Project Global: Ground


This exploration of our current day metropolitan condition as a system of systems deals with the crust of the Earth as a primary carrying capacitor of human activities, from the extraction of resources deep within the ground, to agricultural operations that barely scratch the surface.

Part 1: Lexicon

Part 2: Atlas



Part 1: Lexicon index

︎ Formation

    ︎ Kaapvaal Craton
    ︎ Johannesburg Dome
    ︎ Vredefort Dome
    ︎ Topsoil
    ︎ Müggelsee


︎ Measurement    ︎ Schwerbelastungskörper
    ︎ Mining Earthquakes
    ︎ Low-tech Soil Testing
    ︎ Soil Texture Triangle
    ︎ Geologic Time Scale 
    ︎ Stratigraphic Colum
    ︎ Geographic Information System
    ︎ Ecotone
    ︎ Cultural Landscape

︎ Prototype
    ︎ Unter den Linden
    ︎ Zoological Landscape
    ︎ Counterculture
    ︎ Cultural Agency
    ︎ Mine-pit Lakes
    ︎ Parliament of Things

︎ Land distribution
    ︎ 1913 Natives Land Act
    ︎ District Six
    ︎ Eavesdropping
    ︎ Reconciliation Policy
    ︎ Land Grabbing
    ︎ Land Acting
    ︎ The Red Ants
    ︎ #PutSouthAfricansFirst
    ︎ Suburban Enclaves
    ︎ Parallel State

︎ Extraction
    ︎ Cullinan Diamond Mine
    ︎ Platinum Group Metals
    ︎ Zamazamas
    ︎ Gold Rush Inertia
    ︎ Sinkhole
    ︎ Maize Doctor
    ︎ Coal Hands

︎ Infrastructure
    ︎ Gautrain
    ︎ Le-guba
    ︎ Lesotho Water Project
    ︎ Deutscher Wald
    ︎ Arrival City

︎ Production
    ︎ Safari Economy
    ︎ Agritourism
    ︎ Rainfall Line
    ︎ Upington Airport
    ︎ Tiergarten Transformation
    ︎ Pivot Irrigation
    ︎ Allotment Garden
    ︎ Bokoni Terracing
    ︎ Johannesburg Forestation
    ︎ Game Farming Cycle

︎ Waste
    ︎ Trümmerberg
    ︎ Fab-Soil
    ︎ Mining Waste Belt
    ︎ Sanitary Landfilling
    ︎ Soil Structure
    ︎ Biogas Technology

︎ Pollution
    ︎ Dry Stacked Tailings
    ︎ Water Pollution
    ︎ Soil Pollution
    ︎ Uranium Sandstorms
    ︎ Poaching

︎ Remediation
    ︎ European Green Belt
    ︎ Conservation Agriculture
    ︎ Airfield Urbanism
    ︎ Solar Park
    ︎ Gold Reef City
    ︎ Mine Pit Lake
    ︎ Loess Plateau
    ︎ Erosion Control




Sinkhole

“ ⁠— ”


Sinkholes are cavities in the ground that are formed when groundwater dissolves underlying soluble rock layers. A considerable part of Gauteng province is underlain by dolomitic formations,1 a soluble carbonate rock which is highly susceptible to erosion when groundwater levels change. Sinkholes do occur as part of the slow, natural process of erosion over thousands of years but human activity has been recorded to trigger and accelerate the process. Rainwater (H2O) absorbs carbon dioxide (CO2) from the atmosphere and soil (where the concentration of this gas may be up to 90 times greater than in the atmosphere) to form a weak carbonic acid (H2CO3).2 The subsequent dissolution by percolating groundwater that circulates along tension fractures, faults, and joints in the dolomitic succession have led to the formation of caves and voids in the rock. When the underground water level changes - by natural or as a consequence of mining - the overlying materials collapse into the underlying voids: a sinkhole has been created.
        Sinkholes are usually unpredictable and can be catastrophic, particularly when they are sufficiently large, sinkholes cause property damage or loss of life.  Human activity is a major cause of sinkholes, especially in the Gauteng region where gold mining was historically the basis of the economy and socio-economic development.3 The byproducts of extensive mining operations was the extraction of massive quantities of groundwater to dig mine shafts that contributed to ground instability. Despite waning mining activity as a result of depressed gold prices since the 2008 global financial crisis and increasingly-more expensive investments needed to extract gold (since most of the readily accessible gold has been already extracted),4 the risk of sinkholes is expected to increase.



Image source:  Oosthuizen, Johannes Marthinus. ¨Picture of the sinkhole, at the Blyvooruitzig mining village that claimed the lives of the Oosthuizen family¨. Wikitree. Accessed March 5, 2022.https://www.wikitree.com/photo/jpg/Oosthuizen-1433-1


References
1.   De Bruyn, Ian & Bell, Fred; Jermy & Colin A. ¨The Problem Of Sinkhole Formation In Two Dolomite Areas Of South Africa¨.  ISRM-IS-2000-588.  ISRM International Symposium, Melbourne, Australia, November 2000. https://onepetro.org/ISRMIS/proceedings-abstract/IS00/All-IS00/ISRM-IS-2000-588/50533
2.  Oosthuizen A.C & S. Richardson. ¨Sinkholes and subsidence in South Africa¨. Western Cape Unit, Council for Geoscience. Council for Geoscience Report number: 2011-0010, https://geoscience.org.za/images/geohazard/Sinkholes.pdf
3.  Ngcobo, T.A.¨The risks associated with mines in dolomitic compartments¨ . The Journal of The South African Institute of Mining and Metallurgy. April,  2006. https://www.saimm.co.za/Journal/v106n04p251.pdf
4.  Brown, Brian Lenora. ¨Built on gold riches, Johannesburg succumbs to sci-fi sinkholes¨. The Cristian Science Monitor. September 9,2014. https://www.csmonitor.com/World/Africa/2014/0909/Built-on-gold-riches-Johannesburg-succumbs-to-sci-fi-sinkholes