Bookshelf: The Power of the Sea

The Power of the Sea: Tsunamis, Storm Surges, Rogue Waves, and Our Quest to Predict Disasters – Bruce Parker

The Power of the Sea by Bruce Parker is a highly readable introduction to freakishly large ocean phenomena, most notably tsunamis and rogue waves (which have particularly interested me since reading Susan Casey’s The Wave). Parker is an oceanographer who has worked at NOAA.

I was grateful that the author spent some time explaining tides – the most basic oceanographic feature, universally familiar. How can some places have two high tides every day, some places have one, and some have none at all? What about the differences in tidal range around the world? I think I’ll need it to be explained to me a few more times before I’m comfortable with it, but between him and Rachel Carson we’re off to a good start.

In the early sections of the book there is a good deal of historical background provided as Parker fills in the background of modern oceanography, and I enjoyed the accounts of how understanding of tidal phenomena has assisted generals, rebels and others in achieving their goals (or thwarted them). The success of the D-Day landings at Normandy during World War II were critically dependent on predictions of the tide on five French beaches. Tidal data did not exist for those particular locations, and some intelligent guesswork and interpolation was required to determine which days would be suitable for an invasion.

Parker also discusses the expensive and difficult task of defending our coastlines – particularly urbanised, developed locations – from storm surges such as the one caused by Hurricane Katrina. The Dutch are particularly forward-thinking in this regard.

The latter half of the book is mainly devoted to tsunamis, their causes and effects, and the problem of giving advance warning of their approach. In order to understand how tsunamis and storm surges function, it’s necessary to have a basic grasp of how energy is imparted to the ocean. Most of the time the energy is from the wind, and a combination of factors may give rise to waves of unbelievable dimensions, or just to common and garden wind waves and swell. In the case of a tsunami, it is usually an undersea earthquake that gives rise to the wave. A significant portion of the book is devoted to the timeline of the 2004 Thailand/Banda Aceh Tsunami that killed nearly 300,000 people, and the afterword deals with the Japanese tsunami of March 2011 that has led to one of the largest nuclear disasters of all time at Fukushima.

Predicting tsunamis is difficult; in order to do the best job possible, one would need to be able to predict earthquakes, which is in itself very, very difficult. Not every undersea earthquake causes a tsunami. The next best approach – if we can’t predict earthquakes – is to have high-powered mathematical models that can, based on when a tremor occurs, give an indication of whether the resulting waves will be tsunami waves, or not. For this kind of predictive power a huge network of ocean observation buoys and sensors is required. Tsunami warnings are generated and quickly sent to nations whose coastlines are at risk. The notice period is potentially very short, so countries at risk from tsunamis need to have evacuation procedures and good public awareness for these systems to work properly.

All the phenomena Parker describes (except perhaps for tsunamis) will be exacerbated by climate change, which leads to more regular, fiercer storms, higher winds, and rising sea levels. This makes it all the more important to be able to predict what conditions will give rise to the conditions that are conducive to storm surges, large waves, and phenomena such as El Niño. Worldwide initiatives such as the Global Ocean Observing System (GOOS for short), which encompasses a wide range of observational projects, will make it easier to pick up tsunami waves before they reach land, and to provide real time data on developing weather and wave patterns across the globe.

You can buy The Power of the Sea here (if you’re in South Africa), otherwise here or here. For a kindle copy go here.