Chat Ed : Good evening everyone and welcome to our live webchat with Oceanographer Dr. Simon Boxall as featured in tonight’s Equinox Special: The Wave that Shook the World which discussed the recent tsunami disaster in Indonesia. Dr Boxall is here to answer your questions on this phenomenon…
Dr Simon Boxall : Hello everyone, Simon Boxall here joining you after the Equinox programme. I'm an Oceanographer who studies the physical structure of the oceans and in particular water movements and waves.
Carla : Given the low-lying land in the area that the tsunami hit, would an early warning have saved many lives?
PaulH : The scariest part of the whole event was that we had no warning of any sort. How much notice would a tsunami warning system have given us on Phuket?
Dr Simon Boxall : In the various islands, many of which don't rise more than four or five metres above sea level, it would have made little or no difference unfortunately. In Sumatra where the waves hit before any early warning system could have helped, it would have made no difference at all. With a very efficient warning system, in Thailand, it would have only been a few minutes. Although on the programme the indication was that they realised things were happening within minutes, in reality it was more like half an hour to an hour. By the time a warning has been issued to a particular country it would still be an hour to an hour and a half before the warning would reach the beach. This would have been good in Sri Lanka, but anywhere closer, it would have been of very limited use.
dangl : What is the likelihood of a Tsunami hitting the UK?
michael : can it happen in Britain
Robb : Is there any such warning in place in the Atlantic?, is there a significant threat of a Tsunami in the Atlantic?
Dr Simon Boxall : Virtually zero, dangl. Even if the Canary Islands collapse happens, (and the majority of scientists expect it to be a gentle slide rather than a catastrophic plummet) the wave results would be dissipated by our continental shelf. Other parts of Europe, such as Portugal and the south of Spain would be much harder hit as they don't have a gentle sloping shelf. As with the Indian Ocean there is no warning system in the Atlantic as tsunamis are relatively rare. The last tsunami of any substance in the Indian Ocean was about 120 years ago. The last tsunami in European waters was off Italy, which happened as a result of a submarine (in the sea) earth slide which did cause damage to southern Italy about 30 or 40 years ago.
PaulH : We stayed in Bangtao (Phuket), and experienced the wave firsthand. The destruction was not as bad as in other areas, due to the headlands to the southwest. However, you indicate in the program that the waves came from the northwest. How can this be, as Phuket lies Northeast of Sumatra?
Dr Simon Boxall : A lot will depend on the general shape of the coastline as well as the offshore submarine contours. These contours can focus and defocus the waves, a bit like a magnifying glass. So even though your resort faced the wave with such a complex coastline the wave was defocused from where you were (luckily).
David : How effective do you think the temporary cover provided by the Japanese detection system will be if it’s needed in the near future?
Dr Simon Boxall : Scientifically one can install a system with the potential of tracking a tsunami very quickly (days). However, in order to fully protect an ocean area, a very, very complex network of sensors is required. The second problem and by far the bigger problem is getting the information to these areas. In Hawaii it's easy. To begin with most of the earthquake generating areas are a four to eight-hour travel time, which provides plenty of warning and also in Hawaii there is a much better network of information on the beaches. It is like trying to get information to a remote beach in Cornwall, as opposed to Brighton beach. The other thing to remember is that hindsight is wonderful. On Christmas Day if someone had run along the beach shouting 'Tsunami!' people would just have looked in bewilderment. 24 hours later they would know what those words meant. In the Pacific it's a common part of their language as there are four or five minor tsunamis every year.
Carla : Do you think that another tsunami could hit the same area in the near future?
Dr Simon Boxall : Carla - the probability that another tsunami could hit the same area next year is the same as one hitting in the next 120 years. One will happen, it could be tomorrow, it could be next century.
Kyle : Has the tsunami affected the weather at all. Here in Britain we keep getting high winds which is classed as severe, new york is suffering from low temperatures i have a friend in Virginia and they’re getting snow
Carla : As so much water was displaced onto the land, will that have evaporated and will it mean an increased rainfall in that area or anywhere else?
Dr Simon Boxall : The tsunami has no effect on climate or weather. The total surface area, which was inundated with water, is still very, very small on a local area and virtually un-measurable on a global scale. The devastation of the tsunami came about because of a high population that inhabits our very narrow coastlines.
Anjalika Sagar : Was the Tsunami caused by environmental damage caused by humans
John : is there any scientific link to global warming and tsunamis?
Dr Simon Boxall : For once we have played no part in the tsunami. It's one of the few environmental disasters that we cannot be blamed for in any way.
Daryl Reilly : Sir - do you think that, had the politicians of these countries taken into account the safety of the environment as a high priority and had they implemented a Tsunami warning system that the loss of life would have been a lot less? I believe it is true that these governments put the economy ahead of the environment by deforesting huge areas on the coastline to pave way for hotels etc.
Dr Simon Boxall : One has to bear in mind that these are countries with very poor economies. In an ideal world they would have earthquake, tsunami, meteor, hurricane and many other types of warning systems. Where poverty and hunger are a big demand on economy they have to think carefully about where the money is spent. That so many people lost their lives in this natural disaster is a tragedy, many more lost their lives this month through hunger and war, which are totally preventable. It's a question of where the priorities lie.
Mel : What effect did the Tsunami have on the underwater terrain? Would the sea life be better at reacting to the change than the life on land?
Dr Simon Boxall : The sea life in the near-shore zone will have been severely disrupted, but it will, with time, recover. As will, eventually, the human population. In the open ocean away from the immediate epicentre it will have had no effect.
Tony : I was stated that one effect of the earthquake was to cause the earth to wobble. How long will this be for?
Dr Simon Boxall : It was explained very elegantly on the programme as a ballet dancer pirouetting and changing position slightly. This affects his/her spin rate. A slight movement in the earth has the same effect. However, it was a very, very small (three millionths of a second) wobble, which would not be measurable and is a hypothetical calculation. Don't forget our mountains and our oceans are moving all the time, for example, the Atlantic sea floor is moving about five centimetres per year. This all has similar effects on the earth, it's not a precise globe spinning at a precise speed. Far worse things have happened to it in geological timescales.
scott : Hi, how many people are living in areas of significant tsunami risks?
Dr Simon Boxall : It depends on one's definition of significance. It's estimated that about 80% of the world's population lives within about 50km of the coast. On this basis a high proportion of the world's population could be affected by tsunamis. A similarly high number will also be affected by sea level rises that are occurring as a result of global climate change. The difference is that tsunamis happen much, much quicker and we have no time to adjust.
Rob : I noticed that Western Australia lies on a line of sight from the epicentre of the earthquake, which gave rise to the tsunamis. The Western Australian coastline is considerably closer to that epicentre than the east coast of Africa, yet I am not aware of any report that it was appreciably affected. I imagine this is because of the directionality of the tsunamis.
john : How did the Tsunami affect the costal areas of Australia
Dr Simon Boxall : That's correct Rob, if you look at your map, the island of Sumatra and the Indonesian Peninsula effectively blocked the eastward progression of the wave. It was only Thailand that was really affected to the east as the wave moved around the north of Sumatra.
Carla : How long is it going to take for the land to recover from the tsunami?
Nadia : Has there been major damage to the coral reefs in these areas?
Chat Ed : Our time with Dr. Simon Boxall is almost up, so last few questions now...
Dr Simon Boxall : The coral reefs may well have been severely damaged in some areas. This damage is not so much from the initial surge of the wave, more from the debris (rocks, stones, trees, cars etc.) that is then back-washed onto the reefs. It is hard to estimate how long recovery will take and a team of scientists from the Southampton Oceanography centre flew out yesterday to join a Royal Naval vessel which will begin surveys around the epicentre. We will know more in a few weeks time.
Di : Who do you normally call when something of this size is detected - do you contact the Government first?
Dr Simon Boxall : It depends on the country, Di. And this is the problem. In the UK we have a series of standard practices and in the case of a marine event we have hotlines to the Marine Coastguard Agency. The US and Japan have similar set-ups. The big problem in many of the countries bordering the Indian Ocean is that no such infrastructure exists. The problem scientists at the Earthquake Monitoring Station in Hawaii had was they didn't know who to call.
wallace : how can i learn about these sort of natural disasters, get to work in your sort of field, I am very interested but don’t know what to do next
Dr Simon Boxall : The subjects that are needed to cover natural disasters are very varied. Geologists study the earthquakes and volcanoes of our planet. Oceanographers study the tsunamis that result along with the life in the ocean, the climate of the oceans and many other aspects on our planet. Meteorologists study hurricanes, tornadoes and monsoon events. All need a good background in science and a passion for their subject. Many of these subjects can be studied these days through changes in the school curriculum that are now occurring and of course at University. There are also many good books, some of which are shown on the Channel 4 website www.channel4.com/tsunami.
davebristol : DR Simon fascinating chat
Joan : Thanks for your time Dr Boxall. It was very interesting.
Carla : Thanks for coming. :)
Guy : Thanks Simon, nice one!
lyralice : byee :o)
leslie : excellent
Thais : Thank you
DerekUK : ty
Dr Simon Boxall : Thank YOU for logging on and bear in mind that these events are fortunately very rare, so do sleep easily and do keep going down to the sea :)
lickle : thanx dr
joe_v : very informative
Dr Simon Boxall leaves the room
