July 27, 2020 Earthquake: Son LA Province, Vietnam
A magnitude 4.9 earthquake struck Son LA Province, Vietnam on July 27, 2020 at 05:14:50 UTC, 10 km below the surface.
Map
Where it struck, with the other significant earthquakes within 200 km. Circles are sized and colored by magnitude; select one for its page.
The earthquake
- Date
- July 27, 2020
- Time
- 05:14:50 UTC
- Place
- Son LA Province, Vietnam
- Magnitude
- 4.9 (Mw)
- Magnitude scales
- Mw 4.9 · mb 4.8
- Focal depth
- 10 km (6 mi)
- Intensity
- IV, light shaking, on the Modified Mercalli scale
- Tsunami
- None recorded
- Epicenter
- 20.863° N, 104.624° E
- Country
- Vietnam
- Region
- East Asia
- USGS record
- The USGS’s page for this earthquake
Mw: moment magnitude, based on the slip on the fault and the area that slipped. mb: body-wave (P-wave) magnitude. NCEI’s headline magnitude is the best of these for the earthquake.
The toll
- Damage
- Moderate (about $1 to $5 million)
- Houses damaged
- Many (101 to 1,000)
Where the literature gives no number, NCEI records a description on a scale of 1 to 4, printed here in its words. Damage is in millions of US dollars of the year of the event, not adjusted for inflation.
What happened
The USGS’s account of the effects of this earthquake.
At least 127 houses damaged at Moc Chau.
From the USGS event page for us6000b4kv. U.S. Geological Survey text and figures are in the public domain.
Magnitude estimates
The magnitudes the USGS catalog lists for this earthquake, by scale and by who computed them. NCEI’s own scales are in the table above.
| Mag. | Scale | Computed by | Notes |
|---|---|---|---|
| 4.9 | Mwr, regional moment | USGS National Earthquake Information Center | Preferred · Reviewed · ±0.083 · 14 stations |
| 4.97 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
What the record says
NCEI’s account, from the sources it cites.
Reference #13456:
At least 127 houses damaged at Moc Chau. Hue, Khu Bon Cu, Vietnam - CDI: 4; Hoa Binh, Mien Nui Va Trung Du, Vietnam - CDI: 3; Ha Noi, Dong Bang Song Hong, Vietnam - CDI: 3; Viet Tri, Mien Nui Va Trung Du, Vietnam - CDI: 3; Son Tay, Dong Bang Song Hong, Vietnam - CDI: 3
Reference #12757:
Hundreds of houses in the northern mountainous province of Son La's Moc Chau District have been damaged by a 5.3 magnitude earthquake on Monday.
The earthquake which occurred at around 12:15 pm caused many houses and headquarters of agencies to subside. In the communes of Na Muong, Ta Lai and Long Sap, headquarters of the people's committee saw cracks with mortar peeled from walls and ceilings and an electrical fire.
Meanwhile, 127 houses and many local agencies in the districts of Moc Chau and Yen Chau districts experienced the same situation.
Sources NCEI cites
The publications NCEI lists for this record. The numbers match the “reference #” notes in its account above.
- #1053 National Earthquake Information Center (NEIC) (1971 to 2013). Preliminary Determination of Epicenters (PDE), a weekly and monthly publication, National Earthquake Information Center, U.S. Geological Survey, Golden, Colorado, 1971 to 2013.
- #12757 DTI News (Vietnam) (2020). Hundreds of houses damaged by Son La earthquake. Published 28 July 2020. Link
- #13456 U.S. Geological Survey (2017 to present). Earthquake Hazards Program, Advanced National Seismic System (ANSS) Comprehensive Catalog of Earthquake Events and Products.
Other significant earthquakes nearby
Within 200 km, the deadliest first.
More
Significant earthquakes of 2020The 2000sEvery quake the USGS located in 2020Recent earthquakes near hereThis day in weather history
Sources
Significant earthquakes from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-10-01. NCEI earthquake 10511. The written accounts and the magnitude estimates are from the USGS earthquake catalog, event us6000b4kv, matched to this record by time, place and magnitude.