Tuesday, August 30, 2011

Preliminary damage report of Trinidad, Colorado M5.3 earthquake



The Colorado Geological Survey posted a preliminary damage report on last week's M5.3 earthquake near the town of Trinidad:



At 11:46 PM MDT on August 22, 2011, a Mw 5.3 earthquake was recorded by U.S. Geological Survey seismometers and located the epicenter approximately 9 miles (+/- 7.8 miles) WSW of Trinidad, Colorado. Early reports by local news media indicated that significant damage to buildings had occurred in the towns of Segundo and Valdez, 15 miles west of Trinidad on Colorado State Highway 12. Prior to the Mw 5.3 event, three smaller events were also recorded in the same vicinity, the largest being an Mw 4.6 event at 5:30 PM MDT.



On the morning of August 23rd, the Colorado Geological Survey dispatched geologists to the area to document the damage related to the largest earthquake in Colorado within the last 44 years. Locations with observed structural damage included (from most severe to least): Segundo, Valdez, Cokedale, and Trinidad.

[right, the front of this brick building in Segundo Colorado collapsed, sending debris onto State Highway 12. Note the crushed mailbox. Figure 8 in the report.]



[co-posted on StateGeologists blog]