•Experts warn of recurrence, want government to be proactive
By Cosmas Omegoh, Tessy Igomu and Job Osazuwa
Perhaps the earth goddess is angry. Or perhaps Nigerians are approaching unusual times, times when things untoward happen, things that most people here have never witnessed before that are common phenomena in foreign lands, which Nigerians used to pass off as natural disasters that torment climes unlucky to have them.
But now, the phenomenon is here and might soon enlarge in scale to rattle Nigeria with the same ferocity it used to wreak havoc in other lands. The signs are here that earth tremors have berthed in the country.
Lately, earth movements have been noticed in areas around Shaki in the north-western fringes of Oyo State, a shouting distance from Nigeria’s border with Benin Republic, and Kwoi in the southernmost tip of Kaduna State. reports said the ground in those areas was vibrated violently. Residents were confronted with shaky ground that convulsed inexplicably, something they had never seen before. Probably the most elderly ones in their midst could not tell if their ancestors ever experienced such upheavals.
The incidents took the residents by surprise. The earth beneath them was rumbling and roaring like a lion desperate to keep its game. Houses, trees, rocks and the ground on which they all stood were gyrating, dancing to a macabre musi. The novel development left everyone in utter shock. No one could run anywhere; everything, tribe, tongue and creed, possessions and social status all vanished. All that mattered was survival. Residents of near and distant towns and communities who heard the unusual happenings stood in awe, rooted to the ground, wondering what was amiss.
A couple of weeks ago, a devastating earthquake occurred in Amatrice, a town in central Italy, killing no fewer than 290 people.
A days after, a similar sad incident occurred in Tanzania when a 5.7-magnitude earthquake struck the county’s northwestern part, killing no fewer than 16 people and injuring over 253 people. It was reportedly felt throughout the countries in the Great Lakes region.
And the phenomenon seems to be spreading in Nigeria. A few days ago, earth tremors occurred in Sambang Dagi in Jaba Local Government Area of Kaduna State. Daily Sun learnt that the first tremor happened in Nok village. Almost 24 hours later, the second took place in Sambang Dagi. It was unclear if any lives were lost. However, it was gathered that first tremor shook the community and threw many residents of the area into a panic.
It was also gathered that in May this year, a similar earth tremor rocked Saki, Oyo State. Reports said residents of some quarters in the community such as Medinat, Veterinary and Ogbooro heard deafening, underground vibrations.
On September 11, 2009, similar occurrence was reported in areas around Abeokuta, Ogun State. It was learnt that the incident was felt in some parts of Lagos State.
Even areas in the Niger Delta region have not been spared. Earth tremors were reported in Akenfa and Igbogene in Bayelsa State, and Akinima, Akieoniso (Oruama) and One Man Country and Mbiama communities in Rivers State, leading to widespread panic among the residents.
According to Wikipedia, an earth tremor is “the perceptible shaking of the surface of the earth, resulting from the sudden release of energy in the earth’s crust that creates seismic waves.”
An online research platform, Research Gate, in a review of earthquake occurrences and observations in Nigeria wrote that: “Although Nigeria is not located within the major seismic zones of the world, over the years, several minor earthquakes have been experienced in some parts of the country. ”
Going down memory lane, it noted that: “The first widely reported occurrence of an earth tremor in Nigeria was in 1933. Other events were reported in 1939, 1964, 1984, 1990, 1994, 1997, 2000 and 2006. The intensities of these events ranged from III to VI, based on the Modified Mercalli Intensity Scale. Of these events, only the 1984, 1990, 1994 and 2000 events were instrumentally recorded. They had body wave magnitudes ranging from 4.3 to 4.5, local magnitudes between 3.7 and 4.2, and surface wave magnitudes of 3.7 to 3.9.
“When these events occurred, there were no functional seismological observatories in Nigeria. However, that has now changed with the establishment of a seismographic network managed by the Centre for Geodesy and Geodynamics, Toro, Nigeria. Presently, the network has four operational stations equipped with 24-bit 4-channel recorders and broadband 30-second seismometers. Efforts are being made to establish more stations and migrate to real-time collection of seismic data using the general packet radio service technology as well as automatic location of events. Remote sensing, geological and geophysical studies have revealed the presence of a NNE-SSW trending Ifewara-Zungeru fault zone which has been shown to be linked with the Atlantic fracture system. The dynamics of the Atlantic fracture zones have been suggested to be responsible for the seismic activities experienced in the areas.”
Researchers at the National Space Research and Development Agency (NASRDA) have said that repeated tremors being felt across the country were signs that Nigeria might be earthquake-prone.
One of the researchers, Dr. Abraham Adekunle Adepetumi, of the Department of Geology, Obafemi Awolowo University (OAU), Ile Ife, Osun State, said not too long ago that there were clear signs that the country was prone to earthquakes.
