Thursday, 25 April 2013
Every wave encounter is unique (and potentially powerful)
Lately I’ve been dealing a lot with uncertainties, both stochastic and knowledge based, as well as the effects of waves on floating constructions. As a result I’ve reflected on what could be seen as an unpredictability of the maritime domain.
The shape (including height and so on) of waves at sea are stochastic, there are theories about the probability distribution but not necessary perfect ones. So there is both a natural (never ending) variation of waves (aleatory uncertainty) and the fact that we don’t know exactly how this variation looks like (epistemic uncertainty). So in short, every wave is unique and there is no way of measuring it after it has hit the ship. The wave was the product of that instance and place and can never be recreated.
Another interesting or daunting aspect of waves is the high level of energy (as a result of the density of water) and how effortless it can be transported for long distances (which lead to the highest waves were many waves combine to a monster wave). Terrifying results from waves has been seen as results of both tsunamis and monster waves suspected to sink ship without a trace.
The situation isn’t the same for other areas, they have their set of uncertainties (aleatory and epistemic).
So should we give up and say that we know nothing of the future at sea, off course NOT! But we have to be better at understanding and dealing with the uncertainties (aleatory and epistemic). We have to take decisions (about such things as design and security) even if there are uncertainties!
There is therefore a need to further develop marine specific knowledge (to reduce the epistemic uncertainty) but also to use that specific knowledge when it comes to marine studies.
In short if you don’t know about the specific aleatory and epistemic uncertainties in the maritime domain, don’t work with trying to analyze the future in maritime cases and if you are to commission a study for the maritime domain make sure to demand maritime competence.