Human-Induced:
* Wastewater disposal: The largest contributing factor is the injection of wastewater from oil and gas production into deep underground wells. This process, known as fracking, increases pressure in the subsurface, triggering movement along existing faults.
* Increased pressure: The injection of wastewater can also lead to increased pressure in the subsurface, making faults more likely to slip.
* Fluid migration: Wastewater injected into deep wells can migrate along existing faults, lubricating them and making them easier to move.
Natural Tectonic Factors:
* Central Oklahoma Uplift: Oklahoma sits on the edge of the Central Oklahoma Uplift, a geologically active area where the Earth's crust is being uplifted.
* Pre-existing faults: The Central Oklahoma Uplift has numerous pre-existing faults that are reactivated by human-induced stresses.
* Stress transfer: Earthquakes in one area can transfer stress to nearby faults, triggering other earthquakes.
It's important to note:
* The magnitude of earthquakes in Oklahoma is influenced by both human-induced and natural factors.
* While natural tectonic activity plays a role, human activity is considered the dominant factor in the recent increase in earthquake frequency and intensity in Oklahoma.
Therefore, the tectonic setting of Oklahoma earthquakes is a complex interaction of human-induced factors, primarily wastewater disposal, combined with the presence of pre-existing faults and natural tectonic activity in the Central Oklahoma Uplift.
