User:Djachambers/sandbox

Wiki assignment
This is a rough draft of the final assignment for the NIOSH intro to wiki course. For this assignment I plan to expand the mining induced section of the induced seismicity page. The following shows the text of the section as it stands now, as well as my draft.

Current section
Mining leaves voids that generally alter the balance of forces in the rock, many times causing rock bursts. These voids may collapse producing seismic waves and in some cases reactivate existing faults causing minor earthquakes. Natural cavern collapse forming sinkholes would produce an essentially identical local seismic event.

Draft
Mining affects the stress state of the surrounding rock mass, often causing observable deformation and seismic activity. A small portion of mining-induced events are associated with damage to mine workings and pose a risk to mine workers. These events are known as rock bursts in hard rock mining or bumps in underground coal mining. A mine's propensity to burst or bump depends primarily on depth, mining method, extraction sequence and geometry, and the material properties of the surrounding rock. Many underground hardrock mines operate seismic networks in order to manage bursting risks and guide mining practices.

Seismic networks have recorded a variety of mining-related seismic sources including:


 * 1) Shear slip events (similar to tectonic earthquakes) which are thought to have been triggered by mining activity. Notable examples include the Bełchatów earthquake (1980), and the Orkney earthquake (2014).
 * 2) Implosional events associated with mine collapses. The Crandall Canyon mine collapse (2007) and the Solvay Mine Collapse are examples of these.
 * 3) Explosions associated with routine mining practices, such as drilling and blasting, and unintended explosions such as the Sago mine Disaster. Explosions are generally not considered "induced" events since they are caused entirely by chemical payloads. Most earthquake monitoring agencies take careful measures to identify explosions and exclude them from earthquake catalogs.
 * 4) Fracture formation near the surface of excavations, which are usually small magnitude events only detected by by dense in-mine networks.
 * 5) Slope failures, the largest example being the Bingham Canyon Landslide.

Reference https://link.springer.com/article/10.1007/s40789-016-0102-9

https://www.researchgate.net/publication/30509741_The_risks_to_miners_mines_and_the_public_posed_by_large_seismic_events_in_the_gold_mining_districts_of_South_Africa