Earthquake Did Not Alter Monument's Settling

The latest survey of the National Mall shows the 5.8-magnitude earthquake one year ago did not affect how fast the 555-monument is settling. Since 1901, it has settled approximately 2.2 inches.

The 5.8-magnitude earthquake that occurred Aug. 23, 2011, from a fault located in Virginia did not affect how the 555-foot Washington Monument is settling, according to a 2012 survey conducted by NOAA's National Geodetic Survey. NOAA shared the findings of the survey on Aug. 22, just ahead of the event's anniversary.

Based on five leveling surveys taken since 1926, the part of the National Mall built on landfill where the monument is located has settled about 1 inch, moving at a rate of approximately 0.013 inches per year. The monument itself is settling 0.02 inches per year, according to multiple measurements taken since 1901 that indicate it has settled about 2.2 inches overall since then.

The latest NGS survey, conducted at the request of the National Park Service, included the entire National Mall. Repairs to cracks in the monument that resulted from the earthquake have yet to begin.

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