M5.5 Earthquake near off the west coast of northern Sumatra — September 27, 2023
2023-09-27 17:47:21 UTC (2023-09-27) · approx. 11:47 PM UTC+6 local
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On September 27, 2023 at 17:47 UTC, a magnitude 5.5 shallow crustal earthquake struck near off the west coast of northern Sumatra, at a depth of 10.0 km and coordinates 0.8622°, 93.1129°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. This earthquake was detected by 101 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 465, placing it among routine seismic activity.
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.
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
Earthquake Details
93.1129°E
Technical Information
Common Questions
How strong was the magnitude 5.5 earthquake near off the west coast of northern Sumatra?
The magnitude 5.5 earthquake that struck near off the west coast of northern Sumatra on September 27, 2023 at 17:47 UTC had a depth of 10.0 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at 0.8622°, 93.1129°, which is near off the west coast of northern Sumatra.
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.
Actions
Authoritative source: USGS event page (event ID: us6000lb60). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, September 27, 2023). M5.5 Earthquake near off the west coast of northern Sumatra — September 27, 2023. Retrieved December 9, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000lb60/