Written by on . Last updated November 28th, 2023.

Under land 20 kilometer from Masbate in The Philippines, a shallow M4.9 earthquake occurred in the early morning of Tuesday October 3rd, 2023.

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

Earthquake Summary

The earthquake struck on land in The Philippines, 20 kilometer (12 mi) south of Masbate in Bicol. The center of this earthquake had a very shallow depth of 10 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time: Oct 3, 2023 05:30AM (Manila Time)
- Oct 2, 2023 21:30 Universal Time.
Location: 20 km south of Masbate, Bicol, The Philippines.
Coordinates 12°11'26"N 123°37'39"E.
Map: Map of area around epicenter.
Map of area around epicenter. Click to open in Google Maps.
Magnitude: MAG 4.9
Detected by 83 stations. Maximum Error Range ±0.061 .
Depth: 10 km (6 mi)
A very shallow depth.
Tsunami Risk: Tsunami very unlikely
While this was a shallow earthquake in a coastal area, it appears to have occurred under land (6 km from the sea) with a magnitude that is usually not strong enough to cause tsunami's.
Always stay cautious - More info here.

Nearby towns and cities

This earthquake may have been felt in The Philippines . Masbate in Bicol, The Philippines is the nearest significant place from the epicenter. The earthquake occurred 20 kilometer (12 mi) south of Masbate.

Major cities near this earthquake: Cebu City is located 210 km to the south. Bacolod City is located 185 km to the south-southwest. Mansilingan is located 187 km to the south-southwest.

An overview of nearby towns and cities is available in the overview below.

Overview of nearby places

Distance Place
20 km (12 mi)
N from epicenter
Masbate

Bicol, The Philippines.
60 km (37 mi)
NNE from epicenter
Bulan

Bicol, The Philippines.
72 km (45 mi)
NE from epicenter
Irosin

Bicol, The Philippines.
96 km (60 mi)
NNE from epicenter
Sorsogon

Bicol, The Philippines.
106 km (66 mi)
N from epicenter
Legaspi

Bicol, The Philippines.
106 km (66 mi)
E from epicenter
Calbayog City

Eastern Visayas, The Philippines.
109 km (68 mi)
N from epicenter
Tagas

Bicol, The Philippines.
114 km (71 mi)
S from epicenter
Bantayan

Central Visayas, The Philippines.
115 km (71 mi)
ENE from epicenter
Catarman

Eastern Visayas, The Philippines.
117 km (73 mi)
SW from epicenter
Roxas City

Western Visayas, The Philippines.
123 km (76 mi)
N from epicenter
Polangui

Bicol, The Philippines.
125 km (78 mi)
N from epicenter
Libon

Bicol, The Philippines.
126 km (78 mi)
N from epicenter
Malilipot

Bicol, The Philippines.
129 km (80 mi)
N from epicenter
San Jose

Bicol, The Philippines.
130 km (81 mi)
N from epicenter
Tabaco

Bicol, The Philippines.
132 km (82 mi)
NNW from epicenter
Bato

Bicol, The Philippines.
133 km (83 mi)
SSE from epicenter
Bogo

Central Visayas, The Philippines.
138 km (86 mi)
NNW from epicenter
Nabua

Bicol, The Philippines.
139 km (86 mi)
N from epicenter
Buhi

Bicol, The Philippines.
140 km (87 mi)
S from epicenter
Sagay

Western Visayas, The Philippines.
140 km (87 mi)
N from epicenter
Iriga City

Bicol, The Philippines.
143 km (89 mi)
NNW from epicenter
Baao

Bicol, The Philippines.
143 km (89 mi)
SSW from epicenter
Cadiz

Western Visayas, The Philippines.
144 km (89 mi)
ESE from epicenter
Catbalogan

Eastern Visayas, The Philippines.
148 km (92 mi)
SSW from epicenter
Manapla

Western Visayas, The Philippines.
148 km (92 mi)
WSW from epicenter
Kalibo (poblacion)

