The Hellenic Trench is a hemispherical-scale long narrow depression in the Ionian Sea

Ionian Sea

The Ionian Sea , is an arm of the Mediterranean Sea, south of the Adriatic Sea. It is bounded by southern Italy including Calabria, Sicily and the Salento peninsula to the west, southern Albania to the north, and a large number of Greek islands, including Corfu, Zante, Kephalonia, Ithaka, and...

.

The hadal zone

Hadal zone

The hadal zone , also known as the hadopelagic zone and trench zone, is the delineation for the deepest trenches in the ocean...

 of the Hellenic trench is roughly to 5,300 metres (17,388 feet) deep. The names of the three major parts of the Hellenic trench are: Matapan Deep System or Matapan–Vavilov Deep, roughly , the Kithera–Antikithera System, , and the Zakinthos–Strofadhes system, . A region of the Hellenic Trench is also called the Calypso Deep

Calypso Deep

Calypso Deep, located in the Ionian Sea south-west of Pylos, Greece, is the deepest part of the Mediterranean Sea, with a maximum depth of , at .At the Calypso Deep, the African Plate slides under the Eurasian Plate, creating the Hellenic Trench....

 and is roughly deep.

The region of the Hellenic trench is an ecosystem to sperm whales and other aquatic life. The trench has been used by marine biologists to study the behaviour of various aquatic species.

This is the trench where several earthquakes, including the 365 Crete earthquake, occurred.