1816 Guatemala earthquake

1816 Guatemala earthquake
	Guatemala City Quetzaltenango San Marcos
UTC time	1816-07-22 15:30
Local date	July 22, 1816
Local time	09:30
Magnitude	~7.5 Mw (est.)
Depth	30.0 km (18.6 mi)
Epicenter	15°30′N 91°30′W / 15.5°N 91.5°W
Areas affected	Guatemala
Max. intensity	MMI IX (Violent)
Casualties	23 killed

The 1816 Guatemala earthquake occurred at 15:30 UTC on 22 July. It had an estimated magnitude of 7.5 to 7.75 on the M_w and a maximum perceived intensity of IX (Violent) on the Mercalli intensity scale. The quake, at a depth of 30.0 km (18.6 mi), was caused by movement on the Chixoy-Polochic Fault. The area affected by shaking up to intensity VII (Very strong) was at least 13,000 km². At least 23 deaths were reported.^[1] The discovery of this earthquake 175 years after it occurred was based on study of historical documents, and is notable for showing that this portion of Guatemala, previously believed by many planners to be of low seismic risk, has experienced, and is at further risk of, very large earthquakes.