Prof. Regina Katzman of the University of Haifa explains why the seabed off Israel is an active and complex geological system. Studies in recent years reveal salt layers nearly two kilometers thick, hundreds of landslides and rifts that cross the seabed — and highlight the need for marine seismic monitoring and tsunami and infrastructure risk preparedness.
Mediterranean It seems quiet most of the time. But beneath the surface of the water lies a much more complex geological system: ancient salt layers are slowly deforming, Copies Crossing the continental slope, sediments may slide down the seabed, and in other areas of the Mediterranean Sea, active tectonic systems meet that are capable of generating Earthquakes וTsunami.
Prof. Regina Katzman, head of the Computational Physics Laboratory at the School of Marine Sciences at the University of Haifa, says that traditional seismic research relies heavily on land-based stations, even though some of the important processes occur far offshore and under the sea. According to her, developments in high-resolution seismic imaging and seabed sensors now allow us to better see these structures and examine how they change over time.
Not every seafloor ridge is a deep tectonic fault
One important distinction is that the replicas visible on the seabed off Israel are not all part of the same system and do not necessarily have the same seismic significance.
Research by May Laor and Zohar Gvirtzman from the Geological Survey of Israel and the Hebrew University, published in 2023 in the journal Natural Hazards and Earth System Sciences, shows that along the Israeli continental slope there are many normal faults associated with the movement of relatively soft salt layers at depth. These are “thin-shell” faults—that is, they deform mainly the upper sedimentary layers and do not necessarily continue deep into the crust.
The researchers emphasize that in the south and center of the Israeli continental slope, there is no evidence that the old deep rifts continue to the seabed today. In contrast, further north, in the Carmel, Galilee, and Lebanon regions, the tectonic picture is different: there are active systems there related to, among other things, the Carmel-Tirza rift and the Dead Sea rift system.
Therefore, the mere fact that a crack or a replica step appears on seafloor mapping does not allow us to conclude by itself that it is likely to cause a strong earthquake.
A layer of salt almost two kilometers thick
One of the keys to understanding the geology of the Levant Basin lies in an event that occurred about six million years ago—the Messinian salinity crisis. During this period, the connection between the Mediterranean Sea and the Atlantic Ocean was restricted, sea levels dropped, and vast amounts of evaporite deposits, including salt, were formed.
In the deep parts of the Levant Basin opposite Israel, this salt layer reaches a thickness of almost two kilometers. It was later covered by numerous sediments, including those that came from the Nile.
Salt at great depths does not behave over millions of years like completely solid rock. Under pressure, it is able to flow and deform slowly. Its movement changes the shape of the layers above it and can create ridges and steps on the seafloor.
The 2023 study found that in parts of the Israeli slope, such displacements create steps tens of meters high. The researchers used 3D seismic data to measure both the dimensions of the displacements and the vertical displacement accumulated over the past 350,000 years, and from this they proposed a method to rank their relative risk to marine infrastructure.
Do these copies cause earthquakes?
Here lies one of the most important open questions.
The researchers explicitly state that it is still unknown whether some of the salt deposits off Israel slide during seismic events, or whether they move mainly in a slow creep that does not produce strong earthquakes. Even very precise mapping of the seafloor is not enough to determine this.
In other words, there is a difference between Geological replica active in terms of movement and a replica capable of producing a significant earthquake. Answering the question requires a combination of seismic imaging, stratigraphic dating, drilling, motion measurements, and continuous seismic monitoring.
This is also why Katzman emphasizes the shift from purely passive monitoring to real-time monitoring on the seabed. When sensors are closer to the possible source of the earthquake, smaller events can be detected and their location and depth can be better determined.
447 underwater landslides
An earthquake is not the only risk lurking beneath the sea surface.
A study published in 2015 in the journal Marine Geology Mapped the continental slope facing Israel and identified 447 Underwater landslides, alongside numerous scars of replicas. The areas of the slides ranged from thousands of square kilometers to about 91 square kilometers. More than a fifth of the slope area examined bore signs of slope failures.
Such slides are formed when sedimentary layers lose stability and move downslope. Earthquakes can be one of the factors that trigger them, but not the only one; sediment accumulation, land slope, fluid pressure, and slow geological processes can also have an effect.
In some cases, the rapid movement of a large mass on the seafloor can displace a significant volume of water and contribute to the creation of a tsunami.
