Disaster Rally

  • Facebook
  • Twitter
  • Natural Disasters
    • Earthquakes
    • Hurricanes
    • Tornadoes
    • Fires
    • Floods
    • Tsunamis
    • Other
  • Man-Made Disasters
    • Nuclear
    • Pollution
    • War
    • Other
  • Prepare
    • Plan
    • Supplies
  • Disaster Resources
    • Agencies
    • Aid
    • Medical
    • Rescue
    • How To Help
    • People in need
  • Contact
  • About Us: Disasterrally

How Do Tsunamis Form + Riskiest Countries in the World

Email, RSS Follow
Pin It

December 26, 2004. Millions of vacationers basked on the warm beaches bordering the Indian Ocean. They never knew that they were about to experience one of the most devastating natural disasters in human history. As vacationers frolicked in the peaceful waves, the water suddenly retreated from the shores as if the entire ocean were inhaling deeply.

Those who understood the answer to the question of “how do tsunamis form” knew that this was the first sign of an approaching tsunami and began to seek higher ground. But sadly for most, their retreat was pointless. Within minutes, the coastal communities of 14 nations were inundated with a wall of water up to 30 feet high.

What Is a Tsunami?

Japanese city affected by a tsunami

A tsunami is a wave or series of waves in the ocean that are extremely large and fast. These waves can travel across the oceans at phenomenal speeds, up to 550 miles per hour. This is roughly the speed of a jet. When they are far out in the ocean, they are barely noticeable. However, once they begin to crest at a shoreline, they can become very destructive.

How do tsunamis form at shorelines? This happens because tsunami speed is directly related to the depth of water. As a tsunami approaches the shore, the speed of the wave slows down. At the same time, the total energy of the wave remains the same. This causes the height of the wave to grow as the top of the tsunami wave travels faster than the bottom. So, while the wave may be completely imperceptible in the deep waters of the ocean, the destructive energy of the wave releases on shore as it lands.

The energy released in a large tsunami is astounding. It is nearly impossible to calculate precisely. Nonetheless, it’s estimated that the energy released in the 2011 tsunami that devastated Japan was equivalent to nearly 100 nuclear bombs the size of those that were dropped on Nagasaki and Hiroshima. This is an ironic form of measurement since the tsunami caused a crisis at a nuclear power plant in the Fukushima Prefecture that is still devastating the environment today.

How Do Tsunamis Form?

The answer to the question of how do tsunamis form lies in understanding the different forces of nature that can cause them. Tsunamis form due to an enormous amount of water displacement. Most people think that tsunamis only form from earthquakes. However, there are actually several things that can cause a tsunami to form. Anything that disturbs a large volume of water is capable of generating a destructive tsunami. The possible precursors of tsunamis besides earthquakes include:

  • Volcanic eruptions, both above ground and underwater.
  • Above ground rockslides or landslides.
  • Underwater rockslides or landslides.
  • Asteroid strikes.

In each of these cases, a large volume of water is either thrust up or dropped down. This causes all of the water to create a series of waves called a wave train. The waves in this wave train can be up to 60 miles long and as far apart as an entire hour. Because there is often little or nothing in the ocean to interfere with the path of these waves or absorb the energy, they can travel across the entire planet at breathtaking speeds with very little loss of energy. A tsunami wave train can travel across the entire Pacific Ocean in less than one day.

How Do Tsunamis Form

Historical Tsunamis

Contrary to popular belief, tsunamis can form in a lake, as well as in an ocean. How do tsunamis form in lakes? Landslides often are the cause. In 563 AD, a massive tsunami occurred in Lake Geneva for this very reason. The landslide was so massive that it caused the resulting wave to race across the lake and inundate the city walls of Geneva. The waves swept over the tops and drowned those who were unable to escape the wall of water. This is one of the more common answers to the question of how do tsunamis form from forces other than earthquakes.

This landslide was triggered by an accumulation of sediment that reached a point so massive it collapsed under its own weight. Aside from meteor impacts, these landslide-triggered tsunamis can be the most violent that nature produces. They can cause tsunamis that dwarf the Boxing Day tsunami in height, if not destructive power over a widespread path.

On July 9, 1958, in Lituya Bay, Alaska, a rockslide – this one actually was caused by a large earthquake – generated a tsunami with a run-up height of over 1700 feet. The force of this tsunami destroyed all of the vegetation in its path. But the loss of life in this tsunami was minimal because it occurred in such a sparsely populated area. In fact, only five people total died that day. A later tsunami in Alaska in 1964 took 119 lives and inflicted over $400 million dollars in damage.

Where Do Tsunamis Occur Most Often?

tsunami risk map

Tsunamis can occur along any coastline or in any large body of water. The Pacific Ocean is the place where most of the world’s tsunamis form. This is because subduction zones are so common there. How do tsunamis form along subduction zones? Subduction zones are fault lines that cause one tectonic plate to slide under another.

