

부산광역시, South Korea.
369 km (229 mi)
ENE from epicenter
Kyoto

Kyoto, Japan.
375 km (233 mi)
ENE from epicenter
Nabari

Mie, Japan.
376 km (234 mi)
ENE from epicenter
Ōtsu

Shiga, Japan.
378 km (235 mi)
NW from epicenter
Ulsan

Ulsan, South Korea.
389 km (242 mi)
NW from epicenter
Kimhae

경상남도, South Korea.
398 km (247 mi)
NE from epicenter
Obama

Fukui, Japan.
Cities and Towns around the epicenter of this earthquake.

Earthquake Intensity Map

The maximum intensity (MMI Scale) caused by this earthquake is VIII. 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 100 people in 3 countries

People that feel an earthquake may report their experience to the US Geographic Survey. Currently, 100 people have reported shaking in 55 places in 3 countries (Taiwan, Japan, Korea (South)).We keep updating this article as more ground reports become available. You may report that you felt this earthquake here.

Places with most reports:

  • Iwakuni, Yamaguchi, Japan: 11 people.
  • Uwajima, Ehime, Japan: 7 people.
  • Ōsaka, Ōsaka, Japan: 5 people.
  • Hiroshima, Hiroshima, Japan: 5 people.
  • Pusan, Pusan, Korea (South): 4 people.
  • Innoshima, Hiroshima, Japan: 3 people.
  • Fuchū (E of Hiroshima), Hiroshima, Japan: 3 people.
  • Tamano, Okayama, Japan: 3 people.
  • Okayama, Okayama, Japan: 3 people.
  • Kurashiki, Okayama, Japan: 3 people.

9 Aftershocks detected

After this earthquake struck, 9 smaller aftershocks occurred. At a distance of 1.1 km (0.7 mi) west-northwest of this earthquake, an aftershock struck 4 mins later. It measured a magnitude of 4.8

Overview of foreshocks and aftershocks

Classification Magnitude When Where
Main Shock
This Earthquake
M 6.3 Apr 17, 2024 23:14
(Tokyo Time)
-
Aftershock M 4.8 4 mins later
Apr 17, 2024 23:19 (Tokyo Time)
1.1 km (0.7 mi)
WNW from Main Shock.
Aftershock M 4.3 13 mins later
Apr 17, 2024 23:27 (Tokyo Time)
8 km (5 mi)
SW from Main Shock.
Aftershock M 3.5 38 mins later
Apr 17, 2024 23:52 (Tokyo Time)
7 km (4 mi)
SSE from Main Shock.
Aftershock M 3.7 1 hr later
Apr 18, 2024 00:30 (Tokyo Time)
7 km (4 mi)
SSE from Main Shock.
Aftershock M 4.3 1 hr later
Apr 18, 2024 00:37 (Tokyo Time)
9 km (6 mi)
NNE from Main Shock.
Aftershock M 3.5 1 hr later
Apr 18, 2024 00:44 (Tokyo Time)
7 km (4 mi)
SSE from Main Shock.
Aftershock M 3.7 7 hrs later
Apr 18, 2024 06:31 (Tokyo Time)
7 km (4 mi)
SSE from Main Shock.
Aftershock M 3.7 13 hrs later
Apr 18, 2024 12:16 (Tokyo Time)
6 km (4 mi)
NNE from Main Shock.
Aftershock M 3.8 1 day later
Apr 18, 2024 23:46 (Tokyo Time)
7 km (4 mi)
SSE from Main Shock.
Detected MAG2.5+ earthquakes within within 100km (62 mi), that occurred in the three days before and after the main shock.

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).

This is an unusually powerful earthquake

Earthquakes of this strength are not so common in the region, but it's not the first time. This is the strongest earthquake to hit since January 21st, 2022, when a 6.3 magnitude earthquake hit 66 km (41 mi) further south-southwest. An even stronger magnitude 7 earthquake struck on April 15th, 2016.

In total, 2 earthquakes with a magnitude of 6.3 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 5 years.

Low tsunami risk

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.

Based on early data it appears this earthquake was not strong enough (lower than MAG-6.5) to be likely to cause destructive tsunami's. However this earthquake appeared to have hit at a shallow depth under sea, so 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 This earthquake appears to have struck under the sea. Not this earthquake.
This earthquake had a magnitude of 6.3. Earthquakes of this strength are unlikely to trigger a tsunami.
This earthquake occurred at a depth of of 32 km (20 mi). Earthquakes this shallow could trigger a tsunami.

Sources

Last updated 13/06/24 05:28 (). 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.

  1. US Geographic Society (USGS): Earthquake us7000mcpi
  2. European-Mediterranean Seismological Centre (EMSC): Earthquake 20240417_0000190
  3. Geonames.org: World Cities Database
  4. Google Maps: Static API
  5. Earthquakelist.org: Historic Earthquakes Database

Share this article: Share on Facebook Tweet Submit to Reddit Share on LinkedIn