Publications

Found 29 results

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2016
Patel JP, Karanja PK, Githiri JG, Barongo JO. "APPLICATION OF EULER DECONVOLUTION TECHNIQUE IN DETERMINING DEPTHS TO MAGNETIC STRUCTURES IN MAGADI AREA, SOUTHERN KENYA RIFT." JOURNAL OF AGRICULTURE, SCIENCE AND TECHNOLOGY. 2016;18(1). AbstractFull Text

Magadi area is located in the southern part of the Kenyan rift, an active continental rift that is part of the East African Rift system. Thermal manifestations in the form of hot springs in the northern and southern shores of Lake Magadi and high heat flows suggest geothermal potential in the area. A ground magnetic survey was carried out in the study area with the aim of locating depths to bodies with sufficient magnetic susceptibility that may represent magmatic intrusions. The magnetic data was corrected, a total intensity magnetic contour map produced and profiles drawn across identified anomalous regions. Magnetic survey data in profile form over anomalous regions was interpreted rapidly for source positions and depths by Euler deconvolution technique. Geologic constraint was imposed by use of a structural index 1.0 that best describes prismatic bodies such as intrusive dykes. The magnetic bodies were imaged at depths ranging from 0 km to about 11 km along the profiles. The imaged depths along the profiles display discontinuities in magnetic markers due to presence of numerous faults in the area. The detected magnetic bodies may be cooling dykes that heat the underground water responsible for the numerous hot springs surrounding Lake Magadi. Such a dyke is suspected to originate from a magma chamber conducting heat to the underground water. A model whereby the faults in the region provide escape of water as hot springs is proposed.

Barongo JO, Karanja PK, Githiri JG, Patel JP. "AN INVESTIGATION OF THE STRUCTURE BENEATH MAGADI AREA IN SOUTHERN KENYA RIFT USING GRAVIMETRIC DATA." JKUAT. 2016. AbstractFull Text

Magadi area is located in the southern part of the Kenyan rift, an active continental rift that is part of the East African Rift system. Local seismic activity monitored previously around Lake Magadi revealed an earthquake cluster caused by swarm activity in the rift centre at shallow depths, which was probably triggered by magma movements. There was need for a follow-up to locate any body at depth with sufficient density contrast that may represent magmatic intrusions. Gravity measurements were carried out in 58 established stations and data from 52 other stations merged from existing coverage of previous measurements. Necessary corrections were applied to the gravity data and a Bouguer contour map prepared. Euler deconvolution technique was used to image depth to the causative bodies along selected profiles on the Bouguer anomaly map. Two dimensional gravity forward models of the subsurface structure were generated by using Euler depth solutions in the start models. Among others, a unique body of density of 3.20 gcm-3 was modelled on the northern region near little Magadi at a depth of approximately 0.4 km. The location of the body coincides with the area where earthquake swarm occurs. Such a body of high density contrasts may be caused by mafic intrusions into the crust. Discontinuities in Euler solution cluster along the profiles indicated buried faults in the volcanic rift infill. The high seismicity may hence be associated to magma intrusions.

Barongo J, Masinde A, Simiyu C, Murunga I, Muia G, Waswa A. "A Preliminary Assessment of the Hydrocarbon Potential of Kerio Valley Basin: Gravity and Magnetic Interpretation." Africa Energy and Technology Conference, 2016. 2016. AbstractWebsite

The aim of the study was to assess the hydrocarbon prospectivity of the Kerio Basin in the
Kenya Rift. An Isostatically corrected anomaly map produced from a Bouguer anomaly grid
was filtered using a Hanning low pass filter of order 2 to remove low wavelengths. Four
profiles were extracted from the grid to give 1D interpretation along straight lines. Magnetic
grid was corrected for IGRF, diurnal, filtered using a 1 Hz low pass 10km Hanning filter to
reduce noise, later, reduced to equator to place all anomalies directly over underlying
sources and make anomalies less complicated. Tilt derivative of the magnetic grid was used
to estimate depth to basement. The residual analytic signal anomaly map derived from the
magnetic grid was used to capture the response of existing near surface magnetic
signatures even the reversely magnetized ones.