He said: “We have been working in partnership to monitor what is happening in the subsurface of Nigeria very recently. On September 11, 2009, there was a tremor at Abeokuta, Ijebu-Ode, among other parts of the West, which gave signal that there is likelihood of a substantial earthquake happening in the later future.
“We have learnt before that Nigeria is outside seismic region, that is to say it is safe. In the last two to three years, with what we gathered, some parts of Nigeria, especially the South-West are not safe.”
Also, recently, the Deputy Director, Media and Corporate Communications, NASRDA, Mr. Felix Ale, explained that human activities such as oil and gas exploration, among others, were the likely causes of tremors in the Niger Delta region.
“The report shows that, due to oil and gas exploration, suspected fault zones and man-made activities were among likely causes of the incidents.
“At this stage, it cannot be concluded that the tremors occurred as a result of man-made activities in the region or from tectonic activities from natural sources until a detailed investigation in the entire South-South region is carried out by NASRDA’s research team.
“The detailed analyses by the team will help the agency to adopt requisite mitigating measures to avert loss of lives and property in case of future occurrences.
“In view of the nature of earth tremors or earthquakes, especially natural tremors, the space agency is making plans to deploy monitoring seismic equipment to the affected region for continuous micro seismic and macro seismic activities.
“This is imperative because tremors will continue to occur in the future, depending on either natural or artificial causative agents.
“Scientists from the Centre for Geodesy and Geodynamics, Toro (Bauchi State), under NASRDA, are currently working on relevant seismic data to extract more information from seismic station located in Toro.”
Similarly, a scientist, Dr. Adeneye Talabi, also akkuded to exploration of oil and gas as one of the likely causes of recurring earth tremors on the country.
“There is need for the Federal Government and the Nigerian National Petroleum Corporation, in particular, to enforce all the existing rules guiding exploitation of natural resources like crude oil.
“Regarding the tremor in Bayelsa and Rivers, the fact that oil is being extracted through exploitation processes and methods, vacuum has been created, “ he said.
Meanwhile a hydro geomorphologist/environmental expert in the Department of Geography, University of Lagos, Dr. Shakirudeen Odunuga, has called on the Federal Government to be proactive in addressing any form of environment and natural disasters, including tremors.
He told Daily Sun, that appropriate agencies should, as as a matter of urgency, embark on comprehensive geological surveys to identify more areas that might experience earth tremors in the future. He charged thae authorities to also figure out where there were possible minor and major faults, which are essentially breaks in the layers of rock of the earth crust.
He said when this is done, residents ought to be equipped with the right information and necessary emergency mechanisms.
According to Odunuga, tremors could be caused by human activities such as uncontrolled extraction of water from the ground, resulting in slight dislocation and movement in the earth crust, although tremors are usually natural incidents.
The don noted that Nigeria could not be described as prone to earthquake. However, it might not be out of place for the country to witness an earthquake, considering what has happened in recent time inn several other places.
He warned that the last two incidents, recorded within 24 hours in Kaduna, were signals that an earthquake was imminent.
“Nigeria has experienced tremors here and there, right from 1936, 1964, 1984, 1990, 1994, 1997, 2000, 2006 and now in 2016. With all these, it means we are not totally immune to the major event, which is earthquake.
“In any case, what we are having in Nigeria are simply minor shifts along various faults. A tremor is not a full-blown earthquake but a warning.
“It is not restricted to occur in a particular part of the country. It had happened in the North and South-West and even in Bayelsa State. So it can occur anywhere in Nigeria.
“We don’t have to wait for the disaster to happen before we begin to think of what to do. The damages are usually irreparable. I believe we should be proactive by undertaking surveys. Let the agencies, through the survey, find out if the tremors that occurred in the past could be tied to the faults.
“The government would then prepare the residents’ minds on the possibility of the disaster. I don’t believe in waiting to send relief materials to victims, especially for crises that could be prevented. The people can be relocated to safer environments. Let structures be put in place to minimise the impact if such happens.
“To an extent, one cannot really prevent tremors, except the ones caused by human activities,” he said.
Similarly, the National President, Building Collapse Prevention Guild, Mr. Kunle Awobodu, has warned Nigerians, particularly residents of the South-West, to wake up to the possibilty of earth tremors.
According to him, geophysical and geological studies have revealed that a fault zone that connects with the Atlantic fracture system exists along Ifewara in Osun State and Zungeru in Niger State.
In the same vein, Dr. Emmanuel Adamu, a geologist, has said that there was the need for the country to document various earth tremors as a way of preparing for future incidents. He said tremors were clear signs of major earth quakes in the making.
“Nigeria is not actually a tremor-prone nation but due to earthquakes in the Atlantic Ocean, and volcanoes in some areas around the world, some parts of the country might experience tremors occasionally,” he said.