How Far Inland Would a 2-Mile-High Tsunami Travel?

A 2-mile-high tsunami would be an incredibly rare and catastrophic event, dwarfing any recorded tsunami in history. To put it in perspective, the largest tsunami ever recorded was in Lituya Bay, Alaska in 1958, which had wave heights of up to 1,720 feet (524 meters) caused by a landslide.

If we imagine a 2-mile-high tsunami, which is roughly 10,560 feet (3,219 meters) high, it would be an unprecedented event with unimaginable consequences. The impact would be devastating, with coastal areas experiencing complete destruction and widespread flooding.

The extent of the inundation would depend on various factors such as the slope of the coastal terrain, the shape of the coastline, and the distance from the source of the tsunami. In general, tsunamis lose energy as they travel inland, so the height of the wave would decrease the further it travels.

However, even a tsunami with a height of 2 miles would likely travel far inland, reaching several miles or even tens of miles depending on the topography. Low-lying coastal areas and flat terrain would be particularly vulnerable to inundation.

The aftermath of such a tsunami would be catastrophic, with widespread destruction of infrastructure, loss of life, and long-term environmental impacts. Recovery and rebuilding efforts would be immense and would require international cooperation and support.

While the likelihood of a tsunami of this magnitude is extremely low, it's important to understand the potential impact of such events and to be prepared for more realistic tsunami scenarios. Early warning systems, evacuation plans, and community preparedness are key to mitigating the impact of tsunamis and ensuring the safety of coastal communities.

Understanding Tsunamis

Before we delve into the specifics, let’s grasp the basics of tsunamis:

What Is a Tsunami?

A tsunami is a series of ocean waves caused by the sudden displacement of water. Unlike regular ocean waves, tsunamis have extremely long wavelengths and carry immense energy.

The initial wave height depends on the triggering event (earthquake, volcanic eruption, or asteroid impact).

Factors Influencing Tsunami Reach:

Wave Height: The taller the initial wave, the farther it can travel inland.

Velocity: The speed at which the tsunami moves affects its reach.

Impact Angle: The angle at which the tsunami hits the coastline matters.

The Case of a 2-Mile-High Tsunami

1. Wave Height

A 2-mile-high tsunami would be an unprecedented catastrophe. However, let’s consider the practical limitations:

Height: The height of the tsunami would be 2 miles (approximately 10,560 feet or 3,219 meters). This is far beyond anything observed in recorded history.

2. Velocity

The velocity of the tsunami depends on the triggering event. Here are some scenarios:

Asteroid Impact: If a massive asteroid (similar to the one that created the Chicxulub crater) struck the ocean, the resulting tsunami would be generated mostly by kinetic energy. Objects in space move at incredible speeds (tens of miles per second), so the initial wave would be substantial.

3. Impact Angle

The angle at which the tsunami hits the coastline significantly affects its reach:

Shallow Sea Impact: The height of the tsunami generated by the Chicxulub asteroid impact was limited by the relatively shallow sea in the Gulf of Mexico. In deep ocean, it could have been 4.6 kilometers (2.9 miles) tall1.

Inland Distance: The distance the wave travels inland depends on its forward momentum. An extremely tall wave lacks the momentum to penetrate far inland. My estimate: perhaps northern Tennessee.

Conclusion

While a 2-mile-high tsunami would be catastrophic, its reach would depend on various factors. The shockwave might reach you first! Remember, tsunamis are rare events, and our focus should be on preparedness and early warning systems to minimize their impact.

Sources

Tsunami Travel Time Maps. https://www.ncei.noaa.gov/products/natural-hazards/tsunamis-earthquakes-volcanoes/tsunamis/travel-time-maps

Interactive map of estimated tsunami travel times to coastal locations. https://www.americangeosciences.org/critical-issues/maps/tsunami-travel-times