M4.6 Earthquake 120 km NE of Hengchun, Taiwan — September 13, 2026
2026-09-13 22:44:41 UTC (55 min ago) · approx. 6:44 AM UTC+8 local
Aftershock of the M5.5 mainshock.
On September 13, 2026 at 22:44 UTC, a magnitude 4.6 shallow crustal earthquake struck 120 km NE of Hengchun, Taiwan, at a depth of 10.0 km and coordinates 22.7398°, 121.6019°. This earthquake was detected by 44 seismic stations with good location accuracy and was assigned a USGS significance rating of 326, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 m — a useful intuition for the size of the slip patch on the fault.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.5 mainshock that occurred 19 days ago 108 km NE of Hengchun, Taiwan. Since the mainshock, the USGS has recorded 2 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
The epicenter is located in Taiwan, a region characterized by the collision of the Luzon volcanic arc with the Eurasian continental margin, where the Philippine Sea Plate converges at 80 mm per year. View all earthquakes in Taiwan.
Learn more: Magnitude scale · Aftershock sequences
Earthquake Details
121.6019°E
Technical Information
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Common Questions
How strong was the magnitude 4.6 earthquake near Hengchun, Taiwan?
The magnitude 4.6 earthquake that struck 120 km NE of Hengchun, Taiwan on September 13, 2026 at 22:44 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 22.7398°, 121.6019°, which is 120 km NE of Hengchun, Taiwan. View all earthquakes in Taiwan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.5 one earlier?
No. This magnitude 4.6 earthquake is an aftershock of the larger magnitude 5.5 mainshock that occurred earlier 108 km NE of Hengchun, Taiwan. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Has Taiwan had earthquakes this big before?
The largest recorded earthquake in Taiwan was the M7.6 Chi-Chi earthquake of September 21, 1999. Today's magnitude 4.6 event is significantly smaller than that historical record.
Authoritative source: USGS event page (event ID: us7000th8v). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, September 13, 2026). M4.6 Earthquake 120 km NE of Hengchun, Taiwan — September 13, 2026. Retrieved September 13, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000th8v/