Reviewed by USGSWashington27y ago
M5.8 earthquake 8 km N of Satsop, Washington
Saturday, July 3, 1999, 01:43:54 UTC · 47.074°N, 123.464°W
A magnitude 5.8 earthquake struck 8 km N of Satsop, Washington on Saturday, July 3, 1999, 01:43:54 UTC, at a depth of 40.0 km (shallow). It is the strongest earthquake within 300 km since an M6.7 on April 29, 1965.
- Magnitude
- 5.8
- Moderate · md
- Depth
- 40 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- V
- Moderate (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 75 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
8 kilotons of TNT
That is about 1/2 of the Hiroshima bomb. It released about 16 times the energy of a magnitude 5.0.
Tectonic setting
189 km
from the nearest mapped plate boundary, between the Juan de Fuca and North American plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
40 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 75 km
USGS lists 5 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M3.3 on July 20, 1999. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 3.311 km SSE of Bucoda, Washington27y ago · 65 km SE of this epicenter
- 2.912 km SE of Bucoda, Washington27y ago · 67 km SE of this epicenter
- 2.613 km SSE of Bucoda, Washington27y ago · 67 km SE of this epicenter
- 3.25 km SE of Bucoda, Washington27y ago · 59 km SE of this epicenter
- 3.1Washington27y ago · 66 km SE of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 39 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.74 km WNW of Roy, WashingtonApril 13, 1949 · 66 km E of this epicenter
- 6.71 km ENE of Dash Point, WashingtonApril 29, 1965 · 84 km E of this epicenter
- 6.1Puget Sound region, WashingtonNovember 13, 1939 · 65 km NE of this epicenter
- 6.0119 km SSW of Ucluelet, CanadaSeptember 17, 1926 · 233 km NW of this epicenter
- 5.8Puget Sound area, WashingtonFebruary 15, 1946 · 48 km NE of this epicenter
- 5.738 km NNE of Amboy, WashingtonMay 18, 1980 · 137 km SE of this epicenter
- 5.64 km E of Scotts Mills, OregonMarch 25, 1993 · 236 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 7 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 76 recorded deaths. The most severe:
- 1980M5.2
Mt St Helens
18 May 1980 · 136 km away · intensity V
61 deaths$2.0 billion damagetsunami
- 1949M7.0
Washington
13 Apr 1949 · 65 km away · intensity VIII
8 deaths$25 million damagetsunami
- 1965M6.6
Seattle
29 Apr 1965 · 95 km away · intensity VIII
7 deaths$28 million damage
- 1993M5.6
Washington-Oregon Border
25 Mar 1993 · 236 km away · intensity VII
$28 million damage
- 1700M9.0
Cascadia Subduction Zone
27 Jan 1700 · 259 km away
Severe damage ($5–24M)tsunami
- 1928M5.8
British Columbia
9 Feb 1928 · 243 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.