Station spacing is approximately 18 km. NM Tech Earthworm System broadband and short period stations. The horizontal component data have slightly higher noise levels than the vertical component data at lower frequencies. In a,b,c the black line is the median signal to noise ratio for all events, also plotted in d. Signal to noise ratios are calculated using the ratio of spectra from a 30 second window immediately after event arrival, and a 30 second window immediately before event arrival.
Solid lines are the median spectra for each component, and dashed lines are the standard deviation.
Background noise spectra are calculated using 24 hour time windows containing no events. Receiver functions for earthquakes from a range of azimuths. Mb 6.5, depth 183km, azimuth 243.2. Cross-section of stacked receiver functions along the line of stations showing discontinuities near 400 and 700 km depths. To produce this stack nearly 700 individual receiver functions were placed into depth and geographical bins by back ray tracing using the IASP91 spherically-symmetric Earth model.