These can trigger particularly violent mega – thrust earthquakes that consist of an upward or downward motion instead of a horizontal wave. This motion almost always produces a wave when it occurs underwater. Nonetheless, it is only strong enough to produce noticeable tsunamis part of the time. Those areas along the Pacific that are most likely to see tsunamis are Alaska, Chile, the Aleutian Islands, Japan and the Philippines.

While tsunamis do occur in the above-mentioned areas most often, they have also occurred in the Atlantic Ocean, Indian Ocean, Mediterranean Sea and elsewhere. So if you live along a shoreline, it is best to fully understand the answer to the question of how do tsunamis form and understand the risk of tsunamis in the area. If tsunamis have occurred in the past, they can and most likely will occur again. Be aware of escape routes and possible warning signs of an approaching tsunami.

Some signs of a tsunami are:

  • An earthquake. Very often, local geological services will forecast the possibility of a tsunami and likely strike zones when an earthquake occurs under water or near the shore. Pay heed to these warnings.
  • Active buoys in the tsunami warning system. These buoys can be activated even when underwater earthquakes are not noticeable to those onshore. They are particularly useful to sailors. They can receive warning in time to escape shorelines where the destructive force of the tsunami occurs and move out to the open sea.
  • A very sudden and noticeable rise or fall in the water level. Tsunamis are often preceded by this phenomenon as the energy of the wave begins to displace the water of the coastline. It is estimated that this phenomenon can precede a tsunami by as much as five minutes. This gives the shore bound time to escape to higher ground. Tragically, many of those who were inundated by the Boxing Day tsunami did not know this sign. They went even closer to the shore to watch as the water receded. This is why knowing the warning signs of a tsunami and understanding how tsunamis form is so important.

Finally, make sure that you always have an emergency kit. It should contain enough food, medical supplies and fresh water to last from three days to a week. This is because tsunamis can wipe out local infrastructure and power and will likely destroy local water delivery systems. Heeding these warning signs and being properly prepared will help you to be a survivor and not a victim of this powerful force of nature.

IMAGE SOURCE: 1, 2, 3

Email, RSS Follow
Pin It

5 Safety Tips You Need To Know If You Live Near A Nuclear Power Plant

image source: pixabay.comWhen purchasing a home, there a lot of things to consider. What area of the United States do you want to live? Do you want to be in the country or in the city? Are you going to rent or own, and will it be an apartment or a house? If you have […]

Tornado Warning VS Tornado Watch: What You Need To Know

When it comes to severe weather, nothing is as devastating as a tornado when you consider the inch to inch devastation. Tornados often possess stronger winds than hurricanes, and due to the cyclone shape of a tornado, it increases the damage potential. Tornados are also especially dangerous if you are in its path. A single […]

Long Term Water Storage: The Ultimate Guide

While you hope that a calamity like a water shortage or other emergency will never befall in your lifetime, it is always important to be prepared for the worst while hoping for the best. One of the most important aspects of emergency preparedness is ensuring you have a sufficient stockpile of water to get you […]

10 Best Filter Water Bottle Brands To Use During Emergencies

If there is one thing that all hikers and outdoor enthusiasts have in common, it’s that they all agree you should never blindly drink out of a natural water source. That’s because the unfiltered water, although fresh and natural, contains harmful bacteria and waterborne parasites that would likely go undetected by taste alone. With a […]

14 Deadliest Natural Disasters of All Time

What are the deadliest natural disasters of all time by death toll? Which type of deadliest natural disasters has the greatest death count? More importantly, what are some ways the population was affected by those disasters? Were there things that people did to worsen or better the effects of mother nature angrily smashing her surroundings? […]

4 Frostbite Symptoms And How To Treat Them

With the onset of winter comes the risk of getting frostbite. With all of the outdoor recreation that’s available to us in the winter, it is important to learn how to protect ourselves. Knowing the signs of frostbite in the early stages can help you to avoid permanent damage to your skin and underlying tissues. […]

Fire Escape Plan for Your Family: Our Complete Guide

No one ever thinks a tragedy will happen to them. We see events on the news all the time such as accidents, home invasions, and house fires. We rarely plan for these things because we never think that we will be in such a situation. If you do one thing this coming year, whether you […]

10 Tips for Living Through Power Outages

Most of us don’t think of power outages until we’re searching for flashlights or candles in the dark. Some think the light on their cellphone will be good enough to make it through power outages. That might work if power outages happen only when your phone is already fully charged. But, what about being prepared […]

How To Tell If A Snake Is Poisonous: Your Ultimate Guide

image source: Pixabay Have you ever been startled by a snake in your yard? Snakes are among the most misunderstood and feared animals on the planet, mainly because of the poisonous and potentially deadly bite a snake can inflict on its target. The truth, however, is that most snakes in the United States are non-venomous and […]

Copyright © 2023 disasterrally.com

About · Privacy Policy · Terms of Use · Sitemap · Contact

poisonous snake lying on the rock