The 1986 Kalamata earthquake struck the southern Peloponnese Region of Greece on September 13 at 20:24 local time.

The 12.5 km (7.8 mi) deep moment magnitude (Mw ) 5.9 earthquake had an epicenter near the coastal city of Kalamata[1] and was assigned X (Extreme) on the Mercalli intensity scale.

Greece is a seismically active country located in a complex zone of interaction between the African plate the Aegean Sea.

Along the Hellenic arc, the African plate subducts beneath the Aegean Sea at around 40 mm (1.6 in) per year.

Shallow-focus earthquakes of less than 50 km (31 mi) depth are common—the result of accommodating convergence via subduction-related deformation.

Back-arc extension occurs within the Aegean Sea, above the subducting crust, causing normal and strike-slip faulting earthquakes.

To the east is the Taygetus mountain range; separating it from the graben is a series of normal dip-slip faults, which are part of a seismic zone in West Mani.

[12] They often appeared in terraced olive groves near rocky outcrops, and were several tens of centimeters west of a large fault surface.

[11] The most significant surface rupture occurred within an existing north-northeast trending fault trace in the Mesozoic limestone in Elaiochori and Perivolakia.

[11] Two accelerographs in Kalamata recorded a maximum peak ground acceleration (pga) of 0.27 g in the horizontal component.

[18] At least 20 people died;[19] more deaths were prevented because most residents attended a ferry line opening ceremony when the earthquake occurred.

[23] Some rockfalls occurred in the Taygetus mountains, obstructing a major road that linked Kalamata to Sparta.

[23] Rescuers immediately attended to two buildings in Kalamata; a collapsed apartment and another two-storey house where two people were trapped.

Rescue efforts were disrupted by curious onlookers, friends and family members of those trapped visiting the site.

Many displaced individuals sought refuge across 30 campsites while their homes were reconstructed, while some left the city for other areas such as Athens.

[33] In 1987, Prime Minister Andreas Papandreou did not attend a memorial ceremony on the one-year anniversary of the earthquake, citing his busy schedule.