This segment is from Thursday's edition of Digging for Value, in which sector analysts Joel South and Taylor Muckerman discuss energy and materials news with host Alison Southwick. The twice-weekly show can be viewed on Tuesdays and Thursdays. It can also be found on Twitter, along with our extended coverage of the energy and materials sectors, @TMFEnergy.

The Permian Basin in West Texas has experienced an increase in tremors, but unlike other seismic activity in hydrocarbon plays, these minor earthquakes may be caused by CO2 injections and not water reinjections. While correlation does not mean causation, investors should still monitor the situation, especially if you have exposure to companies that use CO2-enhanced oil recovery techniques. See more in the following video.