August 23, 2011 Earthquake: Segundo, Colorado, United States

Name: August 23, 2011 Earthquake: Segundo, Colorado, United States
Start: 2011-08-23
Location: Segundo, Colorado, United States

August 23, 2011 · M5.4

A magnitude 5.4 earthquake struck Segundo, Colorado, United States on August 23, 2011 at 05:46:18 UTC, 4 km below the surface.

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: August 23, 2011
Time: 05:46:18 UTC
Place: Segundo, Colorado, United States
Magnitude: 5.4 (Mw)
Focal depth: 4 km (2 mi)
Intensity: 7 on the Modified Mercalli scale
Tsunami: None recorded
Epicenter: 37.063° N, 104.701° W
Country: United States

The toll

Damage: Moderate (about $1 to $5 million)

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.

Moderate damage (VII) at Segundo. Minor damage (VI) at Cokedale and Valdez and (V) at Trinidad. A rockslide occurred on State Highway 12 approximately 1 mile (1.5 km) east of Segundo. Felt (V) at Weston; (IV) at Aguilar, Arapahoe, Las Animas, Manzanola, San Luis and Sugar City; (III) at Colorado City, Colorado Springs, Denver, Eads, Florence, Fowler, Holly, La Junta, Lamar, Ordway, Pueblo, Rocky Ford, Rye, USAF Academy and Walsenburg. Felt in most of eastern and central Colorado and in parts of southwestern Colorado as far as Fort Collins, Grand Junction and Wray. Felt (IV) at Raton and Springer; (III) at Des Moines and Maxwell; (II) at Cimarron, Questa and Taos, New Mexico. Felt (II) at Goodland and Syracuse, Kansas. Felt (II) at Boise City, Oklahoma and at McCook, Nebraska. Felt widely in southwestern Nebraska, western Kansas and northeastern New Mexico. Also felt in a few places in Texas, at Cheyenne, Wyoming and at Omaha, Nebraska. (reference #1053)

Significant earthquakes of 2011 The 2000s Every quake the USGS located in 2011 Recent earthquakes near here This 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 9873.