With violent tremors up to 5,000 kilometers away,  a megatsunami struck the eastern coast of Greenland in September of 2024. The vast seismic waves, detected for up to a week following the incident, are a clear descriptor of its magnitude. However, thankfully, nobody was harmed at the time of this signal. 

Generally, tsunamis form due to a large and sudden displacement of the ocean. In other words, they can be considered large earthquakes that occur below or near the ocean floor. This disruption jerks the water out of place and causes giant waves to fall over the land on the coast of the water body. Examples of such a disruption can range from landslides to volcanic eruptions to even meteorites. The speed of a tsunami can vary based on the strength of the disruption on the ocean floor. Still, the average speed is approximately 20 or 30 mph.

Scientists believe that the trigger for this particular massive tsunami was a large landslide. That said, a physics doctoral student reported that the very long period, or VLP, signals that preceded the event by over a week were a suspicious sign that something was about to happen. Seismic signals are shock waves that travel thousands of kilometers into the crust of the Earth, creating a wave within a fjord. 

According to the researchers, this standing wave formed and bounced back and forth between the cliffs surrounding it for more than a week, gaining strength before bursting forth as a tsunami. The initial wave measured a mere 1 meter tall, compared to the 650 feet giant it launched forth as. Based on the satellite image data from numerous stations in Germany, Alaska, and other North American regions, scientists were able to confirm their understanding of the events that led to the tsunami. The first seismic signals aligned with the predicted strength and direction of the rockfall, which led to the landslide and the tsunami. 

Based on previous and continuing research, such standing waves and seismic signals are known to predict large break-offs from glacier edges. Although there were still certain irregularities, including the longer duration of the VLP signal, the authors could model the slow decay and dominant oscillation period with fair accuracy. 

Such events are uncontrollable, but they are part of life on Earth. While they bring harm and fear, we were fortunate to avoid deaths or injuries with this specific incidence. That said, our science industry has learned a lot from this occurrence. Such an event gave researchers hope that they will be able to combine this experience with evidence from the past to understand the geographical phenomena that contribute to such megatsunamis. 

Works Cited

Eisenstein, Richard, et al. “650-Foot Flood: The Megatsunami That Rocked Greenland’s East Coast.” SciTechDaily, 20 Sept. 2024, scitechdaily.com/650-feet-high-the-megatsunami-that-rocked-greenlands-east-coast/. 

Service, National Weather. “National Weather Service – Tsunami Hazards.” U.S. Tsunami Warning Centers, tsunami.gov/?page=tsunamiFAQ#:~:text=A%20tsunami%20is%20caused%20by, comets)%20can%20also%20cause%20tsunamis. Accessed 23 Sept. 2024. 

“What Tsunamies Are & What Causes Them.” What Tsunamies Are & What Causes Them | Brownsville, TX, www.brownsvilletx.gov/301/What-Tsunamies-Are-What-Causes-Them#:~:text=Tsunamis%20are%20most%20often%20generated,before%20a%20warning%20is%20issued. Accessed 23 Sept. 2024. 

Wilson, Jeremy, et al. “650-Foot Run-up: Megatsunami in Greenland Sends Seismic Waves Worldwide.” SciTechDaily, 20 Sept. 2024, scitechdaily.com/650-foot-high-megatsunami-in-greenland-sends-seismic-waves-worldwide/.