M5.4 Earthquake 72 km N of Namuac, Philippines — August 1, 2023
2023-08-01 08:03:19 UTC (2023-08-01) · approx. 4:03 PM UTC+8 local
Maximum shaking intensity MMI 4.9 (moderate).
On August 1, 2023 at 08:03 UTC, a magnitude 5.4 shallow crustal earthquake struck 72 km N of Namuac, Philippines, at a depth of 32.2 km and coordinates 19.2560°, 121.2607°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 114 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 449, placing it among routine seismic activity. The nearest populated place is Namuac (population 3,037).
Physical scale: An earthquake of magnitude 5.4 releases seismic energy equivalent to roughly 2 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 3.2 km — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Philippines, a region characterized by the Manila Trench and Philippine Trench subduction systems, where the Philippine Sea Plate overrides the Eurasian Plate. The nearest mapped fault system is the Philippine Fault. View all earthquakes in Philippines.
Learn more: Magnitude scale · Aftershock sequences
Nearest Populated Places
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Population exposure (USGS PAGER)
Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.
| Shaking intensity (MMI) | Description | Population exposed |
|---|---|---|
| MMI 3 | weak | 2,688,344 |
| MMI 4 | light | 247,848 |
| MMI 5 | moderate | 9,255 |
Earthquake Details
121.2607°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 5.4 earthquake near Namuac, Philippines?
The magnitude 5.4 earthquake that struck 72 km N of Namuac, Philippines on August 1, 2023 at 08:03 UTC had a depth of 32.2 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at 19.2560°, 121.2607°, which is 72 km N of Namuac, Philippines. The nearest populated place is Namuac (population 3,037). View all earthquakes in Philippines.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.4 earthquakes can continue for days to weeks and gradually diminish over time.
Has Philippines had earthquakes this big before?
The largest recorded earthquake in Philippines was the M8.0 Mindanao earthquake of August 17, 1976. Today's magnitude 5.4 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us6000kx06). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, August 1, 2023). M5.4 Earthquake 72 km N of Namuac, Philippines — August 1, 2023. Retrieved October 7, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000kx06/