Broadband Earthquake Monitoring at OAUIFE Station, Nigeria

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Broadband Earthquake Monitoring at OAUIFE
Station, Nigeria

• Dr Adepelumi, A. A
• Department of Geology,
• Obafemi Awolowo University,
• Ile-Ife, Osun State
• Email adepelumi_at_gmail.com or aadepelu_at_oauife.edu.
  ng
• Phone [phone]

1st January, 2009
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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.

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Some of the Events Recorded at OAUIFE Earthquake
station
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Iceland May 29, 2008
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Mexico Event- 2008
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Tonga Event- 2008
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OAUIFE Observatory
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Earthquake Facilities at OAUIFE
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Properties of the Seismometer
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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 29th 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

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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.

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Iceland Earthquake (OAUIFE)
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Iceland Earthquake - Sandpoint, USA
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Nigeria as a case study
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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.

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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
  2028.
• 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.

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

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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.

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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.

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Acknowledgments

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