The risk of a tsunami in the eastern Mediterranean is not theoretical
The Mediterranean has experienced devastating tsunamis in the past. A scientific review of past events in the eastern Mediterranean has found evidence of several large tsunamis linked to earthquakes in the Hellenic border region, some of which caused widespread damage. The researchers stressed that there is still great uncertainty about the exact sources of future events.
The problem for Israel is the relatively short distance from several possible sources. When the tsunami's source is within the Mediterranean Sea and not across the ocean, the warning time may be very short.
Katzman points out that the combination of tsunami risk, underwater landslides, and dense infrastructure along the coast requires us to think of the events not separately but as "cascading risks": an earthquake may cause landslides, the landslide may damage a pipe or cable, and in some cases also produce a sea wave.
Can human activity cause earthquakes?
Another rapidly developing area is Induced seismicity — Earthquakes that are caused or accelerated after human activity changes the state of stress or fluid pressure in the rock.
A broad overview inAnnual Review of Earth and Planetary Sciences determined that changes in fluid pressure in the subsurface can trigger replicas that are already close to the threshold of failure. Such cases have been documented around the world following deep wastewater injection, oil and gas field activity, geothermal energy production, and other engineering operations.
Katzman notes that there are currently several types of activity in the Mediterranean basin that should be monitored in this context: deepwater gas fields, gas storage facilities, geothermal fields where fluids are pumped into the depths, and large dams in Anatolia.
However, it is important to distinguish between a known physical possibility and a claim about a specific event: The information presented here does not prove that Israeli gas fields caused earthquakes. To establish such a relationship, data showing a correspondence in time and space, an appropriate physical mechanism, and a measurable change in pressures or stresses in the subsurface are required.
Infrastructure makes geology a practical question
along Israel's coasts Desalination plants, power plants, ports, and transmission systems are concentrated, and in the sea itself there are pipelines, cables, and gas infrastructure.
That’s why mapping seafloor replicas isn’t just an academic matter. The goal of the 2023 study was to develop a way to help, at the planning stage, choose routes that pass through areas where the relative risk from replicas is lower. More detailed testing can then be carried out in places where replica crossings are required.
In this sense, marine science is progressing from a description of what has already happened towards a monitoring and warning system: 3D imaging of the subsurface, sensors on the seabed, repeated measurements and comparison over time.
The Mediterranean Sea as a dynamic system
According to Katzman, the main scientific message is that the Mediterranean Sea and coastal zone are not a static system. Deep tectonics, salt flow, sediment movement, subsurface fluids, and human activity can operate in parallel, and sometimes influence each other.
These topics will also be the focus of the 12th Haifa Conference on Marine Sciences, which will be held on September 9, 2026 at the University of Haifa and will this year deal with seismology andMarine geophysicsBut scientifically, the broader question continues well beyond the conference: how to monitor a geological system, much of which is hidden under hundreds and even thousands of meters of water and sediment—and how to translate this knowledge into infrastructure planning and disaster preparedness.
Questions and Answers
Does the existence of a replica on the seabed mean that an earthquake will occur there? No. Some of the replicas can move at a slow crawl, and for others it is not yet known whether the movement occurs during seismic events. Mapping the replica alone is not sufficient to determine the risk.
Is gas production off the coast of Al Gore vulnerable to earthquakes? There is currently no proof of this in the sources on which the article is based. It is known worldwide that operations that increase or decrease the pressure of fluids in the underground may, under certain conditions, trigger replicas, and therefore monitoring is required.
Is Israel at risk of a tsunami? Yes. Large tsunamis have occurred in the eastern Mediterranean in the past, and possible sources are at distances that could allow for relatively short warning times. However, there is currently no way to determine when the next event will occur.
Why are sensors needed on the seabed? Land-based stations also detect tremors originating at sea, but sensors closer to the source make it possible to detect weaker events and more precisely determine where and at what depth they occurred.
Sources
The interview with Prof. Regina Katzman on the University of Haifa website: https://www.haifa.ac.il/2026/09/06/
The study on the classification of maritime replicas vis-à-vis Israel, Natural Hazards and Earth System Sciences, 2023: https://doi.org/10.5194/nhess-23-139-2023
More on the subject on the science website
- New study: Moderate earthquakes are moving east along the Marmara Fault, approaching the dangerous section opposite Istanbul
- What's shaking Santorini? Artificial intelligence reveals massive magma movement beneath the Aegean Sea
- Despite the proximity and direction, the Dead Sea replica and the replica in eastern Turkey are not connected
- The Hidden Mechanisms Behind Earthquakes: Uncovering the Secrets of the Seismic Process
- Seismology – Seconds Before the Big Earthquake
