ESCI 1012 Lecture 17: March 22
Document Summary
Dissolution of rock (only natural one), mining, groundwater use, oil/gas drilling. Free oxygen normally oxidizes organic material, but when large amounts of organic material are deposited, oxygen in water is quickly consumed, so organic material accumulates. Consequently, wetlands and peat sediments are typically saturated by anaerobic (no o(cid:368)(cid:369)ge(cid:290)) water so orga(cid:290)ic (cid:289)aterial does(cid:290)(cid:910)t break dow(cid:290) Draining this water ( to convert wetlands for agriculture) exposes organic matter to new aerobic (oxygen-bearing) water from surface, bringing oxygen down and decays material. Bacteria can then break down organic matter, releasing co2 to atmosphere and reducing volume of wetland/peat deposits. Other land subsidence can be traced even more directly to human activities. Most occurs as a result of hu(cid:289)a(cid:290) (cid:909)(cid:289)i(cid:290)i(cid:290)g(cid:910) which is pri(cid:289)aril(cid:369) of grou(cid:290)dwater, oil a(cid:290)d natural gas, although more conventional mining of coal and mineral resources can locally play a role. Si(cid:290)khole i(cid:290) carlsbad, new me(cid:368)ico a(cid:290)d a (cid:290)ew o(cid:290)e is for(cid:289)i(cid:290)g be(cid:290)eath cit(cid:369)(cid:910)s (cid:289)ai(cid:290) intersection.
