September 30, 1970 Earthquake: Basco, Sabtang, Batan Islands, Philippines
A magnitude 6 earthquake struck Basco, Sabtang, Batan Islands, Philippines on September 30, 1970 at 09:52:25 UTC, 40 km below the surface. It caused a tsunami.
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
- September 30, 1970
- Time
- 09:52:25 UTC
- Place
- Basco, Sabtang, Batan Islands, Philippines
- Magnitude
- 6 (Mw)
- Focal depth
- 40 km (25 mi)
- Intensity
- 7 on the Modified Mercalli scale
- Tsunami
- Yes: the tsunami it caused
- Epicenter
- 20.675° N, 122.009° E
- Country
- Philippines
The toll
- Damage
- Severe (about $5 to $25 million)
- Houses destroyed
- 3
- 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 the record says
NCEI’s account, from the sources it cites.
Two buildings collapsed and 60% of houses damaged at Basco, Batan Islands. Minor local tsunami generated. (reference #45)
1970-09-30 09:52:25.53 UTC, magnitude 5.98 Mw (reference #10476, v.11)
This earthquake occurred at 5:52 AM and was located about 30 km NNE of Batan Island. The quake caused the collapse of three houses in the town of Basco and damaged the walls of 65% of the remaining houses. Slight damages were reported in Uyugan and Sabtang towns. There were also landslides on the slopes of Iraya Volcano which damaged the local water system while some small sea level changes were observed in the coastal areas of Batanes (SEASEE, 1985). The exact location of the affected shores in Batanes was not indicated. (reference #10958)
Other significant earthquakes nearby
Within 200 km, the deadliest first.
- August 15, 1959, Taiwan
- July 26, 2019, Itbayat, Batanes, Philippines
- December 26, 2006, Pingtung, Taiwan
- September 13, 1918, Ivana,sabtan,san Vicente, Batanes, Philippines
- March 8, 1892, Batan Island,san Domingo, Philippines
- July 16, 2000, Basco, Mount Irada, Batan Islands, Philippines
- June 7, 1987, Philippines
- September 5, 1996, Taiwan Region
- October 31, 1720, Tainan, Taiwan
- July 23, 1978, Taiwan
More
Significant earthquakes of 1970The 1900sEvery quake the USGS located in 1970Recent 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 2026-09-24. NCEI earthquake 4547.