Reviewed by USGSTaiwan118y ago
M6.8 earthquake 13 km ENE of Hualien City, Taiwan
Sunday, November 21, 1909, 07:35:59 UTC · 24.014°N, 121.735°E
A magnitude 6.8 earthquake struck 13 km ENE of Hualien City, Taiwan on Sunday, November 21, 1909, 07:35:59 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M7.2 on January 11, 1908.
- Magnitude
- 6.8
- Strong · mw
- Depth
- 35 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquake
In context
How big was it, and why here?
Energy released
247 kilotons of TNT
That is about 16 times the Hiroshima bomb. It released about 519 times the energy of a magnitude 5.0.
Tectonic setting
23 km
from the nearest mapped plate boundary, between the Okinawa and Philippine Sea plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
35 km
Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.
Did You Feel It?
Where it was felt
No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.
I felt it — report to USGS ↗USGS PAGER estimate
Who was exposed to shaking
USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.
After the main event
Aftershocks within 100 km
USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 7 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.2108 km E of Hengchun, TaiwanJanuary 11, 1908 · 216 km S of this epicenter
- 7.012 km N of Pizitou, TaiwanApril 13, 1906 · 137 km W of this epicenter
- 6.910 km NE of Pizitou, TaiwanMarch 16, 1906 · 134 km W of this epicenter
- 6.73 km WSW of Banqiao, TaiwanApril 14, 1909 · 114 km N of this epicenter
- 6.519 km SSE of Douliu, TaiwanApril 13, 1906 · 122 km SW of this epicenter
- 6.250 km WSW of Hengchun, TaiwanSeptember 22, 1907 · 283 km SW of this epicenter
- 6.197 km ENE of Hengchun, TaiwanMarch 26, 1906 · 184 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 25 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 61,717 recorded deaths. The most severe:
- 1782
Tainan
22 May 1782 · 136 km away
40,000 deathsSevere damage ($5–24M)tsunami
- 1771M7.4
Ryukyu Islands
24 Apr 1771 · 261 km away
13,486 deathsExtreme damage ($25M+)tsunami
- 1721
Tainan
1721 · 193 km away
2,000 deathsExtreme damage ($25M+)tsunami
- 1862M6.5
Tainan
6 Jun 1862 · 189 km away · intensity VIII
2,000 deathsSevere damage ($5–24M)
- 1906M6.8
Jiayi
16 Mar 1906 · 134 km away
1,258 deathsSevere damage ($5–24M)
- 1848M6.8
Zhanghua
3 Dec 1848 · 126 km away · intensity IX
1,001 deathsExtreme damage ($25M+)
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.