Western Visayas, The Philippines.
148 km (92 mi)
S from epicenter
Paraiso

Western Visayas, The Philippines.
151 km (94 mi)
S from epicenter
Escalante

Western Visayas, The Philippines.
156 km (97 mi)
SSW from epicenter
Victorias

Western Visayas, The Philippines.
161 km (100 mi)
SW from epicenter
Passi

Western Visayas, The Philippines.
166 km (103 mi)
NNW from epicenter
Naga

Bicol, The Philippines.
169 km (105 mi)
SE from epicenter
Ormoc

Eastern Visayas, The Philippines.
173 km (107 mi)
SSW from epicenter
Binonga

Western Visayas, The Philippines.
173 km (107 mi)
WSW from epicenter
Pandan

Western Visayas, The Philippines.
177 km (110 mi)
SSW from epicenter
Talisay

Western Visayas, The Philippines.
182 km (113 mi)
S from epicenter
Ualog

Western Visayas, The Philippines.
183 km (114 mi)
SE from epicenter
Panalanoy

Eastern Visayas, The Philippines.
183 km (114 mi)
SE from epicenter
Tacloban

Eastern Visayas, The Philippines.
183 km (114 mi)
SSE from epicenter
Cogan

Central Visayas, The Philippines.
185 km (115 mi)
SSW from epicenter
Bacolod City

Western Visayas, The Philippines.
187 km (116 mi)
SSW from epicenter
Mansilingan

Western Visayas, The Philippines.
191 km (119 mi)
SSE from epicenter
Danao

Central Visayas, The Philippines.
202 km (126 mi)
SW from epicenter
Iloilo

Western Visayas, The Philippines.
202 km (126 mi)
S from epicenter
Toledo

Central Visayas, The Philippines.
204 km (127 mi)
SSW from epicenter
Bago City

Western Visayas, The Philippines.
210 km (130 mi)
S from epicenter
Mandaue City

Central Visayas, The Philippines.
210 km (130 mi)
S from epicenter
Cebu City

Central Visayas, The Philippines.
212 km (132 mi)
S from epicenter
Lapu-Lapu City

Central Visayas, The Philippines.
218 km (135 mi)
S from epicenter
Talisay

Central Visayas, The Philippines.
261 km (162 mi)
SSW from epicenter
Kabankalan

Western Visayas, The Philippines.
279 km (173 mi)
W from epicenter
San Jose

Mimaropa, The Philippines.
291 km (181 mi)
NW from epicenter
Lucena

Calabarzon, The Philippines.
Cities and Towns around the epicenter of this earthquake.

2 Aftershocks detected

This main shock was followed by 2 smaller aftershocks. Just 42 mins after this main shock, an earthquake measuring MAG-4.3 was detected 10 km (6 mi) east of this earthquake.

In the days before this main shock, 2 smaller foreshocks were detected. A 3.3 magnitude earthquake hit 2 days earlier nearby.

Overview of foreshocks and aftershocks

Classification Magnitude When Where
Foreshock M 3.3 2 days earlier
Sep 30, 2023 07:10PM (Manila Time)
61 km (38 mi)
N from Main Shock.
Foreshock M 3.0 2 days earlier
Oct 1, 2023 02:48PM (Manila Time)
31 km (20 mi)
ESE from Main Shock.
Main Shock
This Earthquake
M 4.9 Oct 3, 2023 05:30AM
(Manila Time)
-
Aftershock M 4.3 42 mins later
Oct 3, 2023 06:12AM (Manila Time)
10 km (6 mi)
E from Main Shock.
Aftershock M 3.0 2 days later
Oct 5, 2023 10:32AM (Manila Time)
25 km (15 mi)
ESE 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?

The risk of aftershocks decreases rapidly over time. Usually, aftershocks are at least one order of magnitude lower than a main shock.

The chance that a significant earthquake like this one is followed by an even larger earthquake is not so large. On average, scientists estimate a 94% chance that a major earthquake will not be followed by an even larger one. It is still adviced to be aware of this risk

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 September 18th, 2023, when a 4.9 magnitude earthquake hit 286 km (178 mi) further west-northwest. An even stronger magnitude 7.1 earthquake struck on October 15th, 2013.

In total, 122 earthquakes with a magnitude of 4.9 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 30 days.

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 This earthquake appears to have struck on land near a coastal area (6 km from the sea). Not this earthquake.
This earthquake had a magnitude of 4.9. Earthquakes of this strength are unlikely to trigger a tsunami.
This earthquake occurred at a depth of of 10 km (6 mi). Earthquakes this shallow could trigger a tsunami.

Sources

Last updated 28/11/23 07:38 (). This article contains currently available information about the earthquake and is automatically composed. We continue to update this article up to a few days after the earthquake occurred.

  1. US Geographic Society (USGS): Earthquake us6000lccn
  2. European-Mediterranean Seismological Centre (EMSC): Earthquake 20231002_0000205
  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