Upcountry insight: Earthquake causes and preventive measures

NORTHERN PROVINCE GICUMBI — Recent earthquake that hit Rwanda’s Western Province districts of Rusizi and Nyamasheke including the neighboring Congolese town of Bukavu, has spark many theories and comments from the public and academicians regarding the actual causes of the quake. Some people have linked the quake to volcanic activity common in the neighboring DRC Nyiragongo Mountain while others say it was caused by a sudden and violent movement of earth’s surface, resulting in energy release common in the regions falling under the Great Rift Valley. The truth of the matter is that the recent quake had nothing to do with volcanism because there was no volcanic eruption reported in the region, although earthquakes can also be produced by volcanic activity. Earthquakes are natural disasters that have rocked the world since time immemorial and Rwandans should devise means of minimising their disastrous effects on lives and property instead of devoting time on the causes. According to Dr. Gérard Fryer of Hawaii Institute of Geophysics & Planetology, the earth is divided into three main layers namely; a hard outer layer (about 100 Km thick) called Crust, a soft middle layer and a centre core. Since the surface of the earth is in continuous slow motion, pressure builds up between rocks within the earth breaking the outer layer into massive irregular pieces called “Plates”. The ‘plates’ cover the entire surface of the earth and since they are all moving, they rub against each other, sink beneath each other or spread apart from each other. As the earth continues its slow motion, the pressure builds up to the point where the rock cannot withstand any more bending and as a result breaks and the broken pieces continue moving in relation to the earth’s motion. Dr. Fryer further says an earthquake is caused by the shaking and radiation resulting from the breaking rocks within the earth’s surface. During this process, pressure is built up until it reaches a critical point where the rocks slip off from each other releasing energy known as ‘Seismic energy’. It is this seismic energy released as a wave which causes the earth to vibrate, sometimes violently. Earthquakes are measured by ‘The Richter scale’ which goes from 0 to 9, but there is no real limit for the maximum seismic energy output. The seismic energy released from a focus of the earth spreads through waves in increasing larger circular forms and their effects decrease as distance increases from the centre of the Earthquake or focus. This explains why other parts of the country further from earthquake affected districts of Nyamasheke and Rusizi experienced tremors as a result. The tremors experienced in Kigali and other parts of Rwanda were as a result of weakened seismic waves which originated from a focus around Bukavu in DRC or neighboring Kamembe town of Rusizi district. It is against this scenario that people need to prepare themselves or their homes against disastrous effects caused by natural calamities like this. Researchers at Singapore Seismology Meteorological Services Division have advanced a number of precautions to be undertaken before and during quakes. First and foremost is for countries to install detecting devices known as ‘Seismic sensors’ which monitor the effects of earthquakes, to alert and evacuate people and property to safe areas whenever a quake of high magnitude is detected by the Seismic sensors. Secondly, the public is advised to take advance precautions to minimize damages by protecting falling objects and furniture. This can be done by fastening fragile objects and to anchor heavy and tall furniture to the wall or floor to prevent them from turning over. In addition, hazardous materials such as dangerous spilling chemicals should be stored in safe containers and secured at a place close to a wall with a strong latch. Fire extinguishers and first aid kits should also be put in place in case of a fire outbreak during the quake. Lastly, people are advised to make sure that their homes or tenants Insurance is up-to-date in order to compensate lost lives and property resulting from earthquakes. Ends