5.4

M5.4 Earthquake 28 km NW of Yasuj, Iran — February 17, 2021

2021-02-17 18:35:35 UTC (2021-02-17) · approx. 9:35 PM UTC+3 local

Felt by 5 people across nearby locations. Maximum shaking intensity MMI 6.8 (very strong).

MagnitudeM5.4(mww)
Time18:35 UTC≈ 9:35 PM UTC+3
Depth7.0 kmshallow crustal
Coordinates30.839°, 51.365°
Felt by5DYFI responses· max MMI 6.8
Status✓ Reviewed by USGS· green PAGER
green Alert— no significant casualties or damage expected

On February 17, 2021 at 18:35 UTC, a magnitude 5.4 shallow crustal earthquake struck 28 km NW of Yasuj, Iran, at a depth of 7.0 km and coordinates 30.8390°, 51.3651°. The earthquake was reported felt by 5 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 6.8 (very strong). The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected. The nearest populated place is Sisakht (population 0).

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 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

Nearest Populated Places

Sisakhtpop. 0
MMI 5.5 (strong)
Yasujpop. 96,786
MMI 4.3 (moderate)
Bashtpop. 0
MMI 3.8 (light)
Dehdashtpop. 69,726
MMI 3.7 (light)
Dogonbadanpop. 94,638
MMI 3.7 (light)
Nurabadpop. 64,041
MMI 3.6 (light)
Map showing earthquake epicenter at 30.84°, 51.37°

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 M5.4 earthquake near 28 km NW of Yasuj, Iran

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 5 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 M5.4 earthquake near 28 km NW of Yasuj, Iran

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 3weak6,884,329
MMI 4light785,997
MMI 5moderate45,428
MMI 6strong16,589

Earthquake Details

Magnitude
5.4 mww
Depth
7.0 km
shallow crustal
Location
30.8390°N
51.3651°E
Felt Reports
5
DYFI responses
Intensity (MMI)
6.8
very strong
Community Intensity
7.9
CDI from reports

Technical Information

Event ID
us6000difx
Event Type
earthquake
Status
✓ Reviewed
Significance
453
Azimuthal Gap
30.0°
Min Station Distance
7.265°
RMS Residual
0.86 sec
Last Updated
2025-12-22 18:50:33 UTC

Common Questions

How strong was the magnitude 5.4 earthquake near Yasuj, Iran?

The magnitude 5.4 earthquake that struck 28 km NW of Yasuj, Iran on February 17, 2021 at 18:35 UTC had a depth of 7.0 km. It was felt by 5 people with maximum shaking intensity of MMI 6.8 (very strong). For context, this was a moderate earthquake that could be widely felt.

Where did the earthquake occur?

The earthquake epicenter was located at 30.8390°, 51.3651°, which is 28 km NW of Yasuj, Iran. The nearest populated place is Sisakht (population 0). View all earthquakes in Iran.

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 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 5.4 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: us6000difx). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, February 17, 2021). M5.4 Earthquake 28 km NW of Yasuj, Iran — February 17, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000difx/