Characterisation of the Hydrogeological Properties of the Ntane Sandstone Aquifer Using Co-Seismic and Post-Seismic Groundwater Level Responses to the Mw 6.5 Moiyabana Earthquake, Central Botswana
The 3 April 2017 Mw 6.5 Moiyabana earthquake (Central Botswana) had a significant impact on groundwater levels; a gradual co-seismic increase and a stepwise decline in groundwater levels were observed in response to the earthquake at boreholes MH2 and Z12836, respectively. In this study, we investig...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-05-01
|
| Series: | Water |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4441/15/10/1947 |
| _version_ | 1797598033910693888 |
|---|---|
| author | Tshepang Mmamorena Marema Loago Molwalefhe Elisha M. Shemang |
| author_facet | Tshepang Mmamorena Marema Loago Molwalefhe Elisha M. Shemang |
| author_sort | Tshepang Mmamorena Marema |
| collection | DOAJ |
| description | The 3 April 2017 Mw 6.5 Moiyabana earthquake (Central Botswana) had a significant impact on groundwater levels; a gradual co-seismic increase and a stepwise decline in groundwater levels were observed in response to the earthquake at boreholes MH2 and Z12836, respectively. In this study, we investigated the response of groundwater levels to Earth tides by computing the amplitude and phase shift of the M<sub>2</sub> tidal constituent to estimate the temporal variations of the storativity, transmissivity, and permeability of the Ntane sandstone aquifer (the main aquifer system) prior to and after the earthquake event. The storativity and permeability computed for borehole MH2 showed a decrease in magnitude of 3.17432 × 10<sup>−4</sup> and 1.85 × 10<sup>−13</sup> m<sup>2</sup> respectively, indicating that strong ground shaking at borehole MH2 might have consolidated the aquifer material, thus resulting in decreased aquifer permeability. The aquifer coefficient of storativity decreased by 2.85 × 10<sup>−4</sup> while permeability was enhanced by 0.047 × 10<sup>−13</sup> m<sup>2</sup> at borehole Z12836. Enhanced permeability might have resulted from increased/enhanced fracturing of the aquifer, fracture clearing and dynamic shaking. |
| first_indexed | 2024-03-11T03:13:41Z |
| format | Article |
| id | doaj.art-a8deff3224e74156ba114b97793952a8 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-11T03:13:41Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-a8deff3224e74156ba114b97793952a82023-11-18T03:42:47ZengMDPI AGWater2073-44412023-05-011510194710.3390/w15101947Characterisation of the Hydrogeological Properties of the Ntane Sandstone Aquifer Using Co-Seismic and Post-Seismic Groundwater Level Responses to the Mw 6.5 Moiyabana Earthquake, Central BotswanaTshepang Mmamorena Marema0Loago Molwalefhe1Elisha M. Shemang2Department of Earth and Environmental Sciences, Faculty of Science, Botswana International University of Science and Technology, Private Bag 16, Palapye 10071, BotswanaDepartment of Earth and Environmental Sciences, Faculty of Science, Botswana International University of Science and Technology, Private Bag 16, Palapye 10071, BotswanaDepartment of Earth and Environmental Sciences, Faculty of Science, Botswana International University of Science and Technology, Private Bag 16, Palapye 10071, BotswanaThe 3 April 2017 Mw 6.5 Moiyabana earthquake (Central Botswana) had a significant impact on groundwater levels; a gradual co-seismic increase and a stepwise decline in groundwater levels were observed in response to the earthquake at boreholes MH2 and Z12836, respectively. In this study, we investigated the response of groundwater levels to Earth tides by computing the amplitude and phase shift of the M<sub>2</sub> tidal constituent to estimate the temporal variations of the storativity, transmissivity, and permeability of the Ntane sandstone aquifer (the main aquifer system) prior to and after the earthquake event. The storativity and permeability computed for borehole MH2 showed a decrease in magnitude of 3.17432 × 10<sup>−4</sup> and 1.85 × 10<sup>−13</sup> m<sup>2</sup> respectively, indicating that strong ground shaking at borehole MH2 might have consolidated the aquifer material, thus resulting in decreased aquifer permeability. The aquifer coefficient of storativity decreased by 2.85 × 10<sup>−4</sup> while permeability was enhanced by 0.047 × 10<sup>−13</sup> m<sup>2</sup> at borehole Z12836. Enhanced permeability might have resulted from increased/enhanced fracturing of the aquifer, fracture clearing and dynamic shaking.https://www.mdpi.com/2073-4441/15/10/1947co-seismic groundwater level changesMoiyabana earthquakeCharacterisationhydrogeological propertiespost-seismic groundwater level changes |
| spellingShingle | Tshepang Mmamorena Marema Loago Molwalefhe Elisha M. Shemang Characterisation of the Hydrogeological Properties of the Ntane Sandstone Aquifer Using Co-Seismic and Post-Seismic Groundwater Level Responses to the Mw 6.5 Moiyabana Earthquake, Central Botswana Water co-seismic groundwater level changes Moiyabana earthquake Characterisation hydrogeological properties post-seismic groundwater level changes |
| title | Characterisation of the Hydrogeological Properties of the Ntane Sandstone Aquifer Using Co-Seismic and Post-Seismic Groundwater Level Responses to the Mw 6.5 Moiyabana Earthquake, Central Botswana |
| title_full | Characterisation of the Hydrogeological Properties of the Ntane Sandstone Aquifer Using Co-Seismic and Post-Seismic Groundwater Level Responses to the Mw 6.5 Moiyabana Earthquake, Central Botswana |
| title_fullStr | Characterisation of the Hydrogeological Properties of the Ntane Sandstone Aquifer Using Co-Seismic and Post-Seismic Groundwater Level Responses to the Mw 6.5 Moiyabana Earthquake, Central Botswana |
| title_full_unstemmed | Characterisation of the Hydrogeological Properties of the Ntane Sandstone Aquifer Using Co-Seismic and Post-Seismic Groundwater Level Responses to the Mw 6.5 Moiyabana Earthquake, Central Botswana |
| title_short | Characterisation of the Hydrogeological Properties of the Ntane Sandstone Aquifer Using Co-Seismic and Post-Seismic Groundwater Level Responses to the Mw 6.5 Moiyabana Earthquake, Central Botswana |
| title_sort | characterisation of the hydrogeological properties of the ntane sandstone aquifer using co seismic and post seismic groundwater level responses to the mw 6 5 moiyabana earthquake central botswana |
| topic | co-seismic groundwater level changes Moiyabana earthquake Characterisation hydrogeological properties post-seismic groundwater level changes |
| url | https://www.mdpi.com/2073-4441/15/10/1947 |
| work_keys_str_mv | AT tshepangmmamorenamarema characterisationofthehydrogeologicalpropertiesofthentanesandstoneaquiferusingcoseismicandpostseismicgroundwaterlevelresponsestothemw65moiyabanaearthquakecentralbotswana AT loagomolwalefhe characterisationofthehydrogeologicalpropertiesofthentanesandstoneaquiferusingcoseismicandpostseismicgroundwaterlevelresponsestothemw65moiyabanaearthquakecentralbotswana AT elishamshemang characterisationofthehydrogeologicalpropertiesofthentanesandstoneaquiferusingcoseismicandpostseismicgroundwaterlevelresponsestothemw65moiyabanaearthquakecentralbotswana |