Moikwathai Moidaki

• PhD
• Professor (Associate) at University of Botswana

On the 3rd April 2017 a widely felt Moiyabana earthquake shook Botswana and the rest of southern Africa. Previous Moiyabana earthquake locations used mainly teleseismic or regional seismograms; and/or non-seismic methods which include Synthetic Aperture Radar (InSAR), and magnetotelluric (MT). These results did not agree, as evidenced by the depth...

Soil tests and Multichannel Analysis of Surface Waves (MASW) data were conducted in Hatsalatladi village, Botswana, to investigate the occurrence of ground fissures within the village and to identify the likely causes of the fissures and their depth extent. The MASW data were collected to gain insights into the variation of shear wave velocity with...

New measurements shear-wave splitting (SWS) were determined using a teleseismic dataset from 21 broadband seismic stations belonging to the GSN-BX network in Botswana archived at IRIS-DMC. The stations are distributed across major geologic terrains such as the Kaapvaal craton, Limpopo Mobile Belt and Zimbabwe Craton. Earthquakes with magnitude larg...

Radon monitoring at the Gcwihaba caves, a tourist site

Numerous investigations of the mature segments of the East African rift system (EARS) have significantly improved our understanding of the structure and processes associated with well-developed continental rifts. In contrast, knowledge of rifting processes at their early stage is still significantly limited. Here we present results from a teleseism...

Soil magnetic properties measurements are relatively fast and inexpensive but have been proved to be sufficient for preliminary investigations in diverse socio-developmental issues. This paper presents results of a reconnaissance study of soil colour and magnetic susceptibility (c) in eastern Botswana, where ~80% of the population resides. The work...

Rifting incorporates the fundamental processes concerning the break-up of continental lithosphere and plays a significant role in the formation and evolution of sedimentary basins. In order to decipher the characteristics of rifting at its earliest stage, we conduct the first teleseismic crustal study of one of the world's youngest continental rift...

This study represents the first shear-wave splitting investigation of the Okavango rift zone (ORZ), an incipient continental rift belonging to the East African rift system in northern Botswana. Analysis of broadband seismic data recorded along a 750 km long profile of 22 stations traversing the ORZ and adjacent Congo and Kalahari cratons and severa...

Mechanisms leading to the initiation and early-stage development of continental rifts remain enigmatic, in spite of numerous studies. Among the various rifting models, which were developed mostly based on studies of mature rifts, far-field stresses originating from plate interactions (passive rifting) and nearby active mantle upwelling (active rift...

A total of 93 well-defined PKS, 54 SKKS, and 126 SKS shear-wave splitting parameters are determined at 25 broadband seismic stations in an approximately 1000 by 1000 km2 area centered at the New Madrid seismic zone (NMSZ) in order to test the existence of two anisotropic layers and to map the direction and strength of mantle fabrics. The individual...

Rifting of stable continents is a key element of plate tectonic cycles. In spite of numerous studies, the mechanism responsible for the initiation and evolution of rift valleys such as the East African Rift System (EARS) is still poorly understood, partly because most previous investigations focused on rift segments that were in the mature stage. G...

The Mesoproterozoic Midcontinent rift (MCR) in the central US is an approximately 2000 km long, 100 km wide structure from Kansas to Michigan. During the 20-40 million years of rifting, a thick (up to 20 km) layer of basaltic lava was deposited in the rift valleys. Quantifying the effects of the rifting and associated volcanic eruptions on the stru...

We used Magnetotelluric (MT) and Electrical Resistivity Tomography (ERT) to investigate the geometry and nature of faults activity of the Okavango Rift Zone (ORZ) in Botswana, an incipient rift at the southern tip of the Southwestern Branch of the East African Rift System. The ORZ forms a subtle topographic depression filled with Quaternary lacustr...

The earth's crust and upper mantle have been continually modified by tectonic processes such as rifting, earthquake activity. In this dissertation, shear wave splitting and receiver function techniques were employed to study the extent of crustal and upper mantle modifications beneath the New Madrid Seismic Zone (NMSZ) and the Midcontinent Rift (MC...

Teleseismic shear-wave splitting parameters are determined at 15 permanent and portable broadband stations within and around the New Madrid seismic zone (NMSZ) in order to map the direction and strength of mantle fabrics and to explore the origin of seismic anisotropy. Both the splitting times and fast polarization directions of the fast shear-wave...

Botswana is a landlocked, sparsely populated, arid country with a geological record spanning from Achaean rocks to Recent superficial deltaic/pan deposits, and an economy heavily reliant on the mining sector (diamonds, Cu-Ni, Au; Fig. 1). The principal problem which face geoscientists in Botswana is that exposure of pre-Tertiary formations is restr...

An electrical resistivity survey was carried out at an existing leaking dam site in Salem, Missouri. The purpose of the study was to investigate possible seepage pathways and to provide students at the University of Missouri‐Rolla hands‐on experience in the application of geophysics to engineering problems. The electrical resistivity data were acqu...

Landfilling is now widely accepted in many countries as the major municipal solid waste disposal method, and other methods like incineration, composting and recycling are under utilized in developing countries like Botswana. However, the environmental and health problems created by landfilling of unwanted waste are numerous, and often poorly unders...

Upper mantle anisotropy beneath the Mesoproterozoic Midcontinent Rift (MCR) and adjacent areas is investigated using splitting of P-to-S converted phases (SKS, SKKS and PKS) at the core-mantle boundary. Available data from all the portable and permanent broadband seismic stations in the area of 38-46N and 92-102W are used in the study. Well-defined...