Sunday 21 September 2014

Why Kenya?

Some of you reading this may be wondering, Why Kenya? Why this location? Well here is a brief overview

Setting

The Kenya Rift Valley is a distinct feature bounded by normal faults in an area of lithospheric thinning. I is a tectonic feature that runs from Lake Turkana in the north to Lake Magadi in the south. It froms a classic graben structure ranging from 40 to 80km wide. The Kenya Rift is part of the bigger East African Rift System, which is an intra-continental divergent margin where the Somali and Nubia plates are rifting apart at a rate of 2cm per year, creating a much thinner crust. Continental rifting has never been observed and although the likely break up of Africa will not occur in our life time, the processes can be observed. Making this a very important region for geologists.  The rifting has been accomapanied by volcanism since the late Tertiary, with seravl Quaternary volcanoes peppering the rift floor in Kenya due to the rising of the underlying mantle. Upwelling mantle may melt, rising to the surface using normal faults linked to the deformation and extension, as conduits.
E-W tensional forces have resulted in extension and block rotation. The main rift is bounded by N-S rift scarps. Each side depicts a different type of tectonic style that is thought to indicate crustal detachment. The Molo and Solai TVA’s converge at Menengai and control the geothermal systems here.


Menengai is situated central to this image (http://www.renewbl.com/category/geothermal)

Menengai

Menengai is one of these volcanoes that litter the rift floor. It is characterised by complex tectonics assocuiated with a triple junction formed by the joining Nyanza Rift with the Kenya Rift. It began life around 200,000 years ago as a trachyte shield volcano with a volume of about 30km3. The caldera collapse began about 29,000 years ago with pumice falls and a single ash flow tuff with a volume of 20km3. A further collapse phase occurred around 16,000 years ago with a with the eruption of 30km3 of magma.

A huge project was undertaken by KenGen to thermally map the caldera which brought to light several hotpots within the caldera. This project has since lead to the Menengai Geothermal Project.
It is estimated that 84% of Kenyans do not have access to electricity. Those that do find it very expensive and unreliable, we had a 10 hour power cut during a thunderstorm just a few nights ago. The locals say it usually happens at least once a week and that we have been quite lucky.

The importance to the local communities and beyond

The Menengai Geothermal Project aims to start generating electricity by the end of next year with a long term forecast to produce enough electricity for 500,000 homes and 300,000 businesses. This project along with the project at Olkaria and the proposed project at Longonot means that in around 15 years Kenya is likely to be completely energy independent, with a cheap and reliable source of electricity.


Menengai Geothermal Project

I feel very fortunate to be working on such an important project. I love being in the field and geology has and always will fascinate me. This project allows me to indulge in volcanology and structural geology as well as geochemistry. It has also given me the opportunity to learn the engineering side of the work being done here. But in addition, I am contributing to a project that will very soon be changing the lives of so many people. I have met some amazing and friendly people. Everyone in the caldera who sees us working, stops to say hello, they are curious as to what we are doing, they want to shake hands and wish us luck. The children always wave to us and we have even had a big cheer at the end of a school day. So many people here have very little, but they are all so happy. 

Lala Salama from Kenya!



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