x Abu Dhabi, UAESunday 23 July 2017

Earthquake risk map to help build safer buildings in Abu Dhabi

Earthquake risk assessments will be worked into building codes under development in the emirate.

Abu Dhabi skyline seen from an helicopter during a trip by FAS , Falcon Aviation Services.
Abu Dhabi skyline seen from an helicopter during a trip by FAS , Falcon Aviation Services.

ABU DHABI // The risk of an earthquake striking the UAE is small, but new building codes should ensure that the country's iconic tall structures could withstand even the largest tremor.

In the capital, earthquake risk assessments will be worked into building codes under development by the emirate. A map that outlines the seismic activity in the UAE has been completed and will be used to aid builders in constructing structures in line with risks.

Earthquake activity in the UAE is typically minor. In January, residents were awakened by tremors from a 7.1-magnitude quake with an epicentre in Pakistan. The last seismic activity recorded in the UAE was a minor 2.6-magnitude earthquake in Fujairah in March.

"Without knowing the risk, you don't know what to do," said Dr S K Ghosh, an earthquake engineer and building codes consultant based in Illinois, US, who helped develop the maps.

"Just like you can't build the structure without knowing what it's going to be used for and how many people will be using it, you need to know what kind of wind will blow on it," Dr Ghosh said. "And seismic activity is in the same category as wind. You wouldn't just go in without knowing the risks."

The map creation is part of a large municipal effort to develop an earthquake risk control and management system. As part of the project, the Government is creating a network of 50 tremor monitoring stations across Abu Dhabi.

"It's often what you don't know that will hurt you," said a scientist from the United States Geological Survey, who asked not to be named.

"There are earthquakes and almost everywhere in the world is exposed to them and knowing what your exposure is, that helps your engineering."

The scientist said understanding the history, frequency and intensity of past seismic activity can help officials tailor regulations specifically to the region.

"Some of the most amazing infrastructure is in the UAE, and it's a great question to ask how to protect that," he said.

Experts said specific data on the effects on buildings of different levels of shaking would be collected. Additionally, understanding how structures built on sand will react to an earthquake will be assessed.

"The project here, in developing the seismic maps, is specifically looking to seismic effect here in UAE by studying different faults and how it affects our region," said Ali Bukair, a consultant for policies and regulations with the Department of Municipal Affairs.

In addition to studying the potential effects regional seismic activity would have on the country, the researchers also included data on local faults. Officials said there are at least two fault zones - one along the border with Oman and another that runs along the western coast of the country.

"We are affected by sources in Iran and Pakistan, but we also have local faults," said Khamis Al Shamsi, the senior earthquake engineer with the National Centre for Meteorology and Seismology. "But the risks are very low. Nowhere in the country is the risk more than a moderate risk."

The National Centre for Meteorology and Seismology also operates the National Seismic Network, which collects real-time data from monitoring stations across the country.

The seismic maps being created will help builders understand the best practises specifically for the capital. "Some people tend to think earthquakes are nothing to worry about in the UAE, but the maps indicate that it's not nothing to worry about," Dr Ghosh said.

Buildings need to be separated by "a significant distance" or somehow tethered together to limit damage in case of a quake. Also, other building elements - facades, balconies, lighting - must be anchored somehow.

More maps will be created in the coming year. "Maps do change over time, Mr Bukair said. "This is an ongoing effort, especially considering the uncertainty of earthquakes."

The building codes, which went into effect earlier this year, are still being customised.

Once completed, a new website will be created and the seismic maps will be posted. The website will also provide real-time earthquake information and archive earthquake data as a tool to manage and monitor future risks.

jthomas@thenational.ae