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RELATED ARTICLES: Calls for earthquake provisions in Abu Dhabi | Seismic shift needed in earthquake testing Earthquake resistant
Property owners and developers may face new levies for earthquake insurance if a new report by global reinsurance company Munich Re, stating that the UAE is in a "very strong" earthquake zone, is to be believed.
Munich Re has been producing its World Map of Natural Hazards Report since 1978 but has, for the first time this year, split the MENA region in to its constituent areas and applied risk factors to each based on the amount of earthquake, tropical cyclone and volcanic activity in the region.
Using the Modified Modified system to rate potential earthquake magnitudes, the report says the UAE has the potential to produce "very strong" earthquakes (MM VII). Based on the Richter Scale, that means earthquakes of up to 5.9 in magnitude. Earthquakes that strong have the potential to cause moderate damage well-built structures and cause considerable damage in poorly built or badly designed structures.
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In an interview with Emirates Business, Munich Re’s client management executive for the Middle East and North Africa region, Andreas Pollman said: “The UAE has changed drastically in a short time. The concentration of high-rises, for example.
“Whenever there is a change in risk exposure, there might be a consequent change in the assessment of the risk.
“The change in risk that occurred now is the increase and concentration of values in the region and what we do is that we measure our exposure.”
The report has gained a bit of weight following last month's earthquake in Iran that measured 5.6 on the Richter scale. Iran lies within Munich's top Zone 4, MM IX, meaning it has the potential for major seismic events - which has resonated with neighbouring regions. According to contractors and architects in the UAE, the Emirate of Fujairah is at particular risk, because it's the closest emirate to Iran.
“The higher the exposure to earthquakes, the more rigid you have to make your core and your vertical elements,” says Commodore Contracting Company’s Dubai branch manager Shadi Khuzam.
“In Fujairah particularly, where the risk of exposure to earthquakes is about 10-15% more than in Dubai and Adu Dhabi, it is important to ensure that your vertical elements are rigid enough to take any horizontal movement.
“Buildings are normally only designed to take vertical loads, they can take a bit of wind coming from the sides, but they are not usually designed to take shaking from earthquakes. This means that the core has to be designed in a way to absorb earthquake movements and transmit loads down to the raft foundation.”
He adds however, that this tends to be a bigger issue for high rise buildings and taller structures, the majority of which are built in Dubai and Abu Dhabi.
Speaking about the architectural significance of earthquake risk, Dewan Architects’ executive director Ammar Al Assam says that the seismic zone of the project will have a key role in influencing the structural design parameters.
Earthquake ratings
Richter Scale/ Modified Mercalli Scale
1.0 - 3.0 / Instrumental
Effects: Not felt by many people unless in favourable conditions.
3.0 - 3.9 / Weak - Slight
Typical maximum effects: Felt quite noticeably by people indoors, especially on the upper floors of buildings. Many do not recognize it as an earthquake. Standing motor cars may rock slightly. Vibration similar to the passing of a truck. Duration estimated.
4.0 - 4.9 / Moderate - Rather Strong
Typical maximum effects: Felt outside by most, may not be felt by some outside in non-favourable conditions. Dishes and windows may break and large bells will ring. Vibrations like large train passing close to house.
5.0 - 5.9 / Strong - Very Strong
Typical maximum effects: Difficult to stand; furniture broken; damage negligible in building of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken. Noticed by people driving motor cars.
6.0 - 6.9 / Destructive - Violent
Typical maximum effects: General panic; damage considerable in specially designed structures, well designed frame structures thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations.
7.0+ / Violent, Intense, Extreme and Cataclysmic
Typical maximum effects: Total damage - Everything is destroyed. Total destruction. Lines of sight and level distorted. Objects thrown into the air. The ground moves in waves or ripples. Large amounts of rock move position. Landscape altered, or leveled by several metres. In some cases, even the route of rivers is changed.
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The municipalities of Dubai & Abu Dhabi already require all buildings to comply with Zone2A requirements of the UBC. Sa