5.5

M5.5 Earthquake 35 km S of Hualien City, TaiwanApril 22, 2024

2024-04-22 20:49:57 UTC (2024-04-22) · approx. 4:49 AM UTC+8 local

Felt by 2 people across nearby locations. Maximum shaking intensity MMI 5.2 (strong).

MagnitudeM5.5(mww)
Time20:49 UTC4:49 AM UTC+8
Depth17.0 kmshallow crustal
Coordinates23.654°, 121.616°
Felt by2DYFI responses· max MMI 5.2
Status✓ Reviewed by USGS· green PAGER
green Alertno significant casualties or damage expected

On April 22, 2024 at 20:49 UTC, a magnitude 5.5 shallow crustal earthquake struck 35 km S of Hualien City, Taiwan, at a depth of 17.0 km and coordinates 23.6539°, 121.6164°. The earthquake was reported felt by 2 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 5.2 (strong). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 115 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 466, placing it among routine seismic activity. The nearest populated place is Hualien City (population 350,468).

Physical scale: An earthquake of magnitude 5.5 releases seismic energy equivalent to roughly 3 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 3.8 km — a useful intuition for the size of the slip patch on the fault.

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

Nearest Populated Places

Hualien Citypop. 350,468
MMI 4.2 (moderate)
Douliupop. 104,723
MMI 3.6 (light)
Pulipop. 86,406
MMI 3.6 (light)
Yilanpop. 94,188
MMI 3.5 (light)
Taipeipop. 7,871,900
MMI 3.5 (light)
Pizitoupop. 5,000
MMI 3.5 (light)
Map showing earthquake epicenter at 23.65°, 121.62°

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.

USGS ShakeMap intensity contours for the M5.5 earthquake near 35 km S of Hualien City, Taiwan

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 2 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M5.5 earthquake near 35 km S of Hualien City, Taiwan

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

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)DescriptionPopulation exposed
MMI 3weak20,854,684
MMI 4light2,620,921
MMI 5moderate29,317

Earthquake Details

Magnitude
5.5 mww
Depth
17.0 km
shallow crustal
Location
23.6539°N
121.6164°E
Felt Reports
2
DYFI responses
Intensity (MMI)
5.2
strong
Community Intensity
2.7
CDI from reports

Technical Information

Event ID
us6000mt1n
Event Type
earthquake
Status
✓ Reviewed
Significance
466
Stations Used
115
Azimuthal Gap
67.0°
Min Station Distance
0.392°
RMS Residual
0.67 sec
Last Updated
2024-10-09 08:29:19 UTC

Common Questions

How strong was the magnitude 5.5 earthquake near Hualien City, Taiwan?

The magnitude 5.5 earthquake that struck 35 km S of Hualien City, Taiwan on April 22, 2024 at 20:49 UTC had a depth of 17.0 km. It was felt by 2 people with maximum shaking intensity of MMI 5.2 (strong). For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at 23.6539°, 121.6164°, which is 35 km S of Hualien City, Taiwan. The nearest populated place is Hualien City (population 350,468). View all earthquakes in Taiwan.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.5 earthquakes can continue for days to weeks and gradually diminish over time.

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 5.5 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us6000mt1n). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2024, April 22, 2024). M5.5 Earthquake 35 km S of Hualien City, TaiwanApril 22, 2024. Retrieved October 9, 2024 from https://www.earthquaketracker.org/earthquakes/event/us6000mt1n/