Shale gas extractionFigures from the report

Microseismic monitoring of a typical hydraulic fracturing operation in the Barnett
Shale, Texas, USA (Figure 6)

‘A’ displays a horizontal view of microseismic events along the horizontal well. The thick black line represents the horizontal well. Note that the vertical axis does not begin at the surface but at depth (5120 feet). Each dot represents a separate microseismic event. Each colour represents a distinct fracturing event. ‘B’ displays a cross sectional view of the microseismic events. ‘C’ displays the distribution of these microseismic events by magnitude. (Zoback et al 2010).

Comparisons of fracture growth and depth of overlying water sources (aquifers or
water wells) (Figure 8)

Each of the four figures illustrates fracture height for fracture treatments performed in four major US shale formations between 2001 and 2010. The depth of each fracture treatment is illustrated by the yellow line and sorted by depth. The red spikes represent the extent of upward and downward fracture growth. The dark blue bars at the top of each figure illustrate the depth of overlying water sources. (Fisher and Warpinski 2012)