Broadband Earthquake Monitoring at OAUIFE Station, Nigeria Dr Adepelumi, A. A Department of Geology, Obafemi Awolowo University, Ile-Ife, Osun State or Phone: st January, 2009

Seismology In November 2007, Guralp system was installed at OAUIFE seismic station ( 7º 31'23"N and 4º31'27"E) through the funding provided by UNESCO office in Italy. Inverter and Solar Panel were installed in November 2008 for the smooth running of the seismic station.

Some of the Events Recorded at OAUIFE Earthquake station

Iceland May 29, 2008

Mexico Event- 2008

Tonga Event- 2008

OAUIFE Observatory

Earthquake Facilities at OAUIFE

Properties of the Seismometer

Iceland Earthquake "Iceland is sitting on a plate boundary where the North America and Eurasian plates are drifting apart. So earthquakes are common but large earthquakes are relatively rare," On 29 th May, 2008, A strong earthquake measuring 6.1 hit southern Iceland, 50km from the capital, Reykjavik. The US Geological Survey said the earthquake struck at 1546 GMT at a shallow 6.2 miles (10 km). The earthquake was also picked at the same time at OAUIFE

Implication of the Iceland Teleseismic to Nigeria Insights into the structure of the upper mantle beneath Southwestern Nigeria. Lithospheric structure of Southwestern Nigeria from the teleseismic data. Insights into the Crustal structure beneath Southwestern Nigeria. Character and kinematics of the Megashear systmem in the Gulf of Guinea: Implications for tectonic evolution of Southwestern Nigeria.

Iceland Earthquake (OAUIFE)

Iceland Earthquake - Sandpoint, USA

Recent Seismicity in Nigeria Although, no active faults have been established in Nigeria, however, a careful review of seismicity record in Nigeria had showed that Nigeria may not be aseismic as has hitherto been believed. Recent events in Nigeria: Ijebu-Ode (July and August, 1984); Gulf of Guinea (December, 1984). Warri (1933), Lagos (1939); Umuahia (July, 1961); Kundunnu, Bauchi (1981); Dambatta, Kano (July, 1975); Yola ( December, 1984) and Gombe (June, 1985). Thus monitoring and prediction of earthquake hazards could begin by a proper documentation of the pathways through which they emanate, using seismological data.

Long Term Earthquake Prediction: Southwestern Nigeria The Empirical Earthquake Recurrence Model – a time-dependent model, was employed to predict the probabilistic occurrences of earthquakes in the Ijebu-Ode and environs between the year 2008 and This probability model takes the mean recurrence intervals and standard deviation of historic earthquake events in this area in order to determine the probability of earthquakes occurrence for the predicted years.

Probability of Recurrence of Earthquake of Intensity V-VII in Southwestern Nigeria

The results of the model showed that the probability of earthquake occurrence in the study area between the year 2008 and 2028 increased from 2.8% to 91.1%. The result also showed that the probability of 2 events occurring has the highest likelihood within the predicted years.

Conclusion Therefore, it is instructive as a necessary measure to henceforth incorporate seismic criteria in the site investigations for design and construction of major and sensitive structures like Nuclear power plants the country is seriously considering as alternative source of energy for electricity generation, whose sudden damage can lead to disruption of major essential services, loss of lives and property and general degradation of the environment. Long Term Earthquake Monitoring should be embraced by Nigeria.

Future Plans Expand OAUIFE network to a comprehensive and effective earthquake Information System Center; Acquire through UNESCO more sensitive seismometers that will serve as a Early Earthquake Warning System; Study the Crustal and Mantle structure beneath Southwestern Nigeria.

Acknowledgments UNESCO and TWAS for the financial support. Dr. Eck van, Torild for support.