M5.1 Earthquake 109 km SSE of Bīrjand, Iran — October 31, 2023
2023-10-31 09:13:40 UTC (2023-10-31) · approx. 1:13 PM UTC+4 local
On October 31, 2023 at 09:13 UTC, a magnitude 5.1 shallow crustal earthquake struck 109 km SSE of Bīrjand, Iran, at a depth of 10.0 km and coordinates 31.9891°, 59.7557°. This earthquake was detected by 136 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 400, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 5.1 releases seismic energy equivalent to roughly 674 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 2.0 km — a useful intuition for the size of the slip patch on the fault.
The epicenter is located in Iran, a region characterized by the Zagros fold-and-thrust belt, where the Arabian Plate collides with Eurasia at 20-25 mm per year. The nearest mapped fault system is the Zagros Fault. View all earthquakes in Iran.
Learn more: Magnitude scale · Aftershock sequences
Earthquake Details
59.7557°E
Technical Information
Common Questions
How strong was the magnitude 5.1 earthquake near Bīrjand, Iran?
The magnitude 5.1 earthquake that struck 109 km SSE of Bīrjand, Iran on October 31, 2023 at 09:13 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 31.9891°, 59.7557°, which is 109 km SSE of Bīrjand, Iran. View all earthquakes in Iran.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.1 earthquakes can continue for days to weeks and gradually diminish over time.
Has Iran had earthquakes this big before?
The largest recorded earthquake in Iran was the M7.8 Tabas earthquake of September 16, 1978. Today's magnitude 5.1 event is significantly smaller than that historical record.
Actions
Location
Authoritative source: USGS event page (event ID: us7000l7qg). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, October 31, 2023). M5.1 Earthquake 109 km SSE of Bīrjand, Iran — October 31, 2023. Retrieved January 10, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000l7qg/