An earthquake that shook parts of Uganda early yesterday morning for about 15 seconds, coincided with another in southern Taiwan in the Pacific Ocean.

The United States Geological Survey said the quake measured 5.7 on the Richter scale, and said a similar quake had occurred around the same time in Taiwan. The seismological station in Entebbe measured it at 5.2.

The epicentre was on the Congolese side of Lake Albert at 1.9 degrees north latitude and 30.9 degrees east longitude.

Michael Odong, acting permanent secretary in the Ministry of Energy and Mineral Development, said the quake began at 0233gmt (5:33 am local time) and was not believed to have caused significant damage.

There were no immediate reports of injuries or damage in Kampala from the tremor, but many residents said they were awakened, either by shaking beds or creaking window casements.

In Fort Portal, which is much closer to the epicentre, many residents who were awoken by the tremors ran from their homes shouting.

The tremor lasted more than three minutes in Kabarole district, and by the time it stopped, some weak houses had developed cracks.

According Fort Portal Municipal Engineer Adolf Kahuma, districts in western Uganda, especially those in the Rwenzori region, are prone to earthquakes.

Districts most seriously affected lie on the western edge of the Rift Valley or in the foothills of Rwenzori mountains.

John Tiberindwa, a geology lecturer at Makerere University who monitors earth tremors, told Daily Monitor that people should not be concerned about most tremors.

"Earthquakes are always there. Our machines record earth tremors on a daily basis," he said. "It's the strength and frequency of the strong earth tremor that matters."

Major earthquakes struck western Uganda in 1945, 1960 and, most recently, on April 6, 1994, killing many people and causing millions of shillings in damage in Kabarole, Kasese, and Bundibugyo districts.

Dr Tiberindwa said many tremors occur because the earth's surface is not continuous but divided into pieces called lithospheric plates, where new material is continuously being created at constructive or divergent plate boundaries.

"Two adjacent plates might be moving apart or might be converging. Where they are converging, the denser plate sinks under the lighter plates. Where they are moving apart, new melt (magma) comes up and fills the void that would have been left in between the two plates. The movement along the cracks between plates are among the causes of the earth tremors," he said.

To avoid falling victim to major earth tremors, Dr Tiberindwa advises people, especially those in earthquake-prone areas like those on the western edge of the Rift Valley in western Uganda, to build earthquake resistant houses.

Eng. Kahuma said members of the Association of Western Uganda Earthquake Disaster Preparedness have been building a model earthquake-resistant house as an example to people intending to build houses in the region.

He said whoever fails to comply with the new building guidelines, would be putting their lives and property at risk.

"All the districts of western Uganda in the Rwenzori region are prone to earthquake disasters, and because the tremors are expected to occur any time, all builders must construct earthquake-resistant houses," he said.