By Shina Abubakar, Osogbo
A low magnitude tremor was witnessed in Nigeria at the weekend originating around Omu-Aran in Kwara state.
The tremor, according to Professor Adepelumi Abraham of the Department of Geophysics at the Obafemi Awolowo University, Ile-Ife, Osun, where the phenomenon was recorded, the tremor has focal depth of 15 kilometres.
The report titled, “Preliminary Report on the 5th June, 2021 Earth-Tremor Recorded at the Obafemi Awolowo University, Ile-Ife Osun State, Nigeria”, signed by Professor Abraham, obatined by Vanguard on Monday in Osogbo, added that the tremor’s moment magnitude is 2.6 while it local magnitude is 2.6 on the Richter scale.
The report reads further, “An earth-tremor of low magnitude occurred in Nigeria at 11:11:25.6 am (GMT) on 5th June 2021. The origin time is 11:11.08.2 am (GMT) (Figures 1 to 3).
“The estimated epicentral distance (D) is placed between 108 and 113 km away from the measuring station at the Obafemi Awolowo University, Ile-Ife, Nigeria.
“The S wave particle motion generally trends N – S and NE – SW (Figure 4). This suggests that the wave is traveling perpendicular to the particle motion. Hence, the epicenter is somewhere along the NW-SE direction of Ile-Ife, Osun State, Nigeria.
“Using Single Station, the epicenter is roughly placed closed to Omu-Aran. Kwara State at Latitude (Y) 8o 06’18.0’ N, and Longitude (X) 4o 59’20.4’ E (Figures 5 to 7).
“The estimated focal depth is 15.0 km.
“The Moment magnitude (Mw) is 2.6 on the Richter scale.
“The Local magnitude (ML) is 2.4 on the Richter scale.
“A normal fault mechanism along the Ifewara-Zungeru Transcurrent Fault system due to INTRAPLATE SEISMICITY was deduced. This suggests that this fault system is still active.
“The fault that caused the Earth-tremor has a Stress drop of 5.9 bar.
“Preliminary Report on the 5th June 2021 Earth-Tremor Recorded at the Obafemi Awolowo University, Ile-Ife Osun State, Nigeria”.