Barongo J, Mathu E, Kianji G, Roberts R, Lund B, Shomali H. "Preliminary seismic catalogue for Kenya and adjoining areas, 1900-2014; Challenges and constraints.". 2016.
2015
Barongo J, Macheyeki AS, Mdala H, Chapola LS, Manhica VJ, Chisambi J, Feitio P, et al. "Active fault mapping in Karonga-Malawi after the December 19, 2009 Ms 6.2 seismic event." Journal of African Earth Sciences. 2015;102:233-246. AbstractFull Text

The East African Rift System (EARS) has natural hazards – earthquakes, volcanic eruptions, and landslides along the faulted margins, and in response to ground shaking. Strong damaging earthquakes have been occurring in the region along the EARS throughout historical time, example being the 7.4 (Ms) of December 1910. The most recent damaging earthquake is the Karonga earthquake in Malawi, which occurred on 19th December, 2009 with a magnitude of 6.2 (Ms). The earthquake claimed four lives and destroyed over 5000 houses. In its effort to improve seismic hazard assessment in the region, Eastern and Southern Africa Seismological Working Group (ESARSWG) under the sponsorship of the International Program on Physical Sciences (IPPS) carried out a study on active fault mapping in the region.

The fieldwork employed geological and geophysical techniques. The geophysical techniques employed are ground magnetic, seismic refraction and resistivity surveys but are reported elsewhere. This article gives findings from geological techniques. The geological techniques aimed primarily at mapping of active faults in the area in order to delineate presence or absence of fault segments. Results show that the Karonga fault (the Karonga fault here referred to as the fault that ruptured to the surface following the 6th–19th December 2009 earthquake events in the Karonga area) is about 9 km long and dominated by dip slip faulting with dextral and insignificant sinistral components and it is made up of 3–4 segments of length 2–3 km. The segments are characterized by both left and right steps.

Although field mapping show only 9 km of surface rupture, maximum vertical offset of about 43 cm imply that the surface rupture was in little excess of 14 km that corresponds with Mw = 6.4. We recommend the use or integration of multidisciplinary techniques in order to better understand the fault history, mechanism and other behavior of the fault/s for better urban planning in the area.

2012
Githiri JG, J. P P, Barongo JO, Karanja PK. "An investigation of the structure beneath Magadi area in southern Kenya rift using gravimetric data." Journal of Agriculture, Science and Technology. 2012;Volume 24(Number 1):142-160.
2011
2010
2006
O PROFBARONGOJUSTUS. "Munga, D., Mwangi, S., Ong.". In: Editors, pp. 213-228, published by Taylor & Francis/Balkema, The Netherlands. Canadian Center of Science and Education; 2006. Abstract
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2005
O PROFBARONGOJUSTUS, OPIYO PROFAKECHNOBERT. "Mulwa, J. K., Gaciri, S. J., Opiyo-Akech, N and Kianji, G. K., 2005. Geological and structural influence on groundwater distribution and flow in Ngong area,.". In: Kenya. African Journal of Science and Technology, vol. 6, No. 1, pp. 105-115. Canadian Center of Science and Education; 2005. Abstract
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2004
2003
O PROFBARONGOJUSTUS. "Barongo, J. O., 2003. SGL 104 : Geostatistics,.". In: Lecture Notes for 1st Year Bed. (Science) by Distance Learning, 155 pp. Canadian Center of Science and Education; 2003. Abstract
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1999
O PROFBARONGOJUSTUS. "Barongo, J.O., 1999. Selection of a appropriate model for the interpretation of time-domain airborne electromagnetic data for geological mapping,.". In: Exploration Geophysics 29, 107-110. Canadian Center of Science and Education; 1999. Abstract
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1998
Barongo JO. "Selection of a appropriate model for the interpretation of time-domain airborne electromagnetic data for geological mapping.". 1998. AbstractWebsite

A detailed analysis of the time-domain INPUT airborne electromagnetic response to a horizontal layer of variable conductivity and thickness reveals that there are combinations of conductivity and thickness of the layer for which the response behaves like that of a thin sheet (thickness << diffusion depth), those for which it behaves like that of a finite layer (thickness between those of thin sheet and half-space) and those for which it behaves like that of a half-space (thickness >> diffusion depth). Plots of thickness versus conductivity at which the response changes from one category of behaviour to another produces three distinct zones we have referred to as 'thin sheet response zone', 'finite layer response zone' and 'half-space response zone', respectively. The boundaries between these three zones move to higher conductances with increasing sample times. A damped least-squares inversion of the synthetic time-domain airborne electromagnetic response involving all the six channels of the INPUT system and based on singular value decomposition produces a distinct 'boundary' separating pairs of layer conductivity and thickness which can be uniquely resolved from those which cannot. The results further show that conductivity and thickness pairs within the thin-sheet response zone, as expected, cannot be uniquely resolved but those within the finite-layer response zone can be resolved. Using carefully interpreted conductivities and thicknesses of the conductive weathered layer from reconnaissance ground resistivity sounding data from an area flown earlier with an INPUT system, I demonstrate how to apply the general 'response diagram' arising from the above results to select between a thin sheet, finite layer and half-space model for the interpretation of time-domain airborne electromagnetic data for geological mapping.

