M6.8 earthquake in The 2001 Nisqually, Washington Earthquake

Wednesday, February 28, 2001, 18:54:32 UTC · 47.149°N, 122.727°W

A magnitude 6.8 earthquake struck in The 2001 Nisqually, Washington Earthquake on Wednesday, February 28, 2001, 18:54:32 UTC, at a depth of 51.8 km (shallow). USGS received 10,725 “Did You Feel It?” reports, with a maximum reported intensity of VII (very strong). No earthquake of this size or larger appears within 300 km in the USGS catalog since 1900.

Magnitude: 6.8; Strong · md
Depth: 52 km; Shallow
Felt reports: 10,725; Max intensity VII
Est. shaking: VII; Very strong (ShakeMap)
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 100 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

239 kilotons of TNT

That is about 16 times the Hiroshima bomb. It released about 501 times the energy of a magnitude 5.0.

Tectonic setting

245 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

52 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

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
98052<br>0.090	VI · Strong	341	90 km
98501<br>0.090	VII · Very strong	158	56 km
98101<br>0.090	VI · Strong	151	78 km
98103<br>0.093	VI · Strong	106	83 km
98104<br>0.093	VII · Very strong	105	78 km
98004<br>0.093	VI · Strong	105	83 km
98122<br>0.094	VII · Very strong	99	79 km
98105<br>0.094	VI · Strong	98	83 km
98115<br>0.095	VI · Strong	95	85 km
98033<br>0.096	VI · Strong	88	88 km
97201<br>0.097	IV · Light	86	189 km
98225<br>0.098	IV · Light	84	188 km

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 lists 19 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M3.4 on March 22, 2001. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 38 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 8 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 77 recorded deaths. The most severe:

1980M5.2
Mt St Helens
18 May 1980 · 112 km away · intensity V
61 deaths$2.0 billion damagetsunami
1949M7.0
Washington
13 Apr 1949 · 9 km away · intensity VIII
8 deaths$25 million damagetsunami
1965M6.6
Seattle
29 Apr 1965 · 43 km away · intensity VIII
7 deaths$28 million damage
2001M6.8
Olympia, Seattle, Tacoma
28 Feb 2001 · 0 km away · intensity VIII
1 death$2.0 billion damage
1993M5.6
Washington-Oregon Border
25 Mar 1993 · 235 km away · intensity VII
$28 million damage
1700M9.0
Cascadia Subduction Zone
27 Jan 1700 · 296 km away
Severe damage ($5–24M)tsunami

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers