It relates to an issue that has concerned us in the past when considering investing in Dubai beachfront property, in particular the reclaimed islands such the the Palms and the World.

Having been literally raised from the sea so recently and with nothing similar nearby of any history or track record to compare against, that primitive part of our mind, the place where ‘gut instinct’ resides (the amygdala) has always nagged away at us about the question of whether such reclaimed islands could just as easily go back to where they came from, whether through erosion over time, or by a one-off event such as a tsunami.

Could a tsunami affect Dubai?

The answer to this question is ‘probably not’. A Tsunami Seminar held in Tehran in September 2006 assessed the risks to the Gulf area of future seismic events, in the wake of the Indian Ocean tsunami disaster of 2004. Representatives from various high ranking Meteorological, Oceanographic and Seismology organisations were at the event as well as various professors. A full report from the Iran Daily newspaper can be read here.

Map of The Persian Gulf

For the Sea of Oman/ Arabian Sea region overall, there is actually an identifiable tsunami risk. This is attributable to the Makran Subduction Zone that runs along the coast in Southern Pakistan and into Iran. A seismic event in this zone could generate destructive tsunamis in the Sea of Oman, south of Iran. Should a tsunami occur in the region, tidal waves could reach Iranian and Pakistani coasts in between 15 and 30 minutes and could inflict irreparable damage on coastal regions. The last time such an event occurred in this area was in November 1945 when the Balochistan Earthquake, measuring 7.8 on the Richter scale triggered a huge tsunami that hit the whole Makran coast, reaching heights of up to 40m and killing 4000 people in Pakistan.

As for Dubai and the Emirates, it would seem that they may, fortunately for investors in the Palm, be at very low risk from tsunami events due to the shallowness of the waters in the Persian Gulf. The average depth of waters in the Gulf is a mere 50m, with a maximum depth around 90m. That’s shallow enough to flatten any tsunami trying to push its way through the Strait of Hormuz.

OSAC assessment of earthquake risk

On the topic of earthquake and tsunami risk in the UAE, The American “Overseas Security Advisory Council” (OSAC) which provides information to organisations operating in various regions worldwide has this to say:

“In response to the recent tremors, seismic experts have provided the following information:

- Parts of the UAE have the potential for a substantial earthquake. This potential is greatest for regions near the Oman Mountains.

- In much of the UAE, the weakly consolidated materials on which buildings are constructed would tend to amplify ground-motions (i.e., liquefaction), thus increasing the likelihood of damage to buildings.

- Because the recurrence interval of earthquakes is not known, a useful assessment of seismic risk in the UAE probably cannot be made at this time. It is probably reasonable to conclude that seismic risk in the UAE is less than that in western California, but it also is reasonable to conclude that it is not zero.

- One should also consider the tsunami risk to the eastern coast of the UAE, as a large displacement along the Makran Fault (fault offshore of Iran and in the Gulf of Oman), could produce a tsunami.”

The full report can be read here.

Earthquake Risk lower than London?

On the flip side to the OSAC assessment, the UAE Interact website reported in April 2007 the following:

“The seismic risk in Dubai is lower than that of London and it is not dangerous as has been reported in some risk assessment reports, said an expert. “There is also no possibility of a tsunami in this region because Arabian Gulf waters are not deep enough to trigger a tsunami,” said Angus McFarlane, Technical Director of Building Structures at Hyder Consulting Middle East.

Speaking at a seminar on ‘Seismic Hazards in the Gulf’, he said the seismic risk assessment indicates that the seismic hazard in the UAE, Qatar, and Bahrain is significantly low. ”

The full article can be read here.

Beach Erosion and Sea Levels

The visionary World Islands

“…the hundreds of thousands of new islanders will be living just 10 feet above the waterline. Last month, giant waves swept away five workers on the Palm Jebel Ali, one of whom drowned.”

In the same article Frederic Launay, director of World Wide Fund for Nature in Abu Dhabi, said, “If you build on a low coast like that you’re exposing yourself to dramatic consequences, a high wave or high sea, or even if the sea rises.”

As for the problem of beach coast erosion, this is a long-term problem that predates the man-made island projects themselves. According to a Gulf News report dated Dec 7, 2007, available here the coast erodes at a rate of 50m every 2 years! This is from a hoard of data collected by engineers from the Coastal Management Section at Dubai Municipality since 2000.

Without five-tonne bags of sand strategically positioned 100 metres from the shore to form protective groynes the recently nourished Umm Suqeim I beach would wash away, potentially taking houses along with it.

To combat coastal erosion caused by the impact of the sea, 500,000 cubic metres of sand had been poured along the shore to pad out the receding coastline during 2004, said Alya Abdulrahim Abdullah, head of the coastal management section at Dubai Municipality (DM).

The area under her authority stretches between the Sharjah and Abu Dhabi border, almost 70 kilometres, 10 nautical miles offshore and 1 kilometre inland. This area is defined as Dubai Coastal Zone.

The new man-made islands for their part had contributed to an increased rate of erosion as they had altered the wave patterns hitting the natural beaches. However since the erosion issue is a known one it is something that the Coastal Management Dept will be keeping one step ahead of, with initiatives such as sand replenishment, wave-breaks, and policies for construction companies whereby they must dump any excavated sand of beach quality at specified sites on the coast to help in replenishment.

Man-made, Man-maintained, Man-dependent

Without question, the Dubai palms and the World archipelago are amongst the most beautiful and audacious creations of man in modern history. They are of course a modern day miracle. Yet they are subject to the same old forces of nature, forces that prefer to pull down organised structures into disorganisation, to turn order into chaos.

The Dubai coastline and these islands will always remain a dynamic battle between Man and Nature. The gradual erosion effect of the tides will need a sustained replenishment effort over the years. However if anything more dramatic were to occur, such as global warming causing sea levels to rise, or a tsunami-type event (though unlikely) then the best efforts of Man may not be enough.