The 1932 Ierissos earthquake occurred at 19:20 on 26 September. It caused severe damage in

Ierissos Ierissos ( el, Ιερισσός) is a small town on the east coast of the Akti peninsula in Chalkidiki, Greece. It is located 160 km from Thessaloniki, and 10 km from the border of the Autonomous Monastic State of the Holy Mountain, or M ...

, Greece and the surrounding part of the

Chalkidiki Chalkidiki (; el, Χαλκιδική , also spelled Halkidiki, is a peninsula and regional unit of Greece, part of the region of Central Macedonia, in the geographic region of Macedonia in Northern Greece. The autonomous Mount Athos region co ...

peninsula, with 161–491 casualties reported.

Tectonic setting

The

Aegean Sea The Aegean Sea ; tr, Ege Denizi (Greek language, Greek: Αιγαίο Πέλαγος: "Egéo Pélagos", Turkish language, Turkish: "Ege Denizi" or "Adalar Denizi") is an elongated embayment of the Mediterranean Sea between Europe and Asia. It ...

is an area of mainly

extensional tectonics Extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary body's crust or lithosphere. Deformation styles The types of structure and the geometries formed depend on ...

caused by the

subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...

of the

African Plate The African Plate is a major tectonic plate that includes much of the continent of Africa (except for its easternmost part) and the adjacent oceanic crust to the west and south. It is bounded by the North American Plate and South American Plat ...

beneath

Aegean Sea Plate The Aegean Sea Plate (also called the Hellenic Plate or Aegean Plate) is a small tectonic plate located in the eastern Mediterranean Sea under southern Greece and western Turkey. Its southern edge is the Hellenic subduction zone south of Crete, ...

. In the northwest Aegean, extension on approximately W-E trending extensional faults is accompanied by dextral (right lateral)

strike-slip In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

on SW-NE trending faults, and minor sinistral (left lateral) movement on NW-SE trending faults, accommodating the diffuse plate boundary zone between the

Eurasian Plate The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent and ...

and the Aegean Sea Plate. The earthquake has been attributed to movement on the Stratoni fault, one of the W-E trending faults that shows predominantly dip-slip extension.

Damage

The earthquake destroyed the town of Ierissos and several villages in the surrounding area. 10,000 people were left homeless. The cost of the damage was estimated as 5 million

drachma The drachma ( el, δραχμή , ; pl. ''drachmae'' or ''drachmas'') was the currency used in Greece during several periods in its history: # An ancient Greek currency unit issued by many Greek city states during a period of ten centuries, fro ...

s. The minor

tsunami A tsunami ( ; from ja, 津波, lit=harbour wave, ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explo ...

caused no damage.

Characteristics

The Stratoni fault was identified as the fault responsible for the 1932 event because of evidence of surface ruptures recorded soon after the earthquake and from the pattern of isoseismals, which were elongated in a W-E to NW-SE orientation and similarly orientated volume of recently observed seismicity. From the observation of

slickensides In geology, a slickenside is a smoothly polished surface caused by frictional movement between rocks along a fault. This surface is typically striated with linear features, called slickenlines, in the direction of movement. Geometry of slickens ...

along exposed fault planes, the movement along the fault is dip-slip extensional with local areas of oblique slip with a component of sinistral (left-lateral) strike-slip. The extension direction is currently oriented north-south but, when the fault was formed, was oriented NNE-SSW, perpendicular to the fault trace, possibly due to subsequent clockwise rotation of the area. The earthquake was followed by three strong

aftershock In seismology, an aftershock is a smaller earthquake that follows a larger earthquake, in the same area of the main shock, caused as the displaced crust adjusts to the effects of the main shock. Large earthquakes can have hundreds to thousand ...

s (M=6.0, 5.7 & 6.2) in the period 26–29 September, and the largest (M6.3) on 11 May of the following year. A minor tsunami was reported, which was recorded by a temporary

tide gauge A tide gauge is a device for measuring the change in sea level relative to a vertical datum. It its also known as mareograph, marigraph, sea-level recorder and limnimeter. When applied to freshwater continental water bodies, the instrument may ...

, giving a maximum height of 1 m. The movement awoke the operator of a

dredger Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing da ...

, who saw a current spreading up the Strimonas River about an hour after the earthquake.

References

External links

* {{Earthquakes in Greece Earthquakes in Greece Ierissos Earthquake, 1932 History of Chalkidiki Ierissos Earthquake, 1932 1932 tsunamis 1932 disasters in Greece

Tectonic setting

Damage

Characteristics

See also

References

External links