On the tenth anniversary of the January 12, 2010 magnitude 7.0 earthquake in Haiti, it is important to reflect on the plate tectonic context and human impact of that event.

This earthquake was five times more fatal than any historical magnitude 7 earthquake and the fourth most lethal earthquake of any magnitude in the last 100 years.

Strike-slips faults like the one that devastated Haiti don't generally cause tsunami, except for small local ripples. The Haiti earthquake was a horizontal motion. Tsunamis are caused by either an uplifting of the ocean floor, or by a huge chunk of land sliding into the ocean. Subduction-zone earthquakes raise the ocean bottom suddenly to push the water in tsunamis. 

Hispaniola straddles four plates: the Caribbean Plate and the Gonâve, Hispaniola, and North Hispaniola microplates. It is squeezed between the North American and Caribbean Plates. The island, which includes both Haiti and the Dominican Republic, is home to 22 million people.

[updated 2021] Earth-science educators, do you ever get asked, "What is stress? Why do faults form in Earth’s crust? or How are faults related to plate boundaries?"  This animation describes stress in Earth's outer layer and how it leads to both faults and tectonic plate boundaries.

In January 2020, Puerto Rico was rattled for more than three weeks by over 400 earthquakes greater than M3. Before addressing that sequence, this animation will look at the broader tectonic setting and earthquake history.