1996
Legge PL, Barongo JO, Opiyo-Aketch N, Mathu EM, Nyambok IO. "Development in earth Science Education in East Africa.". 1996.Website
O PROFBARONGOJUSTUS. "Barongo, J.O., 1996. Studies of Geoelectric Structure Beneath Eburru Geothermal Region, Rift Valley.". In: Kenya, Research Report for National Council of Science and Technology, Project No. NCST/SEC/4400.343, 55p. Canadian Center of Science and Education; 1996. Abstract
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1994
Barongo JO. "Euler’s differential equation and the identification of the magnetic point‐pole and point‐dipole sources.". 1994. AbstractWebsite

The concept of point‐pole and point‐dipole in interpretation of magnetic data is often employed in the analysis of magnetic anomalies (or their derivatives) caused by geologic bodies whose geometric shapes approach those of (1) narrow prisms of infinite depth extent aligned, more or less, in the direction of the inducing earth’s magnetic field, and (2) spheres, respectively. The two geologic bodies are assumed to be magnetically polarized in the direction of the Earth’s total magnetic field vector (Figure 1). One problem that perhaps is not realized when interpretations are carried out on such anomalies, especially in regions of high magnetic latitudes (45–90 degrees), is that of being unable to differentiate an anomaly due to a point‐pole from that due to a point‐dipole source. The two anomalies look more or less alike at those latitudes (Figure 2). Hood (1971) presented a graphical procedure of determining depth to the top/center of the point pole/dipole in which he assumed prior knowledge of the anomaly type. While it is essential and mandatory to make an assumption such as this, it is very important to go a step further and carry out a test on the anomaly to check whether the assumption made is correct. The procedure to do this is the main subject of this note. I start off by first using some method that does not involve Euler’s differential equation to determine depth to the top/center of the suspected causative body. Then I employ the determined depth to identify the causative body from the graphical diagram of Hood (1971, Figure 26)

1993
1991
1990
O PROFBARONGOJUSTUS. "Barongo, J.O. and Nyambok, I.O., 1990. Earthquakes and their measurements,.". In: Geophysical 56, 133-138. Canadian Center of Science and Education; 1990. Abstract
Science News 2, 125-132.
1989
O PROFBARONGOJUSTUS. "Barongo, J.O., 1989. Application of ground resistivity and airborne electromagnetic methods to geological mapping in tropical terrains,.". In: Ph.D. thesis, McGill University, Montreal, PQ, Canada. Canadian Center of Science and Education; 1989. Abstract
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1987
O PROFBARONGOJUSTUS. "Barongo, J.O., 1987 Geophysical detection of mineral conductors in tropical terrains with target conductors partly embedded in the conductive overburden,.". In: Geophysical Prospecting 35, 568-589. Canadian Center of Science and Education; 1987. Abstract
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1985
O PROFBARONGOJUSTUS. "Barongo, J.O., 1985. Spectral analysis of the vertical gradient of the total magnetic field anomalies due to two-dimensional dykes,.". In: Kenya Journal of Science and Technology Series A, 6(1), 49-58. Canadian Center of Science and Education; 1985. Abstract
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O PROFBARONGOJUSTUS. "Barongo, J.O., Method for depth estimation on aeromagnetic vertical gradient anomalies.". In: Geophysics 50, 963-968. Canadian Center of Science and Education; 1985. Abstract
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1984
O PROFBARONGOJUSTUS. "Barongo, J.O., 1984. Euler.". In: Geophysics 49, 1549-1553. Canadian Center of Science and Education; 1984. Abstract
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1983
O PROFBARONGOJUSTUS. "Barongo, J.O., 1983. Geophysical investigations for kimberlite pipes in the greenstone belt of western Kenya.". In: Journal of African Earth Sciences 1, 235-253. Canadian Center of Science and Education; 1983. Abstract
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1982
O PROFBARONGOJUSTUS. "Geoelectric structure below Eburru geothermal field, Rift Valley, Kenya,.". In: Proceedings of the regional seminar on geothermal energy in Eastern and southern Africa, 15-21 June, 1982, Nairobi, Kenya. Canadian Center of Science and Education; 1982. Abstract
Barongo, J.O.,1982. Proceedings of the regional seminar on geothermal energy in Eastern and southern Africa, 15-21 June, 1982, Nairobi, Kenya.
1977
O PROFBARONGOJUSTUS. "Barongo, J.O., 1977. Magnetic model theory in the analysis of vertical gradient anomalies, M.Sc. thesis,.". In: Queen. Canadian Center of Science and Education; 1977. Abstract
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