Depth of Recorded Events Over Tim e Located Using Local Network - PowerPoint PPT Presentation

Depth of Recorded Events Over Tim e Located Using Local Network 11/1/2013 1/30/2014 4/30/2014 7/29/2014 10/27/2014 1/25/2015 4/25/2015 0 -5,000 Lower Barnett Ellenberger -10,000 Basement M>=3.0 2.5<=M<3.0 Depth [ft] 2.0<=M<2.5 -15,000 1.5<=M<2.0 1.0<=M<1.5 -20,000 -25,000 -30,000

Seism ic Station Distribution The local network provides accurate locations, but the WMOK station recorded the full earthquake sequence.

Shear W aveform Com parison Shallow vs Deep Events Shallow Event Located with Local Network 1/28/2014 – M2.4 12,100 ft depth Event Not Located No Local Network 12/08/2013 – M3.6 Deep Event Located with Local Network 12/22/2013 – M3.1 21,700 ft depth

Shear W aveform Com parison Shallow vs Deep Events Shallow Event Located with Local Network 1/28/2014 – M2.4 12,100 ft depth Xcor coeff. = 0.34 Event Not Located No Local Network 12/08/2013 – M3.6 Xcor coeff. = 0.61 Deep Event Located with Local Network 12/22/2013 – M3.1 21,700 ft depth Events that occurred prior to the local network installation are highly correlated with later, accurately located events deep in the basement.

Cross Correlation Detection Colored by Depth

Mom ent Release vs. Depth Moment (Nm) 0.00000E+00 5.00000E+14 1.00000E+15 1.50000E+15 10,000 Basement 10,200 ft 12,500 Depth (ft) 15,000 17,500 20,000 22,500 25,000 Q4_2013 Q1_2014 Q2_2014 Q3_2014 Q4_2014 Q1_2015 Q2_2015