article_snippet: Fault lines dating back hundreds of millions of years in Oklahoma that have been recently reactivated could lead to a devastating quake in the state where many structures were not built to withstand major seismic activity, The new report said.
article_snippet: The state, which has seen several hundred seismic events over the past five years, has 'a high degree of potential earthquake hazards,' according to the study accepted for publication this month whose authors include researchers from the U.S. Geological Survey (USGS). '
article_snippet: The majority of the recent earthquakes in central Oklahoma define reactivated ancient faults at shallow depths in the crust' of less than 3.7 miles (6 km), said The new report.
article_snippet: However, USA Today, reported that previous research has identified hydraulic fracturing, or fracking, as being behind 3,600 small earthquakes in Oklahoma from 2009 - 2014.
article_snippet: Daniel McNamara, one of the paper's authors and a research geophysicist at USGS, said on Tuesday the 300 million-year-old subsurface faults that had not been active are suspected to be associated with the recent seismic activity. '
article_snippet: Any one of these fault zones that are producing magnitude 3 or 4 earthquakes could rupture into a larger earthquake.
article_snippet: There are as many as 12 different fault zones that are capable of producing a large, 5 to 6 magnitude earthquake,' Daniel McNamara, one of the paper's authors and a research geophysicist at USGS said.
article_snippet: The 300-million-year-old fault lines in Oklahoma are being reactivated by multiple earthquakes in the state that scientists previously have said were linked to fracking - although the most recent research did not look at the energy extraction technique .
highlights_snippet: Deep fault lines older than the dinosaurs are being reactivated by small earthquakes .
  