Remote sensing and geophysical investigations of the geodynamic activities at lake Magadi, Southern Kenyan Rift.
Date
2012Author
Komolafe, Akinola Adesuji
Kuria, Zacharia Njuguna
Woldai, Tsehaie
Noomen, Marleen
Anifowose, Adeleye Yekini Biodun
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
The tectonic lineaments and thermal structure of Lake Magadi, southern Kenyan rift
system, were investigated using ASTER data and geophysical methods. Five N-S faults
close to known hot springs were identified for geoelectric ground investigation.
Aeromagnetic data were employed to further probe faults at greater depths and determine
the Curie-point depth. Results indicate a funnel-shaped fluid-filled (mostly saline
hydrothermal) zone with relatively low resistivity values of less than 1Ω-m, separated by
resistive structures to the west and east, to a depth of 75m along the resistivity profiles.
There was evidence of saline hydrothermal fluid flow toward the surface through the
fault splays. The observed faults extend from the surface to a depth of 7.5km and are
probably the ones that bound the graben laterally. They serve as major conduits for the
upward heat flux in the study area. The aeromagnetics spectral analysis also revealed heat
source emplacement at a depth of about 12km. The relative shallowness implies a high
geothermal gradient evidenced in the surface manifestations of hot springs along the lake
margins. Correlation of the heat source with the hypocenters showed that the
seismogenetic zone exists directly above the magmatic intrusion, forming the
commencement of geodynamic activities.
Citation
International Journal of Geophysics Volume 2012 (2012)Publisher
School of Physical Sciences
Subject
Remote sensinggeophysical investigations
geodynamic activities
lake Magadi
Southern Kenyan Rift