Hellenic Arc
Greece · subduction interface · 879.8 km of mapped active fault in 14 traces
elevated as of 7 November 2026.
rate above baseline
| Window | the last 30.0 days |
|---|---|
| Earthquakes counted | 3 at M4.5 or above |
| Expected in that window | 0.72 |
| Rate against normal | 4.17x |
| Largest | M4.9 |
| Gap to the second largest | 0.2 magnitude units |
What this system normally does
From 1995 to 2025 the catalogue holds 262 earthquakes of M4.5 or larger attributable to this system: about 8.73 a year. That figure is what "elevated" on this page is measured against.
The fault itself
| Mapped length | 879.8 km |
|---|---|
| Traces | 14 |
| Tectonic setting | subduction interface |
| Slip types | Subduction_Thrust |
| Depth attributed to it | down to 700.0 km |
| Extent | 34.20 to 38.69 latitude, 18.89 to 27.68 longitude |
Recorded history
NOAA's hazard records hold 13 significant earthquakes and 8 tsunamis attributed to this system since 365.
The deadliest was the 21 July 365 magnitude 8.0 earthquake (Greece: Crete: Knossos), which killed 5,000 people.
The most recent entry is the 2 May 2020 magnitude 6.6 earthquake (Greece: Crete).
Across the entries that record a death toll, 9,522 people died.
| Date | What | Where | Toll |
|---|---|---|---|
| 21 July 365 | magnitude 8.0 earthquake | Greece: Crete: Knossos | 5,000 dead, damage over $25 million |
| 21 July 365 | tsunami | Crete | 5,000 dead, damage over $25 million |
| 8 August 1303 | magnitude 8.0 earthquake | Greece: Crete | 4,000 dead, damage $5 to 25 million |
| 8 August 1303 | tsunami | Aegean Sea | 4,000 dead, damage $5 to 25 million |
| 30 September 1636 | magnitude 7.2 earthquake | Greece: Cephalonia | 520 dead, damage $5 to 25 million |
| 11 August 1903 | magnitude 7.8 earthquake | Greece: Mitata (Kythera) | 2 dead, damage $5 to 25 million |
| 17 January 1983 | magnitude 7.2 earthquake | Greece: Ionian Sea | - |
| 2 May 2020 | magnitude 6.6 earthquake | Greece: Crete | - |
| 12 October 2013 | magnitude 6.6 earthquake | Greece: Crete: Chania | damage under $1 million |
| 27 January 1915 | magnitude 6.5 earthquake | Greece: Ionian Sea | - |
| 1 July 2009 | magnitude 6.4 earthquake | Greece: Crete | - |
| 15 June 2013 | magnitude 6.2 earthquake | Greece: Crete | - |
| 7 May 1673 | magnitude 6.0 earthquake | Greece: Zakinthos (Zante), Iraklion (Candia) | damage $1 to 5 million |
| 15 May 1979 | magnitude 5.6 earthquake | Greece: Crete | - |
| 5 April 2000 | magnitude 5.5 earthquake | Greece: Crete | - |
| 2 May 2020 | tsunami (waves to 0.9 m) | Crete | - |
| 5 April 2000 | tsunami (waves to 0.5 m) | Crete | - |
| 1 July 2009 | tsunami (waves to 0.3 m) | Crete | - |
| 12 October 2013 | tsunami (waves to 0 m) | Crete | damage under $1 million |
| 15 June 2013 | tsunami (waves to 0 m) | Crete | - |
| 17 January 1983 | tsunami | Ionian Sea | - |
A dash means NOAA recorded no number, not that nobody died. Older entries are fewer because fewer were written down, not because less happened.
Recorded history: NOAA NCEI hazard databases, public domain, retrieved 2026-10-22.
Who to listen to if you live here
EPPO, Earthquake Planning and Protection Organization is the agency that tells people on this system what to do. https://www.oasp.gr/en (in English)
Other systems in Greece
Where these numbers come from
Fault geometry, length and segment counts: GEM Global Active Faults Database (GEM GAF-DB), GEM Foundation, https://github.com/GEMScienceTools/gem-global-active-faults Licence: CC-BY-SA-4.0. Figures derived from it here are offered under the same licence. Earthquake counts, magnitudes and depths: United States Geological Survey, public domain. The activity judgement is ours, computed from those two inputs, and is not a statement by either agency.