Reviewed by USGSTimor Leste6y ago
M4.6 earthquake 110 km NNE of Lospalos, Timor Leste
Friday, December 20, 2019, 09:35:25 UTC · 7.626°S, 127.446°E
A magnitude 4.6 earthquake struck 110 km NNE of Lospalos, Timor Leste on Friday, December 20, 2019, 09:35:25 UTC, at a depth of 175.6 km (intermediate). USGS received 1 “Did You Feel It?” report, with a maximum reported intensity of III (weak). It is the strongest earthquake within 300 km since an M4.9 on December 13, 2019.
- Magnitude
- 4.6
- Light · mb
- Depth
- 176 km
- Intermediate
- Felt reports
- 1
- Max intensity III
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
120 tons of TNT
That is about 1/126 of the Hiroshima bomb. A magnitude 5.0 releases about 4 times more energy.
Tectonic setting
50 km
from the nearest mapped plate boundary, between the Banda Sea and Timor plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: intermediate
176 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
Did You Feel It?
Where it was felt
Reports sent by people to USGS, grouped by place (most reports first). Intensity uses the Modified Mercalli scale (I–X): what people felt, not the magnitude.
| Place | Intensity | Reports | Distance |
|---|---|---|---|
| Nhulunbuy, Northern Territory, Australia | III · Weak | 1 | 1152 km |
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 50 km
USGS lists 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.5 on January 11, 2020. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 1,033 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.11963 Banda Sea EarthquakeNovember 4, 1963 · 249 km E of this epicenter
- 7.7Banda SeaNovember 2, 1950 · 211 km NE of this epicenter
- 7.6196 km S of Ambon, IndonesiaJanuary 27, 2006 · 251 km N of this epicenter
- 7.563 km NW of Maubara, Timor LesteNovember 11, 2004 · 290 km W of this epicenter
- 7.3145 km NNE of Lospalos, Timor LesteAugust 30, 1917 · 36 km NE of this epicenter
- 7.3172 km NE of Lospalos, Timor LesteNovember 24, 1983 · 81 km E of this epicenter
- 7.3Banda SeaJune 24, 2019 · 234 km NE of this epicenter
- 7.2187 km N of Baukau, Timor LesteFebruary 11, 1969 · 134 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 9 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 45 recorded deaths. The most severe:
- 2004M7.5
Kepulauan Alor
11 Nov 2004 · 290 km away
34 deathsSevere damage ($5–24M)tsunami
- 1995M6.9
Timor, Dili, Maliana, Maubara
14 May 1995 · 279 km away · intensity VII
11 deathsLimited damage (under $1M)tsunami
- 2015M6.5
East Nusa Tenggara: Alor
4 Nov 2015 · 294 km away · intensity V
$9 million damage
- 1989M6.2
Timor: Alor
14 Jul 1989 · 260 km away
Moderate damage ($1–5M)
- 1963M8.3
Banda Sea
4 Nov 1963 · 250 km away
Limited damage (under $1M)
- 1918M8.1
Banda Sea
18 Nov 1918 · 185 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.