1867 Manhattan, Kansas earthquake

1867 Manhattan earthquake

Manhattan
UTC time	1867-04-24
USGS-ANSS	ComCat
Local date	April 24, 1867 (1867-04-24)
Local time	14:30[1]
Magnitude	5.1 Mfa[1]
Epicenter	39°12′N 96°18′W / 39.2°N 96.3°W / 39.2; -96.3[1]
Areas affected	Kansas United States
Max. intensity	MMI VII (Very strong) [1]
Casualties	Several injured

The 1867 Manhattan earthquake struck Riley County, Kansas, in the United States on April 24, 1867, at 20:22 UTC, or about 14:30 local time. The strongest earthquake to originate in the state, it measured 5.1 on a seismic scale that is based on an isoseismal map or the event's felt area. The earthquake's epicenter was near the town of Manhattan.

The earthquake had a maximum perceived intensity of VII (Very strong) on the Mercalli intensity scale. It caused minor damage, reports of which were confined to Kansas, Iowa, and Missouri, according to the United States Geological Survey. Felt over an area of 200,000 square miles (520,000 km²), the earthquake reached the states of Indiana, Illinois, and possibly Ohio, though the latter reports have been questioned.

Manhattan is near the Nemaha Ridge, a long anticline structure that is bounded by several faults. The nearby Humboldt Fault Zone in particular poses a threat to the city. Kansas is not known for earthquake activity, but an earthquake could occur at any time. A 2016 hazard map from the United States Geological Survey estimated a 1% or lower risk for a major earthquake in Kansas for the following year, though scientists from the agency think an earthquake of magnitude 7.0 remains possible.