What happens if there is a Hurricane, or a rogue wave, or a tsunami? Wouldn’t the Seastead be destroyed?
In oceanography, rogue waves are more precisely defined as waves whose height is more than twice the significant wave height, which is itself defined as the mean of the largest third of waves in a wave record. Therefore, rogue waves are not necessarily the biggest waves found on the water; they are, rather, unusually large waves for a given sea state. This means that in relatively calm waters, like those in the tropics, a rogue wave might only be as large as an ordinary wave in the North Atlantic, which would not be dangerous. In areas further away from the Equator however, like off the coast of South Africa or in the North Atlantic and North Pacific, rogue waves can absolutely be dangerous. That being said, since the year 2000 only 4 reported and confirmed encounters with rogue waves have occurred around the world, so even in conditions where these waves really do pose a threat, they are very rare, and usually do not occur in near coastal waters.
That brings us to our next common concern: tsunamis. Tsunamis are only dangerous to those on land and in coastal waters very very near shore, within a few hundred yards where the tsunami begins to gain height as the bottom of the wave pushes against the ground. Before this point, tsunamis (which often originate from underwater earthquakes) travel across oceans not as tall menacing waves but very wide flat rollers. Any boats that come across these waves drift harmlessly over them without suffering any damage, as tsunamis do not usually travel much faster than other waves in the area. The safest place to be in fact, for either an earthquake or a tsunami is on the water, as in both cases absolutely no harm can be done to you, while being on land by contrast, can be deadly even when you are more than a mile away from the ocean.
What about Hurricanes?
This brings us to our real main concern: Hurricanes. Usually called Typhoons in Asia and parts of Africa, Hurricanes form about 10 degrees north or south of the equator, where average water temperature is hot enough (about 81 degrees Fahrenheit or 27 degrees Celsius) to allow them to form, and also where the Coriolis Effect can grab hold of the storm and begin to spin it and push it further and further away from the equator as it intensifies. So long as the Hurricane is passing over warm water it will continue to magnify in intensity after forming.
Hurricanes form in seven distinct basins over the Earth’s oceans, some of these are more active than others.
The first strategy to deal with Hurricanes, is simply to over engineer and evacuate. Modern UHPC (Ultra High Performance Concrete) has incredibly high tensile as well as compressive strength, and while it may be an undesirable experience to ride out a hurricane in a Seastead, evacuating one beforehand and leaving the structure in the ocean to come back to is a perfectly viable choice, as the strength of modern materials allows us to have a high degree of certainty that when you return, very little damage will be done to your home or business, thought it may have shifted location a small distance.
The other option to deal with hurricanes is to simply relocate Seasteads to areas where they are not present, such as at the equator, in the South Atlantic, South Pacific, and South Indian Oceans, as well as much of the area between Australia and New Zealand. There are many safe places to put Seasteads that don’t have to worry about being struck by hurricanes, the largest area being the South Pacific, where a patch of ocean larger than South America is hurricane free, while two other excellent locations are the coastal waters near both Singapore and Panama which see enormous amounts of global trade while also having very safe and protected waters.
In the long term, while we can engineer structures capable of handling hurricane force winds, and we can choose to freely inhabit areas without the dangerous presence of hurricanes, we can also change our environment to be more beneficial to human life. While global warming may have increased the presence of hurricanes around the world, and we have already discussed how we can reverse the effects of global warming with carbon recapture in our last blog post Eco-Restoration we can also target directly, the conditions that cause hurricanes to become so aggressive. OTEC (or Ocean Thermal Energy Technology) is a technology that provides many useful benefits. Primarily, OTEC is designed to generate electrical energy using a green renewable process that taps into stored solar energy in seawater, with two side effects. The first one, is generating clean fresh water as a byproduct of this process, excellent for a seasteading city seeking to be independent, the second side effect, is that it slightly cools the water immediately surrounding the Seastead. Since Hurricanes need waters at 81 degree or above to form, using OTEC in areas that are primary producers of hurricanes could actually disrupt their formation before they even begin, saving coastal cities and much coastal sea life from sure destruction. In the future, perhaps Seasteads can do more than just recycle carbon output from land nations to produce food and energy, but even change the temperature of the water to protect coastal nations from continuing to be battered by powerful ocean storms.