Did the Turkey Earthquake Cause a Tsunami?

The devastating 7.8 magnitude earthquake that struck southern Turkey and northern Syria on February 6, 2023 has left tens of thousands dead and many more injured or homeless. With such a powerful quake occurring so close to the sea, some have wondered if it also generated a deadly tsunami. Let’s examine the facts around earthquakes, tsunamis and the potential for this Turkish quake to have triggered a killer wave.

What Causes a Tsunami?

Tsunamis are giant waves typically caused by large earthquakes or landslides underwater. Most occur in the Pacific Ocean in the “Ring of Fire” a zone of frequent quakes and volcanic eruptions encircling the basin. However, the Mediterranean Sea region where Turkey is located also sees occasional tsunamis.

When an offshore quake thrusts the seafloor upward, that motion displaces massive amounts of water above it This forms tsunami waves radiating outward in all directions from the quake epicenter. Depending on the quake magnitude, these waves can propagate for hundreds of miles and strike distant shores

Tsunamis can also result from submarine landslides or volcanic eruptions. However, over 80% originate from seismic events.

Turkey’s Earthquake Threat

Turkey sits atop some of Earth’s most active fault lines, making severe quakes a persistent risk.

The Anatolian Plate under central Turkey abuts the Arabian Plate to the southeast and the Eurasian Plate northward. Movement between these tectonic blocks builds pressure that is occasionally released in quakes, especially along plate boundaries.

Turkey’s lengthy coastlines are vulnerable to both shaking damage and tsunamis from offshore quakes near these boundaries. Historical records document over a dozen tsunamis hitting Turkish shores in the past 2000 years.

The Aegean Sea off Turkey’s west coast overlies complex fault systems that generate frequent moderate quakes and occasional major ones like that in 2023. In 1999, a magnitude 7.4 shock just east of Istanbul killed over 17,000 people.

Did This Quake Trigger a Tsunami?

The February 6th quake off southern Turkey did have the potential to create a regional tsunami. However, while localized small waves occurred, no damaging Pacific-scale tsunami resulted.

The quake struck just 25 miles from Turkey’s Mediterranean coast at a relatively shallow depth of 11 miles. This proximity to shore and the seafloor displacement from slippage along the East Anatolian Fault generated observable wave activity locally.

Multiple tide gauge stations along the Turkish and nearby Syrian/Lebanese coasts recorded tsunami waves up to 1 meter high in the hour after the mainshock. These arrived too quickly after the quake to be ordinary tides.

Larger tsunami waves over 2 meters high also hit the eastern Mediterranean island of Cyprus 300 miles west of the epicenter. Wave heights diminished rapidly with distance, sparing more distant coastal areas in the region.

Why No Widespread Tsunami Occurred

While shaking and tsunami waves affected the nearby Turkish-Syrian coastline, what limited this event from triggering a more destructive ocean-wide tsunami?

Tsunami Size Factors

Several aspects of the earthquake itself restricted the resulting tsunami strength:

• Magnitude of 7.8, powerful but not record-breaking. The very largest ever quakes exceed 9.0.

• Fault slip of around 10 feet, large but not maximum for a 7.8 quake.

• The fault rupture propagated north-south, directing energy along the Turkish coast rather than outward.

• Much of the seafloor displacement occurred deeper underwater, limiting water volume displaced.

Prior Tsunami History

The region’s tsunami history also provided clues that this event would lack basin-wide impact:

• The Mediterranean’s last destructive regional tsunami was in 365 AD from an 8.0 quake. Far stronger than the 2023 event.

• Prior large Turkish quakes triggered only localized tsunami waves historically.

• Modeling studies indicated major tsunamis here would need at least a magnitude 8.0 shock.

Tsunami Warning Systems

Though no destructive tsunami resulted, emergency managers did issue cautions for the nearby Turkish and Syrian coastlines based on seismic data. Tsunami warnings aim to reduce loss of life from potentially dangerous wave activity.

Multiple interconnected tsunami monitoring networks watch for earthquakes that could generate tsunamis in the Mediterranean basin:

• The Turkish Disaster and Emergency Management Agency (AFAD) quickly notified citizens after this quake. Coastal residents evacuated to higher ground as a precaution.

• Regional systems like NEAMTWS (North-eastern Atlantic and Mediterranean) help coordinate tsunami response cross-nationally.

• Dozens of tide gauges and seafloor instruments deployed by Turkey and neighbors supply real-time data to feeding into warning decisions.

Looking Ahead at the Tsunami Threat

The 2023 Turkey earthquake serves as a reminder of the region’s lingering tsunami risk from major quakes near the sea. Although it caused only minor tsunami waves itself, future events could unleash more destructive flooding.

Coastal cities like Istanbul should continue developing robust evacuation plans, public education programs and redundant warning systems. Efforts to improve earthquake and tsunami readiness will reduce potential casualties during the inevitable next large seaborne quake.

While luck spared Turkey’s densely populated coasts this time, its citizens must stay vigilant and prepared.